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Symposium Steering Committee

William G. Bickert, Michigan State University Michael F. Broder, National Fertilizer & Env~ronmental Research Center, TVA Glenn A. Church II, Midwest Plan Service (MWPS) James F. Dowd Ill, National Fertilizer Solutions Association Steven E. Dwinell. Florida D e ~ t of Environmental Regulation Thomas Gilding, National Agricultural Chemicals Association -

Tom Helmer, CIBA-GEIGY John F. Hester, Wilbur Ellis Vernon L. Hofman, North Dakota State University Dennis F. Howard, Environmental Protect~on Agency David W. Kammel, University of Wisconsin Marsha Landretti, University of Wisconsin Dave McLeod, Dow Elanco Ronald T. Noyes, Oklahoma State University Bradley K. Rein, USDA Extension Service Kenneth E. Root, National AgriChemical Retailers Association C. Dean Scott, ICI Americas John Thorn, Alliance for a Clean Rural Environment (ACRE)

Acknowledgments

The Midwest Plan Service would like to thank the members of the Symposium Steering Committee for their direction during the planning of this symposium. A special thanks to David Kammel and Ken Root who have unselfishly given of their time and energies considering the short planning time-line.

The Midwest Plan Service is grateful to those who submitted papers for this symposium. Their diligence in responding to the short time-line so these proceedings could be distributed at the symposium was greatly appreciated.

The Symposium Committee is extremely appreciative of the financial aid provided by the Co-sponsors.

National Symposium on Pesticide and Fertilizer Containment:

Design and Management

Conference Proceedings

February 3-5, 1992 Westin Crown Center Hotel, Kansas City, Missouri

TABLE OF CONTENTS

Agricultural Chemical Containment: The Chal- lenge of Integrating Law, Policy, Education, Re- search and Private Enterprise Robert L. Denny, U.S. Environmental Protection Agency

Federal Laws Affecting the Design and Manage- ment of Pesticide Mixing and Loading Facilities Steven E. Dwinell, Florida Department of Environ- mental Regulation

OSHA Requirements for Pesticide Storage Burt A. McKee, United Agri-Products

Secondary Containment And Containment Pads: Emerging Federal Pesticide Regulations Dennis F. Howard, U.S. Environmental Protection Agency

Pesticide Storage and Spill Containment; State Initiatives Ned Zuelsdorff, Wisconsin Department of Agricul- ture, Trade and Consumer Protection

Fire Safety Design Considerations in Pesticide and Fertilizer Facilities Jon R. Nisja, Mlnnesota State Fire Marshall Division

Why Containment - Industry's Perspective Donald L. Paulson Jr., CIBA-GEIGY Corporation

Legal Liability for Groundwater Contamination Arising from the Agricultural Industry Richard A. Pettigrew, Morgan, Lewis & Bockius

Transact ional and Operat ional Assess- ments1Audits of Farms and Agricultural Facili- ties Thomas M. Missimer, Missimer & Associates, Inc.

Worker Safety Vern Hofman, North Dakota State University

53 Secondary Containment for Large Tanks Edward L. Waddell and Michael F. Broder, Tennes- see Valley Authority

67 Design Criteria for Concrete MixingILoading Pads Ronald T. Noyes, Oklahoma State University

73 Protective Coatings and Joint Sealants For Con- crete in Pesticide and Fertilizer Facilities Fred Hazen, Master Builders, Inc.

88 Containment of Fertilizers and Pesticides at Re- tail Operations Michael F. Broder, Tennessee Valley Authority

107 Management of Pesticide Containers Nancy Fitz, U.S. Environmental Protection Agency

114 Pesticide Application Equipment Rinse Water Recycling Darryl Rester, Louisiana State University Agricul- tural Center

121 Combination of Landfarming and Biostimula- tion as a Waste Remediation Practice E. Kudjo Dzantor, Tennessee Valley Authority

134 Current Approaches to Development of Pesti- cide Rinsate Disposal Technology Cathleen J. Hapeman-Somich, Agriculture Re- search Service, U.S. Department of Agriculture

138 Disposal of Pesticides by Microbial Degradation Glen H. Hetzel, Virginia Tech

143 Management and Disposal of Pesticide Spray Tank Wastes Frank R. Hall, R. A. Downer and A. C. Chapple, The Ohio State University

149 Closed MixingILoading Systems Review Ronald T. Noyes, Oklahoma State University

Agricultural Chemical Containment: The Challenge of Integrating Law, Policy, Education,

Research, and Private Enterprise

Robert L. %MY Environmental Fate and Effects Division Ofice of Pesticide Programs U. S. Environmental Protection Agency

Abstract

The Federal statutory and regulatory structure will be described in the context of setting public policy for fertilizers and pesticides that may require containment. The options for Federal command-controls, performance triggers, and incentives will be discussed along with the strengths and limitations of each approach. Also, the author will illustrate how state regulations may augment federal containment policy. The author contends that there are limitations to purely federal or federal-state approaches to regulation agrichemical containment. Conversely, the author will argue that although almost all o f the technical breakthroughs have originated from the private sector's development programs, there are dangers in allowing undirected growth. The only approach that makes sense is to use the oversight powers of the relevant multiple statues in a minimal way, that will provide a regulatory floor for pesticide handlers, yet will encourage growth in the private development of innovative ideas and eventual dissemination of those ideas through publications and education.

Introduction

Although the science, engineering and policy making centered around the control and containment of agricultural chemicals is a relatively new topic, the problems of storage and containment of liquids and dry materials are older than any historical records themselves. From archeological sites such as the Egyptian pyramids and Greek and Phoenician shipwrecks, evidence is revealed of mans earliest attempts a t protecting commodities: drinking water, wine, aromatic oils, fuels, and other precious materials. Although only a few whole earthen or glass containers are available for study, it is nevertheless remarkable that any containers survived intact the centuries of

floods, shipwrecks, earthquakes, fires, wars and just hard use. Furthermore, the nearly ubiquitous use of the Greek or Roman amphora for hundreds of years is a tribute to early designers of a containment system that although somewhat breakable, was nevertheless normally leak proof, sealable, fire resistant, refillable, and poured well due to a lip configuration that accelerated a departing liquid away from the body of the container.

Coincident to the rise of cultural and technological development in Middle Europe, the development of the wooden cask signaled the beginning of a container type that would increase in size until the quantities of materials held in this type of vessel would, a t the dawn of the Industrial Revolution, rival the bulk tanks that are a topic today. And although the sudden release of the contents of, for instance, a railroad water tank might cause some damage due to the inevitable laws of physics, most water tanks or containers of beverages and foodstuffs did not pose a serious threat to environmental or human health. This concern was forever changed by the late nineteenth century and the increased use of chemicals and petroleum. Therefore, nearly 50 years prior to the passage of the first federal pesticide control statute specific for storage of bulk and packaged pesticides, other industries and associated regulators had already worked out some of the fundamental concepts for protecting environmental health from either slow or rapid escape of liquid contaminants, particularly from bulk containers.

Federal-State Controls

At first glance, federal attempts a t regulating containment of pesticides appears complex. Perhaps that perception cannot be completely dispelled, but breaking down the effective components can at least make the topic somewhat understandable. The Federal Insecticide, Fungicide, and Rodenticide Act of 1947 was a labeling and registration statute that regulated the "use" of a pesticide. Even in the 19401s, USDA, the pesticide regulatory agency a t that time, interpreted "use" to include the storage of a pesticide. In 1974, the EPA responded to the 1972 amendments to FIFRA by promulgating 40 CFR 165 guidelines for warehouse and end user storage procedures for

highly toxic and moderately toxic pesticides that bear signal words "Danger," "Poison," or "Warning." And even later in the 19701s, the Agency became aware that bulk filling of certain pesticide containers, particularly in the monoculture areas of the Midwest, was potentially an effective way to distribute some pesticides. Therefore, in 1977 the EPA issued the Pesticide Bulk Policy that allowed filling of containers of greater than 55 gallon capacity a t the retail producing-establishment or dealer level. Importantly, i t was also established that certain containers were not appropriate for nonregistrant repackaging, and containers of less than 56 gallons were not authorized for dealer refilling.

It is true that most of the above provisions are still in effect today. However, the 1988 Amendments to FIFRA provide for enforceable regulatory changes in bulk packaging, storage, and pesticide container design. The EPA will implement these provisions in several phases of regulatory packages that will be promulgated in the next few years. Later in this session, presentations prepared by Nancy Fitz and Dennis Howard will provide more details concerning these possible regulatory changes.

In most instances, the federal environmental statutes are implemented by state or territorial regulatory agencies that can be more restictive than the federal government. Some states are not waiting for EPA to promulgate regulations governing pesticide storage, containment, and bulk management. As of the Fall of 1991, 13 states regulated dealer warehouses andlor end user storage through minimal requirements in addition to labeling. Seven states have comprehensive bulk containment regulations, while an additional six have minimal bulk storage rules. Florida has taken a different approach by regulating bulk pesticides as aboveground storage tanks for pollutants. Interestingly, approximately one half of the above number of states also regulate fertilizers with the same bulk storage requirements, although frequently the thresholds for applicability are higher.1

FIFRA is not the only statute that impacts the containment of pesticides. And, importantly, fertilizers are not regulated under FIFRA unless they are combined with pesticides. There are federal statutes that could impact the containment of both pesticides and fertilizers. Under Section 319 of the Clean Water Act Amendments of 1987, states must develop management programs to address non-point

source pollution from agricultural operations. Many states complement the federal requirements with groundwater protection legislation of their own. Through this process a state may develop a program that affects storage and disposal by controlling the location, design and operation of storage facilities and the installation and maintenance of mixing and loading pads. Section 319 of the CWA and many state groundwater protection programs incorporate the concept of "best management practices" (BMP's). Although BMP's are usually voluntary guidelines, states have the authority to make the practices mandatory.1

Another section of the CWA, Section 304, has potential impacts on the design and management of bulWstorage agrichemical facilities. Surface water discharges of effluent from pesticide producing establishments that repackage bulk materials, commercial applicators, and custom blenders of pesticides and fertilizers will be the proposed object of amendments to 40CFR Part 455. These proposed regulations are expected to be published in the Federal Register after January 1, 1993 and may be promulgated as early as August of 1994.2

There are a number of other federal statutes that definitely impact or potentially could impact the operation of storagehulk distribution facilities for pesticides and fertilizers. In most instances these federal programs are implemented by the states and, a t times, the state programs are more restrictive than the federal requirements. For instance, waste management is an inevitable part of most bulWstorage facilities. If an agrichemical cannot be used, and the intent is to dispose of the contaminant, such as a sludge, then the regulatory statute is the Resource Conservation and Recovery Act. Disposal of solid wastes, and particularly hazardous wastes, is expensive. And the well designed storagehulk agrichemical facility will minimize, recycle, reuse, or clean rinsates, equipment washings, spray equipment flushings, and even spills wherever possible.

Local Codes

The implementation of the Clean Air Act, CERCLA, and other federal provisions a t the state level may have future or even current impacts on some storagehulk containment designs. But facility designs are far more impacted by local building codes that are influenced by organizations such as the Building Officials and Code Administrators International (BOCA) based in Illinois, the Southern Building Congress International and the Southeastern and

Southwestern Fire Chiefs in Birmingham, Alabama, and the International Conference of Building Oficials in Whittier, California. Generally these standards incorporate national models developed by organizations such as the National Fire Protection Association (NFPA) and are administered by local fire department inspectors, code enforcement officials, building inspectors, or state fire marshals. The focus of these codes is decidedly oriented towards fire prevention. However, certain provisions may at times run counter to pesticide waste minimization provisions sought by pesticide and fertilizer re y l a to ry officials. 1

Education

Another area of increasing concern for facility designers and managers is the field of and employee training particularly as related to personal safety and facility operations. FIFRA effectively included dealers and distributors under the pesticide regulatory umbrella for the first time with the '88 Amendments to FIFRA. Yet FIFRA makes no provisions for the training or certifying of dealer/distributors as i t does for farmers or other applicators that use restricted use pesticides. And while all but one state licenses dealers, very few require training even for handlers of thousands of gallons of bulk pesticides. Some training may be required under the Occupational Safety and Health Act (OSHA) through the implementation of 29 CFR Part 1910 that requires employees exposed to hazardous chemicals to provide information by means of hazard communication programs that may include labels, material safety data sheets, training and llaccess to written records. Some state universities, registrants, and dealer associations are concerned that facility managers become better informed in every area of environmental safety and regulatory compliance. If we are going to avoid disasters from chronic or sudden releases of chemicals, then education must be as important as the regulatory efforts.

Conclusions

Since the 1988 amendments to FIFRA, the EPA has been educating itself on pesticide waste minimization issues, particularly those related to bulk handling and distribution. From the Agency's inspections of pesticide storage and distribution facilities in almost half of the

United States, EPA has noticed that minimal requirements are necessary in order to assure the safe storage and handling of both packaged as well as bulk pesticides and probably fertilizers, too. In different geographic areas, EPA noticed that uniformity of environmental protection was being achieved by states with comprehensive bulk regulations. Yet, a trip of only a few miles across state lines, where exactly the same crops are grown and the same products from the same manufacturers are sold, reveals a mosaic of responsible and irresponsible practices; the latter posing significant risks to workers and the environment.3

And yet the EPA recognizes the limits of their influence as well. A national program that regulates all storage and bulk distribution of pesticides cannot anticipate the differences in cropping practices and hence chemical needs, as well as climate factors that may have a significant impacts on pad maintenance , whether facilities need to be covered, heated, resurfaced frequently, etc. Maintenance schedules obviously differ for bulk facilities that are ensconced in ice and snow for several months per year versus those that must endure intense heat, humidity, and virtual year around use. Once minimal federal standards are promulgated, states can achieve better environmental protection due to their understanding and tailored prescriptions for their regulated community.

There are limitations, however, to even the state approach to containing stored pesticides and fertilizers. Specific formulations have specific problems that need the input from the formulators and the educational community. There has never been a time when the potential for shared financial liability was greater than today. Responsible manufactures will increasingly need to assure that their product is handled in the safest way possible, from the time the pesticide or fertilizer leaves the plant gate, until ultimate use. This means that industry will have to assure that the facilities where chemicals are packaged are appropriate for environmental health and that they meet or exceed federal, state, and accepted industry standards.

If the facilities where agrichemicals are stored and distributed are to become uniformly safe, then that means that increasing pressure must be placed on all participants to develop reasonably priced designs for chemical management; designs for facilities that can be maintained for ten, twenty years or more that will still minimize or control any off-site emissions while protecting the workers within. This goal of safe, affordable pesticide and fertilizer containment may be produced by groups

such as this one. If so, it will be achieved not by just enforceing federal or state regulations, but by a dedication from EPA, state regulators, educators, and private industry to see that both quality facilities are designed and built and that operational personell are trained to standards that exceed the minimum requirements that currently exist, or those that are contemplated.

References

1. Lounsbury, B. 1991. "1991 State of the States: Pesticide Storage and Disposal." Draft report to Office of Pesticide Programs, U. S. EPA.

2. Goodwin, J. 1991. U. S. EPA, OEce of Water. Personal communication with U. S. EPA Office of Pesticide Programs. December 17, 1991.

3. U.S. EPA Office of Pesticide Programs. 1990. Trip Report to California, Oregon, Washington, September 16-22,1990.

Federal Laws Affecting the Design and Management of Pesticide

Mixing and Loading Facilities

Steven E. bvinell Environmental Manager Pesticides and Data Review Section Florida Department of Environmental Regulation

Abstract

Pesticide miuitzg/loading facilities are brlilt to reduce tlze poterztial for soil, ground water and surface water contanzi~zation. In general, facilities tlzat are desigtted and operated with e~zvirorzt~zentalprotectio~t in tnitzd will conzply wifh tlie provisions of four basic laws tltat are pertirze~zt to pesticide nzixitzg/loadi~tg facilities design and operation. Tllese four firridanzental laws are tlze Federal I~zsecticide, Fzingicide, arzd Rodettticide Act (FIFRA), the Resource Conservation and Recovery Act (RCRA), tlze Conzyrehetzsive Ertviro~zmental Response, Conzpensation a~zd Liability Act (CERCLA) aftd tlze Clea~z Water Act (CWA). Tlzese laws, and tlze regz~latiotzs intple~netztitzg dzenz, establislz a set of requirenzents for tlze ltandli~zg of pesticides and pesticide waste nzaterials. Designers and operators of tltese facilities slior~ld be aware of the per-tinent provisioris of tlzese laws and review design a~zd operatiort featrires to be certain that tlzey are in conzpliance.

Introduction

Pesticide applicators build pesticide mixing and loading facilities in order to contain the pesticides and pesticide containing materials being handled. They are attempting to reduce the potential for contamination of soil, ground water, and surface water, and are responding to personal and societal concerns about environmental contamination, as well as existing or proposed governmental regulations that require such mixing and loading facilities. While keenly aware of these concerns and requirements, designers and operators may not be as aware of a set of existing federal requirements that affect the design and management of pesticide mixing and loading facilities. It is in their interest to learn about the federal laws that establish these requirements and to review design and operation features to be certain that they are in compliance.

There are four federal laws that affect the design and operation of pesticide mixing and loading facilities by either establishing requirements for the management of pesticides and pesticide related materials or by preventing the use of land that may have been previously contaminated. There are, of course, other laws, both Federal and state, that pertain to pesticide mixing and loading facilities in the same way that they pertain to other structures or facilities - such as building and fire codes, wetland protection laws, etc.,. The laws discussed here are, however, those that have provisions intended to prevent the degradation of the environment through contamination with toxic materials, and, therefore, pertain to facilities intended to manage pesticides.

The four federal laws are the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), the Resource Conservation and Recovery Act (RCRA), the Con~prehensive Environmental Response, Conlpensation and Liability Act (CERCLA) and the Clean Water Act (CWA). These laws are complex and much has bcen written about their intent and provisions. This discussion, though, will focus on the provisions of the laws, or the policies established under the authority of the laws, that are most pertinent to design and management of pesticide mixing and loading facilities.

It should be noted that, as of the time of this writing, there are no federal regulations that directly specify how a pesticide mixing and loading facility is to be built or operated. There are state regulations, but no federal regulations. Proposed federal regulations that will specify how these facilities are to be built and operated arc discussed in a separate chapter in these proceedings.

Federal Laws Affecting Design and Operation

The Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA)

This law, and its numerous amendments, regulates the production, sale, and use of pesticides. The law is found in Chapter 7 United States Code part 136 et. seq. (7 USC 136) and the regulations enacted under the authority of the law are found in Chapter 40 Code of Federal Regulations parts 152 - 186 (40 CFR 152-186).

FIFRA allows the United States Environmental Protection Agency (USEPA) to establish regulations and policies that protect the environment from improper or unsafe use of pesticides. USEPA requires certain pesticide handling practices and prohibits others primarily by requiring certain statements to be placed on the pesticide label. FIFRA Section 12 (a) (2) (G) prohibits use of a pesticide in a manner inconsistent with its labeling. This provision establishes that pesticide users must comply with directions on the label such as application rate, application site, and use of personal safety equipment. There are two label requirements that affect design and management of mixing and loading facilities. Both of these were standardized in PR Notice 83-3 issued by the Office of Pesticide Programs in 1983. These are:

Prohibition of Contamination of Water, Food, or Feed - This requirement is found in the "Pesticide Disposal" statement on the labels of all pesticides except those intended for household use. It prohibits the contamination of water, food, or feed through storage or disposal.

This statement establishes the basic requirement for designers and operators of pesticide mixing and loading facilities. The facility must be built and operated in such a manner that pesticides and materials that contain pesticide residues do not come into contact with ground water, surface water, food, or feed. The label statement applies to the use of the pesticide itself, not to the facility, yet it affects the facility directly. If the facility is poorly designed or managed, and contamination of water, food, or feed results, then the pesticide user will have used the pesticide in a manner inconsistent with the label, and violated FIFRA Section 12 (a) (2) (G).

This label statement can be the basis for enforcement action. If, for example, containers leak onto soil or into a drain which is connected to a surface water supply and ground water or surface water becomes contaminated with a pesticide, then the pesticide has not been used in compliance with the label, since contamination of water has occurred as a result of storage. Similarly, discharge of rinsewater from application equipment or container cleaning to soil or a water body can be a violation of this label statement if contamination by pesticides occurs. Contamination of soil can lead to a violation if the

pesticide leaches from the soil to contaminate ground water. These occurrences may also be violations of other regulations or laws, but there can be instances when laws such as RCRA or the Clean Water Act have not been violated by a spill or release that would still be a violation of this label statement. This can occur if a pesticide not regulated under RCRA or CERCLA is involved in the contamination incident.

Requirement for Proper Cleaning of Empty Containers - This requirement is found in the "Container Disposal" section of the label. Pesticide containers must be cleaned in some manner before they are disposed. Most commonly this is triple rinsing or pressure rinsing of plastic containers with water. Paper or plastic bags must be "completely emptied and perhaps "shaken clean". The facility must be set up so that containers can be cleaned quickly and easily as part of the container emptying operation. Facilities that make container cleaning inconvenient or require container cleaning be done as an operation separate from container emptying will likely result in instances where containers are not properly cleaned before disposal.

Properly cleaning pesticide containers also allows pesticide applicators to avoid violating provisions of RCRA. Containers that held pesticides regulated as hazardous waste are hazardous wastes when empty unless they have been properly cleaned. Facilities that do not provide for proper cleaning of pesticide containers may find themselves in violation of laws other than FIFRA.

There is one other provision of FIFRA that affects design and management of pesticide mixing and loading facilities in a fundamental way. Section (2) (ee) is a definition in FIFRA that states that application of a pesticide at a r a t e h than the specified rate is not a use inconsistent with the label. This definition allows the application of rinsewater containing low concentrations of pesticides resulting from cleaning of application equipment and containers as a pesticide. Facilities can therefore provide for the storage of pesticide rinsewater prior to application as a pesticide, and manage that rinsewater by applying it as a pesticide.

Congress passed amendments to FIFRA in 1988 that allow the USEPA to develop regulations that will directly affect the design and operation of pesticide mixing and loading facilities. Regulations under development will also likely strengthen requirements for container cleaning. These proposed regulations are discussed in a separate chapter in this publication.

Resource Conservation and Recovery Act (RCRA)

This law establishes requirements for the management of materials managed as wastes. One part of RCRA, Subtitle C, found in 42 USC 6905 et. seq. and the regulations found in 40 CFR 260-281, establishes requirements for certain materials designated as hazardous wastes. These materials are defined as hazardous in 40 CFR Part 261, and are either listed by chemical name or defined as hazardous based on certain characteristics, such as flammability or corrosivity. Persons who produce waste products (generators) that meet the definition of hazardous wastes must manage those wastes in compliance with the requirements established in the RCRA regulations. Violations of hazardous waste regulations can result in expensive fines. O.R. Ehart (1985) and F.W. Flechas (1987) provide lists of those pesticides that meet the definition of hazardous wastes. Only a limited number of pesticides are regulated as hazardous wastes, and most commonly used pesticides are not defined as hazardous under RCRA. A few com- mon ones, such as 2,4 D, aldicarb, and phorate, are, however.

RCRA pertains to facilities where pesticides are mixed and loaded whenever a waste is produced. Wastes are those materials that are discarded, abandoned, or used in a manner constituting disposal. If these materials are not used as a pesticide or there is no intention to use them as a pesticide, then they are a waste that must be managed. If the pesticide or pesticide residue in the materials meets the definition of a hazardous waste, then the waste must be managed as a hazardous waste. In most cases, wastes classified as hazardous wastes will have to be removed by a licensed hazardous waste contractor. Costs for hazardous waste disposal vary but are in the neighborhood of five hundred to one thousand dollars per fifty-five gallon drum.

Wastes generated by pesticide applicators can include pesticide formulation or mixture, empty pesticide containers, rinsewater from application equipment or empty containers, or material used to collect or contain a spill. The best management practice for operators of mixing/loading facilities is to use all pesticide containing materials produced in the facility as pesticides. Effects of RCRA provisions on facility design and operation for these types of waste products are:

Pesticide Rinsewaters

Pesticide equipment rinsewaters and empty container rinsewaters should be applied to a labeled site as a dilute

pesticide. Rinsewaters can also be collected and used at a later time to make a batch of the same or conlpatible pesticide. As long as the pesticide containing material is used as a pesticide, it will not be a waste.

If the rinsewater contains pesticides regulated as hazardous waste, it should not be stored for more than ninety days. Although the rinsewater may be intended for use as a pesticide, it may be possible for RCRA enforcement authorities to construe long term storage as "abandonment". RCRA requires notification and permitting of storage of hazardous waste for more than ninety days. It is preferable to avoid this potential by using all collected rinsewater as soon as possible.

Never store pesticide rinsewater in a sump. Sumps are essentially underground storage tanks, and the possibility of a leak always exists. Ideally, sumps should be pumped dry every day. Storage or abandonment of rinsewater in a sump could trigger RCRA requirements for registration and permitting of underground storage of hazardous wastes. Failure to notify and permit such an operation can lead to heavy fines.

It is possible to treat pesticide rinsewater or other pesticide containing materials that can not be used as a pesticide. Treatment technologies available include carbon filtration and evaporation/degradation. If the material to be treated contained a pesticide regulated as a hazardous waste, then the treatnlent facility would have to obtain either a RCRA hazardous waste treatment facility permit or, if applicable, a Clcan Water Act permit for waste water treatment. RCRA facility permits are very difficult and expensive to obtain. Until RCRA regulations are changed, it is i~npractical for pesticide mixing and loading facilities to attempt to use treatment systems for pesticides regulated as hazardous waste due to the cost of obtaining the necessary permits, and designers should avoid including such systems in facilities.

Sediments, sludges, and spill control materials

Materials used to collect spills and leaks, and sediment and sludges that acculnulate on the pads or in the sumps of mixing/loading facilities require diligent management. The facility operator must know what pesticides these solid or semi-solid materials contain. This is only practical when the operator knows what pesticides have been present on the pad. If the sediment or sludge is collected on a frequent and regular basis, the operator will know what materials have been used and, consequently, what pesticide residues will be in the sediment. Spill control materials should be stored as a pesticide with proper identification until application or disposal can be made.

These materials can be applied as a pesticide if the applicator knows the pesticide and the amount of pesticide in the material. If the amount is not known, the applicator can apply it as if it was one hundred per cent active ingredient. An application using that assumption would always be less than the labeled rate.

If the pesticide or pesticides in the solid, sludge or sediment is not known, the material cannot be legally applied as a pesticide. It will have to be managed as a waste, and, if some of the pesticides are regulated as hazardous wastes, the sediment will have to be disposed of as a hazardous waste.

The pad design plays a large role in sediment and sludge management. The pad should be designed to minimize sludge and sediment accumulation and allow easy clean-out of sumps. Examples of features that can accomplish this are troughs to wash tires before the equipment comes on the pad and sump liners that can be removed for cleaning. Designs that do not take sediment and sludge management into account may lead to accumulations of sediments that have to be managed as hazardous wastes.

Clean Water Act (CWA)

The Clean Water Act (CWA) affects design and operation of pesticide mixing and loading facilities in one very direct way. One part of the law (Title 111) prohibits the discharge of pollutants to waters of the United States without a permit. This law, found in 33 USC 1251 et seq., and the regulations implemented under its authority, found in 40 CFR 122-124, also establish what levels of pollution are acceptable for permitable discharges to water bodies. As a result of these provisions, water produced by pesticide mixing and loading facilities cannot be discharged into surface water bodies that are considered "waters of the United States" Any release of water containing pesticide residues into a water body may be a violation of this law.

The CWA also includes effects on surface waters due to storm water run-off. For some pesticide mixing and loading facilities, this may mean that storm water that runs off of pads or other parts of the facility that have been exposed to pesticide residue will have to meet the effluent guidelines before it reaches a water body.

The CWA does allow for discharge of treated effluent, or water that has been treated in such a way that it meets the effluent limitation standards established under the Act. In general, these standards require removal of pesticides to very low levels (less than one ug/kg). For most facilities, use of a treatment system to remove

pesticide residues from rinsewater will not be cost effective. For those operations where use of the rinsewater as a pesticide is not possible, the use of a treatment system permitable under the CWA can be explored. Such a system would have to be capable of removing the pesticide residues very effectively. Monitoring of the effluent would be required to ensure compliance with the CWA.

Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA)

This law, also known as Superfund, requires notification of releases of materials that are considered hazardous to human health or the environment and investigation and clean-up of sites contaminated through such releases. The law is found in 42 USC 9601 et. seq. and the regulations in 40 CFR 300-373.

CERCLA defines "hazardous" more broadly than RCRA, and many commonly used pesticides are considered hazardous under its definitions. CERCLA also gives the USEPA broad authority to require investigations of suspected releases of hazardous materials, and to require clean-ups of areas found to be contaminated. Under the authority of CERCLA, USEPA can conduct investigations and clean-ups and then recover costs plus penalties from land-owners that have contaminated property.

CERCLA affects design and operation of mixing and loading facilities in two ways. These are:

Requirements for Site Investigation and Clean-up

Under CERCLA, USEPA can require investigation and clean-up of any site it suspects is contaminated with hazardous materials. A tracking system, called the CERCLIS, is maintained by USEPA or state governments under contract to USEPA for all sites that have been reported to be contaminated through a release of a hazardous substance. Sites can be placed on the list through discovery by a state agency, USEPA personnel, or public complaints. Every site placed on the list is supposed to be evaluated for the environmental and human health hazard. Sites for which information is sufficient will be evaluated, ranked for hazard, and if ranked high enough, placed on a priority list for clean-up, the National Priority List (NPL). Sites for which data are insufficient may be investigated further. In some states, this investigation will be conducted by the state hazardous waste regulatory agency, in other states by USEPA or a USEPA contractor. The investigation may consist of a

records check, site visits, and environmental sampling. If significant contamination is found, the landowner may be held responsible for the cost of the investigation and whatever clean-up action is appropriate.

Locations where pesticide mixing and loading has occurred in the past may have contamination of the soil or water as a result of releases of hazardous materials, ie. pesticides. Consequently, such places will bc of eligible for inclusion on the CERCLIS and evaluation using the CERCLA process. Such sites may require extensive investigation and clean-up to meet CERCLA standards.

Because of this possibility it is important to avoid locating new pesticide mixing and loading facilities on sites where pesticide mixing and loading, or any other activity involving hazardous materials, has occurred. If facilities are built on contaminated sites, the possibility exists that the facility or parts of the facility would have to be demolished to allow an investigation of the extent of previous contamination. It is also possible that a new facility would have to be removed in order to comply with a required clean-up action, such as soil removal or on-site incineration.

Designers and builders of pesticide mixing and loading facilities must take this into account when determining where to locate a new facility. The best practice is to locate the facility at a site never used for the storage, handling, mixing, loading, or disposal of pesticides, fuel, solvents, or any other hazardous material. If such a site is not available, the second best alternative is to conduct a bona-fide environmental audit of the site to be used. Professional environmental consultants familiar with pesticide contaminated sites should be used. Trade associations may have information on consultants that have experience in the area. Audits that are not done to professional standards will probably not be acceptable to regulatory agencies and the money spent on them will have been wasted.

If contamination is discovered, and the site is still to be used, a clean-up to CERCLA standards should be undertaken. This may add significantly to the cost of the facility, but, the cost of not responding to known contamination may be higher. These costs could include the cost of replacing the facility, fines for violating the reporting requirements of CERCLA, and potential liabilities for exposing workers to site contaminants.

Reporting of releases to the environment

Facilities that have design features or operating practices that allow releases of pesticides or pesticide containing materials to the environment may eventually end up dealing with CERCLA. Releases are those activities that

result in a hazardous material entering the environment through the air, water or soil. Legal applications of pesticides are not considered releases. CERCLA requires reporting of releases of certain materials above specific quantities. Compliance with these reporting requirements should be a goal of facility operators and they should be familiar with the SARA Title I11 program. The reporting requirements under CERCLA act to reinforce the pro- hibitions against contamination of water and soil estab- lished under FIFRA. Facility design and operation should be reviewed to ensure that all pesticides and pesticide wastes are either contained within the facility, applied as pesticides, or disposed of properly as wastes.

The reporting requirement becomes very important when spills and leaks occur, and also as the facility ages. As the facility develops cracks, leaks, and other structural weaknesses, the potential for "releases" increases. Maintenance of the facility is critical for preventing these occurrences.

Determining compliance

Designers, builders, and operators of pesticide mixing and loading facilities should make an honest effort to determine if they are in compliance with applicable requirements for design, construction, and management of these facilities. State agency personnel, USEPA personnel, Extension Service workers and trade association representatives are all potential sources of information on what is required in a particular state. Do not rely exclusively on the advice of consultants for determining compliance with applicable regulations.

Responsibility for ensuring compliance varies depending on the law being considered. It is the responsibility of the pesticide applicator to ensure compliance with label requirements. The owner of the operation will be responsible if hazardous wastes are generated and not properly managed. The owner of the operation will also most likely be responsible for violations of state regulations that require pads or specify facility characteristics. It is the property owner who will ultimately be responsible under CERCLA if contamination occurs. Although it may be time-consuming to determine if the facility is in compliance with all applicable regulations, it can be done, and the potential penalties avoided make it worthwhile.

Facilities that are designed to contain all pesticides and pesticide residue-containing materials within the facility will generally be the most likely to be in compliance with applicable regulations. The common intent of the four Federal laws, and many state laws, is that the

environment and humans be protected from exposure to toxic materials. Facilities that are designed to keep pesticides away from contact with soil, ground water, and surface water will be accomplishing the goals of these laws. Facility designers and operators should review their systems to determine pesticides and pesticide residues are being adequately contained. Tables 1 and 2 are examples of design features and operational practices, respectively, that may cause facilities to be out of compliance with these laws.

Facility designers and operators should also recognize that laws and regulations are always changing. A practice that is acceptable today may not be acceptable tomorrow. There are two general ways to cope with this phe- nomenon. One way is to do your best to keep informed and influence law and regulation development through trade associations and other organizations.

The other way to "stay ahead of the curve" on regulations is by adopting the prevention of contamination as a goal. This approach will be more sucessful in the long run than trying to do the minimum needed to comply. Designers and operators of facilities that handle pesticides can review their operations, identify potential sources of environmental contamination, and adopt design features and practices that prevent or eliminate these potentials. Prevention of environmental contamination at pesticide mixing and loading sites is mostly a matter of common sense. If pesticides or pesticide contaminated materials come into contact with soil, surface water, or ground water, the potential exists for environmental contamination. All operations that involve pesticides or materials that have been in contact with pesticides should be reviewed for the potential to contaminate the environment.

The laws and regulations that exist and are being developed are imperfect attempts to require actions that prevent or eliminate contamination. As contamination problems are discovered, government must respond, and the environmental laws are revised and made stricter. The more common the approach of reducing contamination potential is among pesticide mixing and loading facility designers and operators, the less likely it is that the USEPA or state agencies will impose strict mixing and loading facility requirements on pesticide applicators.

provisions of four basic laws that affect pesticide mixinglloading facilities design and operation. Four Federal laws, the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), the Resource Conservation and Recovery Act (RCRA), the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA) and the Clean Water Act (CWA), and the regulations implementing them, establish a set of requirements for the handling of pesticides and pesticide waste materials. Designers and operators of these facilities should review design and operation features to be certain that they are in compliance. Designers and operators should also strive to reduce the potential for contamination from the pesticide mixing and loading operations in order to reduce the need for stricter regulations and government oversight.

References

Flechas, F.W. 1987. Resource Conservation and Recovery Act permitting of on-site waste storage and treatment. in Proceediilgs: Natioital Worksltop on Pesticide Waste Disposal. USEPA Report No. 60019-871001.

Ehart, O.R. 1985. Overview: Pesticides Waste Disposal. in Proceedings: National Workshop on Pesticide Waste Disposal. USEPA Report No. 60019-851030.

Conclusion

Facilities designed and operated with environmental protection in mind will most likely comply with the

Table 1 . Examples of Design Features and Potential Compliance Problems for Pesticide Mixing and Loading Facilities.

Design Feature

Drain in storage area

Storage of food or feed with pesticides

Rain water collected on operational area pad and then discharged outside of pad area

Container cleaning area seperate from mixing area

Facility built on site previously used for mixing and loading

Equipment rinse- water stored underground

Pertinent Law

FIFRA, CWA

FIFRA

FIFRA, CWA

FIFRA, RCRA

CERCLA

RCRA CERCLA FIFRA

Potential Compliance Problem

Contamination of soil or water with pesticide

Contamination of food or feed

Contamination of soil or water with pesticide

Containers not cleaned immediately will be harder to clean or may not get cleaned

Site may be contalllinated

Storage of rinsewater that contains pesticides regulated as hazardous may require a permit. If storage tank leaks, hazardous substances may be released, contamination of ground water may occur.

Remedy

Eliminate drain in storage area or connect drain to above-ground collection tank so material can be collected for use as a pesticide.

Store food and feed in seperate storage area.

Prevent rain accumulation by using roof or collect rain water and apply as a pesticide.

Provide for container cleaning area as part of mixing area .

Use site not used previously or have Environmental Audit conducted to demonstrate no contamination.

Store pesticide rinscwatcr above ground inside of containment dike.

Table 2. Examples of Operational Practices and Potential Compliance Problems for Pesticide Mixing and Loading Facilities.

Operational Practice

Storing waste water over ninety days

Cleaning sludge from sumps infrequently

Discharge of equipment rinse- water to site not on label of pesti- cide residue in rinsewater

Discharge of rain water from operational area pad offsite without treatment or permit

Dumping of sediment or sludge that collects on operational area pad

Remedy

Use rinsewater as a pesticide witbin ninety days.

Collect sludge or sediment after each days operation or when pesticides used are changed, keep track of pesticides used in facility.

Apply rinsewater to a site on label of pesticide.

Prevent rain water accumulation by use of roof or other cover, or collect and use all rain water as a pesticide.

Manage sludge and sediment by using as a pesticide.

Pertinent Law

RCRA

RCRA FIFRA

FIFRA RCRA CERCLA

CWA FIFRA

FIFRA RCRA CERCLA

Potential Compliance Problem

Might be considered violation of regulation requiring permit for storage of hazardous waste

Unknown pesticides in sediment, sludge. Not legal to apply as a pesticide since unknown material.

Use inconsistent with label. If pesticide regulated as hazardous then improper disposal of hazardous waste. If listed in CERCLA as hazardous then release of hazardous substance.

If rain water discharged to surface water, possible violation of CWA. If contamination of soil or water occurs, possible violation of label prohibition of contamination of water.

Use of pesticide inconsistent with label. If pesticide regulated as hazardous under RCRA, then improper disposal of hazardous waste. If regulated under CERCLA, then release of hazrdous material.

OSHA Requirements for Pesticide Storage

Burt A. McKee, M.P.A. Environmental Manager United Agri-Products

Abstract

Facilities wlzich store agricultural materials present some unique challenges to regulatory agencies. Since tltere is no uiziversal standard for how you may store tliese materials, it has become a very discretionary issue. Today, you may find tltese materials in anytlzing from an open pole barn, to a modem facility which assumes a leading role in fire and safety issues.

Frorn the outset, there is a question of which agency or agerdes slwuld be tlze players wlzen the storage of agricultural materials is considered. While OSHA has not been the most activeplayer in previous years, a facility would be remise if it did not irlcorporate tlze appropriate OSHA standards into wizsideratwil during tlle design, wirstructwrb and mailageme?lt of a chemical storage area.

There are two basic OSHA staizdards which come into play; Part 1910, is tile Occupational Safety and Healtlz Sta?zdards for general industry. Part 1928, Occupatioizal Safety and Health Standards forAgriculture, is the starldard for agriculture. Manufactlcres and distributors are clearly under tile more encornpassirig 1910 standard. Many farrn facilities, however, will be under the 1928staizdard wlrich is very finite in scope.

This paper will first look at Parts 1910 and 1928. It will tlzen focus on wliat may be the most important co~zsideratioiz, the General Duty Clause. In essence, you will provide a place of employmeilr fi-ee of recognized hazards for the purpose of preveirting serious injury or deatll.

Tlie stewardship of agricultural nzaterials is of paranzount irnportailce as we enter a time of increased safety, healtlz, and eilviroiimeiltal concern. This paper will focus 012 these issues as it addresses OSHA concerns for agricultural material storage.

Introduction

The building of a facility designed to store pesticides requires appropriate planning. The potential liabilities associated with both the loss of human lives, and environmental damage enormous. While there will be many regulatory and environmental agencies which may be involved, this paper will be addressing storage through an OSHA perspective.

OSHA which is the acronym for Occupational Safety and Health Administration is normally the lead organization when it. comes to safety at the workplace. When pesticides are brought into the picture, however, there may be additional players. The Environmental Protection Agency, The United States Department of Agriculture, State Departments of Agriculture, State Departments of Environmental Regulations (actual names may vary), Water Management Agencies, and others may have regulatory authority in the storage of pesticides.

The issue may be compounded even within OSHA itself. Many states initially elected to write their own OSHA program which is equivalent or more severe than the federal program. The sum total of this all is the possibility of overlapping jurisdictions and perhaps some confusion over who will be over what. In an attempt to strike a common cord, this paper will assume that any given state is under the federal program.

OSHA Standards

There are three main standards which should be addressed when considering OSHA requirements: Part 1928, Part 1910, and the general duty clause, 5 (a)(l). Part 1928 is the Occupational Safety and Health Standards for Agriculture i.e. farm standard. While the standard addresses such topics as temporary labor camps, anhydrous ammonia, pulpwood logging, slow-moving vehicles, and hazard communications, absent is any information which may be used for facility construction.

Part 1910 is used for general industry. It should be used by manufactures and distributors. This standard will provide information such as; appropriate railings to be used around dock and overhead areas, aisle maintenance, and egress/ ingress requirements. It should be noted that there will still be no comprehensive amount of information that may be used for pesticide storage. The answer may be the general duty clause.

Any standard that OSHA may enforce should be viewed as a minimum standard. The overriding concern of OSHA is that an employer provide a place of employment free of recognized hazards, and that appropriate training be conducted. This is a performance standard. A company may provide training every week or every month, but it is the results that indicate whether or not the program is a success. The general duty clause can be used to enforce safety at the workplace.

Practical Considerations

A general standard for aisles is to keep them the minimum width of the door. Go to any existing pesticide storage facility, and stand at the most distant point from an exit. Yell Fire! If you have to climb over, jump over, trip over anything, or find your progress impeded in any way, you did not pass the test.

A fire extinguisher is a tool used to protect property during the incipient phase of a fire. But more importantly, they may be used for a rescue. If the fire extinguisher is missing, wrapped with cords, located in the back of the building or in any location other than protecting the ingresslegress of the facility, you may be meeting every requirement of various laws except the one that really matters, results.

Emergency equipment such as protective suits and respirators must be kept in an accessible condition. Again, the worst case scenario would be the need to rescue an employee who was overcome with some type of pesticide. If it made one employee lose consciousness, how safe would it be for other employees to attempt a rescue without appropriate equipment. For any equipment to be acceptable in an emergency, it must not be contaminated, nor should the rescuer have to don the equipment in a contaminated environment.

The availability of water is an important concern for a pesticide facility. Provisions should be made for both routine and emergency chemical removal. This is often more a problem at a remote farm storage facility as opposed to a distributor on city or county water systems. Again, the acid test is performance when needed. If you blindfold yourself in the middle of the facility could you access the emergency shower? It is not uncommon to find conventional showes used as additional storage or emergency systems located on the edge of a dock. Other potential problems include; insects using the piping for nests, pieces missing off showers or other physical damage, and in some instances, the shower is never plumbed.

MSDS must be immediatly available when needed. Accessibility is more important than how pretty the binder is in which they are kept. The acid test: can you send the MSDS in with an injured employee, or will you still be looking when the ambulance leaves?

Looking Good

All pesticide storage facilities should have an employee bulletin board. Posted should be all posters required by law such as the JOB PROTECTION & HEALTH PROTECTION notice from the U.S. Department of Labor.

But, there is a lot of opportunity to create good will. The company Hazard Commmunication Program should be clearly posted on the bulletin board. Also, this is a great place to hang a set of all appropriate MSDS that the employees could be potentially exposed to.

There is no good reason not to have this information available to employees. Copies are easier to make than doctor bills are to pay.

Contingency Planning and Training

One of the most neglected OSHA requirements is an updated contigency plan, and the associated training that goes with it. Employees must know who to call and what procedures to follow during emergencies. OSHA Fact sheet No. 89-19 provides excellent information on what should be included in the plan.

As is the case in many requirements, the commitment is not passed on to employees. If there is a contingency plan written, it is placed in a folder, later to be found on a bookshelf or in someones' desk.

Employees must be thoroughly trained in what their responsibilities will be should an emergency occur. It may even be that the employees' sole responsibility will be to evacuate to a predetermined, safe location away from the incident. In this instance, the employee stays at a safe location until management can account for all employees. The employee does not return to the scene without the permission of management and/or the emergency responders.

Obviously, the more an employee is expected to do during an emergency, the higher the level of expected training. It is not uncommon for companies which store or transport pesticides to have hazardous wastes operations and emergency response training. The higher the level of training that the employees have, the more likely it is that emergency responders and company personnel will work effectively together for common goals.

In 1992, companies should not be overly zealous about locating and using exemptions. Contingency planning is no exception. A good example is what we may call the "10 employee rule". Companies with less than ten employees may orally communicate emergency action plans as opposed to having a written plan.

There are many good reasons for having a written plan. First, and of most importance, is employee safety. People tend to forget what they don't use. When the emergency does happen, it is much better to have the written word to fall back on as opposed to memory. Secondly, there is the subject of turnover. Unless it is a family operation, small business suffer a high degree of turnover as employees seek additional income and benefits. Taking the time to train employees what they should do during emergencies is often given a low priority.

It should be kept in mind that the pesticides are a very fragile commodity in the 1990's. Having a workable contingency plan that addresses what a company will do during an emergency, is one way to help steward these products. This is true regardless of the size of the operation. Again, if you want to get along with OSHA, or any other regulatory agency, you should consider doing more than the bare minimum. Always work closely with your emergency responders before and during emergencies.

Conclusion

Providing a safe workplace with appropriate training is the most important consideration when attempting to meet OSHA standards. OSHA as is the case of other regulatory agencies, has developed a minimum standard to be followed by facilities.

Proactive companies will seek to build and maintain facilities that provide a workplace free of recognized hazards. Appropriate emergency planning and employee training should be given high priority.

References

Code of Federal Regulations Part 1910 1988 Office of the Federal Register

Code of Federal Regulations Part 1928 1991 Office of the Federal Register

Pesticide Fires: Preventable Disasters 1987 Office of the Attorney General The Capitol Albany, N.Y.

Secondary Containment And Containment Pads: Emerging Federal Pesticide Regulations

Dennis F. Howard, PhD. Environmental Fate and Effects Division Office of Pesticide Programs U. S. Environmental Protection Agency

Abstract

In 1992, the EPAplans to propose for public comment a comprehensive rule on pesticide containers, part of which would set minimum federal standards for containment of pesticide bulk containers and pesticide dispensing operations. The proposed requirements may include standards for design, structure, maintenance, operation and cleanup of secondary containment structures and containment pads. Taken together, these requirements seek to prevent costly soil and water contamination both from catastrophic releases and from small but chronic discharges. This paper will describe key factors guiding the development of the proposed containment rule and will discuss EPA's intentions to develop rules for pesticide storage and disposal operations.

Introduction -- Three Phases

In its 1988 amendments of the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA), Congress mandated the promulgation of regulations to promote the safe storage and disposal of pesticides, including the safe refill and reuse of pesticide containers. The Environmental Protection Agency (EPA) is responding to this Congressional directive by developing a comprehensive rule-making package to establish standards for pesticide container design, residue removal, storage, handling, transportation, and disposal.

To accommodate the complexity of the subject as well as Congressionally imposed deadlines, EPA's proposed regulations are being prepared in three phases. Phase 1 rules establish procedures for the storage and disposal of recalled, canceled and suspended pesticides. A Notice of Proposed Rulemaking (NPRM) for these procedural regulations was scheduled to appear in the Federal Register prior to the MWPS conference. Phase 2 regulations

probably bear more directly on attendees of this conference. These draft rules set forth design and cleaning requirements for refillable and nonrefillable pesticide containers (see paper in these proceedings by EPA's Nancy Fitz) and they propose containment standards for certain bulk pesticide systems and for pesticide container refilling operations. The evolution of the Phase 2 containment requirements is the subject of the present paper. An NPRM for the Phase 2 regulations will be published in the Federal Register later in 1992. Completing the regulatory package are the Phase 3 rules, which address such wide-ranging issues as criteria for pesticide mixing and loading pads, storage of pesticides (e.g. warehousing), disposal of excess pesticides and rinsates, and transportation of pesticides. The Phase 3 NPRM is not expected to appear before 1993.

Factors Prompting Federal Regulations for Containment

The numbers of facilities handling bulk quantities of agricultural pesticides has risen significantly in recent years. The EPA estimates that more than 5,000 agrichemical dealerships currently store bulk pesticides, and many additional bulk tanks are used by other segments of the pesticide industry (basic producers, formulators, distributors), nonagricultural industries, independent commercial applicators, roadside maintenance operations, farmers, and other end users. Bulk storage and refilling operations are likely to gain further acceptance when Phase 2 regulations facilitating the safe use of refillable containers are implemented.

The need for proper secondary containment of bulk tanks and for containment pads to protect areas where pesticides routinely are transferred has been underscored by the high incident rates of environmental contamination and by the cleanup costs now confronting agrichemical facilities. Preliminary data being gathered to support federal containment regulations indicates that each year, more than 1 in every 100 bulk pesticide storage facilities report a significant spill, and that under-reporting may mean that the actual spill rate is much greater. Failure to install proper agrichemical containment systems and to properly manage pesticide wastes may have resulted in significant contamination of soil and water

resources (sometimes tainting municipal water supplies) a t thousands of dealerships and related agrichemical facilities across the nation. Experiences in several midwestern states suggest typical per-site costs for assessment and remediation range from tens of thousands to hundreds of thousands of dollars, and million-dollar cleanups may not be rarel.

Containment of bulk pesticide containers and operational areas makes good economic sense for several reasons. If a bulk tank or fixture fails, a catastrophic release of product can be circumvented. This not only avoids the high costs of an environmental cleanup and reduces exposure to personnel, but it also allows for the recovery of expensive pesticide product. It is not surprising, then, that many pesticide registrants require dealers who purchase their products in bulk quantity to install protective containment systems. In fact, pollution liability insurance underwriters typically will not insure agrichemical dealerships that lack functional containment systems. Containment also can intercept smaller but more routine leaks and spills of pesticide concentrates, rinsates and equipment wash water, thus preventing their release and eventual environmental degradation.

Approximately 20 states have implemented or are drafting bulk containment rules which apply to pesticides2. These rules vary widely in their scope and stringency. Federal rules would establish a minimum set of standards applicable to all states, although states so desiring could develop or preserve requirements more stringent than the federal standards.

Underlying Principles

In drafting federal containment rules, EPA staff has attempted to adhere to several guiding principles, among the most important of which are the following:

The regulations should be cost-effective; that is, risk reduction and economic benefits should outweigh the costs of compliance.

The requirements should be performance-based rather than design-based. In this way, facility owners may be provided choices in containment materials and design, and advances in technology may be accommodated.

In an effort to identify requirements that are effective and widely accepted, regulatory approaches taken by states and other entities should be considered.

The rules should consider impacts on operations that have already installed containment systems, often a t considerable expense. Where justified, the continued use of safe existing structures should be permitted, either through retrofitting, "grandfathering," phase-in schedules, or similar provisions.

Highlights of Issues

Caveats

Given the numerous opportunities for review and revision which permeate the federal rulemaking process, a draft rule can be reshaped at many points along the way to publication of the final version. At the time of this writing, EPA staff is finalizing the proposed containment rules in preparation for review by EPA management. After the draft rule clears internal hurdles as well as reviews by other relevant federal agencies, the NPRM will be subject to public scrutiny. Based on comments received during the comment period, the draft rule may again be revised prior to finalization. Thus, the draft containment rule is far from "cast in concrete"; issues and regulatory prescriptions may undergo significant evolution before the final rule is crafted. With these caveats in mind, listed below are some of the more prominent issues which have thus far surfaced in the containment rulemaking effort.

Scope and Applicability

The EPA must decide to whom containment regulations should apply. Although it is reasonable to assume that any operation which stores or handles significant quantities of pesticides may risk spillage, data currently amassed by the Agency suggests that episodes of soil or groundwater contamination are most frequently documented a t agrichemical dealerships and commercial applicator facilities. Installation of proper spill prevention and control systems at such facilities is particularly urgent given their growing use of refillable pesticide containers, bulk systems andlor refilling operations. Thus; initial regulatory emphasis has been on containment requirements for pesticide dispensing, refilling and bulk storage activities a t such types of facilities.

Pesticide storage and handling activities that warrant consideration for containment but, due to limited time, cannot directly be addressed in the proposed rule should soon be addressed in Phase 3.

Meanwhile, to assist the EPA in prioritizing rulemaking, the Phase 2 NPRM may request information from the public regarding the extent to which additional types of facilities and operations need to be addressed.

Structural and Design Features

The draft rule seeks to establish performance standards for materials, design and construction of containment for bulk pesticide containers and for containment of pesticide refilling/dispensing operations. Requirements are being developed for both liquid and dry pesticides. No single structural material is currently prescribed, although any system should be sufficiently rigid and structurally sound to withstand the full load and impact of stored materials and equipment. A key issue with which EPA staff is grappling is deciding the optimal method for requiring that the structure be designed and constructed to prevent the migration of deleterious amounts of spilled or discharged pesticide. Whether the standard should specify that the structure be impervious, pesticide-tight, able to hold pesticide for a specified length of time, meet a quantitative permeability standard, or meet some other related criteria is still being evaluated. Whatever approach is selected, compliance should be attainable through several avenues. Those could include the use of structural materials, surface coatings or sealants, synthetic liners, or combinations of these materials.

Concrete is widely utilized in agrichemical containment systems. One of the concerns to be addressed in the NPRM is concrete's susceptibility to cracking. Even microscopic cracks, which can be difficult to detect by visual inspection, may provide escape routes for spilled pesticides. This may lead to the undesirable situation of facilities operating under the false assumption that their containment system is not leaking.

A question for which the EPA continues to seek expert advice is under what circumstances, if any, does concrete alone provide adequate containment? Other pertinent questions are: Can treatment of concrete with sealants provide adequate protection? Can coatings? Are candidate containment materials available and can they readily be documented to be effectively impervious and pesticide-compatible?

Another important question is whether leak-detection systems should be required for

containment structures. One option likely to be discussed in the NPRM is that bulk tanks be situated in such a way that leaks into the secondary containment area are readily observable. Elevating tanks on legs, beams or raised beds of smoothed gravel are possible approaches. Similarly, by avoiding gravity drains, by keeping pipes and tanks aboveground and by using working surfaces which slope to a watertight sump, the need for leak detection systems may be reduced.

The proposed rule will introduce capacity requirements for containment systems. States with containment rules have selected a number of variations on a capacity theme, but one ubiquitous principle involves using the volume of the largest container, or some multiple thereof (1.1 or 1.25), to set the minimum capacity. The states also require that the volume displaced by containers and equipment be compensated for when calculating containment capacity. Most states require larger capacities for containment systems not protected from precipitation, although the quantity of extra protection can vary among states (e.g., 6 inches of freeboard; capacity to contain a 25-year, 24-hour storm; 125 percent of the volume of the largest container). The proposed federal rule may consider setting different capacity standards based on whether the system is protected from precipitation and whether it was built prior to implementation of the federal standards.

Existing Structures

Variation in containment capacity is but one of many examples of the differences in requirements by states with promulgated bulk pesticide regulations. Further, most states currently do not specifically regulate the structure or design of containment systems. The result is a national patchwork of existing containment structures that vary significantly in their ability to meet environmental protection objectives. With such heterogeneity, it is unlikely that all stringent federal structural and design standards could be broadly and easily met. One option is to require new structures to be built or existing structures to be retrofit. However, because many of these containment systems have been constructed a t considerable expense and with materials and designs that are not always amenable to modification, abandoning or significantly modifying them to meet new standards could be financially burdensome. Another approach would be to "grandfather" existing structures, exempting them from some or all of the structural standards. An alternative approach, which staff believes is

more balanced, is to establish an interim period during which a set of minimal performance standards would apply. Compliance with these standards may require some existing structures to upgrade, but the upgrades should be cost-effective. After the interim period has expired, more stringent federal performance criteria would apply.

Key to a successful interim requirement system is the development of a reasonable set of minimum performance standards. Another pivotal factor involves selecting an appropriate duration for the interim period. On one hand, the period should be long enough to allow owners to use well-designed existing systems for the majority of their intended service life. Conversely, the period should be brief enough to induce owners of severely substandard existing structures or prospective owners of new systems to build to the full standards, rather than to the interim standards.

Operation and Maintenance

Even the best of containment systems will fail without proper housekeeping and maintenance. The NPRM will discuss the need for the timely cleanup of spills, frequent inspections of pesticide containment structures and equipment, and proper maintenance of containment systems. If less stringent, interim structural standards (as discussed above) are adopted, provision could be made for more vigilant operational and maintenance requirements during the interim period.

Conclusions

The above discussion provides a glimpse of the relatively broad range of issues and options being considered by the EPA as i t strives to prepare rules for pesticide containment systems. Currently, the Agency is giving priority to those aspects of containment that are most closely linked to co-evolving rules on refillable and non-refillable containers. These sister rules should emerge as the Phase 2 NPRM later this year. The Agency plans to consider additional important containment issues in Phase 3.

The development of prudent, cost-effective federal containment rules hinges on the Agency's thorough understanding of the subject. Thus, staff continues to seek out and welcome information from a variety of informed sources,

both inside and outside of the EPA. A particularly significant opportunity to communicate your knowledge and opinion on the subject of containment will be provided during the formal public comment period in the NPRM. By clearly stating and documenting your views on the proposed rule (whether your views include concerns, disagreements, suggested revisions andlor agreements with the proposed rule), you can assist the EPA in developing meaningful regulations for pesticide containment systems.

References

1. Buzicky, G. (Minnesota Department of Agriculture), P. Morrison (Wisconsin Department of Agriculture), A. G. Taylor (Illinois Environmental Protection Agency). 1991. Personal communication with Office of Pesticide Programs, U. S. EPA, November, 199 1.

2. Lounsbury, B. 1991. "1991 State of the States: Pesticide Storage and Disposal." Draft report to Office of Pesticide Programs, U. S. EPA.

PESTICIDE STORAGE AND SPILL CONTAINMENT; STATE INITIATIVES

Ned Zuelsdorff, Director Bureau of Agrichemical Management Wisconsin Department of Agriculture,

Trade and Consumer Protection

Abstract

Several States have enacted or are developing regulations requiring secondary containment of bulk pesticides in response to groundwater contamination concerns. At least one State also requires use of spill containment pads a t all significant pesticide mixing and loading sites. Most of these requirements specify performance standards. Similar federal regulations are currently being developed by EPA. Site remediation prior to mandated construction is a n issue because of regulatory construction deadlines9 lack of cleanup standards and remediation technology, and costs associated with site investigation and remediation. Containment structure design should facilitate spill recovery and reuse, and m i n i m i z e t h e p o t e n t i a l for future contamination of the site.

Introduction

Groundwater and other environmental contamination resulting from pesticide mixing and loading activities has been documented in several States. A recent studyu of these commercial sites in Wisconsin found that 213 of the sites had significant soil contamination. Pesticides were detected in groundwater a t more than half of the sites, with concentrations exceeding groundwater standards a t 113 of the sites surveyed. Officials and the pesticide industry in Wisconsin and other States recognize that use of spill containment structures is one important component of a comprehensive plan to address this health and environmental concern.

State Regulations and Initiatives

More than seven States have already enacted comprehensive secondary containment and spill pad requirements for bulk pesticide storage and handling sites2/. Several other States and EPA are currently in the process of developing similar regulations. The Association of American Pesticide

Control Officials (AAPCO) has published its Model Rule for Bulk Pesticides a s a guideline for States considering developing regulations. These regulations are normally administered by State agriculture or environmental agencies, however other agencies may also be involved. There are differences in the specific State requirements, and regulations are and will continue to be updated. I t is therefore highly recommended that engineers and facility managers contact the appropriate State officials early in the construction planning process.

General Requirements

Bulk storage and spill pad requirements related to construction generally address the types of materials that can be used for storage tanks, appurtenances, and storage and spill containment structures. In addition, containment capacity and general construction guidelines are specified. Performance standards are generally identified and while permits and submission of construction plans are sometimes required, few if any States actually "approve" plans. Performance standards provide greater flexibility for development and use of new materials and technologies since subsequent rule amendment is not necessary.

The regulations normally apply to sites that meet certain thresholds related to size of storage containers or quantities of pesticides mixed and loaded. The regulations can extend to both commercial and private (farm) sites.

Most States allow use of concrete, steel, solid masonry and other "approved chemically compatible materials for secondary containment. Containment systems must not only be resistent to cracking or other failure but must be easily repaired to remain useable under State regulations.

Spill containment pads must be paved and sloped to both contain spills and prevent water from running onto the surface.

Underground storage of pesticides is generally prohibited.

Construction at Existing Sites

Soil and groundwater contamination is often found a t existing pesticide mixing and loading sites. Science based cleanup standards a re only now starting to be developed and the process will take time. Remediation technology also is not well developed and in fact does not currently exist, a t least from a n economical standpoint, for pesticideb) in groundwater. This presents a dilemma for site managers and engineers who face regulatory deadlines for construction of containment systems. Consideration should be given to relocating to a "non-contaminated" site for construction, if this i s an option. Building on a contaminated site prior to remediation could result in the need to subsequently dismantle some or all of the construction to allow remediation.

Site Management and Related Design Concerns

Engineers obviously must take many site management issues into account when designing containment facilities. System design must facilitate spill recovery and subsequent reuse. This not only reduces the potential for environmental contamination caused by pesticide residues being carried off or out of the containment structures but also minimizes the volume of solid and hazardous wastes generated. "New" soil contamination has been found at Wisconsin sites where containment structures a re already in place.

Wisconsin and other States a re beginning to develop laws and regulations tha t will mandate routine environmental monitoring around pesticide facilities. This can include both soil and groundwater. Significant contamination would trigger additional monitoring, remediation and related expenses.

Conclusion

Many States now have or a re developing specific requirements for pesticide containment structures. While similar in some ways, there are significant differences between States. Facility managers and design engineers should contact appropriate State officials early in the construction planning process to assure tha t they are in compliance with regulations.

Re fe rences

11 Morrison, P. and S. Kefer. 1991. Report on Wisconsin Pesticide Mixing & Loading Site Study. Wisconsin Department of Agriculture, Trade and Consumer Protection, Madison, WI.

Lounsbury, B.B. 1991 State of the States: Pesticide Storage and Disposal. Office of Pesticide Programs, U.S. EPA, Washington, D.C.

Fire Safety Design Considerations in Pesticide and Fertilizer Facilities

Jon R. Nisja Supervisor-Code Development Minnesota State Fire Marshal Division

Abstract History has shown that agricultural buildings present unique fire hazards based, i n part, on the large quantities of agricultural chemicals, including pesticides and fertilizers, which they contain. The 1988 editions of the Uniform Building Code and Uniform Fire Code contain new requirements relating to the construction, chemical storage and use, fire protection features, and secondaly containment in buildings which are used for c?t,nmkal sts:'agc.

Fire Safety Design in Agricultural Buildings Over the past few years, a pattern of serious fires with long term health and environmental effects have been observed in buildings containing large amounts of chemicals. Among the most notable of these incidents was a large fire in a paint storage facility which was located over large water supply aquifers. Due to the potential water contamination concerns along with limited firefighting resources, the decision was made to allow the fire to burn itself out; which took several days.

in industrial, manufacturing and storage properties. Granted, not all of these fires involved agricultural chemicals, however, i t is safe to assume that a significant number of the incidents did.

In consideration of these factors, the fire service had to take a leadership role in developing aggressive prevention strategies for dealing with haz-mat incidents. Although other governmental agencies, such as OSHA and EPA, regulated hazardous materials from a worker safety, waste, or transportation standpoint, there was really no means for the fire service to address their unique concerns, such as firefighter safety, and resource capabilities.

Strategies to Deal With These Problems In 1986 several concerned fire service officials submitted numerous revisions dealing with hazardous materials to the Uniform Building Code and Uniform Fire Code committees. Their goals were to develop requirements which would prevent, control, and mitigate adverse conditions which might result from the storage, use, and handling of hazardous materials. Many of these proposals were adopted for inclusion in the 1988 editions of the Uniform Building Code and Uniform Fire Code.

These fires have led to concerns by first responding agencies (fire, police, and emergency These requirements, which are found in Chapter

medical services) as to their abilities to deal with 9 of the Uniform Building Code and Article 80 of

these chemical incidents; known to the fire service the Uniform Fire Code, are intended to protect

as hazardous materials (or haz-mat) incidents. employees, emergency response personnel, the public, and the property itself against a haz-mat spill, leak, or fire a t the property. They are not Fire involvement in designed to impose any regulations relating to the

Chemical Emeraencies transportation of hazardous materials, nor were Y

Many hazardous materials incidents involve fire or they intended to protect the environment (these ignition anG fire is the way in which itens are under the jurisdiction of other reg'datoi-y hazardous materials or their by-products are agencies). spread; by explosion, smoke migration, or run-off from firefighting operations. All too often the fire HOW the Codes Deal With Chemical service is called upon to mitigate these haz-mat Storage or Use incidents due, in part, to their normal roles as emergency providers and the presence of protective The first step is to classify the building as to its equipment (such as self contained breathing type of occupancy. The most common classifications apparatus). for buildings containing relatively small quantities

of hazardous materials would probably be Group

In the state of Minnesota there were 1,052 fire incidents involving agricultural properties in 1989. These fires did an estimated $14,267,000 in damage. Although the statistics for 1990 showed a decrease to 890 fires and $7,800,000 in damage, these fires still represent 113 of the total fire loss

B (Business) and Group - M (&-ricultural) occupancies. In these types of occupancies, the codes allow some chemical storage based upon a "control area" concept. A control area is defined as an area separated from other areas by one-hour fire-resistive construction and multiple (up to four) control areas are allowed per building. If the

amount of chemical storage is exceeded, the classification of the building is changed to an H (Hazardous) occupancy.

The amount of chemicals permitted in each control area varies with the classification of the chemical(s). They are classified based on their hazards in accordance with the criteria which is found in the Code of Federal Regulations (29 CFR Part 1910.1200) into the following categories:

Physical Hazards: Explosives, Blasting Agents Compressed Gases Flammable & Combustible Liquids Flammable Solids Organic Peroxides Oxidizers Pyrophoric Materials Unstable (Reactive) Materials Water-reactive Materials Cryogenic Fluids

Health Hazards: Toxic or Highly Toxic Materials Radioactive Materials Corrosives Other Health Hazards

Most often the hazard classification can be found on the chemical's Material Safety Data Sheet (MSDS) which is supplied with the chemical or can be obtained from the manufacturer. Increases in the amounts of storage and use of most chemicals are allowed if the area is protected by an automatic fire extinguishing system (such as a fire sprinkler system) or if the chemicals are stored in an approved storage cabinet. These increases are based on the theory that any fire will be extinguished or controlled before i t can spread to the other materials in the room.

The use of chemicals generally presents a greater hazard than merely storage. By definition "use" means placing in service a material whereby i t is liberated to the atmosphere (in other words, the container is now open and the material is being pczred, transferred, ?-azc!!ed, etc.).

Storage Requirements Once the exempt amounts of storage per control area are exceeded, certain requirements are imposed. These requirements vary with the hazard classification of the chemical. In general, the following requirements are applicable to chemical storage:

Container & Tank Design and Construction Defective Containers & Tanks to be Taken Out

of Service Chemical SignageIIdentification Control of Ignition Sources Shelf Storage of Materials Spill Control, Drainage, Containment

Ventilation Separation of Incompatible Materials Protection from Vehicle Collision Clearance from Combustible Materials

Use Requirements The requirements for the above items are also imposed when chemical use is occurring. As a general rule, the requirements are more strict in use situations based on the increased hazards because the chemicals are in an open condition and are no longer contained.

Are These Requirements Enforced RetroActively? To a large degree i t depends on the regulations in your particular state or municipality. As a general rule, the requirements of a building code are only enforced in the case of new construction, major alteration or addition, or a change in use or occupancy of a building. An example of a change in use or occupancy would be the conversion of a building from an ofice into a warehouse.

Typically, fire code requirements are imposed in the case of new construction or change in use or occupancy (similar to the building code) or in cases where the fire official determines the condition or situation to be a distinct hazard to life or property requiring some manner of corrective measure(s). If you have questions as to the applicability of specific chemical storage or use requirements, please consult with the appropriate building or fire official.

References

International Conference of Building Officials. 1988, 1991. UNIFORM BUILDING CODE. Whittier, Califor-nia: International Conference of Building Officials.

National Fire Protection Association. 1989. FIRE PROTECTION W I D E OX HMARDZIUS MATERIALS. Quincy, Massachusetts: National Fire Protection Association.

Minnesota State Fire Marshal Division. 1991. FIRE IN MINNESOTA-1990. St. Paul, Minnesota. State of Minnesota, Department of Public Safety- Fire Marshal Division.

Western Fire Chiefs Association. 1988, 1991. UNIFORM FIRE CODE. Whittier, California. Western Fire Chiefs Association.

Why Containment - Industry's Perspective Donald L. Paulson, Jr. Environmental and Public Affairs CIBA-GEIGY Corporation

Abstract

To review with examples the importance of a n operational pad and secondary containment for minimizing the envirolzmental and economic impact of a fertilizer or pesticide spill. "What i f ' a spill OCCURF - What's the cost of clean-up from a.n "uncontuined" spill? from a "contained" spill? What's the dealer's 'payback" for installing a n operational pad? Is a covered dike and operational pad worthwhile? How is industry helping the dealer to meet his containment and handling reql~irements?

We, in the agricultural chemical industry, recognize the need to promote safety from a personal protection standpoint. CIBA-GEIGY and other basic manufactul-ers of agricultural chemicals support the "Rubber Glove Zone" concept promoted by the National Agricultural Chemical Association. Sometimes, however, we don't always recognize or appreciate how important "Environmental Safety" is to our business.

I have been with CIBA-GEIGY's Agricultural Division for 23 years. I have been directly involved with emergency response for over 15 years. I, or my emergency response team members, receive one way 01. another, all spill or fire calls for the CIBA- GEIGY's Agricultural Divisioll involving our custon~ers, dealers, growers, transporters, and home owners. The Agricultural Division receives an average of 200 calls per year of which approximately 75 involves spills of some kind.

I have personally been a t several dealer sites involving spills and clean-up of CIBA-GEIGY products. I have had my feet stuck in the mud, I have worked in the rain in freezing weather. I have argued with state agencies over clean-up and dispos- als, and I have faced news reporters who asked the tough questions. I pay the clean-up bills, and I know how much they cost. I have watched the states one by one develop and pass regulations on storage of bulk fertilizers and chemicals.

"Why a dike?" Let me answer this question from industry's viewpoint. Before CIBA-GEIGY insisted that all of bulk tanks stori~lg our pl*oducts be diked, I spent large sums of money cleaning up spills. I11 1981 clean-up of one spill alone cost CIBA-GEIGY $207,714.00. In 1982 clean-up of one spill cost

$51,300.00, and in 1983 clean-up costs for one spill cost CIBA-GEIGY $184,440.00.

So why a dike? From my perspective, saving product and expensive clean-up costs are very important. There are certainly several other benefits of secondary colltainme~lt - spilled product is contained in a small area, there is no run-off. Diking eliminates all contamination and prevents contamination of both surface and groundwater. Spill clean-up is much easier, costs and losses are minimized. Safety is important. Pumps and meters can be elevated to keep then1 out of water, and they are inside the dike in case a gasket, valve, hose or pipe ruptures or leaks. If all piping is rigid and supported and each tank has a separate line, cross-contan~irlation is prevented and potential damage to piping is minimized. Security is an important aspect of bulk storage and an extra advanta e if the diking f system is inside a roofed and locke building. In these circumstances all mixing and loading is conducted under roof, all vehicles are loaded on a rinse pad and all rinse water and spills are collected in a sump and pumped into above ground and diked tanks for reuse. Overhead doors can be closed and locked a t the end of each work day.

Other benefits of a good secondary containment system are peace of mind for the dealer by knowing that there is a back-up security system and containment. The dealer continues to be a leader in the comnlunity through safe handling of bulk products. Secondary containnlellt results in protection of the dealer's business and lowering of insurance premium because losses and potential clea~i-up expenses are minimized. There is a positive public relation's benefit in the community and with the dealer's customers.

There are also incentives and cost savings that are offered to dealer's from major suppliers like CIBA-GEIGY to install secondai-y containment systems. CIBA-GEIGY has a bulk storage pro am as do several other basic manufacturers. ~ n g r CIBA-GEIGY's program, a dealer is covered if a spill occurs involving a CIBA-GEIGY bulk prodgg stored as bulk in a Farm-PakO or Field-Pak or transported by the dealer and the bulk product is or had previously been in storage under our program.

Other benefits of a good secondary containment system are peace of mind for the dealer by knowing that there is a back-up security system and containment. The dealer continues to be a leader in the community through safe handling of bulk products. Secondary containment results in protection of the dealer's business and lowering of insurance premium because losses and potential clean-up expenses are minimized. There is a positive public relation's benefit in the conlmunity and with the dealer's customers.

There are also incentives and cost savings that are offered to dealer's fi-om major suppliers like CIBA- GEIGY to install secondary containment systems. CIBA-GEIGY has a bulk storage program as do several other basic manufacturers. Under CIBA- GEIGY's program, a dealer is covered if a spill occurs involving a CIBA-GEIGY b u l \ ~ o d u c t stored as bulk in a Farm-PakO or Field-Pak or transported by the dealer and the bulk product is or had previously been in storage under our program.

What if a dealer does not have a dike, rinse pad or good handling system for chemicals and fertilizers? The dealer should ask himself what if he had a spill, where would it go? If a spill is on the ground, will I have to dig up soil or gravel? What would I do with it if I have to dig it up? If spilled product ran off my site, would i t result in crop injury or environmental problems? Are my pumps, meters, and hoses in an environmentally safe location? Are the valves on my storage tanks locked? If I have secondary containn~ent, is it adequate? Is my containment volume adequate? Do I have a spill or fire emergency contingency plan? How do I go about developing a plan?

Secondary containment is not only economical but it will provide protection against major loss of product and clean-up expenses. In addition, it benefits the dealer's operation, protects his neighbor, and their local environment, provides peace of mind to the dealer, and protects the dealer's future business.

Legal Liability For Groundwater Contamination Arising From The Agricultural Industry

Richard A. Pettigrew, Esq. Morgan, Lewis & Bockius

Abstract

The liability of those responsible for contamination of the gmundwater by pesticides and fertilizers can be far-reaching and severe. Consequently, the legal and financial consequences of our inattention to the laws governing groundwater contamination can be staggering. This paper reviews the risks and liabilities inherent in any land use involving agricultural chemicals or in any agricultural property transaction where the condition of the groundwater may be of concern. We also consider here how state and federal regulatory agencies are planning strategy and setting policy for controlling agricultural chemicals in the groundwater.

Introduction

Groundwater becomes contaminated when hazardous wastes and other materials are mis- managed or used without attention to their long term effects on the landscape. Pesticides and fertilizers used on agricultural crops infiltrate the soils and may eventually leach into the groundwater. Likewise, s p a s or losses of ~esticides, fertilizers or their constituents during processing may threaten the groundwater if not promptly or adequately contained.

Once in the groundwater, these materials may reach or exceed regulatory levels. This creates legal liability, requiring those responsible for the use and disposal of hazard.ous materials to restore the groundwater to its former condition. Because groundwater moves, however slowly, cleaning up all affected properties and sources of drinking water can be extremely costly and extensive.

controls rather than clean-up of contaminated waters, all of those involved with agricultural practices are best advised to keep informed of changing regulatioae and policies and appropriate legal protections.

EPA's Pesticides and Groundwater Strategy -- An Update

Before reaching the legal issues, a brief update of the evolving policies of the Environmental Protection Agency (EPA) concerning pesticides in groundwater is warranted. As of November 6, 1991, EPA released its fmal strategy statement entitled "Pesticides and Ground-Water Strategy." 56 Fed. Reg. 56643. The Strategy describes EPA's goals, policies, management programs and regulatory approaches for protecting groundwater resources from risks of contamination by pesticides.

According to the EPA, the general goal of the Strategy is to manage the use of pesticides to prevent unreasonable adverse effects to human health and the environment and to protect the integrity of groundwater resources. The Strategy focuses on source reduction and controls rather than clean-up of contaminated water in the ground or at the point of use. 56 Fed. Reg. 56643. An expanded role is contemplated for the states in managing the use of pesticides above and beyond the controls imposed a t the federal level by FIFRA. EPA proposes that State Pesticide Management Plans be approved, and users in states without an appmved plan may not be permitted to use or buy certain pesticides.

The Strategy may be obtained from EPA's Public Information Center at the following address: U.S.E.P.A., Public Information Center

Those who deal with agricultural (PM-211B), 401 M St., S.W., Washington, DC

properties or who operate facilities involving 20460. More information, including public

agricultural chemicals can best protect against comments on the proposed version now made final

these costa by becoming more aware of how the by this document, may be received by contacting

legal system assigns the risks and costa arising the EPA regional office in your area.

from groundwater contamination. And, because regulatory agencies are moving towards a preventive program of source reduction and

Scope of Liability For Groundwater Contamination

Types of Transactions Involved

Any sale, purchase, lease or other real property transaction is potentially of concern, including stock acquisitions. Any land use practice involving regulated chemicals must take into consideration the location of drinking water sources and surface waters that are hydrogeologically connected to such sources. Any company selling regulated agricultural chemicals should provide clear instructions for use and should consider becoming involved with training, monitoring and certification programs to make , users aware of groundwater issues and measures available to protect this resource.

Legal Bases for Liability

The primary federal laws regulating groundwater include:

Comprehensive Environmental Response, Compensation and Liability Act of 1980 ("CERCLA" or "Superfund"), as amended by the Superfund Amendments and Reauthorization A d of 1986,42 U.S.C. 9 9601 &. sea. ("SARA");

Resource Conservation and Recovery Act of 1976, 42 U.S.C. 9 6901, et. seq. ("RCRA"); and

Underground Storage Tank Program, RCRA subtitle I, 42 u.s.c.-9 6991, et. ieq. ('IUST").

Groundwater contamination began long before governments enacted statutes for groundwater protection. Consequently, federal and state legislation seeks to remedy effects of past activities as well as to regulate ongoing and future activities. In this section, we review the these major laws and the enforcement powers

Principles of CERCLA Liability

Joint and several liability: Responsible parties are jointly and severally liable for cleanup and cost reimbursement a t a Superfund site absent proof that harm a t a site is divisible. United States v. Monsanto Co., 858 F.2d. 171-73 (4th Cir. 1988) cert. denied 109 S. Ct. 3156 (1989) (defendant's volumetric evidence was insufficient to afford basis for dividing harm a t the site); U.S. v. Bliss, No. 84-2086C-(i) (E.D. Mo. 1988); and O'Neil v. Picillo, 883 F.2d 176 (1st Cir. 1989) cert. denied 110 U.S. 1115 (1990) (two non-settling defendants were held liable for all outstanding past & future costs, although each had sent minimal amounts of waste to site -- they had not proved divisibility of harm.)

Strict liability without regard to fault: In United States v. Cannons Engineerinp Corn. et al. The First Circuit reaffirmed that potentially responsible parties may be held strictly liable (without regard to fault) even in circumstances where to do so will result in disproportionate allocation of costs between potentially responsible parties, 899 F.2d 79 (1st Cir. 1990) (nonsettlors asked by government to pay a premium were not allowed to challenge prior government settlements with & minimis parties on more favorable terms). See, e.g. Levin Metals Con. v. ParrRichmond Terminal Co., 799 F.2d 1312, 1316 (9th Cir. 1986); U.S. v. NEPACCO, 810 F.2d 726, 732, n. 3 (8th Cir. 1986)) cert. denied 108 S.Ct 146 (1987).

Elements of a prima facie case: Following the SARA amendments, the government is required to demonstrate "a release or threatened release of a hazardous substance by a potentially responsible party (present or past site owner, substance generator or substance transporter) causing the government or private party to incur response costs", see e.g. United States v. Bell Petroleum Services, Inc., 734 F. Supp. 771 (W.D. Tex. 1990). (Discussion of underlined terms set forth in Part I11 below).

given to agencies in assessing liability costs and The government need not show any penalties for groundwater contamination. connection between the generator's particular

CERCLA waste and the resulting harm, but only that the generator's waste was shipped to the site and that hazardous substances similar to those contained in

CERCLA imposes liability for cleanup of generator's waste were a t the site a t the time of groundwater that has become contaminated by release. United States v. Monsanto Com~anv, 858 past hazardous waste activities. F.2d 160 (4th Cir. 1988) cert. denied, supra.,

Tancrlewood East Homeowners v. Charles Thomas, Inc 849 F.2d 1568 (5th Cir. 1988). .I

Scope of CERCLA Liability

"Hazardous substance" includes toxic or hazardous substances under the other environmental statutes (Clean Water Act, Clean Air Act, OSHA, RCRA, TSCA) and substances designated by EPA under CERCLA, §101(33).

"Petroleum exclusion" - Petroleum materials are not normally hazardous substances. EPA has indicated that used oil containing contaminants a t concentrations above that normally found in refined oil are hazardous substances subject to CERCLA.

"Release" includes virtually any means by which a hazardous substance might come in contact with the environment, including spilling, leaking, pouring, emitting, or discharging.

CERCLA also covers "threatened" releases -- the pzsence of hazardous substances a t an abandoned facility constitutes a threat of a release. United States v. Northernaire Plating Co 670 F. Supp. 742 (W.D. Mich. 1987). See also 2 1

~ e d h a m Water Co. v. Cumberland Farms DairyZ Inc., 889 F.2d 1146 (1st Cir. 1989)) (potential release of hazardous substances from deteriorating containers).

Continued seepage from past spills of hazardous substances is a release. United States v. Vertac Chemical Cow., 671 F. Supp. 595 (E.D. Ark. 1987)) Dedham Water Co. v. Cumberland Farms Dairv, Inc., Op. Cit. (continued leaching of hazardous substances from a pipeline); cf, Ecodvne v. Shah, 718 F. Supp. 1454 (N.D. Cal. 1989).

Where a government response action is predicated on an actual release from a site, the release must be in excess of some state or federal regulatory threshold, Amow Oil Co. v. Borden, Inc 889 F.2d 664 (5th Cir. 1989). .I

"Disposal" -- CERCLA Section 101(29), as defined in Section 1004(3) of RCRA, essentially allowing hazardous or solid waste to be emitted into the environment.

Flow of hazardous substances into a river and leaching of hazardous substances through soil and into groundwater is "disposal". Emhart Industries. Inc. v. Duracell International Inc., 665 F. Supp. 549 (M.D. Tenn. 1987).

Disposal is not a one-time occurrence -- disposal continues when hazardous materials are

moved, dispensed, or released during landfill excavations. Tan~lewood East Homeowners v. Charles-Thomas. Inc., 849 F.2d 1568 (5th Cir. 1988).

"Past or Present Owner or Operator of a Facility":

Present Owners: CERCLA applies to current owners or operators even if no hazardous substances were disposed of during their ownership. Tanglewood East Homeowners v. Charles-Thomas, Inc., 849 F.2d 1568 (5th Cir. 1988); United States v. Strindellow, 661 F. Supp. 1053 (D. Cal. 1987). However, when such past disposal activities do not result in actual or threatened releases following transfer of a contaminated site, courts have held that the subsequent "passive" owner is & a liable party. Kempf v. Citv of Lansing, (W.D. Mich. 1990) 5 TXLR 287 (August 1, 1990). Similarly, in Ecodvne Cow. v. Shah, 718 F. Supp. 1454 (N.D. Cal. 1989), a passive owner (Shah) who did not dispose of hazardous substances at a site was not responsible for subsequent release of such substances after conveyance of the property on the theory that Shah had never been an owner a t the t i e of diS~0Sd.

Government Entities: Except where states or local governments acquired property involuntarily, they may be liable under CERCLA to the same extent as other PRPs. United States v, Union Gas Co., 832 F.2d 1343 (3rd Cir. 1987)) aff*d, 109 S. Ct. 2273 (1989).

Lessees: will often be considered "operators" under the CERCLA definition. United States v. Monsanto, 858 F.2d 160 (4th Cir. 1988); United States v. Northernaire, 670 F. Supp. 742, 748 (W.D. Mich. 1987).

Past owners or operators a t the time disposal are liable. Sunnen Produds Co. v. Chemtech Industries. Inc., 658 F. Supp. 276 (E.D. Mo. 1987). An owner's liability is not extinguished by a subsequent transfer of property. Citv of Philadelphia v. Stepan Chemical Co., 1987 Westlaw 16690 (September 3, 1987).

Contractor that designed a facility, trained the facility's employees to operate the machinery therein, licensed the owner of the facility to use its trademark in connection with the facility's processes, and supplied the facility with raw materials, was held not to be an "o~erator" of the facility because the facility owner continued to

exercise day-to-day control, hire employees, and make all production decisions. Edward Hines Lumber Co. v. Vulcan Materials Co., 861 F.2d 155 (7th Cir, 1988).

Generators: Persons who "by contract or otherwise" arrange for disposal

Remote Generators and Transshivment: The person need not have selected the disposal site in order to be held liable. United States v. Conservation Chemical Co., 619 F. Supp. 162 (W.D. Mo. 1985).

Sales of Produds or Secondam Materials: A person who sells a hazardous substance may still be held liable under CERCLA, where the substance had no further use to the seller and was therefore a "waste" rendering the sale an "arrangement for disposal", United States v. A&F Materials, Inc., 582 F. Supp. 842 (S.D. Ill. 1984). Parties that remove asbestos containing materials may not, however, maintain a CERCLA cause of action against asbestos manufacturers on the view that such manufacturers initial sale of the producta constituted "disposal", pee Davton Independence School District v. U.S. Mineral Products Comvany (5th Cir. 1990), 5 TXLR page 345 (August 8, 1990). Similarly, in Florida Power and Light Comvanv v. Allis Chalmers (11 Cir. 1990)) the l l t h Circuit recently found that manufacturers of PCB equipment could not be held liable for clean-up costs when unforeseeable distant purchasers chose to dispose of the same, TXLR page 1156 (March 14, 1990). See also United States v. Sharon Steel Cow., Civil No. 86- C-924J (D. Utah May 17, 1989), (seller of commercial unprocessed mining ores containing hazardous substances not liable for contamination resulting from pmhases use), Amland Properties Corn. v. Aluminum Comvanv of America, 711 F. Supp. 784 (D.N.J. 1989)) (sale of PCB transformers do not constitute generation of waste), and Prudential Insurance Comvanv v. U.S. Gvvsum, 711 F. Supp. 1244 (D.N.J. 1989), (sale of asbestos products did not constitute generation).

Brokers that make arrangements for disposal between a manufacturer and a disposal company may be liable even absent any role in the creation of the waste. United States v. Bliss, 661 F. Supp. 1298 (E.D. Mo. 1987).

Product Revrocessors: Pesticide manufacturers which arranged with a pesticide formulator for reprocessing of their chemicals held potentially responsible parties under CERCLA (and also

under the Resource Conservation Recovery Act); the court found that chemical companies can be presumed to have expected that some chemicals would be discarded as waste in the reformulation process and that they would not recover all the pesticides that they sent for reformulation. United States v. Aceto, 873 F.2d 1371 (8th Cir. 1988).

Mul t i -~a rh Generation: Where more than one company may be involved in the creation, storage, treatment and shipment of waste materials which later become the aubjed of CERCLA action, generator liability will attach only to those companies that make the critical decision to ship such materials to the site which is the subject of a CERCLA enforcement action, Jersey City Development Authoritv v. PPG Industries, 655 F. Supp. 1257 (D.N.J. 1987) (Company liable as generator for shipment of waste created by prior landowner).

Governmental Entities: Pursuant to amendments added by SARA, governmental entities are fully liable as generators, United States v. Union Gas Co., 832 F.2d 1343 (3d Cir. 1987), a, 109 S.Ct. 2273 (1989)) Dickerson Inc. v. U.S., ( l l t h Cir. 1989)) 4 TXLR (BNA) 229 (August 2, 1989). USEPA hm, however, recently issued a policy indicating that municipalities will not be held liable for municipal solid waste generation absent specific evidence that such waste contained hazardous substances, Interim Munici~al Settlement Policy, 54 Fed. Reg 51071 (December 12, 1989). The policy has been challenged by a group of industrial generators a t a Connecticut landfill in B.B. Goodrich and Co, v. Murtah, (D.C. Conn. 1989), see 5 TXLR, page 182 (July 11, 1990).

Judicially-Expanded Definition of Owner/Operator

Courts broadly interpret the language in CERCLA naming an "owner and operator" of a CERCLA facility liable for cleanup costs. Included now are those parties whose connection to a site is more remote than one might infer from the plain meaning under the statute.

Secured Creditors

By statute, secured creditors are not liable for CERCLA costs; however, courts have held liable those secured creditors who foreclose and/or who actively manage the CERCLA facilities that they have an interest in. Recently, one court set a

new and broader standard. any secured creditor with the cavacity to control a CERCLA facility, even if the power is not exercised, will be held liable. EPA is now working on a rule to eliminate this decision as precedent; Congress has also proposed new legislation to contract lender liability under CERCLA.

CERCLA 9 101(20)(A), 42 U.S.C. 9 9601 (20) (A) (1989); United States v. Mirabile, 10 Chem. Waste Lit. Rep. 668 (E.D,Pa. 1985); United States v. Maryland Bank & Trust Co., 632 F.Supp. 573 (D. Md. 1986); U.S. v. Fleet Factors, 901 F.2d 1150 ( l l t h Cir. 1990).

Trustees in Bankruptcy

The Bankruptcy Code does not shield a trustee in bankruptcy from liability for the costs of a CERCLA cleanup. Authorities are split on whether CERCLA claims are dischargeable in bankruptcy.

Midlantic National Bank v. New Jersev Department of Environmental Protection, 106 S.Ct 755 (1986); Ohio v. Kovacs, 469 U.S. 274 (1985); United States v. Nicolet, Inc., 13 Chem. Waste Lit. Rep. 389 (E.D. Pa. 19%); United States v. MacKav, 13 Chem. Waste Lit. Rep. 253, No. 85- C-6925 (N.D. Ill. 1986); United States v. ILCO, Inc 48 Bankr. 1016 (N.D. Ala. 1985); United 2)

States v. Standard Metals Corn., 10 Chem. Waste Lit. Rep. 208 @. Colo. 1985).

Successor Corporations

Successor corporations will generally assume the CERCLA liabilities of their predecessors.

United States v. Distler, - F. Supp. -, 31 E.R.C. 1092 (W.D. Ky. 1990); Martine v. Abbott Laboratories, 102 Wash. 2d 581, 609, 689 P.2d 368, 384 (1984); 15 W. Fletcher, Cvclovedia of the Law of Private Corvorations at 7122 (rev. perm. ed. 1983); Bud Antle. Inc. v. Eastern Foods. Inc., 758 F.2d 1451, 1457-58 ( l l t h Cir. 1985); Philadelphia Elec. Co. v. Hercules, 762 F.2d 303 (3d Cir. 1985)) cert. denied, 474 U.S. 980 (1985); United States v. New Castle Countv, No. 80-489 (D.C. Del. 1988); Smith Land & Im~rovement Con. v. Celotex Corn., 851 F.2d 86 (3d Cir. 1988); Barnard, EPA's Polic of Co orate successor Liabilitv Under CERCLA, 6 Stan. Envtl. L.J. 78 (1986-87); Note, Successor Corporate Liabilitv for Improver Disvosd of Hazardous Waste, 7 W. New

Eng.L.Rev. 909 (1985); EPA Memorandum, Liabilitv of Corvorate Shareholders and Successor Corvorations for Abandoned Sites under CERCLA, June 13, 1984.

Cf. Ans~ec Co. v. Johnson Controls, Inc., 734 F. ~ u ~ ~ . 793 (E.D. Mich. 1989).

Parent Corporations

A parent corporation may be held liable for CERCLA costs under traditional "veil piercing" theories.

United States v. KavserRoth Cow., 724 F. Supp. 15 (D.R.I. 1989); Joslvn Mfa Co. v. T.L. James & Co., Inc., 893 F.2d 80 (5th Cir. 1990); Vermont v. Staco, Inc., 684 F.Supp. 822 (D.Vt. 1988); Liabilitv of Parent Corvorations for Hazardous Waste Cleanup and Damages, 99 Harv. L. Rev. 986 (1986).

Others

A corporation's officers, directors, shareholders, and employees, if they actively participated in the management of a CERCLA facility. Kellev v. Thomas Solvent Co., 727 F. Supp. 1532 (W.D. Mich. 1989); United States v. NEPACCO, 579 F.Supp. 823 (W.D. Mo. 1984); United States v. Mottolo, 629 F. Supp. 56 (D.N.H. 1984); United States v. Carolawn, 21 Env't Rep. Cas. (BNA) 2124 (D.S.C. 1984).

Absentee landlords, estates, states and possibly real estate agents. United States v. Monsanto Co., 858 F.2d 160 (4th Cir. 1988) (landlord); United States v. Ar~ent , 8 Chem. Waste Lit. Rptr. 476 (D.N.M. 1984) (lessor); h Peerless plat in^ Co., 70 B.R. 943 (W.D. Mich. 1987) (estate); United States v. Strindellow, 19 C.W.L.R. 1034 (E.D. Cal. 1990) (state); Tandewood East Homeowners v. Charles-Thomas, Inc., 849 F.2d 1568, 1574 (5th Cir. 1988) (real estate agents).

Mere sales of hazardous substances may not subject suppliers to CERCLA liability. Florida Power & Light Co. v. Allis Chalmers Corn., 893 F.2d 1313 ( l l t h Cir. 1990); Edward Hines Lumber Co. v. Vulcan Materials Co., 685 F. Supp. 651 (N.D. Ill. 1988); Kalik v. Allis-Chalmers Corn., 658 F. Supp. 631 (W.D. Pa. 1987); but cf. New York v. Gen. Elec. Co., 592 F. Supp. 291 (D.C.N.Y. 1984).

Proposed Federal Laws groundwater from an underground storage tank. 42 U.S.C. § 6991, et. seq.

Two bills are proposed to limit the judicial expansion of lender liability - one for trustee Common Law Liability liability and another for fiduciary lenders who foreclose. Users and manufacturers or formulators of

agricultural chemicals may also incur liability Proposed State Legislation from "toxic tort" claims filed by private third

parties. Contact may of course be through direct

Several state statutes require cleanup of exposure, but also through drinking water. Third

groundwater contamination before a transfer of parties may also invoke their common law rights

commercial property may occur. to i n d e d i c a t i o n and contribution. Common law theories relied upon include negligence, nuisance,

RCRA

The Resource Conservation and Recovery Act of 1976, 42 U.S.C. 9 6901, et. seq. ("RCRA") regulates ongoing and future generation, transportation, treatment, storage and disposal of hazardous wastes.

United States v. Charles George Trucking Co., Inc., 642 F. Supp. 329 (D. Mass. 1986); United States v. Waste Indus., Inc., 734 F.2d 159 (4th Cir. 1984); United States v. Conservation Chem. Co., 589 F. Supp. 59 (W.D. Mo. 1984).

RCRA permits are required for every facility handling hazardous wastes, and permitees must cleanup and prevent groundwater contamination. The strict liability provisions of RCRA, like those of CERCLA, extend liability for groundwater contamination to parties having even a remote connection with the affeded site.

United States v. Conservation Chem. Co., 660 F. Supp. 1236 (N.D. Ill. 1987); New York v. Shore Realtv Corn, 759 F.2d 1032 (2d Cir. 1985); United States v. Mottolo, 695 F.Supp. 615 @.N.H. 1988); Colorado v. Idarado Mining. Co., 707 F.Supp. 1227 (D.Co1. 1989); Vermont v. Staco. Inc., 684 F.Supp. 822 (D.Vt. 1988); Idaho v. Bunker Hill &., 635 F.Supp. 665 @.Idaho 1986). But see Joslvn Manu. Co. v. T.L. James & Co.. Inc., 893 F.2d 80 (5th Cir. 1990).

Underground Storage Tanks

trespass, strict or absolute liability, and produds liability.

Titan Holdings Svndicate v. Citv of Keene, N.H., 898 F.2d 265 (1st Cir. 1990) (trespass and nuisance pleaded); North Dade Water Co. v. Adken Land Co., 130 So. 2d 894 (Fla. 3d DCA 1961) (trespass and nuisance for surface water pollution); Burr v. Adam Eidemiller, Inc., 126 A. 2d 403 (Pa. 1956) (nuisance); Phillips v. Sun Oil Co 121 N.E. 2d 249 (N.Y. 1954) (trespass). A,

Marvland Heights Leasing. Inc. v. Mallinckrodt, Inc., 706 S.W. 2d 218 (Mo. Ct. App. 1985); DeMeo, R.A., Groundwater and drinking. water, Annual Envir. and Land Use Law Update, Florida Bar CLE Program, August 1990, a t page 7.34.

Criminal and Civil Penalties

All state and federal regulations applicable to groundwater contamination impose civil and criminal liability for "knowing violations" and for failure to report certain violations. On the other hand, statutory penalties are regulatory, not punitive, and seek as their goal to enhance compliance with environmental legislation.

CERCLA, 42 U.S.C. § 9603(b)(3) (imprisonment for not more than 3 yeare for knowingly failing to report a hazardous substance release); RCRA, 42 U.S.C. 9 6928(d) (knowing endangerment sentence up to 15 years and $1 million, knowing violation up to $50,000 per day); UST Program, 42 U.S.C. $6991e(d) (knowing failure to notify or comply, $10,000 per tank per

Environmental pollution from the day); Fla. Stat. 9 403.161 (imprisonment of 1 year

pervasive use of underground storage tanks is and fine of up to $25,000 for knowing or negligent

particularly worrisome because these tanks place violation).

hazardoussubstances so close to the groundwater.

Under the federal UST program, EPA is empowered to compel cleanup of releases to

Protections From Liability

As we have seen, the scope of liability for groundwater contamination under federal and state law is broad. Parties to business transactions involving real property must take steps to proted themselves.

An awareness of applicable laws and the duties they impose is essential. The best protection now is to presume that any potential polluting activity, including agriculture, or any waste disposal site will have legal ramifications under some environmental statute. Active planning with environmental liability in mind can secure a greater degree of predictability for most business transactions.

Our array of recommended protections include compliance with permitting and reporting requirements, conducting environmental audits, including contractual provisions, and considering insurance coverage.

Compliance With Permitting and Reporting Requirements

Hazardous Material Licenses and Permits

Businesses handling hazardous materials must comply with federal, state and county regulations. The fmt step is to determine if an unused or discarded material is hazardous, as defined by 40 C.F.R. §§ 260-266. (Whatever goes into the final product is not a waste material, but if it spills onto the ground it is a waste.) Storage is governed by the Title 111, Emergency Response and Community Right to Know Act. States like Florida requires notification of the Fire Department and submission of a floor plan describing where the materials will be stored.

County Permits

Because of the diversity and stringency of local county ordinances, i t is always important to check local laws before handling, disposing of or otherwise dealing with hazardous materials.

Wellfield Protection Ordinances

most severely the use of lands near wellfields. The storage, handling, use or production of hazardous or toxic substances are governed according to the distance from wellfields. The permitted land use depends on the time i t takes a contaminated plume to move to within the physical cone of influence of the wellfield.

Covered activities include septic tanks, liquid waste disposal, storm water discharge, and the use of hazardous materials in other than residential and agricultural pursuits.

OSHA Regulations

OSHA standards, 29 C.F.R. § 1910.1200, apply to any chemical which is known to be present in the workplace where employees may be exposed under normal conditions of use or in a foreseeable emergency. The regulations for employers are designed to keep employees fully informed of health risks of the hazardous materials they deal with.

Reporting Requirements Under the Emergency Planning and Community Right-to-Know Act

Industries that use, store, process, or release hazardous substances must comply with Title 111 of the Superfund Amendments and Reauthorization Act, titled "Emergency Planning and Community Right to Know" and the Florida Hazardous Materials Emergency Response and Community Right to Know Act of 1988, $253, Fla. Stat. (1989).

Legal Defenses Against Liability

Until recently, the defenses to liability for landowners under CERCLA and RCRA have been extremely limited or nonexistent. Section 107(b) sets forth three defenses to liability: (1) an act of God; (2) an a d of war; (3) an a d or omission of a third party.

United States v. Strindellow, 661 F. Supp. 1053 (C.D. Cal. 1987); Smith Land & Imp. Cow. v. Celotex Corn., 851 F.2d 86, 90 (3rd Cir. 1988) (no caveat emptor defense).

Local regulations may use land use The SARA Amendments added a narrow controls to protect wellfields. For example, in exemption from liability for certain real estate Florida, the wellfield protection ordinances restrict pmhasers. Under the "innocent landowner1'

defense, landowners who acquire property without knowing of any contamination at the site, and without any reason to know of such contamination, may have a defense to liability under CERCLA.

Section lOl(35) of CERCLA; United States v. Hooker Chem. & Plastics Cow., 680 F. Supp. 546 (W.D.N.Y. 1988).

SARA also allows the EPA to enter into & minimis settlements with landowners who may qualify for the innocent landowner defense but who do not want to risk going to trial or incurring litigation costs.

U.S. EPA Guidance Document, Superfund P r o m : De Minimis Landowner Settlements, Pros~ective Purchaser Settlements, 54 Fed. Reg. 34235 (August 18, 1989).

Environmental Audits

An environmental audit is an investigation into the environmental compliance status of a facility, including the nature and extent of groundwater contamination. The selection and use of an experienced environmental consultant to perform an audit is a critically important process. This subject is dealt with in depth elsewhere in these proceedings.

Contractual Provisions

Liability for cleanup of hazardous waste sites under CERCLA may not be contracted away. However, individuals or corporations primarily liable under Section 107 may seek indemnification or contribution from others. Once the results of the environmental audit are known, a party to a transaction can negotiate contractual mechanisms which will best operate to protect it from liability.

Representations and Warranties/lnclemnification

Representations and warranties as to the environmental compliance status and hazardous waste disposal activities of the facility can be requested. An indemnification clause will protect the acquiring party from both known and unknown environmental hazards.

Negotiated Cleanups

If the financial capabilities of a surviving party are in doubt, the party acquiring an interest in a facility should negotiate short term protective mechanisms which will ensure the remediation of any substantial environmental problems. Such mechanisms may include: a hold-back of the purchase price, an escrow agreement, a line of credit, a limited agency agreement with a former manager to oversee the cleanup of a site, and divestiture of certain assets, subsidiaries or divisions with extensive environmental problems.

Covenant Not to Sue

Buyers of property who know that the property may be contaminated with hazardous waste may, in some circumstances, receive an assurance that the federal government will not sue them for cleanup costs.

Insurance Considerations

Comprehensive general liability (CGL) insurance policies should be examined to determine if coverage may be available for cleaning up environmental contamination. Most policies issued prior to 1986 contain only a partial pollution exclusion, so the law of each state will determine if coverage will be afforded. However, prompt notice should be given to carriers who issued policies during any t i e when contamination may have occurred.

Scope of Remedial Action

Cleanup of contaminated groundwater is a complex and lengthy process. The process generally involves:

A. Site investi~ation, including installation of groundwater monitoring wells;

B. Assessment of engineer in^ alternatives for remedial action;

C. Governmental ~a r t i c i~a t ion in the selection of a remedy; and

D. Short and long-term remedial actions potentially including removal or containment of the source of contamination, groundwater remediation, and follow-up groundwater monitoring over

a period of yeam to ensure that no further releases occur.

Because the process of groundwater cleanup demands substantial long-term involvement, it is imperative that those dealing with agricultural chemicals or involved in agricultural land use fairly characterize the risks associated with their industries to avoid significant hidden liabilities.

TRANSACTIONAL AND OPERATIONAL ASSESSMENTS/AUDITS OF FARMS AND AGRICULTURAL FACILITIES

Thomas M. Missimer, P.G. Missimer & Associates, Inc. 428 Pine Island Road, S.W. Cape Coral, Florida 33991

ABSTRACT

Hazardous and toxic substances are stored and used on all agricultural facilities to a variable degree. Liabilities created by the federal Comprehensive Environmental Response compensation and Liability Act of 1980 (CERCLA) requires that agricultural facility operators must prevent the possible contamination of soil and groundwater in order to maintain financial viability. Because of the risks caused by contamination liability, lending institutions are requiring environmental assessments/audits of most agricultural facilities prior to approving loans for acquisitions, construction, and even operating capital. Lending institutions are rapidly becoming the primary enforcers of federal and state contamination laws with the environmental assessment/audit being the only protection for the facility operator.

INTRODUCTION

Each day the news media contains at least one story concerning a toxic or hazardous waste problem or a spill of some deleterious substance. In most cases, the media attention is given more to major problems located in or near industrial areas, such as the

Love Canal problem or to major events, such as the Valdez oil spill. However, the problem of hazardous or toxic substance use or waste disposal is confronted by most operating businesses each day. Each month on a national basis, the volume of waste oil, for example, that I1disappears1l is larger than the total Valdez oil spill. Agricultural operations, in particular, must transport, use, and store many types of toxic or hazardous substances. Therefore, the potential to have an accumulation of these substances in the soil or groundwater is extremely high.

The federal Comprehensive Environmental Response, Compensation and Liability Act of 1980 (CERCLA) has created a serious liability problem for all owners and purchasers of properties and businesses. Many states have adopted the federal legislation in what is termed "little CERCLA" state environmental statutes. These laws have created the liabilities for clean-up of toxic and hazardous substance contamination for everyone, including farmers. Although there are certain exemptions contained in the federal CERCLA and FIFRA legislation for the label use of pesticides by farmers, there is no exemption from contamination resulting from improper controls at mixing areas, improper disposal of wastes or residues, or the improper storage of agricultural chemicals.

In 1986, Congress passed the Superfund Amendment and Reauthorization Act. This legislation created the innocent land purchaser provision based on what is termed the Itdue diligencevt test. The implication of the innocent land purchaser defense is that if a purchaser of a property performs a "due diligenceIt investigation of the property before acquisition, then the purchaser may not be held responsible for the costs of contamination clean-up. This "due diligence" investigation is currently termed a transactional environmental audit. It should be noted that when several states adopted the federal CERCLA legislation, there was no "due diligencett provision placed in the act. Therefore, a purchaser of property in various states may be held responsible for the clean-up costs of contamination even if a transactional environmental audit was conducted prior to the acquisition.

Contamination liabilities at agricultural facilities are not limited to those being considered for change of ownership, but all operating facilities must continuously meet the current standards of practice and the current water quality standards, regardless of past practices. The regulatory agencies presently have the right to enter any facility, including farms, to inspect it for compliance to regulations involving toxic and hazardous substances. Agricultural operations have not been a historic target of regulatory agency compliance. However, a large number of legal actions have been recently filed against golf course, nurseries, and other related businesses. New water quality standards are currently being imposed on

agriculture, in environmentally sensitive areas, such as the Florida Everglades. It is quite clear that strict compliance with the federal and state laws regarding toxic and hazardous substances will soon be enforced on all agricultural businesses in the United States.

The question to be considered for all agricultural businesses is how to manage the current environmental risks and assure compliance to the complex standards set by law. One method to manage risk is to conduct an operational environmental audit on every operating facility on a regular basis. This type of audit may be conducted by management, or by a consultant, or by a combination of the two. The procedure in conducting an operational audit will be discussed in more detail later in this paper. Another important way to limit liability is to conduct a transactional environmental audit whenever an acquisition or lease of agricultural property is going to be made. When an existing agricultural operation is to be purchased for any purpose, including the continuation of past uses or conversion to a new land use, it is extremely important to study the past agricultural practices on the site to assess existing site clean-up liabilities.

ENVIRONMENTAL LIABILITIES CAUSED BY HISTORICAL PRACTICES ON AGRICULTURAL FACILITIES

Many of the most expensive toxic and hazardous substance

contamination sites in the rural United States are related to historical use of agricultural chemicals. Some of the past uses of toxic or hazardous chemicals were not actually related to farming activities, but farmlands were used to locate sites.

Two of the most common activities that produced contamination were the turpentine manufacturing industry and the use of creosote to make railroad ties and fence posts. A large number of turpentine stills were operated between the 1850's and 1910 particularly in the southern United States. The waste product produced in the distillation process was termed I1still drossu, which was placed on the ground near the still. This waste material inhibited the growth of plants for periods up to 30 years. Fortunately, the volatile organics contained in the ''still dross1' tend to decay with time and few of the sites left any major residual problems. Creosote use, however, has left some very serious contamination problems. Major railroad tie manufacturing facilities in the early part of this century commonly constructed a pit into which creosote was placed. Railroad ties were placed into the pit and left to soak up the creosote. The clean-up costs associated with some of these sites has ranged to over $10 million. Smaller scale creosote dipping vats were used on many farms and ranches throughout the country between 1910 and 1950.

Beginning in the 19201s, there were a number of chronic disease problems associated with insect pests on cattle. In 1923, the U.S. Department of Agriculture mandated the installation of cattle dipping vats to assist in

the control of insects and parasitic organisms. Originally, the dipping vats were constructed as holes into the ground and were filled with kerosene and other oils. The sites were commonly constructed near the cattle pens. Cattle dipping vats were used into the early 1960's in some parts of the southeastern United States. The fluid placed in the vats changed with time from kerosene to diesel fuel, and eventually contained chlorinated pesticides, such as DDT or toxaphene. Some of the dipping vats were operated by private land owners, but many were operated on private land by the U.S. Department of Agriculture. There are many thousands of these sites located in the United States. The cost of clean-up for a dipping vat site could range to several hundred thousand dollars depending on the location, type of fluid used, and the length of time it was in use.

As the use of motorized vehicles and pumps increased from the 1930's to present, hydrocarbon fuels became an increasingly more important requirement of agricultural operations. Many farms installed underground fuel storage tanks to accommodate the on-site fuel requirements. Many of these tanks were installed over 20 years ago and the tanks were constructed of steel. Thousands of these tanks contain leaks either directly in the tank, in the associated plumbing, or in the pump. Also, little care was taken at the fueling area, where spillage was common. A large number of surface fuel tanks were also placed adjacent to lift pumps and well pumps

throughout the farms. Many of these facilities contained leaks between the tank and the pump, caused by corrosion or the use of incompatible metal fittings. The hydrocarbon contamination problem at many agricultural facilities is quite extensive and clean-up costs can range over $200,000 per site.

Prior to 1940, the use of agricultural chemicals was somewhat limited, but some of the chemicals used could have left significant contamination problems. Some of the common insecticides used prior to 1940 on vegetable crops included: Paris green (arsenicals), lead arsenate, calcium arsenate, magnesium arsenate, sodium fluosilicate, rotenone, and kerosene emulsions (Watson and Tissot, 1942). Ornamental flower crops (Gladioli) were treated with dithane and zinc sulphate (Brooke, 1948). Many of these chemicals are quite persistent in the environment. Historic storage and mixing areas can tend to maintain high concentrates of these chemicals, even many years after use was discontinued, leaving significant quantities of contamination.

Beginning in the 1940's and continuing into the 1 9 7 0 ' ~ ~ the number and toxicity of agricultural chemicals increased substantially. The chlorinated pesticides, such as DDT and toxaphene, were found to be effective as pesticides beginning in the 1940's. General use of these chemicals, as well as other chemicals, began at some time in the late 1940's or earlier depending on the specific location in the United States and continued until many chlorinated pesticides were banned in the 1970's and 1980's. Control of

pests on improved pastures in 1955 was accomplished based on these recommended pesticides: parathion, TEPP, malathion, toxaphene, chlordane, and DDT (Genung, 1955; Kehsheimer, Jones, and Hodges, 1955). By 1962, the list of recommended pesticides for control of insects and diseases on commercial vegetable crops increased substantially to include: aldrin, DDD, DDT, diazinon, dibrom, dyrene, EDB, endrin, guthion, kelthane, lindane, malathion, maneb, nabar, phosdrin, parathion, rotenone, sevin, systox, thiodan, toxaphene, and zineb (Brogdon, Marvel, and Mullin, 1962). Many of these older pesticides are extremely persistent in the environment and do not breakdown into other harmless compounds (not biodegradable). Therefore, historic storage areas, mixing areas, and equipment cleaning areas may contain substantial contamination liabilities. Because some of the chlorinated pesticides presently cannot any longer be landfilled (land ban chemicals), clean-up costs for contamination sites containing some of these chemicals can be extremely high.

Agricultural operations tend to generate a large quantity of solid waste being both toxic and non-toxic. Historically, many farms created large, unregulated landfills. Nearly every site used for agricultural production that is over 10 years in age contains at least one landfill area, either covered or exposed. The disposal of pesticide containers, waste oil, and solvents used to clean engine parts were commonly placed in these small landfills. Again,

all historic agricultural landfill sites contain potentially significant environmental liabilities.

It is unfortunate, but many of the historic practices that create present environmental liabilities to agricultural operations are continuing today. Many of these problems can be discovered and corrected by an effective environmental auditing program.

OPERATIONAL ENVIRONMENTAL AUDITS

One method of managing environmental liabilities on an operating agricultural facility is to conduct an operational environmental audit. There are many aspects involved in conducting this type of site evaluation. An operational environmental audit commonly consists of assessing: 1) compliance to environmental regulations, 2) evaluation of operational efficiencies, 3) compliance to health and safety regulations, 4) evaluation of past practices that could have caused contamination, and 5) others. The scope of an operational environmental audit must be very carefully planned prior to initiating the work effort.

When management makes the decision that an operational environmental audit is necessary, a commitment must be made to correct any type of environmental problem discovered in the process. Once a problem is discovered and the information is made available to the owner or management, there may be legal reporting requirements that must be met. If certain types of

contamination problems are not reported, the owner and/or management may be subjected to both civil and criminal penalties in addition to the clean-up cost liabilities. Since the information collected during an operational environmental audit may be quite sensitive, it is common practice on larger facilities to have a lawyer involved in the process to retain the team of audit experts and to report the information to the owner or management. If an operational audit is not conducted properly, misleading information could be obtained that a regulatory agency might use against the owner or operator. This discussion is not to imply that a team of consultants must perform operational environmental audits on all agricultural facilities. An individual farmer or a management team can perform a regular audit, if trained to evaluate regulatory compliance in a number of areas. A large part of evaluating an operation is simply observation and common sense. Regardless of who conducts the operational audit, it is necessary to carefully prepare checklists to be sure that every area is adequately covered. Environmental auditing methods are thoroughly discussed in the textbooks authored by Blakeslee, and Grabowski, 1985; Cahill, 1987; and Moskowitz, 1989. Many state universities having strong agricultural programs offer a course in environmental auditing every year or two. Commonly, many different industries utilize lawyers and consultants to conduct the initial operational audit and

to monitor continuing audits conducted internally.

Because of the differing types of information that may be desired in the performance of an operational environmental audit, it is not possible to fully describe the process. It must be emphasized that the objectives of an audit must be determined before any useful information can be obtained. If the objective of an audit is to evaluate fully past and present compliance to environmental regulations at an old agricultural facility, the following procedure could be used :

1) Assemble a consulting team, which may consist of an environmental lawyer, an environmental consultant, and the designated environmental compliance person. 2) Decide which individual is to lead the effort. 3) Determine what the objectives of the audit are to be - emphasis must be given to the objectives given by management. 4) Plan the audit - determine the responsibilities of each team member and how reports will be made. 5) Obtain as much background data as possible concerning what laws and regulations apply to the facility and what agencies files must be searched, such as the checklist given in Table 1. 6) Perform a detailed historical investigation of the property beginning with a certified updated abstract, and using old aerial photographs, historical records, interviews with on-site operating personnel, retired personnel, and management personnel, check inventories of fuel, pesticides, and fertilizer, assess past practices, interview neighbors, check with disposal

companies used to remove waste from the site, etc. 7) Conduct a search of all federal, state, and local government regulatory files to check for violations without breaching the confidentiality of the audit. 8) Conduct multiple on-site inspections of the operation documented with color photographs and inclusive of interviews with site personnel ranging from owners or managers to field hands. 9) Conduct an inspection of properties adjacent to the site with emphasis on upgradient (groundwater flow toward site) areas. 10) Have a team meeting to determine what on-site testing must be conducted to assess the various possible contamination sites located. 11) Have the environmental lawyer orally report the preliminary findings to management. 12) Complete the report on the investigation and testing with a prioritization of the problems found. 13) Have the environmental lawyer inform management concerning any legal reporting requirements. 14) Construct a plan to bring the facility into full regulatory compliance, which may include clean-up of contamination or other remedies.

This is a very general procedure and each operational audit will be different based on the site-specific operation and the objectives of the audit.

Operational audit programs have been used successfully by many major industries in the United

States for the past 20 years. Industries using this process have saved millions of dollars in fines and in the avoidance of toxic and hazardous substance spills and contamination. Regulatory agencies have consistently supported the concept of the operational environmental audit and have been less stringent in enforcement actions against companies with strong environmental compliance programs.

TRANSACTIONAL ENVIRONMENTAL AUDITS

There are several different situations that could necessitate the performance of a transactional environmental audit on an agricultural property. The most obvious situation is when an agricultural facility is to be purchased. Because of the potential liabilities for clean- up costs, any prudent purchaser would demand an environmental audit to assess the site condition and potential financial responsibilities. An owner may be required to perform a transactional environmental audit because either a lending institution may require it during a re-finance situation, or the owner may wish to assess environmental liabilities prior to a sale of the property, or to check the validity of the purchasers audit. Another case when an environmental audit should be performed is in a lease situation. A lessor should assess the condition of a site prior to conveying a lease in the event that the lessee causes the site to become contaminated. On the other hand, a lessee may wish to assess the condition of a farm prior to signing a lease in order to avoid future cost-recovery

actions for contamination clean-up that was caused by the lessor or by a previous lessee. There are a number of other circumstances that can lead to the performance of a transactional audit related to off-site contamination issues or regional contamination problems.

There are no specific guidelines given by any law or agency with regard to the scope of a transactional environmental audit. A modification to CERCLA has been recently proposed by Representative Weldon to define the innocent land purchaser test or Itdue diligencett investigation. Based on common practice and case law, the Weldon definition for the minimum scope of a Itphase I Environmental Audittt consisted of:

It (I) Recorded chain of title documents regarding the property, including all deeds, easements, leases, restrictions, and covenants. The chain of title shall be of a sufficient length of time to account for previous ownership and uses of the property which are likely to have an adverse environmental impact on the property, but in no event for a period less than 35 years. (11) Commercially available aerial photographs of the property which may reflect prior uses of the property. (111) Determination of the existence of federal, state, and local environmental clean- up liens against the property. (IV) Reasonable obtainable federal, state, and local records of existing and potentially contaminated sites,

including site investigation reports for such contaminated sites; reasonable obtainable federal, state, and local environmental records of activities likely to have an adverse environmental impact on the property (including records of environmental problem sites, landfill and other disposal site records, underground storage tank records, and known hazardous waste handler and generator records); and such other reasonable obtainable federal, state, and local environmental records which report incidents or sources of contamination on the property. (V) A visual site inspection of the property and all facilities and improvements on the property, and a visual inspection of immediately adjacent properties from the subject property, to determine or discover the obviousness of the presence or likely presence of contamination on the property (including chemical use, storage, treatment and disposal practices, past or present) . Recently, various national organizations, such as the Association of Groundwater scientists and Engineers and the American Society of Testing and Materials, have begun to formulate a uniform set of performance standards for environmental audits. There is currently no specifically accepted standard of practice in this field.

The common terminology used to describe the level of effort involved in performance of a transactional environmental audit is often referred to as ttPhasestt. A Phase I audit is the initial investigation and does not usually contain sampling and

analysis of soil and/or groundwater. Phase I1 of an environmental audit involves some type of site assessment, which may involve test drilling, soil gas surveys, geophysical investigations, monitor well construction, soil sample collection and analysis, groundwater sample collection and analysis, and surface-water sample collection and analysis. ~nformation collected in Phase I1 is used to verify if contamination is present. Phase I11 of an environmental audit is the detailed investigation of a contamination site discovered during the initial two phases. This investigation would be detailed enough to allow a clean-up cost estimate to be made.

Based on the recently recommended definition, past litigation, and generally accepted practices in the field, an environmental audit, at a minimum, should include: 1) an evaluation of site history, 2) a check of regulatory agencies for liens or violations of law, or citations on the property, and 3) an on-site and off-site inspection. The level of detail within each of the primary areas of investigation necessary to protect a purchaser against liability is variable based on the history of the site, the land use in the general vicinity, and a number of other factors. Regardless of the legal definition of Itdue diligence", the true purpose of an environmental audit is to determine if there is a hazardous or toxic substance problem on the site. Therefore, the investigation

must be designed accordingly to make this determination.

When a parcel of property is being purchased for agricultural use, the potential contamination risks are much greater for an existing operation compared to previously unused land. Therefore, the minimum scope of each Phase I environmental audit is based on the differences in risk. The minimum scope of Phase I transactional environment audits for vacant, unused land views compared to an existing operation is shown in Table 2. Since an agricultural operation is a very high risk property in terms of contamination liability, the inspection of a site must be conducted in more detail. The actual past operation of the facility must be carefully evaluated. If an agricultural facility is more than a few years old, it is likely that some on- site areas will be discovered that will require testing to assess whether or not contamination is present. The high risk areas commonly requiring Phase I1 audits are: landfills or trash accumulation areas, storage areas for pesticides and fertilizers, fueling areas, any fuel storage areas, and major water retention areas.

Transactional environmental audits should be performed by qualified companies, which employ specialists in a number of fields. Since agricultural operations can include rather complex sites, it may take a number of professionals trained in several different disciplines to properly perform the audit. The development of a detailed site history requires local knowledge and where to.find information, such as old aerial

photographs, gas and oil drilling leases, or historical documents. The on-site and off-site inspection must be conducted by hydrologists, geologists, engineers, chemists, agricultural specialists, or others with special knowledge. Any auditing effort involves cooperation between the team of experts and the people on the site. Existing owners or operators must disclose information concerning the site to the team or face possible future personal liability (fraud issue) . Those conducting a transactional environmental audit must have a good level of knowledge concerning regulatory fields, because most regulatory agencies will not do a compliance search for anyone. Documentation of all facts on a site is extremely important.

One of the most important parts of a transactional environmental audit is the report. A high quality environmental audit report will contain detailed documentation of every significant piece of information collected concerning the property. The report should contain a detailed description of the scope of the audit performed. The site documentation should commonly contain color photographs to show conditions at the time of inspection. A well prepared report will contain a statement concerning the overall condition of the site. This statement may read "There is a low probability of contamination on this site" or "Based on the scope of the investigation, there was no evidence found for contamination on this siten or

"Most of the site contained no evidence of contamination, but additional testing will be required at ....I1. No competent environmental auditor will ever state in a report that "the site is cleanl1. Regardless of how careful an audit is performed, it is not economically possible to test every square foot of every site for contamination with one of our several hundred chemicals classified as toxic or hazardous. Therefore, it should be understood that there is always some risk in the acquisition of real property or a business. If the purchaser purposely reduces the scope of an audit, the risks involved will tend to increase. It is quite important that the scope of the audit matches the risks involved in order to properly protect the purchaser of the property.

DISCUSSION

Storage and use of chemicals is a major operating problem for all agricultural facilities. The use of hydrocarbon fuels, pesticides, cleaning solvents, and fertilizers is necessary for most farms. All chemicals should be stored in contained areas, should be mixed in areas where the fluids can be contained, and should be applied as indicated on the labels.

The appearance of an agricultural site is a common indicator used by regulatory agencies to assess the necessity of a detailed inspection. Therefore, the site should be maintained free of debris and all maintenance and storage facilities should be cleaned on a regular basis.

Operational environmental audits should be used to assess the compliance of any agricultural

facility to existing environmental laws and regulations. All agricultural operators should obtain education with regard to how to manage environmental risks on their property. This education should be available through high schools, universities, and local agricultural extension agents.

Any buyer or leaser of an agricultural property should be familiar with the transactional environmental audit process and the risks involved. Recently, a Mid-West farmer acquired a small parcel of property for a tax deed costing less than $500. This farmer was rather shocked when an environmental agency filed a $1 million contamination claim against the property and individually against the new owner only a month after the transaction was completed. While a transactional environmental audit does not provide an absolute insurance policy, it can be used to significantly reduce the risk for a sophisticated buyer of agricultural property.

REFERENCES

Blakeslee, H. W. , and Grabowski, T. M., 1985, A Practical Guide to Plant Environmental Audits: Van Nostrand Reinhold Company, Inc., New York, 299p.

Brogdon, J. E., Marvel, M. E., and Mullin, R. S., 1962, Commercial Vegetable Insect and Disease Control Guide: University of Florida, Agricultural Extension Services, Gainesville, Florida, Circular 193B, 47p.

Brooke, D. L., 1948, Commercial Production of Gladiolus in Lee County, Florida: Florida Agricultural Experiment Station.

Cahill, L. B., editor, 1987, Environmental Audits: Government Institutes, Inc., Rockville, Maryland, 5th ~dition, 656p.

Earl, W. L., 1986, Environmental Land Use Law, Environmental Auditing: What Your Client Doesn't Know Hurts the Most: The Florida Bar Journal, v. LX, no. 1, p.47-49.

Genung, W. G., 1955, Pasture and Livestock Insects and Their Control: Florida Agricultural Experimental Station, Gainesville, Florida, Mimeo Rept. 55-8.

Kehsheimer, E. G., Jones, D. W, and Hodges, E. M., 1955, Control of Some Insect Pests of Improved Pastures: University of Florida, Agricultural Experiment Station, Gainesville, Florida, Circular S-64.

Moskowitz, J. S., 1988, Environmental Liability and Real Property Transactions: John Wiley & Sons, New York.

Watson, J. R., and Tissot, A. N., 1942, Insects and Other Pests of Florida Vegetables: University of Florida, Agricultural Experiment Station, Gainesville, Florida.

Zinn, T. L., and Frexedas, R., 1988, Transactional Environmental Audits: What to Expect From Your Consultant: The Florida Bar Journal, Apr. 1988, p.55-58.

TABLE 1. PARTIAL CHECKLIST OF LAWS REQUIRING COMPLIANCE ON VARIOUS

AGRICULTURAL PROPERTIES

Federal

1. Resources Conservation and Recovery Act

- hazardous waste disposal - discharge of toxic or hazardous substances

2. Federal Insecticide, Fungicide & Rodenticide Act

- use of pesticides

Clean Water Act

- point source discharges - future non-point source discharges

Superfund Amendment and Reauthorization Act - Title I11

- material safety data sheets - community right to know

Occupational Safety and Health Act

- employee right to know

Safe Drinking Water Act

- drinking water for employees based on numbers

Clean Air Act

- if incinerator or processing facility is present

Toxic Substance Control Act

Wetlands ~egulations

- U.S. Environmental Protection Agency - U.S. Army Corps of Engineers

TABLE 1. PARTIAL CHECKLIST OF LAWS REQUIRING COMPLIANCE ON VARIOUS

AGRICULTURAL PROPERTIES Continued:

State (State of Florida, for example)

1. Department of Environmental Regulation

landfill rules (Chapter 17-700) underground tanks (Chapter 17-700, 17-761) toxic and hazardous substances (little CERCLA) air permitting special rules (i.e. dairy rule) domestic wastewater rules (where treatment facility is present) industrial wastewater rules (where treatment facility is present) dredge and fill rules

2. Water Management Districts

- water use permits - well construction permits - surface water management permits - special water quality compliance (i.e. Lake

Okeechobee Water Quality Management Plan) - wetlands

3. Department of Agriculture

- pesticide compliance - packing house inspections

Local

1. Local Environmental Programs (where approved)

- wetlands - wastewater - underground tanks - contamination

TABLE 2. MINIMUM SCOPE OF A TRANSACTIONAL ENVIRONMENTAL AUDIT

Items in scope of Phase I Audits Vacant Land

1. Site History X

- certified updated abstract X - aerial photographs review X - historical records X - interviews with knowledgeable X

persons

Regulatory Compliance Search X

- federal government files - state government files - local government files

On-site Inspections X

- single field inspection X? - interdisciplinary field inspections - interviews with site personnel X - multiple interviews with site

personnel - color photographs X

Off-site Inspections X

- single field inspection X? - interdisciplinary field inspection - interviews with knowledgeable X

persons - color photographs X

Evaluation Report X

- final report - final report with possible

testing requirements

xi sting operation

Worker Safety

Vern Hofman Extension Ag Engineer North Dakota State University

Abstract Worker safety while handling pesticides and

fertilizers is a major concern. A worker safety area should be developed in any facility to minimize the risk o f bodily injury. The size of the area and the amount o f safety protection equipment needed depends on the type of facility, the number of employees and the types of chemicals handled. providing proper worker safety procedures and instruction on use of safety equipment to reduce potential exposure takes little time and in the long run will usually pay good dividends.

I. Background Proper handling of pesticides involved in

mixing, loading and application is essential to minimize the risk of personal injury. Safe handling procedures and body protection to reduce chemical exposure is essential. When dealing with pesticides, a simply formula to remember is: RISK = TOXICITY X EXPOSURE

Toxicity or the hazard is inherent in the product and cannot be changed. Exposure can be reduced which will reduce risk. The severity of exposure is dependent on the exposure time, the chemical makeup and the path of entry into the body. No matter how toxic a substance may be, if the exposure is low enough, the risk can be reduced to an acceptable level.

Pesticides may enter the body in a wet or dry state through the skin (dermal), through breathing (respiratory) and through the mouth (oral and gastrointestinal). Dermal is the most common route of entry although the rate of absorption is higher for a given amount of chemical in the sensitive tissues of the respiratory and digestive tracts.

A review by Kuhlman of California information show that parathion is absorbed a t different rates on various areas of the body and that protective clothing must be worn to prevent absorption. Special care should be given to protect the scalp, ear canal and forehead. The abdominal area should be protected with an apron or rubber suit and the hands and feet should be protected with lightweight; unlined

gloves and boots. Field applicator exposure studies show the

primary source of exposure is absorption through the forearms and hands. Dermal exposure data in Figure 1 shows deposition of pesticide residue on various parts of the body when measured under field conditions. The data demonstrate the wearing of rubber gloves can reduce potential exposure to the mixer, loader and applicator. by simply wearing appropriate chemical resistant gloves and washing the gloves and hands, significant potential exposure can be reduced. At the same time, ingestion of chemical residues to the mouth and eyes by unwashed hands can be minimized or almost eliminated.

Data have shown that most accidents occur during the mixing and loading operation; therefore, i t is extremely important to wear protective clothing when concentrated chemicals are being handled as well as during application. I t is required by law that all pesticide handlers and applicators follow the personal protective equipment instructions that appear on the chemical label. Chemical manufacturers' specifications of protective clothing requirements on container labels has not been highly effective. Most pesticide handling and mixing takes place in warm or hot weather and a lot of specified clothing is bulky and hot. Lighter weight breathable clothing that is more comfortable is very expensive and many applicators are reluctant to spend the extra money. So handlers and applicators purchase the cheaper equipment to abide with laws and much of i t is not used as i t is uncomfortable.

If handlers and applicators are reluctant to wear personal protective equipment when measuring and mixing concentrated pesticides, an alternative solution should be found. FIFRA (Federal Insecticide Fungicide Rodenticide Act) states that applicator mixing and loading personnel using closed pesticide mixing systems are exempt from stringent clothing requirements listed on pesticide container labels. EPA (Environmental Protection Agency) statistics show that a completely closed liquid transfer and mixing systerh reduces the risk of dermal absorption by up to 90 percent and vapor inhalation by up to 85 percent, compared to open systems. Whenever probes are changed from one container to another, personal protective equipment as recommended on the chemical label is required. The problem with most "closed" mixing systems is they are not completely closed. Opening containers and inserting or removing probes provides potential

exposure to pesticides. Closed systems should be developed further and promoted a s an improved alternative to pesticide handling with "open" systems.

11. Pesticide Label Information on protective clothing a s well a s

proper application and handling procedures a re included on the pesticide container label. The pesticide label is the law. Important worker safety information is included. The signal words Danger, Warning and Caution are printed on the label to warn the user of the toxicity level of the pesticide being handled. From the signal word, the kinds and types of protective clothing to wear can be determined.

The word Caution appears on pesticides tha t have a relatively low level of toxicity. I t means that from animal studies the pesticide is not extremely toxic, bu t some basic handling precautions should be followed. Controlling exposure, using safe handling practices and wearing protective clothing such a s wearing a long sleeve shirt, long pants, shoes, socks, chemical resistant gloves and a ha t should be considered. More toxic materials will carry a Warning or Danger signal or sometimes Poison. These words suggest that very specific protective measures must be followed. Label information must be read and directions followed closely. Failure to do so may result in serious illness and sometimes death.

111. Protective Clothing and Equipment The type of clothing purchased and how i t is

worn will determine the level of protection from pesticide exposure. Some protection is provided by wearing regular work clothing. However, liquidproof, chemical-resistant clothing will provide much better protection.

A summary of clothing guidelines include the following:

1. Wear work clothing with long pants and sleeves.

2. Always wear unlined, liquidproof, chemical resistant gloves plus unlined neoprene or rubber boots and a wide brimmed hat .

3. When mixing, loading and handling concentrated pesticides, wear a chemical resistant apron over coveralls.

4. Wear eye or face shields whenever there is a risk of pesticide coming in contact with the eyes.

5. Wear a liquideproof, chemical resistant suit with a hood or wide brimmed h a t if there is any chance of becoming wet with pesticide.

6. Wear a respirator whenever there is a risk of inhaling pesticide vapors, fumes or dust.

Leather or cloth gloves, leather boots or shoes absorb chemicals. They are very dificult or almost impossible to decontaminate and should not be worn. Rubber boots over leather footwear will provide protection.

IV. Worker Safety Area A worker safety area should be provided in any

size facility. The size of the area and the amount of equipment required depends on the type of facility, number of employees and the chemicals handled.

All worker safety areas should have a place to store safety equipment away from the pesticide storage area and have clean water available. The washing of gloves and hands after handling pesticides and flushing of the body or equipment in the event of a spill or an accident is critical if exposure is to be reduced. Water is inexpensive and an effective safety tool. A good supply of clean water should always be a t the mixing and loading site and available for emergencies.

A shower/eyewash should be located near the mixinglloading area in the event of chemical accidentally being spilled on an individual. A wash basin should be nearby for washing of hands to reduce the transfer of pesticide to other parts of the body.

Place a telephone near the mixinglloading area so help can be quickly summoned if an accident occurs. Also, an emergency alarm is recommended to alert other workers or to summon help. A portable fire extinguisher should be located outside storage areas and smoke alarms or fire detection equipment i s recommended in all facilities. Place exit signs above all exits to inform workers and visitors where to leave in an emergency.

Summary Following product label instructions will go far in

allowing pesticides to be safely used for i ts intended purpose. The signal words Caution, Warning or Danger tell about product toxicity. The formula Risk = Toxicity X Exposure provides the principle for risk reduction. When exposure is reduced by wearing proper protective equipment, risk is reduced. Remember tha t the pesticide label is the law and following label instructions will reduce potential personal injury. Always use proper personal protective equipment such a s unlined gloves, eye protection, boots, respirators and rubber suits a s required by the chemical handled. Provide plenty of fresh water for washing of gloves, equipment and rinsing of hands after use.

Closed mixing systems should be developed and promoted as an alternative to open handling of pesticides a s many handlers do not use the proper personal protective equipment. This is due to much of the equipment being bulky and uncomfortable to wear, especially in warm weather.

Chemical handlers and applicators must be careful while handling and applying pesticides to avoid unnecessary exposure and to prevent chemical contamination of the environment.

Bibliography

- ACS Symposium No. 182

Front V Back of Face Fore- Hands- Hands- of Neck Neck Arms No Gloves Glvoes

"Applying Pesticides Correctly, A Guide for Figure 1. Percentage of measured spray Private and Commercial Applicators." 1991. deposits on various parts of the body. Rubber USDA-Extension Service and Environmental gloves on hands reduced potential dermal Protection Agency, Washington, D.C. exposure by over 95 percent.

"Crop Protection Chemicals Reference." 1991. 7th Edition CPCR, John Wiley and Sons, New York.

Kuhlman, D.K and D.C. Cress. 1981. Aerial Application Handbook for Applicators, Cooperative Extension Service Publication No. MF-622, Kansas State University, Manhattan, KS.

McBride, D.K., G. Maher. 1991. Pesticides, E- 759, NDSU Extension Service, Fargo, ND.

Noyes, R.T., J.B. Solie, R.W. Whitney. 1987. Precision Vacuum Mixing System for Improved Pesticide Safety, ASAE Paper 87-1068, Department of Ag Engineering, Oklahoma State University, Stillwater, O K

Olson, W.W., F.A. Gahring and D. Herzfeld. 1990. Buying and Wearing Protective Clothing for Applying Pesticides, HE-454, NDSU Extension Service, Fargo, ND.

Secondary Containment for Large Tanks

Edward L. Waddell, Agricultural Engineer Michael F. Broder, Agricultural Engineer Tennessee Valley Authority National Fertilizer and

Environmental Research Center

Abstract

Fertilizer dealers will be required to install secondary containment for liquid product storage facilities. Nine states have developed regulations for secondary containment facilities. An additional seven states and the Environmental Protection Agency are also developing similar regulations. Among the different containment problems encountered at retail dealerships, large fertilizer storage tanks (capacity of 100,000 gallons or more) present the greatest challenge for design and cost evaluation. Designs may be unconventional to some extent, but they must be well engineered and must be incorporate knowledge gained from field experiences. The containment designs must also incorporate leak detection systems to identify product losses through the tank bottom. Leak detection systems are an integral part of the containment design, wl7etl~er for an existing or new tank.

Introduction

There are several technical approaches to designing, constructing, and managing secondary containment systems. Successful systems must protect the environment, satisfy containment regulations, and be cost effective. Innovative alternatives must be submitted for approval prior

Prepared for: National Symposium on Pesticide and Fertilizer Containment Design and Management, February 3-5, 1992, Western Crown Center, Kansas City, Missouri.

to their installation. Some regulations may approve deviations from the basic requirements as long as the deviation will not reduce the effectiveness of the containment. Other regulations may permit Innovative ideas with an "Experimental Permit or Use" in order to research and document the effectiveness of the containment alternative. Regulations usually provide a compliance schedule which will allow fertilizer dealers a time period to complete the secondary containment requirements.

The location and available area around a fertilizer dealership will affect the type of secondary containment selected. A complete site plan should be prepared to indicate the location of all surface features and buildings. Many sites may lack sufficient space for diked impoundments to contain large volumes. Other sites may be impacted by flood plains, shallow groundwater, soils with high shrink/swell tendencies, or soils with poor bearing capacity. Sloping sites may appear conducive for containment structures, but surface water flow and drainage from the property could affect construction and maintenance of the containment. These factors will certainly affect the placement of containment systems and the material used to construct the containment.

Keys to good secondary containment include a proper selection and installation of liner system around the tank which will significantly reduce the infiltration of a spilled product. The dike walls and floor, including the area under the tank must meet permeability factors. OSHA regulations may limit the height of dike walls for personnel safety. Containment floors may be influenced by the type of traffic exposure. Provisions will be needed to anchor the tanks within the containment or

anchor the tanks within the containment or prevent flotation in case of a major spill. Materials commonly used for containment systems include concrete, synthetic liners, clay liners, or amended insitu soils to the required permeability.

Leak detection systems must be integrated into the design. Common techniques include steel false bottoms, bladders, or moving the tank to another containment system elsewhere at the facility--with, of course, a good leak detection system. In designing leak detection system, the "cup and saucer" design could provide leak detection and secondary containment of minor leaks. This concept would confine leakage to a smaller area and would not contaminate the larger containment floor without significantly increasing the cost of the containment system.

Secondary Containment

Containment must be designed to specified volumes and permeabilities. Design containment volumes must provide a volume equal to the volume of the largest tank plus a safety (freeboard) factor of 10 to 25 percent of the largest tank volume and/or a specified rainfall event (usually a 25-year, 24-hour design storm) as required by regulations. The design freeboard for rainfall events can vary according to regulations. Calculations also must take into account volumes displaced by any other tanks inside the containment area.

Containment systems can be constructed of earth, concrete, or other material approved by the appropriate agency and supported by engineering design recommendations. Slopes of earthen berms generally should not exceed 3 to 1 for outer slopes and 2 to 1 for inside slopes. Sloped berms require a larger containment area than vertical walls to provide the same containment volume. Concrete or solid masonry walls must be designed to withstand the full hydrostatic head of any discharged fluid. All piping must be placed on top of the containment floor and protrude over the top of the dike walls.

Since leak detection systems are required for all tanks, existing tanks require additional considerations when designing containment. The tank should be inspected to insure that it Is structurally sound prior to any modifications or

relocation (1). The most common way to install leak detection is the false or second steel bottom if the tank is not to be moved. Should the dealer decide to move the tank, several options will meet the requirements. By moving the tank, the containment system can be designed arid constructed as i f the tank were a new installation.

Figure 1 illustrates a typical system using a steel false bottom. The tank has been retrofitted with a steel bottom which is supported by a six- inch sand lift placed on the original bottom. The original tank bottom should be inspected for leaks and repaired as necessary. Should the existing bottom not be repaired, Figures 2 and 3 illustrate the use of a synthetic liner to render the original bottom leak proof. The existing sump should be covered with a steel plate before the sand lift is placed inside the tank. Slits can be cut in the tank wall and protruding steel plates welded to the wall, inside and outside. Angle iron can be welded around the inside of the tank level with the sand lift for welding the new bottom in place. Weep ports are positioned around the tank between the two bottoms to detect any leaks. Once the extra tank bottom is in place, the remainder of the containment floor can be completed.

Secondary containment is completed using a geocomposite liner as shown or substituting synthetic or clay material. The packed granular bentonite, shown under the tank shoulder, will prevent spilled material from seeping under the tank. The containment floor should slope away from the tank bottom as much as possible to reduce or eliminate the need for anchoring the tank. A six-inch soil or gravel overburden should be placed over the geocomposite or clay liners to protect them from erosion and desiccation. Depending on the type of synthetic liner used, the gravel overburden may not be required.

A synthetic liner can be substituted for the clay liner. Figure 5 shows the use of a flange attached to the tank shoulder. The liner is extrusion-welded to the flange and sealed to provide a leak-proof attachment. Another method is to use a batten-and-bolt arrangement (Figures 6 and 7) to sandwich the liner material between two stainless bands slmilar to a compression fitting.

Concrete can also be used for the containment floor. A piece of synthetic liner would be attached to the tank shoulder and

concrete floor to seal the containment. The liner would be attached to a synthetic embedded profile formed in the concrete (Figure 8).

The liner selected for the containment should extend to the dike wall dimensioned to provide the design volume. A geocomposite liner or earthen liner should extend to the top of the dike wall. Some regulations may require that such materials extend beyond the top of the dike and include about 15 feet of the outside slope. A synthetic liner can be embedded in a soil trench on the top of an earthen dike (Figure 9A) or attached to a vertical concrete wall.

Prefabricated walls can also be used for the dike wall. These partitions are bolted together and anchored in concrete. The synthetic liner is attached to the top of the partition with a bolt and batten arrangement of steel or treated wood.

Tanks are also built on concrete ringwalls. Secondary containment for these tanks is similar to that discussed above. Leak detection can be provided to the steel false bottom. The tank can be moved from the existing ringwall to permit construction of a synthetic-lined leak detection system within the existing ringwall (Figures 10 and 11). The tank is placed back on the original ringwall.

Figure 12 illustrates a ringwall foundation complete with a synthetic-lined leak detection system and containment floor. The various attachment mechanisms for synthetic liners can also be used. Geocomposites and clay liners can also be compacted against the concrete ringwall for the containment floor.

Anticipating the implementation of secondary containment requirements, recently erected large tanks often are placed on an impermeable surface. Figure 15 illustrates a typical arrangement. However, such installations may lack a leak detection system. If a synthetic liner was installed under the new tank, a leak detection system can be built using a low perimeter wall around the tank.

Figure 16 indicates the use of a concrete ring. The existing synthetic liner is turned up and attached to the inside surface of the wall. A leak detection pipe can be placed in the wall as shown or placed in the gravel base as shown in Figure 17. Synthetic liner material is used to make the skirt which is attached to the tank wall to prevent rainwater accumulations in the leak detection system.

Figure 17 illustrates the same leak detection with a perimeter wall made of steel. Wood can also be used. This figure also indicates the tank leak detection system is elevated above the containment floor. Another leak detection alternative is shown in Figure 18. A shallow earthen pond is lined with synthetic liner to extend to the outer edge of the earthen dike. The recessed area is filled with gravel to support the tank. A geotextile rub sheet is placed between the tank and the liner to protect the liner and prevent rainwater accumulations in the leak detection system.

These leak detection alternatives will contain losses and provide easy identification of tank leaks. The leaks are confined in a small area and will not contaminate the entire containment area. If a synthetic liner is used under the tank, it can be extended to the containment wall or dike as previously discussed.

Some containment regulations may indicate the use of perforated pipe under the tank and on top of the liner for a leak detection system. These pipes would be placed under the tank on ten-foot centers. The laterals and main would be plumbed to a sump pipe for leak detection. A possible disadvantage with this type of system is that a leak could by-pass the perforated pipe. Since the tank base and tank will settle with time, depressed areas between perforated pipes could channel leaks away from the pipe and leak detection sump.

There are several alternatives which can be used for effective leak detection systems in new or existing large tanks. Since these systems integrate with the secondary containment floor, several liner materials can be used. As highlighted throughout this discussion, these include amended native soil or clay liners, geocomposite liners, synthetic liners, and concrete, provided there Is sufficient space available to construct a typical containment.

Clay Containment Liners

Regulatory use of native or modified soils for construction of berms around storage containers dates back several decades. To understand the differences and factors needed to consider in choosing a clay liner for secondary containment,

it is necessary to review the soil engineering properties that are important in any clay lining applications. Soils have several quantifiable properties that are important. These properties are among the design criteria normally identified in regulations, and can help determine whether a particular source of soil has properties that may work to prevent or limit liquid movement. For each of the properties, standardized testing methods have been established.

Most state regulations for fertilizer containment structures allow the use of clay as a lining material. In general, these state regulations specify soil properties and construction parameters to assure the liner will inhibit liquid movement in the event of a spill. Soil factors most often considered in containment regulations are particle size analysis, Atterberg limits, organic content, compaction/permeability, and thickness and cover.

Particle size analysis identifies whether or not the soil, based solely on texture, Is likely to exhibit any of the other properties necessary to contain the liquid. In many states a less restrictive particle size is allowed if an expanding clay is incorporated in the native soil, since expanding clays are effective In sealing soil pores. Two concerns, however, if these expanding clays dry out, the liner is more likely to have cracks in it; and i f the bentonite is not uniformly incorporated, some areas will not be as well protected.

Atterberg limits refer to the liquid and plastic litnit of the soil, but the Plasticity Index (PI), the difference between the two, is very important. The PI determines the width of the moisture range under which soils can be effectively compacted without significant loss of strength or cracking. Incorporation of bentonite substantially modifies the Atterberg limits, such that the native soil require a higher PI than do bentonite-amended soils (2).

Organic content reduces the effectiveness of the soil to function as a liner. Organic matter continues to degrade once exposed to drying increases cracking and reduces strength. Soils with more than 2 percent organic matter are not suitable for liner materials.

The importance of compaction/permeability is to assure the construction of the liner allows full performance of the other soil properties in inhibiting liquid flow. Since seepage is the primary consideration for liners, many states

specify a coefficient of permeability rather than compaction. This can be tested in a lab on a recompacted sample of clay, then field compaction testing can be done to assure the field compaction equals that used in the laboratory test. Generally, the clay liner must have a permeability no greater than 1 x 10" cm/sec. Some states may require 90 to 95 percent Standard Proctor Density, either alone or in combination with a required coefficient of permeability.

Liner thickness and cover directly affect the amount of seepage through the liner. Generally consideration of liner thickness is a greater factor when looking at liner integrity and service wear. The same applies where liner penetration or cracking may occur, such as that from drying, frost, or root penetration. A six-inch clay layer with a six-inch soil or gravel cover is recommended to protect the clay liner (3 & 4).

Cost is the primary advantage. If clay is readily available and a large area must be covered, clay may be the cheapest option. Containment size is a factor since space is needed for equipment movement inside the contained area. Much of the soil testing costs are one time and largely independent of size.

Disadvantages include weather sensitivity, maintenance, cleanup, space, leakage, and life. Clay can be damaged by weather extremes, particularly dry and freezing conditions. Product recovery and cleanup is more difficult and expensive. A large spill would require significant excavation and reconstruction. Small leaks of some chemicals may change the properties of the clay to enhance or destroy its containment abilities. Determining how much leakage occurs or where weak spots are in a clay liner is very difficult. Assigning a life to a clay liner is impractical. Under ideal conditions, clay may outlast many or most manufactured alternatives.

Geocomposites

Geocomposite liners can be used for containment. These bentonite clay liners guarantee a uniform thickness of granular bentonite sandwiched between two confining materials. Figures 19-22 illustrate the cross- section design of several geocomposites.

Gundseal, a bentonite/polyethylene liner, features granular bentonite attached to a synthetic liner by a nontoxic adhesive. Table 1 summarizes the characteristics of these materials. Four types of granular bentonite are available, but high contaminant resistant should be recommended.

Geocomposites should be installed on prepared containment surfaces. The subgrade should be free of sharp rocks, graded to fill cracks and voids, and compacted without rutting. Liner placement should begin with the side slopes, unrolling the liner down the slope. Seams at the base should be perpendicular two and five feet from the toe of the slope. Seam overlaps should conform to the printed guides on the liner. Fasteners, anchor pins, or adhesives may be used to secure the panels prior to overburden placement. Liner material should be loosely installed under dry conditions. To compensate for shrinkage, longitudinal and transverse seam overlap should be increased according to manufacturers recommendations.

The use of geocomposites will eliminate the application uniformity concerns addressed for native clay-amended soils and soil testing. However, the disadvantages of clay-amended soils remain applicable. Though clay and geocomposite are reasonable forms of secondary containment, they both have positive and negative attributes.

Synthetic Containment Liners

Synthetic liners can be substituted for clay- based liners. Advantages include simple installation on a prepared containment surface, low cost, durability, and a high level of impermeability. The liner material selected must be compatible with the stored fertilizer. Puncture resistance could be a possible disadvantage.

Five materials can be used for secondary containment: high density and low density polyethylene (HDPE or LDPE), polyvinyl chloride (PVC), chlorosulfonated polyethylene (Hypalon), or chlorinated polyethylene. Physical properties to consider when selecting a liner material are chemical resistance, permeability,low-temperature brittleness, weatherability, puncture resistance, and dimensional stability. Physical properties are listed for several products in Tables 3 and 4. For

some materials, the overburden required for clay- based liners may not be required. This information should be obtained from the material manufacturer prior to designing the secondary containment. If the overburden can be eliminated, detection tank leaks, spill cleanup, and recovery will be much easier. Gravel overburden should be preferred to soil.

Concrete Containment

Generally, the most expensive material used for containment, concrete provides a clean surface which can be easily cleaned.. However, in the presence of fertilizer materials, corrosion will occur. An engineer should be consulted regarding reinforcing steel requirement and joint design. Dealers considering concrete should be cautioned not to compromise structural integrity for the sake of economy (6 & 7).

Since the fertilizer storage will be resting on concrete, leak detection is provided. The concrete surface should be sloped to drain leakage away from the tank bottom. A concrete coating should be applied to the concrete surface to prevent corrosion. Shallow grooves can also be cut in the concrete surface to facilitate drainage of leaks.

The concrete base supporting the tank will require extensive reinforcement and additional thickness to support the weight of the tank and its contents. Reinforcement and concrete thickness can be reduced for the containment floor and walls. All construction joints, seams, and cracks should be sealed with an acceptable sealant.

Tank Bladders

Bladder systems do not provide the required secondary containment volume as specified by most regulations. However, these systems may be permitted under experimental status by some states or considered as alternative designs which provide adequate safeguards to prevent release of material. Technically, the bladder becomes the primary storage container and the existing tank becomes the secondary containment vessel.

A bladder is constructed to fit inside the original tank. The bladder bottom rests on a layer

of sand similar to the construction detail described for the steel false bottom. The bladder is hung from the top of the tank wall using a "J- bolt" attachment and a pipe hanger placed in the hem seamed in the top of the bladder. It is recommended that a geotextile be placed between the bladder and tank wall.

Use of the bladder limits future tank shell inspections and could increase the cost of installing new tank roofs. Also, there Is the possibility of increased corrosion of the tank shell once it is exposed to a new set of physical conditions. Those installing the bladder must also be onsite to alter any plumbing feature. Removal of fertilizer sludges from the bottom of the bladder will also be more difficult.

cost are the number of tanks and tank diameter. For example, it is more costly to install a false bottom in a 60-foot-diameter, half-million-gallon tank than one that has a 46-foot-diameter. Each containment design is unique.

Three case studies have been prepared to address the cost associated with the following example: A fertilizer dealer has two 500,000- gallon storage tanks. Each tank has a diameter of 52 feet, a wall height of 32 feet and a cross- sectional area of 2,124 square feet. Regulations require a design containment volume of 110% of the largest tank plus the volume displaced by additional tanks.

Each tank must be equipped with a leak detection system.

Elephant Rings Case 1:

Elephant rings may be another alternative for containment of many tanks located where sufficient space is not available to construct dikes. The elephant ring essentially is a steel tub constructed outside the existing tank wall to provide the required containment volume. Figure 14 illustrates the typical dimensions used: a tub diameter of 1.5 times the diameter of the tank and a tub wall height of one-half the tank height. In addition to the tub, a second steel bottom must installed in the tank to provide leak detection. For many tanks, this may be the only practical way to meet secondary containment regulations.

An important consideration regarding the use of the elephant ring is the confined space that exists between the tank and tub walls. Local health and safety or OSHA standards may require special entry procedures to ensure that employees entering the space can escape easily. Some states may limit containment wall heights which may prohibit the use of an elephant ring.

Large Tank Containment Costs

The unit cost of large tanks and of secondary containment is related to the size of the tank. For example, a one-million-gallon tank is not twice as costly to build as a half-million-gallon tank; thus, the cost per gallon of storage decreases as the tanks become larger. Other factors influencing

A design containment volume of 550,000 gallons or 73,529 cubic feet is required. This volume will be provided by an earthen berm containment pond around the existing tanks. The floor of the containment is sloped to drain rainfall and leakage away from the tank bases. Regulations also suggest optimum dike slopes to be 3:l. The dike should be five feet wide. The containment floor will slope to a sump for liquid removal, and the volume obtained from this slope will be a safety factor beyond that indicated in the containment volume calculations.

The impoundment area required to contain these tanks depends on the depth or dike wall height selected. A depth of three feet requires 24,510 square feet plus 2,124 square feet (the cross-sectional area of the additional tank) or 26,632 square feet. This area can be shaped as a rectangle or square. For this case, dimensions will be 156 feet square. To lay out the floor of the containment, earth work calculations will indicate the appropriate cut/fill to meet the finish grade elevations. The total area required to construct the containment will be 32,041 square feet.

The containment must meet permeability specifications. Four liner materials are considered for this containment from the tables: Claymax, Bentomat, Hypalon, HDPE. Bulk granular bentonite will also be considered as an amendment to the existing soil to meet the permeability requirements. A surface area of

36,100 square feet must be covered. The estimated material costs are:

T V P ~ Installed Cost Total Total w/clravel

Claymax @$I .I 5/ff $41,515 $48,735 Bentomat @$I .I 9/ft2 $42,959 $50,179 HDPE @$I .09/ff $39,349 $46,569 Hypalon @$I . I 0/ff $39,710 $46,930

1. Claymax: is a tradename of James Clem Corporation.

2. Bentomat: is a tradename of American Colloid Company

In addition, the liner surface must be covered with a one-inch layer of washed gravel (one-inch diameter minimum) to protect the liner surface. The estimated cost of gravel and placement is $0.20/ff.

Bentonite requirements will be predetermined based on the engineering properties of the soil. General recommendations for bulk application rates range from two to five pounds sodium bentonite per square foot. Chemically resistant bentonite is recommended at a cost of $180/ton. The amount of material required ranges from 30 to 90 tons, or $6,480 to $16,200 (F.O.B.). Field application and incorporation could be performed by the dealer under the supervision of a material specialist.

The synthetic liners must be attached to the tank. Previous figures detail compression and molded polyethylene flange connections for attaching synthetic liners to the tank shoulder. The estimated cost for these mechanical connections is $5 per linear foot of tank circumference. For these two tanks, 324 liner feet at the flange will cost $1,633. To connect the liner to the tank floor, the base is excavated to expose about one foot of the tank floor around its perimeter. Granular bentonite is compacted in this area providing a seal between the containment floor and the tank bottom. Assuming one ton of granular bentonite is required for this, material cost is $180.

Now that the contalnment is complete, tank bottom leak detection will be provided by installing a second steel bottom (false bottom). The new bottom will be supported by a 4-6 inch layer placed on the original tank bottom. Weep

ports will be cut at the cardinal positions for leak detection. Installed costs for steel false bottoms range from $7-1 0 per square foot. For each tank, the cost range is $14,868 to $21,240, or $29,736 to $42,480 total. Some cost savings may result from having the contractor complete both tanks at one time.

Case 2: Concrete Containment

Concrete will be used to construct the secondary contained for Case 1. The containment floor area will be excavated six-to- eight inches deeper in order to place gravel under the concrete. An eight-inch reinforced concrete pad (60 feet x 60 feet) will be poured to provide a foundation for each tank. The five-inch thick containment floor (19,432 square feet) will be reinforced with wire mesh. The reinforced containment wall will be 3 feet high, 163 feet square, and 8 inches thick. Based on the design dimensions, 667 cubic yards of concrete will be needed. The total construction cost (earthwork, reinforcement material, concrete, and concrete forming and finishing) is based on a cubic yard of concrete. For example, if these costs total $100 for each cubic yard of concrete, the containment would C O S ~ $66,700 or $3.25 per square foot. Likewise, if the total construction cost is $200 for each cubic yard of concrete, the containment will cost $133,400 or $3.75 per square foot. An additional expense of $10,000 will be required to move each tank to the concrete pads.

Case 3: Elephant Ring

Assume that a fertilizer dealer has a 500,000 gallon storage tank situated on a site with insufficient space to construct a typical secondary containment system. To provide 110% design containment volume, an elephant ring, or tub, is recommended. For the tank dimensions in Case 1, the elephant ring dimensions would be 1.5D and.5H where D is the diameter of the storage tank and H is the tank height, or 78 feet in diameter and 16 feet high. The elephant ring will require almost as much steel as in the original tank. Essentially, this results in constructing a new tank where the new bottom is the false bottom built in the existing tank. Additional steel

structural supports must be added to support the tub wall.

If the case for constructing new storage tanks ranges from $.I 1 to $.I4 per gallon capacity, then an estimated cost range for the elephant ring is $55 to $70. This cost may or may not include the false bottom installed in the existing tank.

If the false bottom installation is in addition to the above costs, the additional cost range for the false bottom is $1 4,868 to $21,240 These figures or costs can vary among tank constructors.

Summary

Several designs for tank leak detection systems and selection of construction materials for secondary containment have been discussed. The designs can be applied to existing or new tanks as dictated by the space available at the proposed containment site. State regulations can be met with these designs. Most retail sites may identify the uncertainty of containment, potential for routine small spillage and difficultly of cleanup, as reasons why any cost savings associated with clay-based liners may not be worth the additional risks these material may present. Synthetic liners and concrete can eliminate these concerns but can add significantly to cost.

Cost comparisons indicate ranges of expenditures which would be expected in providing secondary containment for new or existing tanks. By selecting a case which closely matches a dealer's situation, preliminary secondary containment costs can be estimated.

Dealers should visit as many contained facilities as possible before choosing a material of construction. Construction techniques and managerial problems associated with a specific containment can be obtained by exploring what has been done. No one system will work for all site, but a combination of the systems discussed above should provide a sound secondary containment plan which will satisfy regulatory requirements.

References

1 Tank Inspection, Re~air, Alteration, and Reconstruction. American Petroleum Institute, APE Standard 653, First Edition, January 1991.

2. Haddox, Robert. Secondary Containment Conference Proceedings, "Above Ground Storage Tank:" Center for Energy and Environmental Management. San Francisco, CA. October 29-30, 1990.

3. Wisconsin Department of Aariculture, Trade & Consumer Protection, 1988. Chapter Ag 162, Bulk Fert i l izer Storage Wisconsin Administrative Code, Register, 1988, No. 386, Madison, WI.

4. Morrison, Paul. "Use of Clay As A Lining Material for Fertilizer Secondary Containment." Wisconsin Department of Agriculture, Trade and Consumer Protection. Materials of Construction Symposium. Tennessee Valley Authority, Muscle Shoals, AL, September 1991.

5. Cadwallader, Mark and Erin Dixon. "Liner Materials For Waste Containment". Pollution Enaineerinq, July 1988, p 70-73.

6. Broder, Michael F. "Containment of Fertilizers and Pesticides at Retail Operation." Tennessee Valley Authority, National Fertilizer and Environmental Research Center, Muscle Shoals, AL. TVA/NFERC 93 Circular 2-291, February 1991.

7. Pesticide and Fertilizer Containment Facilities Handbook, Midwest Plan Service, Iowa State University, MWPS 37-First Edition.

'I'ablc 1 GEOCOMPOSI-I'E LINERS

Roll-Width x Lengtli

Primary Backing 3.25 OZ/YD' Slit Filn~ Woven Geol'extile

I OZ/YD"OV~~ Silt Filrn Polypropliylerie

314 OZ/YD' Iligllly P r o ~ ~ s NonWoren Fabric

Encapsulating

Tensile Streugtb

Sodiunl Uentonite Sodiurli Uentonite Clay Component

Montmorillonite Percentage

Over XI%

Ilydraulic Conductivity

Seaming Bentonite Hnl~anced 6" Overlap

M i ~ ~ i m r ~ m 6" Simple Overlap Per Sea111

3-6" Overlap No Searuing Necessary

Table 2

NATIVE SOILS VERSUS GEOCOMPOSI'I'ES CLAY LINERS

Native Con~~ac ted Soil Clcocon~~osiles

Thick (21t-5 It, or 0.6-1.5 It) Field Cor~structed fIarci to Brrild Correctly Im~~ossiblc to P~rncture Constructetl with IIeavy Equip~llent Often Requires Test Pad at Each Site Site-Specific Data on Soils Needed Large Tl~ickrless Takes Up Space Variable Cost Dilficult to Repair Performance Is IIiglily Dependent U ~ O I I Quality of Construction Slow Constrnction

'I'II~II ( 10mni) Manufactureci Easy to Build (Utuoll & Place) Possible to Puncture Light Corlstruction Eqr~iprl~ent Carl Be Used Repeated Field Testing Not Needed Manulaclured Product; Data Available Little Space Is Taken Prctlictable Cost Not Difficult to Repair IIydraulic Prol)erties Are Less Sensitive TO Construction Variabilities h4uch Faster Construction

TABLE 3

10 MIL 20 MIL LDPE HDPE LDPE HDPE

Thickness (mil) (mm)

Tensile Strength at Yield ASTM D638, (lbs/incli) 15 30 30 60

Tensile Strength at Break ASTM D638 (Ibslinch) 22 45

Elongation at Break ASTM D 638, (%) 500 800 500 800

Tear Resistance ASTM D 1004, (lbs) 5 9

Puncture Resistance FT MS 101B, (lbs) 30 47 60 90

TABLE 4 Comparative Resistance to Some Commonly

Encountered Solutions

Solution

Water

Hydrochloric Acid

Sulfuric Acid

Acetic Acid

Ferric Chloride

Sodium Hydroxide

ASTM Oil #1

ASTM Oil #3

ASTM Fuel A

ASTM Fuel B

Kerosene

Hypalon*

E

F

E

F

F

E

F

P

F

P

P

PVC*

E

F

G

P

G

P

P

P

P

P

P

CPE* HDPEV*

E E

G E

E E

F E

G E

E E

G E

F E

F E

F E

F E

*From Dow Literature **From Gundle Literature E = Excellent F = Fair G = Good P = Poor

TANK

I, NEW BOnOM

k l G m ' 3

NEW TANK BOTTOM

CHEMICAL REYSTAN r M A S ~ C

MECHANICAL FASTCNERS O'Tt-T. C E N E R S

,- m ~ u s ~ o ~ WLD

FlANGE TO UNER ADAPKR

I TANK WALL

I NEW TANK E O V O M

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. . . . . . I I .. ..

OLD TANK 60 rTOM

I

TANK INSIDE WALL @ SEE FIGURE 7

SINGI F LlNFR ANCHORING TO TANK PO n AN= LLcutxA

NEOPRENE SPONGE NEOPRENE A O I f E 3 K

\ A . ,- l/f'X 2 - B A m N

w A n y , . &- \ \h \ WLDED J/8X 1 SlUD 14- BOLT

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d'

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LLuEEl l

LEAK DEECnON PIPE

SEE 7X'. DETAIL

r LINER 7

TANK FARM SFCONDAR Y CONTAINMFN~ - LlzW5E2

1/2' THICK ASPHALT

- SFCONDARY CON TAINMFN T S E E M -

nCUREI2

EL EPHAN T RING WALL

SAND OR GRAML U F T

I I ELEPHANT RING FLOOR ' I I C 1.5 X TANK DIAMETER

TANK

TANK

TANK

MECtUNICAL ATTACHIIENT SKIRT PREVENTS RAINWATER IN KCONOARY CON TAINUENT

CONCREE RING WALL

LEAK OETECnON

SMRT PREKNTS RAINWA TER IN Y C W O A R Y CONTAINMENT I

12' S7EFL RING (OIAME7ER 2' CREATER n i m T ~ K )

/ "0"" R" ""T

WOKN COElEXllLE

,r- NEEDLE-PUNCHED FIBERS

NON- MMN GEOTEXTlLE

; WOKN POL F'ROPKENE GEOTEXnLE I

1 ,- GRANULAR BENTONIE

I LICH T- K I C H T FABRIC OA CKING -,,

L ~ l ~ ~ - ~ ~ ~ ~ l ~ ~ POL YET?+ KENE SHEET

T

DESIGN CRITERIA FOR CONCRETE MIXING LOADING PADS

Ronald T. Noyes, P.E. Extension Agricultural Engineer Oklahoma State University

Abstract Mixing1 loading pads for use by aerial or

ground pesticide or liquid fertilizer applicators, users or researchers should include containment for storage of full strength and dilute chemicals and rinsates. High strength watertight reinforced concrete, cured, then surface sealed with an appro- priate sealant is the preferred material. Facilities handling few chemicals can use a simple single sump pad design. Facilities using many chemicals and / or both pesticides and fertilizers require mul- tiple containments and sumps. Rainwater man- agement is a major facility design consideration; roofed or enclosed pads should be considered to minimize or eliminate external water.

Purpose

This paper provides a basis for understanding the needs for and design of water tight concrete mixingtloading pads. Two facility concepts that will help meet EPA guidelines are illustrated. Sources of design criteria authority are documented for de- signers who wish to review background references for their facility design specifications.

Background

The best known concept for handling, mixing, and loading agricultural pesticides, processing rinsates, and washing and rinsing applicator vehi- cles and containers was developed by Rester (1986) as a management strategy for aerial applicators in Louisiana from 1983-1986. His concrete wash pad, rinsate storage tank and sprayer rinsing scheme included guidelines on how to manage the system safely on a multiple crop, or pesticide basis.

National Pesticide Waste Management Workshops were conducted in 1985, 1986, and 1987 to address agricultural pesticide waste handling and groundwater contamination problems. The proceedings of four 1987 national workshops listed recolnmendations on container, pesticide waste, and rinsate handling and disposal problems (Gilding, 1988).

Modular concrete ~nixing/loading/ containment. facility designs for aerial and ground pesticide and liquid fert,ilizer applicators were developed by Noyes providing standardized construction details in multiple sizes (1988; 1989-A,B). Designs were in1 proved by Noyes and Kamlnel (1989). Kainmel and O'Neil(1990) reported on a farm sized concrete loading pad designed for sinall facilities.

Management Facilities

Storage, handling, and disposal of pesticides and fertilizers have been identified by State and Federal law makers as practices that create high risks to groundwater quality. Federal regulations on pesticide containment are being revised. Nine states have containment regulations and seven more are developing regulations. Legal liability and remediation costs of contaminated sites is a n important consideration in the decision to build a facility.

A practical, economical concrete pad chemical handling facility with proper management can help: 1) improve environmental safety by prevent- ing contamination of ground and surface water from routine use and accidental pesticide spills, 2) improve worker safety, 3) comply with federal and state regulations, 4) enhance ownedoperator man- agement, and 5) reduce legal liability. Standard- ized economical facility designs that meet regula- tory requirements will encourage applicators to invest in improved facilities.

Modular Pad Designs

A range of sizes of concrete loading/storage/ containment pad designs are needed to fit individual operator requirements. Standardized pad designs can be used by aerial and ground pesticide applicators using 1,100 to 1,900 liter (300- 500 gallon) rinsate tanks, pesticide mini-bulk or small volume returnable (SVR) containers, non- returnable containers, and a range of pesticide or liquid fertilizer bulk tank sizes. Building roofs or enclosures over concrete pads improve manage- ment and function while minimizing risk from handling contaminated storm water or snow.

Concrete pad design criteria:

1. Concrete pads must be suitable for mix- inghoading and rinsing aerial or ground sprayers.

2. Pad must be constructed of watertight, rein- forced concrete capable of resisting ground and weather stress, and chemical or mechanical damage.

3. Pad designs should include shallow easily cleaned watertight sumps.

4. Pads must provide adequate secondary con- tainment for pesticide andlor liquid fertilizer leaks and spills plus freeboard, and storm water if facility is not roofed.

5. Separate containment areas must be incorpo- rated for liquid fertilizer, pesticide, rinsate storage, plus handling/mixing/recovery/disposal.

Pad Layout and Function

Agricultural chemical facility management functions and design factors that should be in- cluded in planning new or remodeled facilities are:

* Pesticide Storage * Worker Safety * MixingJLoading* * Chemical Security * Secondary Containment * Storm Water * Loading Pad * TanksPlumbing

Pesticide Storage

Pesticides should be stored in a building for protection from theft, vandalism, temperature ex- tremes and unauthorized personnel. It should be used only for pesticides and be isolated from other buildings. Toxic material warning signs must be posted outside by all building or fence entrances. Buildings should be ventilated to prevent an accu- mulation of toxic fumes. Figure 1 shows functional areas of a small pesticide facility with a small stor- age building that can be built on or adjacent to con- crete pads. Figures 2 illustrates a double sump concrete pad and storage building for use in larger, more complex facilities. Electrical wiring and equipment inside storage building; must be designed to meet the current National Electric Code plus local and state chemical storage electri- cal codes. Storage layout arrangements for a vari- ety of additional facility layout functions are illustrated in the MWPS-37 Handbook (1992).

Mixinghandling tanks, pumps, valves, hoses, and meters used to transfer chemicals are placed on loading pads for smaller operators, (Fig. 1) or in storage containment or load pad areas in large facilities (Fig. 2). Transfer pumps should be centrally located and elevated above liquid levels, near sumps and mixing tanks.

Containment

Secondary containment allows for recovery of pesticides or fertilizers if storage or applicator tank or plumbing fails, and prevents chemicals from draining into soil or surface water. For small operations, storage and mixinghoading contain- ment areas are combined, Figure 1. A chemical facility with separate storage, loading and con- tainment areas and sumps for pesticides and liquid fertilizers is shown in Figure 2. Secondary containment areas are separated from loading pads by divider walls.

Loading Pad

Loading pads are used for loading or unloading sprayers, equipment maintenance and repair. The large facility (Figure 2) has a separate loading pad containment area to load and rinse sprayers. The concrete pad slopes to a shallow sump to collect rinse water from leaks, drips, or spills for pumping into holding tanks.

Loading pads and sumps should not be used to dump or drain unused spray and rinsate into the sump for recovery as this contaminates the pad and sump, making cleanup difficult, adding unneces- sary management risk. Rinsate should be pumped directly from sprayers into rinsate tanks segre- gated by crop or pesticide for reuse on suitable crops, eliminating disposal as hazardous waste. Exterior washing of ground sprayers should be done in the field a t application sites immediately after each operation to prevent the accumulation of contaminated soil and trash with a mixture of pesticides, which would require disposal as a haz- ardous waste product. Field rinsing and immediate application of rinsate on the target field is the simplest rinsate disposal process.

If there has been a pesticide spill or leak on non-roofed loading pads into rainwater, that con- taminated water must be pumped to rinsate stor- age tanks for use as makeup water for subsequent sprayer loads. If pads are clean, rainwater may be pumped off the pad in most states.

Worker Safety Watertight Concrete Specifications

Worker safety areas near mixingtloading equipment should be equipped for first-aid to work- ers. An eyewash and deluge shower should be provided to rinse chemicals from the eyes, face or body. Use of safety equipment should trigger an alarm for emergency assistance. First-aid and spill response kits should be easily accessible. Material safety data sheets (MSDS) for all cherni- cals stored a t the facility should be readily avail- able. A fire extinguisher with appropriate chemical fill should be positioned outside storage areas or buildings.

Chemical Security

Pesticide and rinsate storage containment areas should be secured by heavy chain-link fenc- ing (Figure 2) or be inside locked buildings. Fenc- ing mounted flush with outer containment walls should have at least 1.8 meters (6 feet) of combined height. Fencing with a concrete ledge should extend 1.8 meters (6 feet) above concrete walls. Containment section widths can be sized to install pesticide storage building;, such as the Oklahoma State University pesticide building (1983), Midwest Plan Service storage building (1979) or other suitable structures.

Empty disposable containers should be stored on a covered, curbed pad to prevent rain entry into containers or leaks from containers contaminating the soil. Empty mini-bulk or SVR containers should also be stored in this area.

Storm Water Control

Divider walls separating loading and con- tainment areas, Figure 2, have no openings. Spills, leakage, or stored rinsate can not be inadvertently discharged into surface water channels without pumping. Cylindrical coned-bottom stainless steel sump liners are used a s inside concrete forms for construction and cleanout convenience.

Tanks and Plumbing

Rinsate tanks should be elevated a t least 8-15 centimeters (3-6 inches) above concrete floors for quick leak detection, and anchored to prevent overturning. Use flexible hoses to avoid pipe rup- tures from tank floatation during major leaks or rain storms. Transfer hoses should be marked by crop or by chemical for positive identification to eliminate cross-contamination,

Watertight concrete must be used to minimize or avoid leakage through sumps and concrete pads. Concrete mixtures for watertight concrete construction should include the following specifications:

* Water-cement ratio of 0.40-0.45 a t a 3-8 cm. (1-3 in.) slump;

* Type IA or Type IIA Portland cement a t 27.6- 31.0 MPa (4,000-4,500 psi) compressive strength;

* 5.5% to 7% air-entrained cement to improve workability and watertightness;

* Concrete plasticity admixture for easier place- ment of stiff mixes;

* 2.5-3.8 cm. (1-1.5 in.) clean, impervious aggre- gate;

* Oven test aggregate for moisture content and adjust added water accordingly; if oven testing not possible, reduce total mixing water assuming 3.5% excess sand moisture and 1.5% excessive aggregate moisture as a percentage by weight.

* Maximum of 70-100 revolutions a t mix in^ meed; 200-230 at agitatinp saeed;

* Discharge load in 1.5 hrs. (ACI-(394); Maximum of 30 min. between loads;

* Vibrate at 5,000 to 15,000 rpm for minimum aggregate segregation;

* Power steel trowel finish, then add surface texture for safety;

* Careful application of water stops a t construc- tion cold joints;

* Control joints cut to a depth of 114 of the con- crete pad thickness a t 3.7-4.9 m. (12-16 ft.) inter- vals, both directions (center sumps between control joints) ;

* DO NOT use plastic sheeting between the con- crete pad and the soil or sand sub-base; concrete must cure uniformly in both directions.

" Flexible waterproof control joint seal materials;

* Immersion or moist cure for 14 days minimum, 2% days preferred.

Plasticizers -- Easier Placement

Although air entrainment improves plasticity and watertightness, chemical plasticizer admixtures are needed to further enhance mixture plasticity for easier placement of verv stiff low- slumv h i ~ h - s t r e n d h wate r t i~h t concrete mixes. Plasticizers temporarily improve plasticity and flowability for about 30 to 75 minutes, depending on the additive and concrete mix temperature. They reduce vibration requirements, minimizing aggregate segregation, voids or bleeding.

Concrete Pad Surfaces

Outer load pad edges should be level to accommodate building walls and doors. Portland Cement Association (1986) recommends that con- crete chemical handling floors be designed with a minimum 2% slope to facilitate washing. When placing loading floor concrete in the multi-sump design, Figure 2, a centerline form-pipe or board can be temporarily positioned down the sloped center-line "valley" to the sump level to establish the centerline slope. As the screed board follows the horizontal side forms and the sloped center-line form, a uniformly increasing floor cross-slope develops from level at the front edge to a maximum slope a t the sump and divider wall.

Moist Curing

Proper curing determines surface integrity, concrete durability, strength, water tightness, abrasion resistance, volume stability, and resis- tance to freezing, thawing and deicer salts. Main- tain a moist surface and temperature above freezing through a minimum curing time of 14 days. Provide extra moisture for evaporative cooling during mild or hot weather curing and insulation below 0°C (32°F). Plastic sheeting should not be used between the concrete and sub- base. Plastic moisture barriers cause poor curing and subsequent problems with surface sealants.

Concrete Protection

Concrete must be ~rotected from chemical attack by protective coatings such as those speci- fied by ACI, NRC (1981), PCA (1986), and Kammel (1989). Full-strength pesticide or liquid fertilizer can cause severe concrete surface deterioration in just a few days if surfaces are not thoroughly flushed and cleaned immediately after chemical leaks or spills, or coated with a suitable surface protective sealant.

Sealer materials should be selected that will remain flexible for many years during extreme weather cycles. Flexible epoxies, silicones, ure- thanes, polyvinylchloride (PVC), neoprene, or Hypalon should be used to keep temperature stress and control joint cracks sealed. Review surface coating material application procedures and re- sistance to the chemicals that will be handled a t the facility before installing sealers. Concrete should be cured several weeks before sealing to make sure moisture is not trapped between sealants and concrete surfaces.

References

Concrete sealers for protection of bridge structures, 1981. National Cooperative Highway Research Program Report 244, Transporta- tion Research Board, National Research Council, Washington, D.C., 12/81, 138p.

Effects of substances on concrete and guide to pro- tective surfaces, 1986. PCA Bulletin IS001.06T, Portland Cement Association, Skokie, IL, 21p.

Gilding, T. J . (Editor), 1988. Managing pesticide wastes: Recommendations for action, Sum- mary of National Conferences and Work- shops on Pesticide Waste Disposal, National Agricultural Chemical Associa- tion, Washington, D.C., July, 1988, 85p.

Joint design for concrete highway and street pave- ments, 1975. PCA Bulletin IS059.03P, Portland Cement Association, Skokie, IL, 13p.

Kammel, D. W., 1988. Protective treatments for concrete, Agricultural Engineering Department, University of Wisconsin, Madison, WI, February, 1988,7p.

Kammel, D. W., 1989. Protective treatment com- panies, Agricultural Engineering Depart- ment, University of Wisconsin, Madison, WI, January, 1989, 3p.

Kammel, D. W. and D. O'Neil, 1990. Farm sized mixinglloading pad and agrichemical stor- age facility, American Society of Agricul- tural Engineers Summer Meeting, Columbus, OH, June, 14p.

Kammel, D. W., G. Riskowski, R. T. Noyes, and V. Hofman. 1992. Designing Facilities for Pesticide and Fertilizer Containment, MWPS-37 Handbook, Midwest Plan Ser- vice, Ames, IA, January, 120 p.

Noyes, R. T., 1989-A. Modular concrete chemical & liquid fertilizer handling pad facility, Agri- cultural Engineering Department, Okla- homa State University, January, 32 p.

Noyes, R. T., 1989-B. Modular farm sized concrete agricultural chemical handling pads, Agri- cultural Engineering Department, Okla- homa State University, February, 25 p.

Noyes, R. T. and D. W. Kammel, 1989. Modular concrete wash/containment pad for agricul- tural chemicals, ASAE Paper No. 89-1613. American Society of Agricultural Engineers Winter Meeting, New Orleans, LA, Decem- ber, 32p.

Pesticide storage building, 1983. Plan No. Ex. 6346, Cooperative Extension Service, Oklahoma State University, lp .

Pesticide storage and mixing building, 1979. Plan ' No. MWPS-74002, Midwest Plan Service,

Ames, IA, 4p.

Powers, T.C., Durability of concrete, ACI Publica- tion SP-47, American Concrete Institute, Detroit, 9p.

Rester, Darryl, 1986. Waste water recycling, Paper No. AA86-001, 1986 Joint Technical Session of National Agricultural Aviation Associa- tion and American Society of Agricultural Engineers, Acapulco, Mexico, December, 1986, 11 p.

Noyes, R. T., 1988. Modular concrete chemical handling pad facility, 1988 NAAA/ASAE Joint Technical Session, Las Vegas, NV, December, 25p.

PESTICIDE0 STORAGE AREA (SECONOARY CONTAINMENT)

F I R E EXTINGUISHER

RINSATE STORAGE

MINIBULK & SVR STORAGE

WORKER SAFETY AREA

LOADING /WASH PAD (SECONOARY CONTAINMENT)

FIGURE 1. SIMPLE SINGLE SUMP CONCRETE PESTICIDE STORAGE/LOADING FACILITY FOR SMALL OPERATORS.

FIGURE 2. SCHEMATIC OF FERTILIZER, PESTICIDE STORAGE, MIXING/LOADING PAD FOR LARGE COMMERCIAL OPERATORS.

Protective Coatings and Joint Sealants for Concrete in Pesticide and Fertilizer Facilities

Fred Hazen - Corrosion Control Specialist

Master Builders Technologies Environmental & Corrosion Control Products Division

Cleveland, Ohio

ABSTRACT

Technical considerations for the selection and installa- tion of protective barrier materials for secondary concrete containment structures to meet EPA regulation on the storage and handling of hazardous mater- ials will be reviewed.

INTRODUCTION

Over the last 10 years, under the Resource Conservation and Recovery act (RCRA), the Environmental Protection Agengy's regulations on the storage and treatment of hazardous waste in tank systems have led to major changes and improvements in the use of concrete for vessels and other structures. Since the use of concrete for secondary contain- ment is one of the key elements of the EPS's proposed strategy, the need for improved products and methods to repair, seal, and protect concrete from a widening variety of chemicals has in- creased signigicantly.

This article will review recently developed products and repair methods designed to address the growing range of hazardous materials and chemi- cals wastes, temperatures, and environmental effects which can reduce the ability of concrete

structures to maintain positive containment. Particular atten- tion is paid to ammonium nitrate, phosphoric acid, sul- furic acid, and other acids/ chemicals commonly encountered in the pesticide and fertilizer industry.

Before addressing the topic of protecting and sealing concrete structures, it is pertinent to discuss some of the problems commonly encoun- tered when using concrete as a building material, as well as some of the design and repair techniques for dealing with common causes of its deteriora- tion.

CONCRETE DESIGN STANDARDS/ REFERENCES

With the increasing focus on the design and use of con- crete for secondary containment systems, many owners, archi- tects, engineers and contrac- tors have had to become more familiar with the American Con- crete Institute's "Recommended Practice for Concrete Floors and Slab Construction" (ACI 302), the standard document on floors .

In addition to the in- creased awareness of good concrete floor and structures construction practice, more attention is being focused on

the use of protective linings cir coatings to minimize leaks. Generic classifications and descriptions of protective barrier materials is provided in the American Concrete Insti- tute's "A Guide to the Use of Waterproofing Dampproofing, Protective, and Decorative Barrier Systems for Concrete", ( 1 ) .

Leak detection equipment or methods for below grade sumps or trench systems may also be employed to reduce seepage.

TROUBLESHOOTING CONCRETE REPAIR PROBLEM

This article does not attempt to review the myriad of classifications of concrete damage or deterioration. They are already thoroughly covered in the ACI's Recommended Practice: and a variety or reprint arti- cles. (2) A veritable arsenal of repair materials and techniques have been developed for dealing with all types of concrete damage or deterioration. In fact, there are so many rehabilitation methods available that concrete structures have a unique distinc- tion of rarely being "beyond re- pair".

Sometimes, the cause of deterioration is readily appar- ent. More frequently, however, it is not, and determining the cause of a particular problem may require a skilled specialist and/or an in-depth examination.

A number of the common pro- blems with secondary containment structures and neutralization basins that must be protected ayainst hazardous materials or aggressive chemicals that severely attaclr concrete are:

1. Ruq Holes and Honeycomb:

These are air pockets, either visible or invisible, directly beneath the surface of the concrete. Correct preparation involves shotblasting or sand- blasting the surface to open up those "bug holes1' that are completely visible and enlarg- ing those that can be filled prior to installation of the protective coating or lining. The fill material must be compatible with the protective system vhich is to be in- stalled.

A number of latex-modified portland cement compositions are available for use with certain light-duty linings, however, they require a some- what extended cure time prior to topcoating. For heavy-duty linings, a combination of the resin normally used with the lining system and a thixotropic filler is preferable, applying the compound with a trowel to fill the holes. This filling procedure is particularly important in two situations.

It is good practice to fill the bug holes where the protection is provided by a relatively thin film coating of 30-40 mils or less. The cavi- ties below the thin film coating are potential fracture sites, especially as the size of the cavity increases.

When the lining/coating must be applied in the direct sunlight without the use of a covering for shade.

In either case, bug holes vhich are not completely filled will trap pockets of air. This entrapped air will expand when warmed by the sun or other means forming bubbles or pin- holes in the protective system, and can lead to lining failure.

2. Cracks in Concrete - Active or Dormant: The causes of cracks in large concrete structures include poor struc- tural design, overloading, excessive shrinkage, alkali- aggregate expansion and low strength concrete.

The pattern or the crack- ing, its location, the depth and width of the cracks, the presence of foreign material on the cracked surfaces and differences in elevation between two conti- guous cracked concrete masses are factors that help determine the causes of crack formation.

In most cases, cracks must be considered active when their cause cannot be determined. Cracks that appear and continue to develop after the concrete has hardened are also considered active.

Cracking can be considered dormant when it is caused by a factor that is not expected to occur again. This category in- cludes plastic cracks, cracks resulting from temporary over- loading (such as from the move- ment of a piece of machinery over a slab), and random cracks caused by improper timing of concrete sawing operation. A dormant crack usually can be permanently repaired after the full extent of cracking has occurred.

Large concrete containment structures have been known to crack, usually before the lining has been installed, but often after the lining is in place. The cracks open and close during temperature changes, thus straining or cracking the lining.

CONCRETE REPAIR TECHNIQUES

Some of the techniques and

methods that have been used successfully to repair cracks in concrete structures include:

1. Epoxy injection qrout- ing: This is a method of re- pairing cracks by injection grouting of an epoxy resin, as shown in Figure 1. (3) Prior to installation of the coating or lining, this method can be successful for repairing cracks, provided the cracks are non-moving. If the cracking is from settling or loading that can continue to stress the structure, cracks may reoccur elsewhere.

2. Routinq and sealinq: As illustrated in Figure 2, the crack is routed out to a groove 1 inch in depth by at least 1/2 inch in width for the length of the crack. The lining is applied into the groove and the remaining space filled with a flexible sealant. This techni- que can be successful only as long as the sealant resists the elements and chemicals.

3. Fiberqlass cloth tape: Narrow, short cracks in areas

with little temperature varia- tion can usually be covered with a layer of fiberglass cloth tape before lining. This method is shown in Figure 3.

4. Elastomeric "slip sheet": This method, illus- trated in Figure 4, is used in concrete vessels and concrete neutralization basins involving immersion service conditions. Large cracks or joints in the structure that are expected to move are bridged with fiber- glass that is disbonded over the elastomeric strip, 1 or 2 inches on each side of the crack and then lined, as shown in Figure 5.

This method provides two basic functions: it reduces the stress-straining of the linins when cracks or joints in the concrete structure open and close during temperature changes, and it eliminates exposure of the joint sealant to immersion ser- vice conditions.

Figure 6 shows an installa- tion of a monolithic reinforced lining with the elastomeric expansion joint beneath the lin- ing system.

WATER LEAKS

It is often difficult to stop water from flowing or seeping through concrete into a concrete vessel or structure. One successful method is to groove out tlie wet area to a depth of an inch or more and then fill the groove with a very fast hardening cement.

For stubborn leaks, it may be necessary to drill a well or excavate and pump water until the wall dries. After the lining has been properly bonded to the dry concrete, it should hold back water pressure.

Other important factors to consider during the design, con- struction or rehabilitation of concrete containment structures that will have protective coat- ings or linings are as follows:

1. Vapor barrier: Although vapor barriers are not always required for slabs on grade or below grade, thick asphalt vapor barriers and other materials are effective in pre- venting moisture from migrating through a slab. These vagor barriers must be lapped and sealed and carried over the edge of the footings (see Figure 7).

A barrier beneath an existing slab to be repaired may influence the type of repair product and lining system to be used. If a signi- ficant amount of water is trapped in the concrete, it could cause problems during or after application of the lin- ing. This concern with water entrapment is why general in- dustry standards call for a minimum of 28 days curing of new concrete prior to lining.

2. Drainaqe bed: Correctly designed floors shoul-d be placed on a bed of gravel or sand, rather than directly on soil, particularly clay. This minimizes the capillary flow of water from the soil through the concrete.

3. Existinq slab condi- tion: Concrete exposed to caustic soda or other chemicals while in service may be satu- rated, contaminating the soil underneath the slab. Moisture passing through the slab by capillary action may carry contaminants with it to a pre- pared surface. Evaluation of previous service and core drill tests on an existing contamin- ated slab may indicate the con- crete should be replaced.

Old concrete may present a variety of surfaces, ranging from a smooth, dense finish to a rough surface with a consi- derable amount of exposed aggregate. The concrete also may be contaminated with oils, grease, tar, or other chami- cals. Figure 8 shows severe degradation of concrete from spillage of 98% sulfuric acid around chemical pumps. Figure 9 shows the same area after the concrete was repaired, and a reinforced lining system

resistant to concentrated acid was installed.

The importance of good construction practice in the design, preparation, and repair of concrete is essential. Quality concrete and substrate conditions are critical to the successful application and pre- formance of protective coatings and linings in concrete secon- dary containment structures.

SELECTION OF PROTECTIVE COATINGS & JOINT SEALANTS

The selection and service life performance of coatings for protection and sealing of con- crete exposed to agricultural fertilizer chemicals involves several important factors. The four major factors that dictate product selection and installa- tion are: 1. Chemical exposure 2. Type of exposure 3. Compatibility with the sub-

strate 4. Application conditions

Chemicals Exposure

In selecting a coating or joint sealant for a specific environment, the most important consideration is the product's chemical resistance. Selection is simplified if the specifier has field history reports of previous exposures in similar environments. If information pertaining to field service is non-existant, the specifier must rely on field or laboratory test- ing.

A very high percentage of chemical exposures in pesticide and fertilizer containment appli- cations can be handled by poly- ester, vinyl ester, epoxy or novolac epoxy resins.

Table 1 provides a brief list of common definitions on thermosetting resin coating and lining systems. Table 2 pro- vides generic descriptions of reinforced and unreinforced epoxy, epoxy novolac, and poly- ester resin coating systems and joint sealants offering ex- cellent resistance to the various agricultural fertilizer chemicals and concentrations listed. The glass filled (re- inforced) coating systems offer the resistance to high chemical concentrations and permeation resistance to meet EPA regula- tions on maintaining positive containment. (4) The unrein- forced coatings listed provide good resistance to the lower concentrations of chemicals shown.

Current market trends and uses are toward high build 100% solids solvent free coatings to meet EPA (Volatile Organic Com- ponents) V.O.C. regulations and to achieve higher service life performance. The epoxy, epoxy novolac, and polyester resin coating systems described are being widely used for chemical secondary containment and other concrete protection applica- tions due to superior chemical resistance and high build, solvent free applications. Bitumious paints, mastics, and enamels such as asphalt or coal tar coatings used in past years are finding less acceptance and use due to concern with V.O.C. regulations and poor resistance to aggressive chemicals.

Type of Exposure

In situations where two different coating/lining sys- tems both appear to offer successful protection, a selec- tion can often be made after

considering the effects of the corrosion rate of the solution being contained, temperature, traffic or abrasion, other ser- vice conditions, and the desired service life of the material. For example, if a system looks successful at a film thickness of 15-40 mils, but the corrosion rate is excessive, the preferred system would be a heavy duty system for the long term, even though the other is more econo- mical in the short term.

Table 3 provides descrip- tions of aggregate fillers that can be used with protective coat- ings in traffic areas to improve wear resistance and to achieve a non-skid finish. Selections of aggregate fillers to be used de- pends on the chemical and traffic exposure conditions, i.e., light, medium, or heavy.

Traffic and potential mech- anical abuse service conditions have a direct bearing on the expected service life performance and annual spot maintenance re- quirements. Table 4 provides a listing of typical coating appli- cations in various areas of plant facilities. Non-skid aggregates are not generally required in secondary containment or other areas exposed to light foot traffic. Use of heavy agyre~ates in coatings on loading areas or truck weight scale areas will improve the wear resistance and service life performance of the protective barrier system.

Compatibility With The Substrate

Proper preparation of the concrete for coating is the single most important factor on the service life performance of the protective coating systems after selection of products to meet the described service

conditions. The importance of proper concrete preparation to remove contaminates and weak concrete to achieve a strong bond of coating system is strongly enphasized. Improper surface preparation is the leading cause of failure or short service life cycles of protective coatings applied to concrete.

Many people continue to recommend acid etching as a method of cleaning and pro- filing concrete substrates. Acid etching can be effective, if done properly, for preparing new concrete floors for appli- cation of protective coatings. Acid etching however is not always a desirable or effective method for cleaning and pro- filing vertical surfaces (walls) or old concrete sur- faces that have been contamin- ated with chemicals, oils, and grease. Other disadvantages of acid etching are: safety of the workers using it, particu- larly for cleaning vertical surfaces, is of concern; dis- posal of the spent acid could be a problem environmentally; and acid salt contamination of the concrete surface with improper use could cause coat- ing to fail through disbond- ment.

Surface profile or anchor pattern is a major factor of importance on obtaining mech- anical bond (adhesion) of the protective coating to the con- crete. This profile can be accomplished using a myriad of mechanical methods. Scarify- ing, abrasive blasting, water blasting, shot blasting, and planning are only a few of these methods.

Abrasive "brush-off" or

sweep blasting and shot blasting have become the most accepted methods of preparing concrete surfaces for protective coatings. Mechanical methods are generally more desirable and effective for achieving the dual objective of cleaning and profiling concrete substrates to be coated. Chemical cleaning, such as acid etching, depending on the circumstances and factors as descriSed above, is also used. (5)

Application Conditions

All of the products listed in Table 2 are two-package sys- tems consisting of resins and curing agents since they offer the best resistance to the chemi- cals encountered. Single package coatings or paints are generally inferior and offer very poor resistance to the chemicals listed.

It is best to follow the coating manufacturer's recommen- dations on mixing and application of products. Field service assistance is available and should be requested from coatiny manufacturers on initial field applications of products until field people obtain suitable training.

A few practical do and don't tips on coating applications based on field experiences are:

Apply coatings in cool mornings or evenings or shade worlc area in hot summer months.

Check the moisture in the concrete to determine potential for ground water vapor pressure transmission by conducting a rubber mat or a polyethylene cover test.

Xix the coating thoroughly in accordance vith the manufac- turer's instructions and apply immediately after mixing.

Schedule coating applica- tion work on sunny days vith no clouds or exi2ected rain.

Call coating manufacturer in for field service assistance on initial product applica- tions.

DON ' T

Don't apply the coating in direct sunlight in hot summer months since the surface tem- perature of the concrete can reach or exceed 130 def.F. The general accepted temperature range for coating application is 50 deg.F to 100 deg.F.

Do not apply the coating over wet or damp concrete or where there is an expected problem with ground water in- trusion.

Do not mix the coating without proper instructions or Let materials set very long after mixing.

Don't schedule coating a2plication work on cloudy days with expected rain.

Don't fail to call manu- facturer to review product application instructions or to provide field assistance.

LONG-TERM SUCCESS

Coating concrete success- fully demands attention to many details of design, surface pre- paration, repair, application and inspection. The lcng-term performance of grotective coat- ings and joint sealants is

directly related to the condition and the degree of surface prepar- ation of the concrete. The better the concrete and its sur- face preparation, the better the bond will be between the protec- tive system and the concrete.

REFERENCES

(1) American Concrete Institute, ACI 515, IR-79 (revised 1985), "A Guide to the Use of Waterproof- ing, Dampproofing, Protective, and Decorative Barrier Systems for Concrete".

(2) A collection of articles reprinted from Concrete Construc- tion have appeared in the follow- ing publications: Concrete Floor Construction. Trobleshootinq Concrete Fltwork and Pavinq Problems. Repair of Concrete. Concrete Repair Techniques.

( 3 ) R.W. Gaul and E.D. Smith, "~ffective and Practical Struc- tural Repair of Cracked Con- crete," American Concrete Institute Publication SP-21, "Epoxies With Concrete".

(4) F.E. Hazen, "Concrete Advice About Containing Leaks and Spills", Chemical Enqineerinq Froqress, August 1991, pages 75-80.

(5) R.A. Nixon and R.H. DeWolf, "Repairing and Protecting Con- crete Floors in Industrial Facilities: An Owner's Guide For Avoiding Resinous Floor Topping Failures", Protective Coatinqs for Floorinq and Concrete Sur- faces Proceedinqs from SSPC91' Conference, Long Beach, Nov. 10-15, 1991, pages 125-150.

K Figlrre I . 14'orker rrses portablc irljec- ti011 grorttirlg prrrrlp to repair cracks.

................ FLOOR SISW.3

? . ' . . SAW CUT . . -. 114" ..

- -

K Figure 2. Tyl~ical concrete s~tDstr(rre arld

.. RElf<TSCED UNlNG SYS'(l3.t

. . ,.VlrlYL TAPE AS BOND 8liEAqfi . . . . . . . . '. -. : >5 ' -

Pi(EP3RUEC RUBBER ...... ......

;;.. :. ........ ........ '. .. 'EXWSION JOIV

....... f ' .. \ . . . . . . . . BONDINS mHCsr:: ... . . . . . . . . . . . . - - - . - . . - - - . - I : - - -- - - - - -

I Figure 3. Fiberglass cloth tape is irzstalled between tlte corlcrete surface and the floor topping sysiern.

E Figure 4. Typical concrete vessel sltrface cross sectioil illus- trates exparlsior~ arzd coiltraction tllcrt materials of constrlrctior~ need to accommodate.

t: Figure 5. A worker sprcrys u protec- t i ~ , e ,coatirlg on a slip sheet.

B Fig l~rc 8. P u n i p i ~ ~ g stntior~ bcforc repair of old co~icrcle.

TABLE 1 . DEFINITIONS

Film Thickness: Thin film 5-15 - Mils; Thick Film: 40-60 Mils; Beavy Duty; 125-160+ Mils.

Coatinq: Briefly stated, protec- tive coatings are mixtures of liquid thermosetting resins and inert fillers, usually reinforced with flake fillers, glass or syn- thetic fibers.

Thermosettinq Resin: A synthe- tic resin used for the purposes in liquid form which hardens at normal temperatures, after addi- tion of a catalyst or curing agent. After hardening, it will not melt.

Reinforcement: Materials used to lend strength to the resin of the coating system.

Filler: Materials used in power form which are chemically stable or inert. These materials are added to the resin to reduce thermal expansion, stress con- centration, permeability, build thickness and aid in application.

Curinq Ayent: A chemical which either initiates the polymeriza- tion of a thermosetting resin or enters into a cross-linking reac- tion with the resin to solidify it.

Coatings and Joint Sealants for Concrete Secondary Containment Structures in

Agricultural Fertilizer Chemical Plants

Type and Concentration Description of Descriptions of of Chemical Coatinys Joint Sealants

Ammonium Nitrate 2 876

Sulfuric Acid 10% - 98%

1. 100% solids glass 1. Polysulfide flake filled epoxy rubber joint coating, total sealant. i6 mils dry film thickness in 3 coats includiny concrete primer.

2. 100% solids unrein- 2. Urethane forced epoxy coat- mastic joint ing, total thick- sealant. ness of 12-15 mils in 3 coats including primer.

3. 58% solids epoxy sur- face sealer (clear) in 2 coats, 3-5 mils total thiclcness.

1. 100% solids glass 1. Urethane flake epoxy novolac mastic joint coating, total 40 sealant up to mils dry film 75%. thickness in 3 coats including primer.

2. 10076 solids glass 2. Silicone or flake filled poly- urethane ester resin coat- rubber joint iny, total 18-20 sealant up to mils dry film thick- 75%. ness in 3 coats including primer.

3. 100% solids unrein- * For concen- forced epoxy coating, tration above total thickness of 7576, contact 12-15 mils in 3 material coats including manufacturer. primer.

TABLE 2 (continued)

Phosphoric Acid 20% - 85% 1. 100% solids glass 1.

filled epoxy novolac coating, total 40 mils dry film thick- ness in 3 coats including primer

2. 10076 solids glass 2. flake filled poly- ester resin coat- ing total 18-20 dry film thickness in 3 coats includ- ing primer.

3. 100% solids unrein- forced epoxy coating, total thickness of 12-15 mils in 3 coats including primer.

Urethane mastic polysulfide, silicone, and urethane joint seal- ants up to 2876.

For concen- trations above 2576, contact material mfg.

4. 58% solids epoxy sur- face sealer (clear) in 2 coats, 3-5 mils total thickness.

NOTES ON ABOVE:

1. 1 is best choice, 2 is next best, 3, 4 next best depending on chemical concentrations.

2. For aggregate fillers for non-skid wear course with above coatings see Table 2.

TABLE 3

Aggregate Fillers That Can Be Used With Protective Coatings By Broadcast Method To Improve Wear Resistance

And To Achieve Non-Skid Finish In Traffic Areas

Type & Description of Aqqreqate Fillers

1. Aluminum Oxide Grit 36 mesh

2. Trap Rock #9 coarse aggregate

3. Silica sand 20 - 40 mesh 50 - 70 mesh

Method of Application and Lbs./Sq.Ft.

Incorporate non-skid aggregate fillers into first coat while coating is still tacky by broadcast sprinkle method. Apply 2nd & final coat over the aggregate to achieve - lbs./sq.ft.

Slight non-skid .10 - .25 heavy non-skid .25 - .75 dense packing .75 - 1.0 for thick build-up.

NOTES ON ABOVE:

1. No. 1 and No. 2 are best choices for high concentrations of strong chemicals that attack silica fillers.

2. Common silica sand is economic choice for lower chemical concen- trations and light to medium traffic conditions.

3. Heavy or dense packing of aggregate fillers suggested for heavy traffic areas.

4. Above aggregates packed in 50 lb. bags available from material manufacturers or local building construction distributors.

TABLE 4

Typical Coating Product Applications in Agricultural Fertilizer Chemical Plants

1. Secondary containment structures Storage of chemicals, Light foot traffic only

2. Truck Weight Scales Medium to heavy traffic

3. Warehouse Truck Dock and Ramps Heavy traffic.

Coatinq System

1. Glass flake reinforced or unreinforced coatings. See Table 1 for selections of coatings based on chemical concentrations.

2. Glass flake reinforced or unreinforced coatings with heavy to dense pack aggregate fillers for improved traffic/ wear resistance. See Table 1 S, 2.

3. Same as above.

CONTAINMENT OF FERTILIZERS AND PESTICIDES AT RETAIL OPERATIONS

Michael F. Broder, PE National Fertilizer and Environmental Research Center

Tennessee Valley Authority

Abstract Retail fertilizer and pesticide dealers across the

United States are installing secondary containment at their facilities or are seriously considering it. Much of this work is i n response to new state regulations; however, many dealers not facing new regulations are upgradingtheir facilities to reduce their liability, lower their insurance costs, or comply with anticipated regu- lations. The National Fertilizer and Environmental Research Center (NFERC) has assisted dealers in 22 states in retrofitting containment to their facilities. Simultaneous improvements i n the operational effi- ciency of the facilities has been achieved at many of the sites. This paper is based on experience gained in that work and details the rationale used in planning sec- ondory containment and facility modifications.

Introduction As a result of the Clean Water Act of 1987 and

subsequent regulations enacted or under develop- ment by states, the majority of fertilizer and pesticide dealers across the nation will be required to install or improve secondary containment a t their facilities. At present only nine states have secondary containment regulations effecting fertilizer and pesticide dealers. Several other states are a t various stages in develop- ing their own regulations. Even in the remaining states where no regulations are being considered, dealers are becoming increasingly concerned about their liability for both existing and potential soil and water contamination resulting from their operations.

Sources of Groundwater Contamination Groundwater is precipitation that 'soaks in,'

filtering down through many layers of soil and rock rather than running off into streams. More than half of the U.S. population-and 90% of rural America- depends on groundwater from aquifers for their drinking water.

Groundwater is never 100% pure. I t picks up minerals as i t moves through the soil. Problems develop when additional materials get into groundwater.

Sources of groundwater contamination can be grouped under three headings: (1) water supplies, (2) transfer areas, and (3) storage areas.

Many dealer facilities are serviced by an on-site well. Awellhead that is poorly designed or has a faulty casing can allow contaminants to move directly into the groundwater. Connections to p~iblic water supplies must be designed to prevent material from back- siphoning into the water system.

Transfer areas are places where fertilizers andlor pesticides are loaded, unloaded, or transferred to and from the mixer. Any spills a t such locations likely will find their way into groundwater if not properly contained. Both dry and fluid products are potential contaminants.

T h e mobility of n i t r a t e in wa te r makes groundwater especially susceptible to leaching of any nitrogen fertilizer. Nitrate in groundwater has been linked to spills of dry fertilizers a t many dealer locations.

Storage areas are potential sources ofgroundwater contamination. Tanks can rupture. Pipes can burst or rupture where they join the tank. Spills can be slow leaks or massive discharges. Either way, spills contaminate surface water or groundwater unless good containment measures are in place.

Sometimes nitrogen fertilizer stored in buildings in low-lying areas gets into surface water during heavy storms. Most storage areas today are not built in flood-prone areas; however, many existing sites are less than ideal from an environmental standpoint.

Selecting a Plant Site Environmental considerations shouldhave high

priority when selecting a new site or planning modifi- cations to an existing facility.

Fertilizer and pesticide handling facilities should be as far from private wells or surface water supplies as possible. By all means, the well should not be downgrade from a plant handling fertilizers or pesti- cides.

Flood plain sites and locations with a shallow groundwater depth should be avoided. Sites should have adequate soil bearing capacity to support the loads of buildings, storage areas and vehicle traffic.

The topography and drainage patterns should be studied to determine surface water movement onto

Prepared for the National Symposium on Pesticide and Fertilizer Containment: Design and Management, February 3-5, 1992, Western Crown Center, Kansas City, Missouri

-88-

and from the site. For example, a loading pad should not be in the path of runoff.

Also, since fertilizer mixing and handling opera- tions generate airborne materials i t would be smart to locate away from heavily populated areas, or a t least downwind. Where urban sprawl has approached or encircled a plant, a dealer may want to consider relocating to a more remote area before making the investment required for a major environmental up- grade of a facility.

When relocating a facility, or part of a facility, it is important to know the extent of contamir!ation from past practices. Contaminated soil should be tested to determine if remediation (clean-up) is feasible. If con- taminants are types that break down in a reasonable time, a structure that prevents further downward movement of water may be desirable. Contaminants that do not break down readily should not be hidden under a structure; future clean-up costs could be insurmountable. Long-term salability of the property should be considered in weighing alternatives. Also, someone experienced in remediation of contaminated sites should be consulted.

Containment Is 'No Pollution' Containment is keeping pesticides and fertilizers

where they are supposed to be. Storagevesselsprovide primary containment. Secondary containment is 'backup' protection against failures of primary vessels and against leaks and spills.

Many people think only of dikes when someone mentions secondary containment. And dikes are a key to containment around fluid storage tanks. But deal- ers in states with good groundwater protection laws know that containment is more than capturing cata- strophic spills from a tank failure. Tanks rarely fail. Contamination is much more apt to occur from spills during product loading and unloading.

Dealers often need to install several kinds to containment measures to be in position to avoid or resolve environmental and legal problems.

Wellhead Protection Dealers should inspect their water source to make

sure the facility is environn~entally secure. In some areas, poorly designed wells and water connections are the main causes of groundwater contamination. If an onsite well is used, the wellhead should be checked. The concrete pad or clay fill should be elevated to force surface water to drain away from the well. Runoffthat ponds a t or near the wellhead can easily get into the well by seeping around the well casing or through a crack in the casing. Because of this risk, some states

now specify a minimum distance between the well and new fertilizerlpesticide handlingfacilities, usually 200 or more feet. Such regulations were implemented by Iowa in 1988 and by Illinois and South Dakota in 1989 (4, 2, 3).

Most states no longer allow installation of frost pits. Dealers having a wellhead in a frost pit should consider extending the casing above the level of the surrounding soil. As a minimum, the pit should be watertight so that no contaminants can get in. Local officials should be contacted regarding requirements for private wells.

Abandoned or rarely used wells can be found on many dealer sites. These should be retired and sealed, which usually requires a permit. The Extension Ser- vice or Public Health office should be contacted for inforr lation regarding well closures.

Water System Protection All connections to the water supply system should

be inspected to ensure that fertilizers and pesticides cannot enter by back-siphoning. This could happen a t the water inlet to the mix tank or where vehicles are filled through a bottom connection. Even hoses submerged in a pool ofliquid can back-siphon material if the system loses pressure.

Standard methods for preventing back-siphoning are to use an air break tank or a reduced pressure principle zone (RPZ) valve.

An air break tank is merely a water supply tank with a n air space between the pipe outlet supplying the tank and the highest water level attainable in the supply tank. Generally, the distance between the pipe and the maximum water level is twice the pipe diameter. Apump is used to boost pressure if the static pressure in the tank is inadequate.

An RPZ valve is a special device with two independently operating check valves and a pressure differential relief valve between the check valves. When there is a loss of pressure in the water supply, the two check valves close, preventing a reversal of water flow.

An undesirable feature of RPZ valves is that they tend to drop the line pressure by as much as 10 psi. RPZ valves may be regulated by state agencies; if so, their installation must be approved and they will be tested periodically.

Containment At Transfer Operations

Any time a fertilizer or pesticide is moved from one container to another, losses can occur. Until recently, the main concern about spillages during transfer

operations was the value of lost product-did losses 'eat up' profits? Today, the first concern about any such loss-whether from overfilling a nurse tank or spreader truck, or leaks from valves, pump seals and conveyors-must be its environmental impact.

Transfer losses can contaminate soil. They also can contaminate groundwater. Thus, containment for loading and mixing areas has top priority in many state regulations (2, 3,4).

Since i t will be impossible to avoid all spills, provisions must be made to capture spilled material before i t escapes to the environment. Loading areas shouldbedesigned to contain any nutrients or pesticides lost while loading tenders, spreaders, nurse equipment and sprayers.

Concrete pads for loading areas should facilitate collection of spilled materials. Main design features to consider are liquid holding capacity, pad length and width, slope, sump location, sump design and solids collection system.

Equipment often is washed on load pads. Pads used to wash dirt and residues from field equipment should be large enough to catch all the wash water. They also should have a good solids removal system, particularly if the rinsate is to be re-used in making fluid fertilizers.

Most dealers use the same pads for loading operations and for washing equipment. The following discussion applies to pads designed for both uses.

Pad Capacity Load pads should have the capacity to hold the

contents of the largest tank to be loaded. Apad used to load large transports should be capable of retaining the entire load, typically 4,000 gallons. Illinois (2) and South Dakota (3) recently established such criteria. Wisconsin requires that pads used to load fluid fertilizers have a capacity of a t least 1,500 gallons (5).

Requirements generally are less stringent for unloading pads. South Dakota (3) does not require a pad for unloading raw materials a t the dealer site. Illinois (2) requires that load-in pads have avolume of a t least 25 gallons.

Load-in pads should be provided since incidental spills are common during unloading operations. Also, the same pad often is used for both load-in and load- out; in this case, the volume required for load-out will prevail.

Providing the necessary volume on a pad designed to accommodate only onevehicle can be difficult. Figure 1 shows such a pad. Note that to hold 4,000 gallons, it is 12 feet wide by 60 feet long, and is 2.2 feet lower a t the sump if all edges are a t the same elevation and all slope to the sump. If the pad had a 12-foot-long trough in the center (Figure 2), the top edge of the trough would be 1.5 feet below the height of the edges.

A bigger pad will provide the necessary volume with shallower walls. However, a bigger pad collects more rainfall. The pad in Figure 1 can hold 9 inches of rain. If the pad was built twice as wide, the walls would need to be only half as high to provide the same volume. With the larger surface, however, the bigger pad would accumulate more gallons of rain and be more likely to overflow in the event of a heavy rain.

Rainfall can be discharged safely from the pad only if the pad is clean. Otherwise, i t must be handled as a dilute fertilizer or pesticide mixture. Building a roof over the loading pad should be considered, especially in areas of high rainfall.

One way to increase pad volume is to form a roll- over curb (one that vehicles can cross easily) on the perimeter. Adding a 4-inch-high roll-over curb to the pad in Figure 1 increases its volume by 45% (see calculations under Figure 1).

Illinois and Wisconsin permit the volume requirement to be met by using an automatic sump pump connected to a storage tank (2, 5). A more reliable approach is to provide for overflow to another basin. This is done most easily by locating the load-out pad a t a higher elevation than the secondary containment dike.

Buried tanks or pits should not be used to store liquid from loading pads. Any such systems should be removed or retired; this involves a thorough cleaning, sealing all inlets, and filling with sand or clay. Some states, including Illinois (2), South Dakota (3) and Wisconsin (5), permit temporary storage ofsuchliquids. Long term storage in pits or wells generally is prohibited, a t least without an approved groundwater monitoring system.

Pad Width and Length The size of the pad should be based on the work i t

is to accommodate. A pad for equipment washing should be a t least 20 feet wide. If the pad is to be used for both loading and unloading, i t should be wide or long enough to accommodate two vehicles. Dealers handling both fluid fertilizers and pesticides may need extra space for loading or unloading mini-bulk containers. Space also must be provided for tanks holding rinsates since they often are stored on the loading pad. Load pads 40 x 60 feet are common.

Padsfor loading dry fertilizers mustbe wide enough to catch all materials spillingover the sides ofspreaders or tenders. Padsgenerally shouldextend 10feetbeyond each side of the vehicles being loaded. The edges ofthe pad should be about 4 inches above the center. Pads for dry materials have no volume requirement. If kept clean, a lockable drain can be used to discharge rain or snow melt. As with fluid operations, contaminated rainfall must be handled as a dilute fertilizerlpesticide

Liquid Holding Capacity in Gallons LHC = 7.5 x L x W x D

3 Where,

By adding a 4" high rollover curb around the pad L = pad length in feet the LHC is increased by 7800 gallons. W = pad width in feet LHC of the curb is computed as follows: D = depth at sump inlet in feet LHC = 7.5 x L x W x CH 7.5 = gallons per cubic feet where.

LHC = 7.5 x 60 x 12 x 2.2 CH = curb height in feet 3 LHC = 7.5 x 60 x 12 x 0.33

= 3960 gallons excluding sump LHC = 1800 gallons

Figure 1. Load pad for a single vehicle.

? - -

LP EL 98.5'

SLOPE t

--

HP EL 100.0'

f i e Liquid Holding Capacity for this pad is computed by the equation LHC =7.5 x L x W x D

2

LHC = 7.5 x 60 x 12 x 7.5 2

LHC = 4,050 gallons excluding the trough

Figure 2. Single vehicle load pad with trough.

mixture. A roof over the load pad will avoid problems associated with rainfall.

Spills while filling bins should be collected and kept away from moisture. Some dealers collect spills by placing the boot of portable augers inside a large tray. The most common containment is a concrete pad from which spilled material can be reclaimed easily.

Dry fertilizer spills a t railcar unloading areas are difficult to reclaim. The best way to keep the area around the tracks clean is by sweeping up spilled material. This i s made easy by paving the area, near the conveyor and between and on the outside of the tracks. The inlet to the conveyor should be elevated and a watertight cover used to keep rainfall out. This is important to preserve quality of the dry product. I t also is important to prevent nutrient escape from the conveyor to the ground if the bottom of the conveyor is not sealed.

Paving between the tracks also is a key to loss prevention while unloading railcars offluid fertilizers. The pavement should be sloped to channel any escaped product to a catch basin for checking andlor recovery. Prefabricated pans of reinforced fiberglass are available for installation between or on both sides of the rails to collect spills. The pans have built-in sumps.

Pad Slope Loading pads should have a slope of a t least 2%.

This minimizes corrosive effects of spilled material and facilitates pad wash-down (1). Lesser slopes are more likely to have puddling areas due to errors in finishing the concrete.

Sump Location The best location for the sump will depend on how

it is to be used and how vehicles travel across the pad. If vehicles are to enter from all four sides, the sump should be near the center of the pad. A disadvantage of centering the sump is that i t can interfere with product movement if the sump must be cleaned out or manually pumped out as product is being loaded. It may be better to place the sump near one side of the pad. This way, the pad is still accessible to vehicles from three sides.

Some dealers have a sump in the middle and a deeper sump on one side. The two are connected by a trough or pipe beneath the pad. The sump in the middle ofthe pad traps most solids while liquid goes to and is pumped from the second sump.

Sump Design Sump designs vary according to how or whether

they are used to handle solids. Suspension dealers typically use simple sumps and pump sediment and fluid directly into applicators. On the other hand,

liquid dealers carefully separate solids from liquid being recycled. These dealers use either an extra sump for solids removal or a sediment trap around the sump.

Figure 3 shows a typical concrete sump with a perimeter sediment trap. The sediment trap can be sloped to one side to help concentrate the solids. Sediment traps must be cleaned periodically to keep sediment from overflowing and re-contaminatingliquid in the main sump.

Figure 4 shows a pad with two sumps. A pan can be fabricated to fitbeneath the discharge ofthe higher sump. Solids can be removed by dumping the pan. Collected solids should not be handled like dirt. Where pesticides are involved, careless discarding can kill vegetation. I t often is satisfactory to slurry the solids in a fluid fertilizer or dry the solids and add them to a dry fertilizer; the pesticide-containing fertilizer can then be applied routinely after verifying that crops growing or to be grown on the field are those for which the pesticides in residues are labeled.

Sump Construction Prefabricated sumps can be used to avoid the

labor required to form and pour a concrete sump. Precast concrete sumps are built in a range of sizes and with fittings to accept piping connected to other load pads and operational areas. Concrete sumps usually have a capacity of about 100 gallons.

Stainless steel sumps also are available. They usually are double-walled with ports on top for detecting leaks between the walls. Although they can be fabricated in any size, most have a capacity of about 30 gallons.

The recycling of rinsates a t large facilities may be simpler if all materials are collected in a common sump. Pipe inlets should be above the bottom of the sump so that liquid can be pumped to a level below the inlets. This reduces the chance for liquid to leak into the ground around pipe inlets.

Some dealers prefer a large sump and sediment collection system. This allows more time for solids settling and permits less frequent clean-out. A large sump is not desirable ifpesticides are rinsed or handled on the pad because of the problems associated with contamination. For example, if you switch from corn herbicides to soybean herbicides, i t will be necessary to clean the sump to avoid contaminating soybean make-up water with corn herbicide residues.

The simplest way to avoid unwanted herbicide contamination is to use a small sump and clean it daily or more often. Sumps in areas not protected from rainfall should be kept clean to permit unrestricted discharge of collected rain water.

There are other ways to segregate rinsates. One is to divide the load pad into two or more areas and slope

60' - 58'-8"

- - li 2% 4' SUMP W/SAND TRAP 4

Q

4" SPLASH CURB - . ., . , - . '.'. . r . . : .. ' ' . .

SECTION A -A Figure 3. Load pad with sump

and perimeter sand trap.

. . .'

SUMP DETAIL

60' - C

8" 58'- 8"

Figure 4. Load SECTION A-A pad with two sumps.

This concrete load pad makes it easy to reclaim spills of dry fertilizers.

each section to a different sump. Another is to slope the pad to a wall where multiple drains and valves are used to direct spills and rinsates to appropriate sumps for subsequent pumping to designated storage tanks. This system is ideal where rinsate segregation is critical.

Many problems ofhandling pesticide residues can be avoided by waiting to add pesticides to fertilizer products until the applicator is in the field (away from the fertilizer storage and handling site). Later, the applicator can be rinsed in the field. This practically eliminates the need to segregate rinsates because they normally will not contain pesticides. Other management practices to enhance environmental security are discussed later.

Containment in the Mixing Area Incidental spills are common in the mixing area,

Spills can occur when materials are addedmanually to the mixer. Fluid piping systems and conveyors of dry materials often leak. Environmental security demands containment of such incidental spills.

Liquid Mixing Areas Containment for the liquid mixing area usually

involves installing a curb along one inside wall of the mix house to force the area to drain onto the loading pad. Containment also can be achieved by installing a curb on all four walls,making sure that the containment volume equals the volume of the mix tank.

Figure 5 shows how a curb can be built on an existing slab. Sometimes, dealers place the mixer on

one corner of the load pad. This often is an excellent choice since mixing and loading usually are adjacent operations and both receive all products handled at the facility.

Areas where pesticides are mixed should not be allowed t o drain into the fertilizer containment. Mixing area containment should be large enough t o accommodatemini-bulk containers and other portable pesticide containers not located in a secondary containment dike. If the containment area serves more than one plant operation (storage, load inlout, etc.), i t may be desirable to sub-divide with smaller dikes in order to minimize the area affected by small, incidental spills. For example, spills from a leaking pipe or a hose connection frequently can be contained in a pan or inside a separate curb.

Piping from storage tanks to the mixer and to the load pad also should be contained. At most facilities, these areas are adjacent and the piping always is above a contained area or over the load pad. Pipes used to transfer full strength materials should not be bur- ied underground unless they are inside larger pipes. If double-piped, the pipes should be sloped so that any leaks will flow to one end where they can be detected.

Buried pipes used to transfer rinsate or material collected in sumps to a larger sump need not be placed in a larger pipe.

Dry Mixing Areas Dry mixing of fertilizers is best done under roof.

Some dealers get weather protection by extending the roof of a fertilizer storage building so it will cover the

This is a large load-out pad for liquid fertilizerlpesticide mixes.

This prefabricated stainless steel sump is double-walled and has leak detection ports.

' 3 # 4 REBAR SET /N #4 REBAR c(P 12"O.C.-' J EPOXY 10" INTO

EXIST CONCRE LE JOINT SEALANT

RECIEM DOWEL

Figure 5. New curb on existing concrete.

blender andload-out conveyor. Other dealerskeep the blender inside the storage building and build a con- crete pad to collect material falling from the conveyor or spilling over the sides of spreaders and tenders.

Blendina Towers Systems having a cluster hopper, weigh hopper,

and blender stacked vertically in a tower-should be enclosed and have a roof over the loading area. The pad beneath the tower should be large enough to catch material spilling over the sides of spreaders and tenders as well as leaks in the blending system.

Facilities where dry fertilizers are impregnated withherbicidesmusthave containment for pesticides. Spills must be confined to prevent pesticide loss and contamination of fertilizer raw materials. Impregnation and load-out should be done under roof; otherwise, rainfall contacting pesticide residues in the blender or conveying system must be collected and handled as a dilutepesticide/fertilizermixture. Spilled materials and product cleaned from the blender should be stored inside and added in small proportions to otherblends. This will dilute pesticide residues enough to allow them to be applied to land without exceeding labeled rates. Any water that is used t o clean the blender must be handled and disposed of as a dilute pesticide.

Dealers without liquid application equipment may not want to use water for blender decontamination. Limestone or potash can be used to purge the system of pesticides, provided it is applied to a crop for which the pesticides in residues are labeled. The Federal Insecticide, Fungicide and Rodenticide Act prohibits the application of pesticides (including those in residues) in excess of labeled recommendations.

Containment in the Storage Area The major difference in secondary containment

for fertilizers and pesticides is the construction material. Dikes lined with clay or synthetic materials are satisfactory for secondary containment of fertilizers, but are not allowed for pesticides (2). Dry fertilizer containment involves storing material in a building that has a roof, walls, and floor that prevent fertilizer from coming in contact with precipitation or surface water.

Liquid Fertilizer Containment Secondary containment for liquid fertilizer consists

of a basin with a floor and walls that are essentially impervious to liquids. The basin usually is sloped t o a sump where the liquid can be pumped from the basin. Volume of the secondary containment, excluding the space taken up by tanks, must be 10 t o 25% greater than thevolume of the largest tankin the containment

(3, 4, 5, 6). Illinois requires that the secondary containment be sized to hold 6 inches of rain in addition t o the contents of the largest tank (2).

Most states do not allow in-ground pitsfor primary containment of fertilizers or pesticides. If allowed, the pits will be regulated as underground storage tanks and must be double-lined and have a means to check leaks in the primary liner.

In-ground systems are well suited for secondary containment (discussed later). Contact local regulatory officials about this use of in-ground pits.

In secondary containment systems, piping runs should be over, NOT through, the containment wall. If piping must pass through the containment wall, a watertight seal should be made between the pipe and the wall. The structural integrity of the wall must not be compromised and the containment volume must not be reduced.

Rain accumulation should be pumped out with a manually controlled pump. Any drains should have lockable valves and be strictly managed to prevent inadvertent release offertilizer (3). Some states prohibit the use of drains (2,4).

Sight gages used to monitor liquid levels in tanks are a liability. A damaged or broken gage will release contents of the tank. Sight gages should be used only if a stainless steel valve, which is normally closed, is installed between the bottom ofthc gage and the tank.

The most difficult aspect of retrofitting secondary containment a t a facility is selecting dimensions that will conserve space without interfering with vehicle and employee access t o the tanks.

Tank Clusters Typical facilities have one or more clusters of

tanks. If possible, tanks should be grouped in one cluster. With a larger grouping, containment wall height will be minimized since containment volume is based on only one tank-the largest one. Putting tanks close together will minimize floor area, but add to wall height and create problems of access.

In general, 48 inches is the highest practical wall height.

Figuring secondary containment dimensions requires determining the volume of the biggest tank (converting gallons to cubic feet by dividing by 7.5), adding a 10 to 25% margin of safety (freeboard factor), determining the volume displaced by other tanks in the containment, and selecting the combination of length, height and width thatbest supplies the required cubic footage. For example:

Assume: Four 25,000-gallon tanks Each is 12 feet in diameter and 29 feet high Containment floor is 20 x 60 feet Containment volume must be 110% of the largest tank

Formula: RV = LTV x FF / 7.5

where RV = Required volume LTV = Largest tank volume

F F = Freeboard factor (1.1 for 110%; 1.25 for 125%) 7.5 = gallons per cubic foot

Calculation: RV = 25,000 gal x 1.1 / 7.5 gaVcu ft RV = 3,667 cubic feet

Next, i t is necessary to determine the Net Contain- ment Area (NCA), in square feet:

NCA = Total area - tank area NCA = (20 x 60) - (3 x 113) NCA = 1,200 - 339 = 861 square f t

Note: Only the area for three tanks is subtracted; spilled liquid will still occupy space in the leaking tank.

Now, wall height (WH) is calculated: WH = RVINCA WH = 3,667 I861 WH = 4.3 feet, or 52 inches

Because this i s higher than preferred, you may want to increase width or length of the containment- if space permits.

Tanks should be anchored to keep them from floating in case of a spill when they are empty. A floating tank can collide with and damage plumbing and other tanks, causing additional spills.

Anchorina Tanks The simplest way to anchor tanks is to weld three

or more brackets to the tank where the sides meet the floor. Each bracket is then bolted to the concrete with anchoring bolts. Chains and tie-down cables can be used with brackets welded above the tank bottom.

In clay-lined earthen dikes, weights can be added to the tanks or cables can be used to secure the tank to anchors outside the dike. Anchors in the soil beneath the liner or cables connected to concrete deadmen can be used if the area where the liner is penetrated is properly sealed.

Neglecting to anchor t a n k s in secondary containments presents a much greater hazard than one might guess. A typical carbon steel tank 12 feet in

diameter and29 feethigh weighs about 13,000pounds when empty. One inch of ammonium polyphosphate solution in the tank weighs 825 pounds; 16 inches of the fertilizer weighs 13,000 pounds, the same as the empty tank.

Thus, an empty, unanchored tank will float any time i t is surrounded by more than 16 inches of ammonium polyphosphate. A 36-inch-high containment wall filled with the fertilizer would 'push' upward with a buoyancy force equal to 20 inches of solution in the tank, or 16,500 pounds.

Stainless steel tanks weigh slightly less than those made with carbon steel. Fiberglass tanks of the same size are much lighter, and thus will float with much smaller spills.

Leveling Tank leveling can be a problem since concrete

containment floors usually have a slope of a t least 2% to minimize corrosive effects of fertilizer on the floor and to ensure proper drainage. The simplest way to level a tank is to place i t in a metal ring filled with coarse, washed gravel. In addition to making leveling easy, the ring provides a space for detecting leaks and keeps moisture away from the tank bottom, thus reducing corrosion.

One problem with gravel is the difficulty in cleaning i t after a spill. Rainwater quality can be affected by the gravel long after the spill is recovered.

Another way to get tanks level is to pour raised concrete pads beneath each tank. This is done most easily by pouring tank foundations first, then making a second pour for the space between the tanks. However, this is not the preferred method because of the sealing required around tank foundations.

The best method is to make the sloped and level surfaces in one pour. The second best method is to pour the bottom of the pad first and then use dowels to attach the tank foundations, which are made in a second pour.

Many dealers have had success using level secondary containment floors and placing tanks directly on the floor. The key is to keep the floor dry and free of fertilizer.

Reinforced concrete i s t h e most common construction material for secondary containment. Major considerations are that the walls and floor be strong enough to support the gravity loads of the tank and the hydrostatic loads of a massive spill, with a minimum of cracking. I t is very important to provide a watertight seal between the floor and wall connection.

Figure 6 shows a typical concrete containment floor and wall construction. Figure 7 shows a containment wall on afloatingslab. Floating slabs are common in colder areas where frost depths are such that deep footings are required.

Figure 8 shows a typical secondary containment with tank foundations and anchors (7).

Dealers not knowledgeable in watertight concrete construction should secure the services of a n experienced contractor. Recommended concrete specifications are given in another section.

Concrete blocks can be used for secondary containment walls. However, they must be reinforced with steel and filled with concrete to withstand expected loads. Also, blocks should be coated with a watertight sealer.

Containment for Large Tanks Designing secondary containment for tanks with

capacities ofmore than 100,000 gallonspresents special engineering challenges. Such tanks usually are built on sand. They cannot be lifted with cranes and placed inside containments. Sometimes new tanks can be built within a concrete containment or some other watertight basin. However, dealers often do not have enough space to build secondary containments for these large tanks.

State regulations regarding large tanks are quite varied. One state grants experimental permits for designs not explicitly defined in the regulations (2).

Leak Detection Akey objectiveis to be able to detect leaks from the

tank. This calls for special construction to get a barrier to downward movement of leaking material, which is not an easy task. The most common way is to build a false bottom in big tanks. The false bottom is a steel floor welded inside the tank over a thin layer of sand (Figure 9).

Before installing a false bottom in a tank, the sump must be covered with a steel plate. The welds around the plate and the existing bottom must be tested and made leak-proof. Then, a layer of sand is placed over the existing bottom. Angle iron can be welded around the inside of the tank just above the sand layer, and the false bottom welded to the angle iron. Or, slits can be cut in the tank wall to accent steel plates welded to the wall, inside and outside, to create the false bottom. Holes or valved fittings are placed in the sand layer for leak detection .

Liners for Containment Areas In most states, clay-lined earthen dikes usually

are made by uniformly incorporating clay into the top 6 inches of soil; Illinois, however, requires 12 inches. Large rocks, gravel and soil high in organic matter must be removed. Soils with more than 2% organic matter are not suitable for use in soil-clay liners (5). The soil must be analyzed thoroughly to determine the amount of clay required per square foot of soil. The amount of clay should be based on a recommendation

from an engineering firm or state regulatory agency. Generally, the clay liner must have a permeability no greater than 1 x cmlsec (one millionth of a centimeter per second) (2, 4, 5). Minnesota has a maximum seepage rate of 0.125 inches per day (6).

The clay seal should cover the area inside the dike and up the inside slope to the top of the dike (Figure 10). The top of the dike should be 3 feet wide and the sides should slope no more than 1 foot for each 2 feet of run. A 6-inch layer of gravel should be placed over the clay liner to protect i t from erosion and desiccation.

Synthetic liners can be substituted for clay liners. Sheets of synthetic liner material are bonded to form a solid barrier inside the containment. A properly installed synthetic liner may be guaranteed for up to 20 years.

Packed earth can be used for the floor and walls. Or, earth can be used for the floor, with concrete or prefabricated panels for walls. The panels must be bolted together and anchored in concrete.

Clay and synthetic liners cost less than concrete or steel. Difficulty of clean-up in case of a spill is their main disadvantage.

Tank in a Tub Sometimes large tanks are contained in a large

steel tub to conserve space. Although the idea may sound bizarre, i t can be quite practical. With a 3-foot- high wall, a one-million-gallon tank will require more than one acre for containment. Containment with a steel tub--sometimes called an 'elephant ring'--will require less than one-fifth acre.

The elephant ring typically is one-half the height of the tank. With this ratio, 110% of the tank volume can be provided by a tub with a diameter 1.5 times that ofthe tank. Atub diameter 1.6 times the tankdiameter provides 125% of the tank volume.

The tank and tub require nearly twice as much steel plate for construction a s does the tank alone. Walls of the ring must be reinforced with braces attached to the tank. Also, the tank should rest on a 2- to 4-inch layer of sand or gravel to reduce corrosion and provide for leak detection.

As with other secondary containments, plan to deal with rainwater. One possibility is to install a roof over the space between the tank and the ring.

Movina a Tank Large tanks are dificult, but not impossible, to

move. In fact, movement into a containment basin may be preferred to installing a false bottom. One way to move a big tank is to float it. However, an engineer or experienced contractor should be consulted before trying this.

Large tanks often are made of steel only three- sixteenths of an inch thick. Such a tank will float in 10

Reinforced concrete secondary containment for liquid fertilizer plant. A gravel base under the tank reduces corrosion, provides for leak detection, and eliminates the need for anchoring tanks.

Figure 6. Containment wall.

Figure 7. Floating slab

T/WALL EL 700.0'>

UP EL 97.42' 1 A

$1 & gI6o , P P

cu

Q -4- .I .I cu ", -4- -4.

P LP EL alol 96.58' 3 2'X 2'X 2' SUMP

I 1 8"

- 21 '-0" 27'-0" 8"

(TYP7 - -4 -

43'- 4 " -

7rjm < -

Figure 8. Typical secondary containment

I SEC llON A -A

EXIST TANK WALL

NEW BOTTOM DRILL I"0

. . . . . . . . , . . . WEEP HOLES , . . . AROUND TANK

' @p ABOUT 5' O.C.

COMPA C E D SAND EXIST TANK BOTTOM

Figure 9. False tank bottom

inches of water. To move the tank, a clay-lined dike is built and filled with water. When the tank floats, it is pushed to its new location, and the water is drained or pumped from the diked area. The area where the tank previously was located is sealed with clay.

To reduce the chances of tank damage, it is a good idea to remove the sump and any other projections before the move is begun. Interior braces may be needed to support the tankbottom against the buoyant force of the water.

Tanks as large as 300,000 gallons have been moved by house-moving methods. Large beams are slid through holes cut in the tank and semi-trailer axles with lift jacks are used to raise the tank by lifting the beams.

Four 300,000-gallon tanks were moved two miles in Nebraska using dollies made from semi-trailer axles and a framework that was welded to the side of the tank. The specially built dollies permitted the raising of the tanks without cutting holes in the tank wall. .

An air cushion also can be used to move a big tank a short distance over a relatively smooth surface. This is done by attaching a skirt around the bottom of the tank and using large blowers welded to the tank to provide the cushion.

Large tanks must be anchored since buoyant force can exceed 100,000 pounds. Weights can be attached to the tank or the tanks can be constrained with cables attached to anchors outside the dike (7). Concrete deadmen or earth anchors can be placed beneath the liner if the clay or synthetic liner is sealed properly.

Another approach is to let the tank float, but restrain any lateral movement. This requires flexible plumbing. Also, it is good practice to leave fittings and manholes open when tanks are empty to equalize liquid levels inside and outside the tank in the event of a spill or rainfall accumulation.

6" CRUSHED STONE OR GRAVEL

61) CLAY/SOIL MIXTURE EARTH

Figure 10. Clay-lined earthen dike

Containment for Stored Pesticides Earth structures are not allowed for secondary

containment of stored pesticides. Also, pesticide containment must be separate from fertilizer containment. They can be adjacent, and the wall between pesticides and fertilizers can be lower than the outside wall to permit the two areas to mix in case of a catastrophe.

Pesticides should be kept under roof. Packaged pesticides should be kept in a separate warehouse and not inside a containment for either bulk pesticides or fertilizers. Flammable pesticides should be kept separate from nonflammable product, and the warehouse should be curbed to contain water that might be required t o extinguish a fire.

Dry Fertilizer Containment Dry fertilizer storage buildings should be on

elevated ground t o prevent rainfall runoff from entering. Floors should be paved with concrete and cracks should be repaired to prevent downward movement of nutrients. The roof and walls should be free of leaks. Floor sweepings and scrap fertilizer materials should be stored under roof. Limestone generally is the only fertilizer material that can be stored outside.

Wood has been the material of choice, but some new buildings are being made primarily of reinforced concrete, largely to reduce labor costs.

The floor is poured with slots to accommodate wall panels. Wall sections are poured horizontally on the floor, with reinforcement steel and clips for connecting sections positioned accurately in each. A crane is used to erect the walls and connect adjoining panels. Bin walls are supported laterally across the top with steel or concrete beams.

Watertight Concrete Construction The following specifications are recommended to

ensure that concrete for load pads and containment structures will resist penetration by moisture and chemicals and have a durable finish (7):

*Use Type IIA or Type I1 cement with air en- trainment, a t 4,000 - 5,000 psi compressive strength. Type I1 provides moderate sulfate resistance. ('A' de- notes air entrained; Type I1 must be air-entrained.)

*Use a water-cement ratio of 0.40 - 0.45 for a stiff (1.5" - 3" slump), relatively dry mix for maximum strength, chemical resistance, freezelthaw resistance, and watertightness.

*Use 5.5% to 7% air entrainment in cement to improve workability a t placement and to improve watertightness and strength of low-slump concrete.

*Vibrate concrete a t 5,000 to 15,000 frequency range during placement to get minimum aggregate segregation.

*Finish the surface with a powered steel trowel to minimize coarseness of texture and make washing and cleanup easier.

*Immerse or moist-cure concrete for a t least 14 days (28-day immersion or moist cure gives maximum strength).

*Allow no more than 30 minutes between loads of concrete during pouring.

*Mix concrete a t 70 - IOORPM, then agitate a t an additional 200 - 230 RPM (maximum of 300 total RPM).

*Discharge mixed concrete within 1.5 hours (per ACI C94).

*Minimize discharge drop distance by using a discharge chute.

*Use large (1- to 1.5-inch), clean, impervious aggregate, or aggregate one-third the size of the slab thickness, for maximum strength and watertightness.

* Use clean, drinkable mixing water having a pH of 5.0 to 7.0.

* Oven-test aggregate for excess moisture and adjust water added accordingly. If oven-testing is not possible, assume 3.5% excess water in sand and 1.5% excess in aggregate.

*Complete all continuous pours of concrete in one day; 'cold' joints are to be avoided.

Joints and Barriers Expansion joints should be spaced close enough to

prevent cracks from forming in undesirable places. Joints should be machine cut to a depth of one-fifth to one-fourth the slab thickness. The rule of thumb for minimum joint spacing in feet is 2.5 times the slab thickness in inches. Thus, an 8-inch slab should have joints no more than 20 feet apart.

Joints should be located where they can be monitored-not under a tank, for example. They should be sealed with a material resistant to fertilizers and pesticides, and the seal should be checked periodically for repair or replacement. Sections between joints preferably should be square; if not square, the length- to-width ratio should not exceed 1.5.

Vapor barriers should notbe usedbeneath concrete pours; the barriers can cause the concrete to retain moisture and increase degradation from freezing and thawing.

Problems offrostheaving can be reducedby keeping the area around concrete slabs dry. The area beneath the concrete should be higher than the surrounding area and surface drainage should keep water from standing near containment structures. Drainage around concrete structures should be monitored for two or three years after construction to ensure that the area is well drained after the structure settles. Curbs andgutters should be used to keep runofffrom buildings and paved areas away from containment sites.

Reinforcement Steel reinforcement bars are recommended for

containment structures. Wire mesh or fiber additives will not provide resistance to cracking over the life of the facility. Reinforcement rods usually are spaced 12 inches apart-in both horizontal directions. Bars in sumps usually are spaced 6 inches.

Waterstops are needed between containmentfloors and walls to keep fluids from seeping under containment walls. Molded vinyl waterstops, which must be embedded in the concrete floor beneath the wall, are available in several shapes. Other waterstops can be placed on the perimeter of the slab after i t has cured.

Many fertilizer and pesticide handling facilities have concrete slabs beneath tanks. If the concrete is in good condition and free from cracks i t can serve as part of the containment floor and the pad can be extended. The wall can then be built above new concrete.

I t is important when joining new and old concrete to seal the crack between the two slabs and to anchor new concrete to the old with dowels inserted into holes

drilled in the existing concrete. Even when existing concrete is in good condition, the best decision may be to remove the concrete, particularly if the slope is incorrect or the pad is too low due to settling. An engineer experienced in concrete design should be consulted regarding the use of existing concrete.

Management Practices Containment systems are an essential part of

environmental security a t fertilizerlpesticide dealerships, but they are no substitute for good management. Environmental management involves (1) proper handling of fertilizers and pesticides, (2) security of the facility during nonoperation, and (3) reliability of equipment used to transport or contain these materials.

Proper materials handling begins with employee training and education. Employees should understand how groundwater can become contaminated and the importance of keeping fertilizers and pesticides contained. The rinsate storage scheme should be understood by all, and all storage containers-including rinsate containers-should be labeled.

A typical scheme might involve separate storage tanks designated for rinsates from corn, cotton, and soybean operations, plus a tank for pesticide-free make-up water. Schemes will vary according to the number of crops treated and the amount of rinsate handled a t the facility. To prevent contamination of materials, spills should be cleaned up immediately. To minimize the amount of rainwater that must be collected and used, the loading pad and containment system should be cleaned and sumps should be pumped out a t the end of each working day or prior to rainfall.

Where to Mix Two approaches are used in pesticide handling:

mixing pesticides with the carrier in a batch mixer a t the plant, and mixing in the applicator.

Mixing a t the facility is common practice. Formu- lation accuracy is enhanced since all mixing can be done under supervision of an experienced mixer op- erator. Also, less equipment is needed since pesticides are not mixed and handled in equipment separate from fertilizer.

The main disadvantage of plant site mixing is the amount of equipment that must be cleaned to prevent contamination when switching products. All equip- ment-mix tank, nurse equipment, and application equipment-must be purged of the particular pesti- cide. Another disadvantage is the hazard associated with transport of large volumes of pesticide-contain-

ticide-laden rinsates-if the applicator is rinsed in the field.

On-board rinse systems with nozzles mounted inside the applicator tank are available to clean the tank walls and baffles. Portable sprayers also are available for cleaning pesticide residues from the outside of applicators. To ensure formulation accu- racy, pesticides should be premixed a t the facility and transported in separate containers on nurse equip- ment. The containers should be approved by the De- partment of Transportation for transporting pesti- cides.

In still another system, pesticide is kept outside the applicator tank. I t is added to the applicator's output stream by on-board injection or impregnation systems. These systems are near ideal for reducing rinsate. However, direct injection and impregnation systems are limited in the number ofproducts they can handle. Also, some dealers are skeptical of their accuracy.

Regardless of where pesticides and fertilizers are mixed, the amount of rinse water handled a t the plant can be reduced by rinsing as much equipment as possible in the field. To reduce the chance of contaminating surface water, rinsing should be done well away from ditches and creeks. Applicator rinsate from on-board rinse systems should be broadcast over the field, not dumped in one spot.

Rinsate Handling Tips Other methods for reducing the volume and cost

associated with handling rinsates include (8):

*Group jobs using similar fertilizers and herbicides so that equipment need be cleaned only once a day.

*Modify equipment to reduce the amount of residue left after tanks are emptied. The pump on large application equipment, for example, is driven by a belt from the engine and is nearly 10 feet from the tank drain. As an option, the pump could be driven hydraulically and placeddirectly beneath the applicator tank.

*Use high-pressure rinse equipment to reduce rinsate generation. Though centrifugal pumps are well suited for handling liquid fertilizer, their high output and low operating pressure make them poorly suited for washing out equipment. High-pressure washers clean better with less water.

ing product. Many dealers now wait to mix pesticides until they *Calibrate equipment properly and know the

are in the field. The pesticide is mixed with the fertil- exact acreage to be treated. This will minimize the

izer in the applicator. This practically eliminates pes-

In this secondary containment, pressure-treated lumber and

masonry nails are used to secure the synthetic liner.

I I

This "elephant ring" or tank within a tank holds 500,000 gallons of nitrogen solution

amount ofpesticide mixture that mustbe either rinsed from the applicator or hauled back for recycling.

Plant Security Facility security during periods of nonoperation

requires daily inspections. Where theft or vandalism is a problem, the plant should have a security fence and gates with locks, or be patrolled regularly. At the end of operations, the facility should be locked up and all valves on tanks and all pumps should be turned off. Some facilities have asingle switch thatbreaks circuits to all pumps and electrically driven valves.

Facilities not especially subject to vandalism may not require a security fence; however, all valves on tanks should be locked in the closed position. Since valves on tanks and valves a t the bottom of external sight gages both need to be locked, the two can be positioned near each other on the tank so that one lock can be used to secure both.

Gravi ty d r a i n s a r e not recommended for containment areas, although they sometimes are permitted for discharge of rain water. Discharge of rain water must be supervised closely; except when discharging rain water, valves should be locked a t all times.

Storage areas and containment systems should be checked frequently when the plant is shut down. Winterize the facility prior to cold weather. Remove

water trapped in lines and in containment basins to prevent freeze damage.

Check regularly the integrity of containment systems, storage containers, and other equipment designed to keep fertilizer and pesticides out of water supplies. Inspect t a n k s , valves, piping, and containment systems for leaks.

Some proposed regulations would require several inspections of these systems and documentation of inspections. Even if not required, documentation is recommended aspart of an overall program ofvigilance and maintenance. Tanks and plumbing should be inspected annually for leaks. Trouble areas should be tested physically by either a vacuum or pressure test.

A strict maintenance schedule shouldbefollowed, not only to protect water supplies but also to reduce down-time during the busy season.

Cost and Work Scheduling Containment of materials can be costly, but i t is a

necessity. Concrete slabs usually can be poured for about

$100 per cubic yard. A survey of dealers in the Midwest and Great Plains showed a cost for loading pads- including site preparation, reinforcement, form work, and finishing-of $140 to $200 per cubic yard of concrete. This high cost was due, in part, to the special requirementsforretrofittingnew and existingconcrete,

site preparation, and thelabor associated with forming sumps. Other costs associated with a load pad include the cost of tanks to hold rinsate and pumps and plumbing to transfer material to and from these tanks.

Most facilities need three or four 500-gallon tanks for rinsates. The total cost for a rinsate recycling system should be around $2,500, depending on the amount of materials that must be purchased.

Cost of secondary containment will depend on the materials used for construction. Concrete has the advantage of conserving space but is more costly than synthetic or clay liners. The following cost comparisons for alternative diking systems were presented by Hansen (9):

*A typical secondary containment for six 12-foot- diameter tanks, with the largest having a capacity of 30,000 gallons, costs about $26,000 if made of concrete. Concrete dikes cost about $11 per square foot of floor area.

*A clay-lined earthen dike with the same floor area cost about $14,000. Due to its sloping sides, the earthen dike can contain a tank with a volume up to 45,000 gallons for about $6 per square foot of floor area.

*A similar dike with a hypalon liner sandwiched between polypropylene liners will cost about $19,500, or $8.25 per squarefoot offloor area. The polypropylene liners, or geotextile liners, are needed to protect the main liner from damage during installation.

In each of the above alternatives, security fencing a t $10 per linear foot and a 10% contingency were included in the total cost.

Dealers typically spread plant modifications over a two- or three-year period; regulations generally have a similar compliance schedule. Regulations usually prioritize areas and materials requiring containment; dealers should establish the same priorities for making changes.

Containment generally is prioritized as follows: wa te r sys tem protection, pesticide storage containment, loading/mixinglequipment washing area containment, and fertilizer storage area containment.

Conclusions Before designing a containment system, dealers

should visit several sites and study several systems. Dealers with good systems are valuable sources of information, particularly if they have operated a system for some time. Experience andhindsight are invaluable.

A good system design should provide for future expansion. Provisions also should be included in the long-range plan for construction of roofs over areas subject to incidental spills.

Even in states with no containment regulations, i t is advisable to contact local agencies involved with water supplies-such as the Health Department, Emergency Management Agency, and Environmental Regulatory Agency-when planning facility modifications.

For assistance in containment design, the Cooperative Extension Service, State Department of Agriculture, fertilizer and ag-chemical dealer organizations, or TVA's National Fertilizer & Environmental Research Center should be contacted.

Fertilizer and pesticide containment provides opportunities for the retail fertilizer industry to take a leadership role in water resource protection.

Water resource protection is everyone's responsibility; after all, we are only borrowing water from our descendants. Also, more, not less, regulation likely will be the rule in the future.

References 1. Noyes, Ronald T. 1989. "Modular Concrete

WashlContainment Pad for Agricultural Chemicals," Paper No. 891613, American Society of Agricultural Engineers, St. Joseph, MI, December 1989.

2. Illinois Department of Agriculture. 1989. Part 255 Agrichemical Facilities; Subchapter i; Pesticide Contro1;Title 8: Agriculture and Animals, S ~ r i n ~ e l d , IL.

3. South Dakota Department ofAgriculture. 1989. Bulk Commercial Fertilizer Operations Manual, Division ofRegulatory Services, Pierre, SD, July 1989.

4. Iowa Department of Agriculture. 1988. Bulk Commercial Fertilizer Storage, Article 12:44, Chapter 12:44:05, Des Moines, IA.

5. Wisconsin Department of Agriculture, Trade & Consumer Protection. 1988. Chapter Ag 162, Bulk Fertilizer Storage, Wisconsin Administrative Code, Register, February 1988, No. 386, Madison, WI.

6.Minnesota Department of Agriculture. 1989. Bulk Pesticide Storage Facility Rule Summary, Agronomy Services Division, St. Paul, MN.

7.Kamme1, D.W., G. L. Riskowski, R.T. Noyes, andV. L. Hofman. 1990. Draft, Fertilizer and Pesticide Containment Facilities Handbook, Midwest Plan Service, Agricultural Engineering, Iowa S ta te University, Ames, IA.

8.Broder, Michael F., and Carl T. Cole. 1987. "Minimizing Hazardous Waste from Application of Fertilizer-Pesticide Mixtures," presented a t summer meeting, American Institute of Chemical Engineers. (Unpublished, TVA).

S.Hansen, T.L. 1990. "Diking Alternatives for Secondary Containment of Liquid Fertilizers," Dultmeier Engineering Services, Inc., Omaha, NE.

Management of Pesticide Containers

Nancy Fitz U.S. Environmental Protection Agency Ofice of Pesticide Programs Environmental Fate and Effects Division

Abstract

This paper describes the current methods used to dispose of nonrefillable pesticide containers, as well as the applicable federal and state regulations. Additionally, other segments of a n overall pesticide container management scheme are presented, including recycling, water-soluble packaging, and refillable containers. Finally, the container design and residue removal regulations that are currently being drafted by EPA are addressed, particularly with respect to the potential effects on pesticide container disposal and management .

Introduction

In 1989, the Virginia Council on the Environment reported its conclusions after conducting a comprehensive review of pesticide management in the state. Regarding disposal, the Council made the following conclusion:

"Overall, the current situation regarding disposal of waste pesticides and containers is characterized by unclear or confusing

have been conducted to collect information on agricultural pesticide container disposal. This section describes several of these surveys.

In 1987, the National Agricultural Chemicals Association (NACA), in conjunction with the American Farm Bureau Federation, National Agricultural Aircraft Association, and the National Fertilizer Solutions Association, conducted a survey on container issues.2 Thirty-eight states were represented in the survey. The breakdown of the 805 responses was:

418 private applicators; 190 commercial aerial applicators; 150 commercial ground applicators; and 47 combined commercial aerial and ground applicators.

The survey was not designed to present any statistical representations; its purpose was to help pesticide manufacturers develop their container management strategies. The survey pi-ovides a useful cross-section of opinions on container disposal.

Respondents were asked to rank five different container issues in terms of the impact on their business. The results are given in Table 1. Commercial applicators ranked container disposal as their main concern, and the ability to empty the containers safely and completely as their second. Private applicators also ranked these two issues as their top two concerns, although the order was reversed.

requirements, conflicting advice, strict and Table 1. Container Issues of Most Concern2 expensive requirements for some chemicals but no regulations for others, and a sense of Commercial Private frustration on the part of many pesticide users. Applicators (%) Applicators (%) Although records obviously do not exist to verify Issue Air Ground Comb. it, this situation probably leads to the - surreptitious, improper disposal of pesticide wastes in numerous cases."l

This statement summarizes the present situation regarding disposal of pesticide containers in all 50 states. Much of the confusion stems from the large number of laws that may address the disposal of pesticide containers, including pesticide, solid and hazardous waste, and air quality laws at both the federal and state level. These laws and the associated regulations are discussed below.

Current Situation

Disposal Safe and complete emptying

Size, shape Closure,

openings Rinsate disposal

In 1987-88, the Minnesota Department of Agnculture conducted a statewide survey of container disposal issues.3 The three different groups surveyed were farmers, dealers, and users.

In order to characterize the current disposal The "users" category includes licensed problems and practices, a number of surveys commercial and noncommercial applicators.

Noncommercial applicators are people (such as government employees) who apply restricted use pesticides, but not for commercial reasons. Responses were received from 535 farmers, 1,065 users, and 408 dealers.

One question involved rating disposal of empty pesticide containers in comparison to other environmental issues in Minnesota. More than 60 percent of the respondents in each group ranked container disposal a s "important" and about 21 percent of each group ranked i t as "most important." Clearly, all groups consider empty container disposal to be a significant environmental issue. In fact, both of these surveys -- NACA's and Minnesota's -- are typical of responses to survey questions that gauge the level of concern about pesticide container disposal. Many pesticide users rank container disposal a s a significant concern.

Pesticide container disposal practices in Minnesota, a s determined by the survey, are given in Table 2. Burning was the most common disposal method for farmers, while most "users" and dealers triple rinse and take the containers to a landfill.

Table 2. Container Disposal Methods in M i n n e s o t a 3

Percent of Respondents o Use Methodl

F a r m e r s Users2 Dealers

Method Burn 65.0 Rinseltake to 23.7

landfill R insehury 27.5 Return to dealer 17.8 Store on site 11.8 Salvage 3.6 Regular --

garbage pick-up Can't dispose 2.8 Out-of-state 1.3

hazardous waste landfill

Other 14.2

1 Columns total more than 100 percent because respondents could list more than one disposal method. 2 "Users" include licensed commercial and

noncommercial applicators.

The results for the farmers in the 1988 survey are consistent with data from surveys of

Minnesota farmers done in 1981-84.4 The methods are ranked in the same order in both the older and more recent surveys, although burning and burying on the farmers' property have increased since the early 1980s.

The Minnesota Empty Pesticide Container Disposal Report also summarizes the results of recent surveys done by Nebraska, Wisconsin, and Iowa. These data, given in Table 3, show that burning was common in all three states. Landfilling was also common in Nebraska and Wisconsin, while a significant percentage of the Iowa farmers returned their herbicide containers to the dealer.

Table 3. Container Disposal Methods in Thme S t a t e s 3

Percent of Respondents - (State) NE1 WI2 LA3a

(Container)4 & fi Hi2 h

Method Burial 24 32 49 86 Burial on 33 7 2 2 own property

Sanitary 36 32 9 4 landfill

Return to 7 11 24 5 dealer

Other - - 19 15 4

1 Pesticide use on major crops in Nebraska, 1982.

2 Pesticide use in Wisconsin, 1985.

3a Pesticide used in Iowa crop production, 1985. 4 Pe=pesticide container; He=herbicide container; In=insecticide container

Several surveys have been done on disposal methods used by dealers. One was conducted by the Illinois Department of Agriculture, which requires agrichemical facilities to register with the state.5 One question on the application for registration asked about methods of container disposal. Table 4 shows that of 1,263 responses, 60 percent of the facilities burned their nonrefillable containers.

In 1989, the National Agrichemical Retailers Association (NARA) surveyed i ts members on empty pesticide container disposal.6 The survey represents 8 percent of the NARA membership and approximately 7 percent of retailers nationwide. NARA believes that the results represent the national pesticide retail industry. About 53 percent of the retailers reported disposing of empty pesticide

containers by burning, 42 percent by landfilling, and 4 percent by recycling.

Table 4. Container Disposal Methods in Illinois5

Percent of Agrichemical Facilities That Use Method

Burn a t facility 32 Burn in field a t application site 26 Triple or pressure rinse 22

and take to landfill Waste pick-up 21

These surveys of container disposal methods used by farmers and dealers are typical of surveys done throughout the United States. Burning and landfilling are by far the two most common disposal methods. Additionally, burying is a method often used by farmers.

Methods sf Container DisposalIManagement

bandfilling

Disposing of pesticide containers in a landfill is the primary disposal method in most states. A sanitary landfill is defined in 40 CFR Part 241 as "a land disposal site employing an engineered method of disposing of solid wastes on land in a manner that minimizes environmental hazards by spreading the solid wastes in thin layers, compacting the solid wastes to the smallest practical volume, and applying and compacting cover materials a t the end of each operating day." Nearly all empty household and institutional and industrial pesticide containers enter the municipal solid waste stream and are disposed in sanitary landfills or incinerated. Additionally, a s shown in Tables 2, 3, and 4, landfilling is one of the main disposal methods for empty agricultural pesticide containers.

However, many landfills are currently refusing to accept certain kinds of waste, including pesticide containers, for several reasons:

'3 Existing landfill space is diminishing and siting new landfills is difficult;

e Concern for ground water contamination from earlier disposal practices is increasing;

States are adopting solid waste management strategies that rank landfilling as the least desirable disposal option; and Potential liability for future releases of hazardous substances is a concern.

Pesticide containers that are triple rinsed or the equivalent are considered non-hazardous solid waste by the federal Resource Conservation and Recovery Act (RCRA), which regulates solid and hazardous waste. These containers are allowed to be disposed in sanitary landfills, although many landfills refuse to accept properly rinsed pesticide containers. In the 1988 Minnesota survey, 4.7 percent of t.he farmers, 10.6 percent of the users, and 12 percent of the dealers reported that landfill operators had refused their triple rinsed containers.3 This occurrence is not limited to Minnesota; the problem is common nationwide.

Open Burning

Open burning is another widely used disposal method for agricultural pesticide containers, because i t is convenient and inexpensive. Plastic containers and bags are usually burned in the field where the pesticide was mixed. Users often replace the empty plastic containers in the shipping box and ignite the whole package. Containers are burned in a pit or a drum, or on the ground.

Regulating the open burning of pesticide containers is an interjurisdictional issue. Federal RCRA Subtitle D regulations prohibit open burning under 40 CFR 257.3-7, and air emissions may be subject to Clean Air Act restrictions. State solid and hazardous waste and air regulations may address open burning. Additionally, some state pesticide regulations include provisions for burning containers.

On-Site Burial

Burial is a disposal method where the containers are placed under soil cover in a site that does not qualify as a sanitary landfill. For many years, burying pesticide containers has been a common practice on farms. As shown in Tables 2 and 3, farmers still use on-site burial as a disposal method.

Many states allow on-site burial by farmers, although restrictions often are placed on soil types andlor the distance from surface water or wells. In general, however, on-site burial is not encouraged. I t is difficult to ensure that only empty, properly rinsed containers are buried. Additionally, there is

the potential to contaminate soil or ground water. Cases of ground water contamination have been documented.

Open Dumping

Open dumping is the practice of throwing waste in an open area and leaving it uncovered. Open dumping is prohibited by federal RCRA regulations and by all 50 states because of the potential public health risks from pesticide residues in soil, surface water, and ground water. However, the open dumping of pesticide containers is a common practice. Several states, including North Carolina, Maine, and Minnesota, have studied open dumps of pesticide containers and found them to be a problem. In 1981-82, the North Carolina Department of Agriculture found 356 pesticide container dump sites by conducting a vehicular survey.7 Similarly, the Maine Board of Pesticide Control found 400 illegal, open pesticide container dumps between 1981 and 1983 through aerial surveillance.8 A recent survey by Minnesota's Department of Agriculture analyzed several sites in great detail and found that the residue in improperly rinsed and discarded containers can adversely affect surface and ground water.9

Disposal as Hazardous Waste

Some users choose to dispose of nonrefillable pesticide containers as hazardous waste (in a hazardous waste landfill or in a permitted incinerator). Even though triple-rinsed containers are not considered to be hazardous waste, this disposal method is used sometimes because of liability concerns.

Hazardous waste disposal is expensive, although the actual cost varies according to the characteristics of the waste, the method of disposal, and the region of the country. Pesticide users in California reported that it costs about $1,000 to incinerate a 55-gallon drum ofhazardous waste and $5,000 to dispose of a 20-yard bin of granulated pesticide containers in a hazardous waste landfill. I t was estimated that it would cost approximately $30,000 to incinerate the 20-yard bin.10

used by growers to hold liquid pesticides decanted from minibulk containers. Additionally, empty pesticide containers are sometimes used to hold other substances such as used motor oil. Reusing nonrefillable containers is not a recommended practice and is prohibited by some labels.

Some pesticide users report disposing of containers by returning them to dealers. However, this is not a permanent disposal method, because it simply places the burden of disposal on the dealers.

Another common disposal method reported in Tables 2 and 3 is storing the containers on-site. Again, this is not a true disposal method and may create some problems. Depending upon the storage conditions, storing the containers on-site may lead to the creation of open container dumps.

Recycling

Recycling is becoming a more common and attractive way for pesticide users to manage their containers. EPA has information on more than 10 container collection and recycling programs that were in place during 1990 and 1991. Many of the programs are pilot projects to determine the feasibility and logistics of container collection and recycling. The programs differ greatly; some of the variables include:

Mandatory vs. voluntary; State-run vs. industry-run; Central collection site vs. mobile collection; The type of container accepted (metal vs. plastic vs. both); and Who inspects the containers.

Despite the differences, there are two common themes for successful collection and recycling programs. First, proper rinsing is essential; and second, inspecting the containers is necessary to ensure proper rinsing.

The number of pesticide container collection and recycling programs is rapidly growing. Over half of the states are expected to have collection programs in 1992.11 Currently, much attention is focusing on resolving several problems with pesticide container recycling. These issues include finding an end use for the collected material, determining the amount of pesticide that is absorbed into or adsorbed to the plastic resin from containers, and improving the economics of pesticide container recycling.

Other Disposal Options Deposit and Return Program

Pesticide containers are occasionally reused to hold pesticides or for other purposes. Observers report seeing plastic pesticide jugs

Another option for managing pesticide containers is a container deposit and return

program. In 1985, Maine initiated a return and deposit program for containers of limited-use and restricted-use pesticides, which is the only program of this type in the United States.

Under the program, dealers affix an alphanumeric identifying sticker on all limited-use and restricted use pesticides purchased in the state. Deposits are $5 for containers smaller than 30 gallons and $10 for those 30 gallons and larger. The containers are returned on an appointed collection day after the growing season. Users are required to triple rinse the containers (or the equivalent). An affidavit listing the number of containers and their sticker numbers is brought to the collection point by the user. At that time, the containers are checked to verify proper rinsing. The user receives a refund for containers that are returned. As the program has evolved, a debivcredit record has occasionally been used instead of deposits.

Collection points include dealerships or other dealer-chosen locations, landfills or other accessible locations chosen by the Maine Board of Pesticide Control staff, or sites arranged by farmers or applicators.

Overall Container Management Scheme

There are several options available to ease the burden of container disposal on pesticide users. To categorize them, EPA has identified a hierarchy of environmentally sound container classes, which is based on information collected on container use, residue removal, and container disposal, a s well a s the concepts of pollution prevention and reducing solid waste. Within the hierarchy, the container classes are listed from most desirable to least desirable:

o Refillable containers and water-soluble packaging;

e Nonrefillable, recyclable containers that are currently being recycled;

8 Nonrefillable, recyclable containers that are not currently being recycled; a n d

8 Nonrefillable, nonrecyclable containers.

The Agency would like to encourage the development and use of the most desirable container classes. Those are refillable containers and water-soluble packaging, because they minimize waste and prevent pollution. More specifically, these types of

containers reduce or eliminate the need for residue removal and reduce the number of containers requiring disposal.

EPA realizes that refillable containers and water-soluble packaging are not possible in every situation and that nonrefillable containers will always exist. The next category in the hierarchy -- nonrefillable, recyclable containers currently being recycled -- is attractive because i t reduces the number of containers requiring disposal a s waste. For the purposes of this paper, a container is considered recyclable if the technology exists to recycle the material from which the container is constructed.

The third category, nonrefillable, recyclable containers not currently being recycled, includes most nonrefillable steel and plastic containers. With the proper infrastructure and market, the containers in this category could move up the hierarchy to reduce the number of containers requiring disposal.

The least desirable category, in terms of resource conservation, includes nonrefillable, nonrecyclable containers. For example, because multiwall paper shipping sacks are usually constructed of more than one material (e.g., kraft paper and a barrier layer), they are not recyclable.

€PA Work on Pesticide Containers

In 1988 Congress amended the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), which now requires EPA to address pesticide containers in three ways: (1) to conduct a study of pesticide containers and report the results to Congress; (2) to promulgate container design regulations; and (3) to promulgate residue removal regulations. These projects are very interrelated because the information collected during the study is used in the report and as support for the regulations being drafted.

Container Study

During the past several years, EPA has gathered the available information on pesticide containers through a variety of methods. Four open meetings were held with representatives from different perspectives, including pesticide manufacturers, pesticide packagers, state agencies, container manufacturers, environmental groups, and trade and user associations. Follow-up meetings were held with many of the participants to discuss specific issues in greater detail. Additionally, EPA staff members have made several field trips to meet

with growers, applicators, dealers, and distributors to increase the Agency's "real world" knowledge of container handling practices.

The report to Congress summarizes and consolidates the existing knowledge and data on pesticide containers and current handling practices. The issues and current practices regarding use, residue removal, and disposal are discussed for both nonrefillable and refillable containers. Also, the EPA's approach to managing containers is described with options and suggestions for further study.

Regulations

Because the regulations currently being drafted address pesticide container design and residue removal, they will not directly impact the current regulations for container disposal. However, one goal of the container design and residue removal regulations is to ease container disposal problems.

For example, EPA believes that a key aspect for the safe recycling or disposal of nonrefillable containers is to have clean containers. One regulatory approach under consideration is to set a performance standard for the maximum amount of residue that remains in a container after a specified residue removal procedure is performed. A different standard could be set for each class of container, e.g., rigid containers with dilutable bags or nonrigid containers. The registrant would be responsible for showing that the containers could meet this standard. The registrant could vary the container (size, shape, etc.) or the formulation in order to meet the standard. Having the registrants ensure that the containers can come clean would make it easier for users to clean containers, which would facilitate the safe recycling or disposal of nonrefillable containers.

EPA would also like to encourage the use of refillable containers. One regulatory approach being considered is to have no limit to the size of refillable containers. Under the present bulk pesticide enforcement policy, dealers can repackage pesticide only into containers larger than 55 gallons. Currently refillable containers are limited mainly to large monocrop areas. Eliminating the minimum size limit could open entirely new markets for refillable containers. However, EPA is also considering a number of container design and procedural requirements to minimize the potential for

cross-contamination and large spills from refillable container failures. For example, EPA is considering the requirement that minibulk containers for liquid pesticides have tamper-evident devices and one-way valves.

Conclusion

Disposing of pesticide containers is a serious problem for pesticide users. Few disposal options are available to end users, and these are becoming more restricted. The trends toward alternative container management options, such as recycling and the use of refillable containers and water-soluble packaging, offer a glimmer of hope. However, these alternatives are not without their own problems. For example, while significant progress is being made toward the development of recycling programs for pesticide containers, we are still far away from having a national infrastructure for collection and an established market for the recycled material. In the long run, however, EPA believes that these alternative container management options will ease the burden of container disposal.

References

1. Virginia Council on the Environment. 1989. Pesticide Management i n Virginia, Special Report.

2. Gilding, T. 1988. National Agricultural Chemicals Association. Letter to principal contacts of member companies. August 17, 1988.

3. Minnesota Department of Agriculture. 1988. Minnesota Empty Pesticide Container Disposal Report.

4. Ibid.

5. Taylor, A. G. 1990. Illinois Environmental Protection Agency. Personal communication with U. S. EPA Office of Pesticide Programs. December 3, 1990.

6. Myrick, C. National Agrichemical Retailers Association. 1989. Summary of National Agrichemical Retailers Association's Empty Container Disposal Survey.

7. McClelland, W. T. 1983. North Carolina Department of Agriculture. "A Study of Pesticide Container Disposal Sites in North Carolina (1981 - 1983)."

8. Denny, R. and D. McLaughlin. 1985. Maine Board of Pesticide Control, Report on Maine Pesticide Container Program.

9. Buzicky, G., e t al. 1990. "Evaluation of Improperly Disposed of Pesticide Containers on Minnesota Farms (Draft)." FIFRA enforcement special project prepared for the U. S. EPA, Region V.

10. U. S. EPA Office of Pesticide Programs. 1990. Trip Report to California, Oregon, Washington, September 16-22, 1990.

11. May, R. 1991. DuPont Agricultural Products. Personal communication with U. S. EPA Ofice of Pesticide Programs. November 4, 1991.

Pesticide Application Equipment Rinse Water Recycling Darryl Rester Specialist (Engineering) Louisiana Cooperative Extension Service Louisiana State University Agricultural Center Baton Rouge, Louisiana 70803

Abstract

The Louisiana Department of Agricultural began enforcement ofpesticide waste disposal regulations on January 1, 1985. These regulations, which were adopted in 1984, apply to all commercial pesticide applicators and require that they adopt procedures and install facilities to clean the equipment spray system, mixing tanks and pesticide containers without contaminating the soil, water or air.

1

After evaluation of various pesticide waste disposal techniques, 60% of Louisiana's 180 commercial aerial applicators elected to use waste water recycling to dispose of aircraft spray system wash water.

Waste water recycling involves collecting the aircraft wash water and storing the water in tanks for use as a diluent on future application jobs. Three to five, 250 to 500 gallon tanhs are normally used to store waste from various pesticides thus preventing label violations and the possibility of crop damage. Thirty percent of the applicators rinsed the aircraft over the field being treated. Ten percent modified the aircraft or used other waste disposal techniques.

During the past four years, several applicators have been interviewed to determine the cost of constructing and operating the waste water recycling systems as well as information on problems.

Most aerial applicators used a 50 X 50' or 50 X 60' concrete wash area and three to f ~ v e 250 to 500 gallon tanks. Most systems cost $8,000 to $12,000 with a range of $3,000 to $15,000. Very few problems were reportcd and there were no reported inczdenccs of crop damage from addrug low rates of wash watcr to the pestrcrde mrs.

Introduction

During 1981 and 1982, discussions were held between leaders of the Louisiana Agricultural Aviation Association, members of the Louisiana Cooperative Extension Service (LCES) and the Louisiana Department of Agriculture. These dis- cussions covered techniques required to comply with proposed Louisiana Department of Agricul- ture pesticide waste disposal regulations (1,2,3).

I t was generally agreed tha t pesticide containers could be converted from pesticide waste to solid waste via triple rinsing (4). Mixing and loading equipment could be washed and the wash water used for dilution. Based on EPA regula- tions, containment of water used to wash the exterior of the aircraft is not required (5). How- ever, the applicator is ultimately responsible for any soil contamination. Water used to wash the interior of the spray system must be contained and disposed of in a n environmentally safe manner.

Current research, s tate of the a r t technol- ogy and other factors were reviewed. I t appeared tha t commercial aerial applicators had the follow- ing options for disposal of pesticide waste:

1. Move off-site for t reatment or disposal a t a hazardous waste disposal facility.

2. Store on-site.

3. Trea t on-site.

4. Recycle.

5. Modify equipment to clean in-flight.

A recent review of current technology indicates t ha t during th? past 8 years advances have been made in sevei iil areas. However, the cost of collection and transportation for off-site treatment or disposal is still too costly for niost commercial aerial applicators. However, this waste disposal technique will be essential in special situations.

On-site storage or t reatment will require collection and containment facilities plus the treating equipment. Applicators who plan to use long term storage or treatment will usually be

required to obtain a permit from a regulatory agency. Engineering fees, legal fees, insurance or bond costs plus the cost of the facilities will be very expensive. In addition, very few commercial applicators have tinie to operate such facilities and comply with ever changing regulations.

I t was decided tha t a n affordable, environ- mentally safe system must consider the following factors (1,2,3,6).

1. The commercial aerial applicators must be able to install and operate the waste disposal facilities and still provide quality aerial application at a n affordable price.

2. The applicator, pilots andlor loading crew members must be able to operate the system with minimal training.

3. The system must be compatible with normal operations and not require a lot of manage- ment time or additional labor.

4. The system must be designed to eliminate t he storage of pesticide waste during the off season, thus eliminating the need for permits, additional insurance and record keeping.

5. The system must dispose of the pesticide waste without requiring the transport of waste to a hazardous waste disposal site.

After further research in 1982, i t was decided tha t waste water recycling, rinsing the aircraft over the treated field or modifying the aircraft for cleaning in flight would meet these five objectives. I t was felt t ha t rinsing over the field would be feasible for aerial applicators who flew less than 300 hours per year. However, i t would be too costly for larger aerial applicators (2).

Engineers from the Louisiana Cooperative Extension Service designed a waste water recy- cling system for applicators with two to five aircraft. This system was evaluated on a limited scale in 1982 and 1983. Regulations adopted in 1984 by the Louisiana Department of Agriculture legalized the use of this system (1,4). Enforcement of the regulations began on January 1, 1985.

During 1982 - 1986 Louisiana Cooperative Extension Service Specialists and County Agents held annual training meetings in eight locations around the state. The training meetings were usually attended by 20 to 40 aerial applicators. At

each of these meetings detailed information and handouts were provided on the regulations a s well a s techniques for compliance. Ample tinie was provided for questions. Enforcement officials from the Louisiana Department of Agriculture a s well a s officers of the Louisiana Agricultural Avi a t ' lon Association also participated in each training session. These training sessions were very helpful in reducing construction costs for the waste water recycling facilities a s well a s enhancing compli- ance with the regulations (2).

During 1985, several commercial aerial applicators built and used waste water recycling systems, others rinsed the aircraft over the treated field and a few applicators modified the aircraft (3).

Aircraft Modifications

Agricultural aircraft a re equipped with 150 to 600 gallon spray tanks. After the comple- tion of a spray job, 6 to 10 gallons of spray mix will be left in the spray system. Three to five gallons of this mix will be in the bottom of the spray tank and three to five gallons will remain in the spray pump, spray booms, and connecting lines. In addition, residue will remain on the inside walls of the spray tank (9).

AIRCRAFT SPRAr TCNt<

7

Figure 1. Aircraft spray tank illustrating location of \.arious corn~~onents a n d remaining3 to 5 gallons of spray mix.

As shown in Figure 2, a simple device can be added to the pump intake to remove 2 to 4 gallons of pesticide. This pump intake extension is now commercially available a t a reasonable cost. This simple device will reduce pesticide waste by 30 to 40%. In addition, installing a check valve in the loader line will eliminate contamination of this area.

AIRCRAFT SPRAY TANK

I-----? FRONT

Figure 2. Aircraft spray tank illustrating installation of pump intake extension and loader line check valve.

Commercial firms now offer on-board washout systems. These systems consist of a 15 to 20 gallon reservoir, a pump with a D.C. motor and a cluster of nozzles inside the spray tank. The reservoir can be a tank or collapsible bag inside the spray tank. The reservoir can be filled with clean water for the last load of a spray job. After exhausting the pesticide the sides of the spray tank can be washed with 8 to 10 gallons of water. This water is then sprayed onto the treated area. the sides of the spray tank are then washed a second time with 8 to 10 gallons of water which is then sprayed on the treated area. If required, the aircraft can return to the loading area where the washout reservoir is refilled and 20 to 30 gallons of water added to the spray tank. This water is then sprayed on the previously treated area to thor- oughly clean the entire spray system.

On-board purging or wash-out systems eliminate the need for costly containment or recycling systems. In addition, these systems are very convenient for use on remote sites.

Waste Water Recycling System

The waste water recycling system de- signed by the LCES consists of a 50 X 50' to 50 X 60' wash area, a sump to contain the waste water, a pump, connecting lines and 3 to 5 holding tanks with a capacity of 250 to 500 gallons each (7).

Cost varied from $1.50 to $2.50 per square foot depending on the site preparation required, fill material required, thickness of concrete, type of underliner, amount of steel used for reinforcement and other factors. As expected, applicators who did most or all of their own construction had the lowest cost (9). Specifications for the wash area, sump and tanks are contained in the Louisiana Department of Agriculture pesticide waste dis- posal regulations (4,7).

Louisiana regulations require elevation of the pesticide waste storage tanks so leaks will be readily apparent. Also, a secondary containment structure capable of holding 110% of the volume of the largest tank is normally required (4).

The number and size of tanks depends on the size of the operation and the variety of pesti- cides used. Under Louisiana conditions, most applicators will have three to five tanks with a capacity of 250 to 500 gallons each. The pesticide waste water mus t be segregated and stored in separate tanks to avoid label violations and the possibility of crop damage.

Tank cost varied depending on tank size, type of tank, and whether new or used. A typical waste water recycling system is shown in Figure 3.

Data for construction cost is shown in Table 1 and data for operating cost is shown in Table 2. This data is based on a system for 3 to 5 aircraft with each aircraft flying 400 to 700 hours per year (9).

Figure 3. Typical waste water recycling system. Number and size of wash water or r insate storage tanks can be varied a s required.

Table 1. Construction Cost for Waste Watcr Recycling Systems

50 X 60' Concrete Wash Area Five Tanks (500 Gallons Each) Plumbing and Electrical P u m p (2 H P , 2" Capacity) L a b o r

TOTAL Range $3,000 - $15,000

Table 2. Annual Operating Cost for Waste Water Recycling Syste~ns

Depreciation (10 year life) $ 1,250 Interest on Investrnellt (12% Interest) 800 Maintenance 600 Labor (75 I lours O $8.00) 600

TOTAL $ 3,250

Note: The concrete wash area can bc: uscld to mix and load pesticides a s well a s ser\.ice the aircraft. Therefore, a portion of these costs should 1 x 2 nttr i l~uted to other phases of the operation.

Operating Procedures

The applicator mus t first decide what pesticide waste will be stored in each tank. Waste from various pesticides mus t be segregated to avoid label violations and compatibility problems. Each tank should be labeled so tha t all pilots and loading crew members will always know what i s stored i n each tank. This will reduce the possibil- ity of errors in utilizing the waste a s a dilution agent on fu ture application jobs. An example of how the tanks can be utilized is shown in Table 3.

The type waste stored in the various tanks will vary from area to area within Louisiana a s well a s from year to year.

In this example, the pesticide waste generated from cleaning the aircraft after applying soybean pre-emerge herbicides will be stored in tank number one. Most soybean pre-emerge herbicides will be applied in April - May. There- fore, this tank can be cleaned and utilized to store soybean fungicide and insecticide waste during Ju ly - September.

Table 3. Example of Waste Water Containment Tank Utilization

Tank Tank Type of Waste Water No. Size Earlv Season Late Season 1 250 Gal. Soybean Pre-emerge Soybean Fungicides

Herbicides and Insecticides

2 400 Gal.

3 500 Gal.

4 500 Gal.

Soybean Post-emerge Soybean Defoliants Herbicides

Cotton Pre-emerge Cotton Insecticides Herbicides

Cotton Post-emerge Cotton Defoliants Herbicides

5 300 Gal. Rice Herbicides Rice Fungicides and Insecticides

NOTE: The number and size of tanks can be varied to meet t he needs of the applicator. Pesticide waste water from post-emerge herbicides can be applied with pre-emerge herbicides. However, waste from pre-emerge herbicides should never be applied with post-emerge herbicides.

Waste water should be recycled by mixing one par t pesticide waste water with four parts fresh water for dilution of t he pesticide.

The second step in utilizing the waste water recycling system requires t ha t the applica- tor decide whether or not to wash the aircraft between spray jobs. As a n example, when chang- ing from soybean fungicides to soybean post- emerge herbicides to soybean insecticides i t will not be necessary to wash the aircraft. All three types of pesticides are labeled for application on soybeans. Therefore, phytotoxicity and label violations \\ . i l l not be a ~ ~ r o b l e m .

The applicator should use his experience, judgement and knowledge of various pesticides to schedule application jobs and aircraft washing to minimize the volume of pesticide waste.

The applicator should never store pesticide waste unless he knows of a future job where this waste can be added to the pesticide mixture and promptly applied. Ideally, this waste should be used within two to three weeks.

The aircraft should be rinsed over the field being treated if the applicator is uncertain about how or when he can recycle the waste. This is especially true i r t he pesticide is seldom used in his oper a t ' lon.

Rinsing the aircraft over the treated field can be costly and time consuming. I-Io\\,e\.e~., this may not be a s costly a s transporting the nraste to an approved disposal site or other types of on-site treatment.

Collection Procedures

The applicator can use two techniques to collect t he pesticide waste water when washing the aircraft spray system. The first technique involves dumping the waste on the concrete wash area. The second technique allows pumping the pesticide waste a n d wash water directly from the aircraft.

If t he first technique is used, the wash area should be washed to remove all soil particles and other debris. The aircraft i s then taxied onto the concrete wash area. After dumping the waste pesticide, t he aircraft spray system is thoroughly washed. This includes washing the spray tank and purging the spray booms, spray pump and all connecting lines.

The waste pesticide, spray system wash water and water used to again wash the concrete wash area drains into a sump located adjacent to the wash area.

The waste pesticide and wash water is then filtered to remove trash and pumped into the storage t ank designated for storage of tliis type pesticide waste.

The second technique requires connecting hoses with appropriate adopters to the outer end of each spray boom or a fitting and valve installed on the bottom of the aircraft spray tank. The spray system is washed a s previously described. The waste pesticide and wash water is then pumped into the storage tank.

Use of tliis technique is recommended because i t reduces contamination problems tha t could cause nozzle plugging a s well a s contamina tion with other pesticides.

cl.oss contaniination and pos.sille label \.iolations as \yell a s crop damage. In atidition, physically connecting the hose to the proper storage ta::ks assures tha t the was11 \vater ~ v i l l 1)e stored in the proper tank. This practice also holds t rue when removing pesticide waste water from the tanks.

Applicators report t ha t i t requires a t least 80 to 100 gallons of \vater to thoroughly wash the aircraft spray system (9). The aircraft spray systeni will normally contain 4 to 7 gallons of field strength pesticide waste. Therefore, the pesticide waste water stored in the containment tanks will have a pesticide concentration of less than 10% of normal field strength (9).

One par t pesticide waste water should be mixed with four par t s fresh water when using the waste for pesticide dilution. The resulting spray mixture will contain a maximum of 2% additional pesticide. This low level of additional pesticide reduces the probability of label violations, illegal residue or crop damage should a n error be made in mixing or loading.

Summary

Interviews with Louisiana aerial applica- tors after the completion of the 1989 spray season indicates tha t problems have been minimal. Pesticide waste water can be disposed of by rinsing the aircraft over the treated field or recycling. There were no reports of illegal crop residues or crop damage caused by recycling of pesticide waste water (3).

Aerial applicators flying less t han 300 hours per year felt t ha t rinsing the aircraft over the field costs less than constructing pesticide waste water recycling systems. Larger applicators felt t h a t the use of a recycling system co~lsisting of three to five 250 to 500 gallon tanks and a 50 X 50' to 50 X 60' concrete ash area was a good invest- ment. Construction cost ranged from $3,000 - $15,000 with most systems c o ~ t i n g $8,000 - $12,000. Annual operating cost was about $3,000 - $4,000 for an applicator ~v i th three to five aircraft with each aircraft flying 400 to 700 liours per \.ear.

The use of flexible hoses to transfer the waste from the aircraft to the containment tanlts is recommended. After cleaning the aircraft, t l ~ c hose is a l ~ v a y s flushed w~itli clean water to rcrno\,e a11 pesticide residue. This practice climin:~tes

References

1. Unuublished Minutes of Pesticide Revue Con~mission. (1983 and 1984). Louisiana Depart- ment of Agriculture, Baton Rouge, Louisiana.

2. Unuublished Minutes of the Louisiana Coo~erative Extension Service Aerial Ap~licators Advisory Committee. (1981 - 1988). Louisiana Cooperative Extension Service, Louisiana State University, Baton Rouge, Louisiana.

3. Calhoun, H. F., Elledge, Ken, and Impson, Dr. John, Louisiana Department of Agriculture, Baton Rouge, Louisiana, Personal Communication (1981 - 1989).

4. LSA 3:3201 - 3280. Section 1.0 - 31.0 Louisiana Department of Agriculture, Baton Rouge, Louisiana.

5. Skinner, Director, Office of Solid Waste (WH-562A) United States Environmental Protec- tion Agency, Washington, D.C. 20460, Memoran- dum on Regulation Inter~retation of Pesticide Amlicator Washing Rinse Water, July 22, 1985.

6. A Guide to Minimizinp Problems of Pesti- cide Waste Management. Illinois Pesticide Waste Management Task Force, July 1, 1982.

7. Noyes, R. T., 1989. Modular Concrete Wash/Containment Pad for Acicultural Chemi- cals. ASAE Paper No. 891613. American Society of Agricultural Engineers. St. Joseph, Michigan.

8. Taylor, A. G., Agricultural Advisor, Illinois Environmental Protection Agency, Per- sonal Communication, 1985 and 1986.

9. Louisiana Aerial Applicators, Personal Communication (1981-1989).

10. Rester, Darryl, 1986. Waste Water Recy- cling, Paper No. AA86-001, 1986 Joint Technical Session of National Agricultural Aviation Associa- tion and American Society of Agricultural Engi- neers, Acapulco, Mexico.

Combination of Landfarming and Biostimulation as a Waste Remediation Practice

E. Kudjo Dzantor, PhD National Fertilizer and Environmental Research Center Tennessee Valley Authority Muscle Shoals, Alabama 3.5660

Allan S. Felsot, PhD Illinois Natural History Survey 607 East Peabody Drive Champaign, Illinois 61820

Abstract

A cor?tbination of landfarming and biostimulation is being evaluated for remediatingpesticide wastes. Soil con- tar?tittafed with alachlor, tri'fluralin, mefolachlor and atrazitie was applied to 1-tn2 subplots in a three-block ran- domized plot design to sintulate 0, 1, 5, and 10 times the agrortontic rate of alachlor application. Sewage sludge or con1 meal was incorporated into ittdividualplots at the rates of 2.5 and 5%, respectively based on the weight of a 7.6 cnt depth of soil, attd the plots were seeded with corn. Soil bioactivify and disappearance ofparent herbicides are being measured to determine the effectiveness of the rentediafiott practice. Data front contaminated soil-treated plots are beittg contpared with data from plots that were treated with fresh herbicides ntktures in amounts sintilar to those in tlte contaminated soil. With a few exceptions, ini- tial bacterial counts did not differ significantly between treatments, attd only small, generally significantly changes in numbers occurred over 16 d. In contrast fingal counts in all corn meal-amettdedplof increased significantly be- tween 7-16 d. Deltydrogenase activities were generally ltigltest in organic nutrient-antended soils. Neither tlte type nor level of herbicide application showed arty consistent relatiortsltip to microbial biot7tass or dehydrogenase ac- tivity. Ajler 60 4 nunterically higher levels of herbicide were recovered front many contamittated soil-treatedplots than from freshly sprayed ones, but fhe differences were general- ly not statistically significant (p = 0.05). Herbicide recoveries were generally lowest in corn meal-amended plots. Initial levels of herbicide application did trot sig- ttijicatttly affect recoveries after 60 d.

Introduction

There is increasing recognition that soils at many agrichemical facilities and farms have been contaminated with high concentrations of pesticides through common practices such as improper handling of product and waste discharge. In addition to problems stemming from these practices, soils may become contaminated from oc-

casional accidents such as fire at chemical storage facilities. High concentrations of ordinarily biodegradable pesticides can be extremely persistent in soil partly because they inhibit soil bioactivity (Wolfe et al., 1973, Staiff et al., 1975, Davidson et al., 1980, Felsot and Dzantor 1990a, Dzantor and Felsot 1991). High con- centrations of many pesticides are more mobile in soils than low concentrations (Davidson et al., 1980). The combination of prolonged persistence and greater mobility increases the risk of surface or groundwater con- tamination by high pesticide concentrations and em- phasizes the need for their expeditious cleanup.

The usual methods of disposing of waste contaminated soils are excavation and subsequent landfilling or in- cineration. These methods are expensive but they usually only represent waste translocation from one site to another, or their conversion into other forms, without the problem of contaminant detoxification being fully ad- dressed. As more contaminated sites are discovered, it is becoming increasingly important to seek alternative cleanup technologies that result in permanent waste reduction and are duly cognizant of the widespread na- ture of the waste problem. Bioremediation has now been recognized as one of the more cost- effective and en- vironmentally desirable cleanup alternatives.

The most common bioremediation strategies that are ap- plicable to soils are 1) landfarming, i.e., controlled ap- plication of con taminated soils to uncontaminated land to accelerate waste degra dation, 2) biostimulation, i.e., addition of nutrients or im provement in some physicochemical characteristic at contaminated sites lo stimulate biodegradative activities of native microflora, and 3) bioaugmentation, i.e., addition of specifically adapted microorganisms to enhance biodegradation of specific compounds.

We previously assessed the feasibility of remediating her- bicide-contaminated soils at an agrichemical facility in Piatt Co., Illinois, by landfarming the soils to corn and soybean fields. (Felsot et a]., 1987). The soils had been highly contaminated with herbicides (eg., 24,000 mg/kg alachlor within 7.6 cm depth of soil) from past discharge of herbicide wastes by the Galesville Chemical Company (GCC). Plots were also freshly sprayed with herbicide mixtures in amounts similar to those applied as con- taminated soil to serve as control for comparing her- bicide dissipation and phytotoxicity. Those studies showed that herbicides applied as contaminated soil generally degraded more slowly than fresh applications, particularly at higher loading rates. A combination of ex-

cessively high contaminant concentrations and space limitation may necessitate higher than normal loading rates during landfarming. Another concern was the potential for phytotoxicity when contaminated soil con- tains a diverse mixture of herbicides.

In the laboratory, experiments were performed to iden- tify factors that may influence herbicide degradation, and how they may be manipulated to optimize the process. We previously reported that the use of different organic amendments accelerated the degradation of alachlor and metolachlor that were freshly added to soil. (Felsot and Dzantor, 1990; Felson and Dzantor, 1991; Dzantor and Felsot, in press). However, the same admendments produced only marginal increases in herbicide degrada- tion in soils containing aged residues. In one experiment (unpublished), contaminated soil from the GCC site was mixed with uncontaminated soil and the mixtures were in- cubated with or without organic amendments. Alachlor and metolachlor degraded fastest when the con- taminated soil was diluted 10-fold and also amended with corn meal. Soil dilution alone, or amending the un- diluted, contaminated soils produced only small in- creases in dissipation of the herbicides compared to the dissipation in corresponding undiluted and unamended controls. The results suggested that a combination of landfarming, which the soil dilutions simulated, and bios- timulation may provide an effective means for detoxify- ing certain herbicide contaminants. This paper is a preliminary report on a study in which we are assessing a combination of landfarming and biostimulation to bioremediate soils contaminated with a mixture of alachlor, trifluralin, metolachlor and atrazine.

Methodology

Herbicide-Contaminated Soil

During April 1990, water used to fight a fire at a pes- ticide warehouse in Lexington, Illinois, flooded the soil surrounding the building and deposited high concentra- tions of trifluralin and lesser concentrations of atrazine, alachlor, and metolachlor. The soil was excavated and stored at a farm where it was eventually disposed of by landfarming during August 1990. Analysis of 18 in- dividual cores (5 cm d i m . x 10 cm deep) just prior to land farming showed that trifluralin was the primary con- stituent; the average concentration was 1582247 ppm (range 3-1003 pprn). Approximately 22 tons of this waste soil was transported to the University of Illinois Cruse Farm during August. The soil was covered with a thick(6 mil) black plastic sheet and stored through the winter. During March 1991, six cores (5 cm d a m x 10 cm deep)

Because we were interested in landfarming high con- centrations of a greater diversity of herbicides, a simu- lated spill of alachlor was created on 7 April 1991 by pouring a 9.5-L jug of Lasso 4E (480 g alachlorb) in 30- cm deep trenches that were dug into the surface of the pile; the trenches were then filled with soil. On 25 April 1991,1.4 L of Aatrex 4F (480 g atrazineb) were spilled on the surface of the pile and the soil was overturned with a spade. On 26 April 1991, a front loader mixed the pile of contaminated soil by completely overturning it in one direction and then overturning it a second time in a direction perpendicular to the first. The soil was then piled about 0.6- 0.9 m high within a 7.6 m x 3.0 m area. On 31 May, 10 cores (5cm dam. x 15 cm deep) were col- lected along a diagonal transect laid across the surface of the pile, and 10 cores (15 cm deep) were collected at a depth of 30-40 cm. Herbicide concentrations (oven-dry weight basis) determined in individual cores averaged 172299 pprn alachlor, 99rt53 ppm trifluralin, 18+9 pprn meto lachlor, and 14211 pprn atrazine.

Experimental Design

A plot measuring approximately 4.5 x 30 m was moldboard plowed and harrowed several times to pro- vide a well prepared bed. The plot was divided into three blocks, and 21 fabricated metal barriers measuring 1 x 1 x 0.15 m were layed out in each block. The metal barriers were pounded into the soil to depths of approximately 0.1 m. The 1-m2 subplots were bordered by buffer zones that measured 0.46 m within and 0.6 m between blocks.

The persistence of herbicides applied as contaminated soil or fresh sprays was monitored in subplots that were either left unamended or amended with corn meal or sewage sludge. The rate of contaminated soil application was determined on the basis of the agronomic rate of alachlor application of 4.49 kg ai/ha.?he fresh spray mix- ture consisted of alachlor, trifluralin, metolachlor and atrazine in the same proportions as that determined in analysis of the waste contaminated soil (172,99,18 and 14 mg ailkg oven dry soil respectively). Combinations of herbicide application and organic admendment were ran- domly assigned to the plots within each block; the treat- ments may be summarized as follows--herbicide applica- tion: none, waste soil or fresh spray at normal agronomic rate of alachlor application (1 X = 4.49 kg ai/ha) 5 X the recommended alachlor rate (22.5 kg ai/ha) and 10 X the recommended alachlor rate (45 kg aiha); amendments: none, 2.5% (w/w) sewage sludge and 5.0% (wlw) corn meal; percentages were based on the weight of 7.6 cm depth of soil.

were collected randomly from the pile. The following- concentrations were found: 118 & 58 pprn trifluralin, Immediately after application, the contaminated soil or

18& 14 pprn metolachlor, 12 1 ppm atrazine, and 1& 1 fresh sprays were thoroughly incorporated into 7.6 cm

ppm alachlor. depth of soil by raking. Sewage sludge or corn meal were

added to designated plots and similarly incorporated into 7.6 cm depth of soil. Within 2-3 hr after the treat- ments, soil samples were taken from the plots to be analyzed for initial herbicide concentrations, and microbial biomass and soil bioactivity. One week after the treatments each plot was planted with two rows of corn spaced at approximately 18 cm within and 30 cm be- tween rows. The buffer zones were seeded with grass.

Soil Sampling, Preparation and Storage

Soils were collected from the plots with a 5-cm diameter bucket auger. Three samples of soil from depths of 0-7.6 cm were collected from each plot within a block for residue analysis. To prevent cross-contamination, the auger was washed with acetone between subsamples taken from different treatments. Soils were sieved through a 3 mm mesh screen. Subsamples of soil from each plot were combined either by plot (yielding three samples per treatment) or by treatment (one sample per treatment) in Whirl- Pak bags and stored at 2OC for analysis for soil dehydrogenase activities and microbial numbers respectively. The individual samples were frozen at -20°C until analyzed separately (nine samples per treatment) for herbicide residues.

Extraction and Analysis

Thirty grams of soil were slurried with 15 mL of distilled water and extracted three times each with 60 mL of ethyl acetate. The extracts were evaporated to dryness on rotoevaporators and the residues were resuspended in ethyl acetate for analysis. All herbicides were qualitative- ly analyzed by packed column gas- liquid chromatog- raphy (GLC, Parkard Model 328) with nitrogen- phos- phorus specific detection. Residues were separated isothermally at 190C on a 90 cm X 0.2 mm i.d. glass column packed with 5% Apiezon + 0.1% DEGS. Residues were quantified by the method of external standards, which were used to calibrate the GLC response each day of analysis.

Measurement of Microbial Biomass and Soil Bioactivity

Bacterial and fungal numbers in soil treatments were es- timated by the plate dilution frequency assay (Harris and Sommers, 1968) using soil extract agar (Lockhead, 1990) and rose bengal-streptomycin agar (Martin, 1950) respec- tively. Dehydrogenase activities in the soils were measured as the amount of triphenyl formazan (TF) formed after incubation of soils with triphenyltet razolium chloride (Frankenberger and Johanson 1986). Soil dehydrogenase assays are reported as averages of triplicate determinations of combined samples from each plot.

Statistical Analyses

Herbicide residue data were statistically analysed using the SAS General Linear Means (GLM) Procedure (Ray 1982); differences between means within treatment groups were tested for significance using the Duncan's multiple range test. Comparisons between microbial populations were made according to the formula provided in reference (11).

Results and Discussion

Microbial Numbers and Dehydrogenase Ac- tivities in Soils during Landfarming and Bios- timulation

On day 0, soil samples from several corn meal-amended plots contained higher bacterial numbers than were enumerated in samples from corresponding unamended and sewage sludge-amended soils (Table 1). By day 7, bacterial counts in all corn meal-amended soils had declined to levels that were similar to those in the other treatments. The low bacterial counts in samples from sewage sludge-amended plots were quite unexpected. In unpub lished laboratory studies, amending three soil types with 2% (wlw) sewage sludge increased bacterial counts by 1-4 orders of magnitude over the counts in un- amended controls. Between 7-16 d in this study, small and mostly insignificant changes occurred in bacterial numbers; the changes did not reflect any consistent relationship to herbicide type and level, organic amend- ments, or combinations of the treatments.

Fungal counts in soils from nearly all unamended and sewage sludge-amended plots were similar and did not vary much over 16 d (Table 2). Initial fungal counts in soils from several corn meal-amended plots were sig- nificantly higher than the counts in samples from cor- responding unamended and sewage sludge-amended plots. Between 7-16 d, fungal counts in all corn meal- amended soils increased to between 10-80 times the levels in unamended soils. Gross colony characteristics of the predominant fungus in these samples were similar to those of a m sp. that had been isolated earlier in a soil that has been incubated with sewage sludge in the laboratory. That isolate rapidly degraded alachlor, propachlor and metolachlor in liquid cultures (data sub- mitted for publication). In this field study, relatively fewer colonies of the isolate were found in sewage sludge amended soils and considerably fewer yet were found in unamended treatments. The changes in fungal numbers in corn meal-amended soils did not have any consistent correlation with type or level of herbicide treatment.

During 16 d, dehydrogenase activities were highest in soils from all sewage sludge-admended plots (Table 3).

With a few exceptions, dehydrogenase activities in soils from corn meal-amended plots were substantially higher than those in corresponding unamended soils, but they were generally significantly lower (p = 0.05) than those in sewage sludge-amended soils. By day 30, dehydrogenase activities in sewage sludge amended soils had decreased slightly, but they had increased significantly in corn meal- amended soils (data not shown). Neither the type nor level of herbicide application appears to influence to any large extent the levels of dehydrogenase activities in the treatments.

Dehydrogenase activities have been reported to reflect closely the microbial biomass in soil (Casida et al., 1964), but measurements in this study, like those that we have reported previously (Dzantor and Felsot, 1991) did not support that observation. For example, the ~ i ~ c a n t l y higher levels of dehydrogenase activity in sewage sludge- amended soils during 16 d. were not reflected by higher microbial numbers in those samples. Probable causes for this discrepancy have been discussed by earlier workers (eg., Stevenson, 1%2).

Herbicide Recoveries from Soil after Landfarming and Biostimulation.

Herbicide recoveries from soil 60 days after various treat ments are shown in Tables 4a and 4b. The results are presented as means of nine determinations expressed as percentages of 0-day recoveries. High variability in residue recoveries prevented detection of significant dif- ferences between many treatment comparisons, com- plicating definitive interpretations of some of the obser- vation. We have previously reported similar variability in samples from another landfarming experiment (Felsot et al., 1988; Felsot and Dzantor, 1991) and from a laboratory study (Dzantor and Felsot, 1991). Sampling error, compounded by segregation of pesticides has been recognized as a major obstacle for obtaining valid repres- tative samples in waste contaminated systems (Junk and Richard, 1984). In spite of the variability in these studies some trends were discernible and a clearer picture may yet emerge when data from other sampling periods haie been analyzed and more detailed statistical analyses have been completed.

The results showed that dissipation of alachlor was in- fluenced most by the form in which the herbicide was ap- plied and by the presence of organic amendment. After GO d, 0-% of initial alachlor applications were recovered in samples from sprayed plots and 15-20% were recovered in samples from contaminated soil-treated plots (Tables 4a and 4b). The more prolonged per sis- tence of alachlor residues in contaminated soil-treated plots was consistent with our previous landfarming obser- vation (Felsot and Dzantor, 1991). Aged pesticide residues in soil have been shown to be less desorbable

(McCall and Agin; 1985, Steinberg et al., 1988), and in some cases more slowly degraded than fresh applications (Steinberg et al., 1988; Byast and Hance ,1981). Within amendment groups, alachlor recoveries were lowest in soils from corn meal-amended plots followed by recoveries in sewage sludge-amended plots. Alachlor level in the range studied did not appear to be a sig- nificant factor in recoveries after 60 d; the 33.5% recovery in samples from the 10X sprayed, unamended soils was not ~ i ~ c a n t l y different (p = 0.05) from the 17.7 and 15.9% recoveries from the corresponding 1X and 5X treatments.

Recoveries of metolachlor were also lowest in corn meal- amended plots and fresh applications of the herbicide ap- peared to dissipate slightly faster than applications as contaminated soil. With the exception of the 1X spray treatment, metolchlor recoveries in sewage sludge- amended plots were either similar to or, in many cases numerically greater than the recoveries in correspond ing unamended treatments. The level of metolachlor ap- plied initially did not appear to be an important factor in recoveries after 60 d.

Like alachlor and metolachlor, recoveries of trifluralin were generally lowest in samples from corn meal- amended A high recovery of trifluralin in the 1X sprayed corn meal-amended treatment was likely an ar- tifact of sampling. Trifluralin recoveries in samples from sewage sludge-amended plots were similar to, and in some cases higher than recoveries in samples from un- amended plots. There were no apparent differences in the dissipation of trifluralin applied as contaminated soil or fresh spray, and the initial rates of application did not seem to affect recoveries after 60 d.

Atrazine recoveries in samples from contaminated soil- treated plots did not differ significantly among treatment levels or among amendment types within treatment levels. In sprayed plots, ~ i ~ c a n t l y lower than control levels of atrazine were recovered in the 1X sludge- amended and 5X corn meal- amended soils only.

Conclusion

Bioremediation has now been recognized as a practical, economical and environmentally desirable waste clean- up alternative. The results presented here are only preliminary observations in an ongoing experiment, but they suggest that a combination of landfarming and bios- timulation may be used effectively to decontaminate cer- tain herbicide wastes. For the practice to be effectice, the appropriate amendments and conditions conducive to en- hanced biodegradation of particular wastes must be determined.

A severe drought immediately following our experiments might have influenced herbicide dissipation in at least two ways: 1) decreased bioavailability for biodegrada- tion, particularly the less water soluble trifluralin and atrazine, 2) delayed establishment of rhiioshpere effects that might have been important in enhancing biodegrada- tion. These field studies were based on laboratory obser- vations that were performed under "optimurn"mndi- tions. Keeping soil aeration and moisture at near op- timum level during landfarming may further enhance waste detoxification.

As we have observed previously, residues tended to dis- sipate more slowly when they are applied as con- taminated soil than as fresh sprays. But the rate of dis- sipation of some of the soil applied herbicides in these ex- periments is quite encouraging. It is too early to draw any fast conclusions based on 60-day observations only. Analyses of samples from later dates (100- and 180- day samples are being analyzed) may yet provide us with a more definitive answer to the applicability of landfarm- ing and biostimulation as a remediation strategy.

Acknowledgements

We wish to thank Laurie Case and Duane Kimme of the Illinois Natural History Survey for technical assistance, and Randy Finch of the Tennessee Valley Authority for statistical analyses. This research is a contribution from the Illinois Natural History Survey, the Unversity of 11- linois at Urbana Champaign, and the Tennessee Valley Authority, and was supported in part by the Illinois Haz- ardous Waste Research and Information Center, Project NO. HWR 91-084.

References

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2. Casida, L. E., Jr., D. A. Klein and T. Santoro. 1%4. Soil Dehydrogenase activity. Soil Sci. 98:371-376.

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5. Dzantor, E. K, and A. S. Felsot (in press). Landfarm- ing and biostimulation for decontaminating herbicide wastes in soil. Proceedings of the International Workshop on Research in Pesticide TreatmenVDis- posaVMineralization. February 26-27,1991. Cincinnati, Ohio.

6. Felsot, A. S., R. Liebl, and T. Bicki. 1988. Feasibility of land application of soils contaminated with pesticide waste as a remediation practice. Final Project Report (HWRIC RR 021). Ill. Hazardous Waste Research and Information Center, Illinois State Survey Division, Savoy, IL, 55 pp.

7. Felsot, A. S., and E. K Dzantor. 1990a. Enhancing biodegradation from detoxification of herbicide waste in soil. Pages 192-213 in K D. Racke and J. R. Coats, editors. Enhanced biodegradation of pesticides in the en- vironment, American Chemical Society Symposium Series No. 426, Am. Chem. Soc., Washington, D. C.

8. Felsot, A. S., and E. K. Dzantor. 1990b. Enhancing the biodegradation of high concentrations of acetanilide her- bicides. Abstract 07B-24, poster presentation, 7th Inter- national Congress of Pesticide Chemistry, Hamburg, FRG.

9. Felsot, A. S., and E. K. Dzantor. 1991. Remediation of herbicide wastes in soil: experiences with landfarming and biostimulation. Pages 532-551 in Pesticides in Next Decade: The challenges ahead. Weigmann, D. L. ed. Third National Pesticide Conference. Virginia Polytech- nic Inst., Blackburg, VA.

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14. Martin, J. P. 1950. Use of acid, rose bengal and strep- tomycinin the plate method for estimating soil fungi. Soil Sci. 69:215-233

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Table 1. Bacterial counts in field soil samples following landfarming and biostimulation

No. of bacteria/q ods [x l o 9 ) after dayb Herbicide ~reatment~ TYPe Level Amendment 0 7 1 6

None OX None 2 . 8 1 . 2 4 .0 (1 .1-6 .8) (0 .5-3 .1) (1 .6-9 .8)

Sewage 20.7 0.2 0 .4 Sludge (8 .4-51 .1) (0 .1-0 .4) (0 .2 -0 .9 )

Corn meal 387.0 2 . 1 2.2 (157.0-957) (0 .8-5 .2) (0 .9 -5 .3 )

Contam. Soil 1 X None 0.9 0 . 1 7 .4 (0 .3 -2 .3 ) (0 .05-0 .3) (3 .0-18 .2)

Sewage 0 . 4 1 . 6 2.2 Sludge (0 .2 -0 .9 ) (0 .6-3 .8) (0 .9 -5 .3 )

Corn meal 27.9 2 .8 2 .9 (11 .3-68 .9) (1 .2 -7 .0 ) (1 .2 -7 .1 )

5 X None 3 8 . 1 7 .3 (15 .4-94 .0) (2 .9-17 .9)

Sewage 5 . 3 15 .9 Sludge (2 .1-13 .0) (6 .5-3 .9)

Corn meal 70.8 0.9 (28 .7-175.0) (0 .3 -2 .3 )

1 O X None 7 .0 9 .6 (2 .9-17 .4) (3 .9-23 .8)

Sewage 2.1 12 .4 12 .6 Sludge (0 .8 -5 .1 ) (5 .0 -30 .7 ) (5 .1 -31 .1 )

Corn meal 1620.0 1 . 6 1 . 6 (655-4000) (0 .7 -4 .0 ) ( 0 . 7 - 4 . 0 )

a. See text for treatment level designations.

b. Values in parentheses are 95% confidence limits calculated according to formula given in reference (11); ods=oven dry equivalent of soil.

Table 1. (Continued)

No. of bacteria/a ods (x lo9) after dayb Herbicide ~reatment~ TYPe Level Amendment 0 7 16

Fresh Spray 1X None

sewage Sludge

Corn meal

5 X None

Sewage Sludge

Corn meal

10X None

Sewage Sludge

Corn meal

a. See text for treatment level designations.

b. Values in parentheses are 95% confidence limits calculated according to formula given in reference (11); ods=oven dry equivalent of soil.

Table 2. Fungal numbers in field plots following landfarming of herbicide-contaminated soil and biostimulation

No. of funqi/q ods (x lo5) after dayb Herbicide ~reatment~ Type Level Amendment 0 7 16

None OX None 5.2 5.4 21.4 (2.1-12.4) (2.2-13.4) (8.7-52.9)

Sewage 7.1 7.3 40.0 Sludge (2.9-17.6) (3.0-18.0) (16.2-98.8)

Corn meal 120.0 123.0 736.0 (48.7-29.7) (49.8-304) (298-1820)

Contam. Soil 1X None 5.3 5.4 9.6 (2.1-13.2) (2.1-13.2) (3.9-23.8)

Sewage 20.6 21.0 16.3 Sludge (8.3-41.0) (8.5-51.8) (6.6-40.2)

Corn meal 20.8 21.2 96.3 (8.4-51.3) (8.8-52.3) (39.0-23.8)

5X None 15.6 16.1 4.0 (6.3-38.5) (6.5-39.7) (1.6-9.9)

Sewage 9.2 9.4 7.4 Sludge (3.7-22.8) (3.8-23.2) (3.0-18.3)

corn meal 12.1 12.3 96.2 (4.9-29.8.0) (5.0-30.3) (39.0-238)

1OX None 3.8 4.0 7.4 (1.5-9.4) (1.6-9.9) (3.0-18.4)

Sewage 9.2 9.5 7.4 Sludge (3.7-22.7) (3.9-23.5) (3.0-18.3)

Corn meal 275 287 398 (111-680) (116-709) (161-984)

a. See text for treatment level designations. b. Values in parentheses are 95% confidence limits calculated according to

formula given in reference(l1); ods=oven dry equivalent of soil.

Table 2. (Continued)

No. of funqi/q ods (x lo5) after davb ~erbicide ~reatment~ Type Level Amendment 0 7 16

Fresh Spray 1X None 15.8 16.1 9.7 (6.4-39.0) (6.5-39.7) (3.9-23.9)

Sewage 5.3 5.4 74.2 Sludge (2.2-13.2) (2.2-13.4) (30.0-183.0)

Corn meal 207.0 210.0 215.0 (82.9-506) (84.9-518.0) (87.2-532)

5X None 7.0 7.2 9.6 (2.9-12.4) (2.9-17.9) (3.9-23.6)

Sewage 9.3 9.5 9.7 Sludge (3.8-23.1) (3.9-23.5) (3.9-23.4)

Corn meal 3.9 3.9 738.0 (1.6-9.5) (1.6-9.7) (299-182.0)

10X None 20.6 21.1 16.3 (8.3-50.-) (8.5-52.1) (6.6-40.2)

Sewage 7.1 7.2 12.6 Sludge (2.9-17.5) (2.9-17.9) (5.1-31.2)

Corn meal 91.0 95.1 737.0 (36.8-225) (38.5-235) (298.0-1820)

a. See text for treatment level designations.

b. Values in parentheses are 95% confidence limits calculated according to formula given in reference (11); ods=oven dry equivalent of soil.

Table 3 . Dehydrogenase activities in field plots following landfarming and biostimulation

Herbicide Treatment Soil dehydrogenase activity (ug TPF/g odds) after dayb

Type ~ e v e l ~ Amendment 0 7

None OX None 7 1 . 5 ( 1 0 . 4 ) 8 3 . 0 ( 2 7 . 1 ) 6 9 . 6 ( 5 . 5 ) Sewage sludge 4 1 0 . 7 ( 2 9 0 . 1 ) 7 1 7 . 1 ( 1 2 1 . 4 ) * 5 4 1 . 3 ( 8 9 . 8 ) * Corn meal 2 5 3 . 8 ( 7 8 . 8 ) 2 1 8 . 8 ( 7 5 . 9 ) 1 2 5 . 9 ( 7 3 . 3 ) ..............................................................

Soil 1 X None 5 9 . 4 ( 8 . 8 ) 6 5 . 1 ( 1 5 . 3 ) 7 3 . 3 ( 6 . 8 )

Sewage sludge 6 0 1 . 4 ( 5 4 . 7 ) * 4 7 9 . 3 ( 1 9 9 . 8 ) * 5 0 8 . 8 ( 1 1 8 . 4 ) * Corn meal 2 0 2 . 5 ( 3 6 . 6 ) * 1 0 4 . 4 ( 1 7 . 7 ) 1 2 0 . 5 ( 4 1 . 2 )

5 X None 7 8 . 9 ( 8 . 6 ) 6 4 . 1 ( 2 3 . 5 ) 9 7 . 3 ( 1 5 . 5 ) Sewage sludge 4 2 7 . 7 ( 7 2 . 4 ) * 5 0 4 . 3 ( 9 . 4 ) * 4 6 1 . 8 ( 4 7 . 9 ) * Corn meal 1 9 9 . 9 ( 4 2 . 1 ) * 1 9 7 . 6 ( 5 3 . 3 ) * 1 1 4 . 4 ( 6 5 . 9 )

1 O X None 1 0 1 . 2 ( 1 5 . 0 ) 1 0 2 . 9 ( 1 2 . 1 ) 1 1 1 . 5 ( 8 . 6 ) Sewage sludge 3 7 0 . 7 ( 3 7 . 2 ) * 3 6 3 . 5 ( 5 9 . 7 ) * 4 1 6 . 2 ( 4 7 . 9 ) * Corn meal 3 4 8 . 0 ( 7 8 . 3 ) * 6 8 . 7 ( 3 0 . 4 ) 9 4 . 1 ( 8 . 3 ) ..............................................................

Spray 1 X None 1 0 4 . 6 ( 2 7 . 8 ) 7 7 . 4 ( 1 4 . 7 ) 9 8 . 9 ( 1 4 . 1 ) Sewage sludge 6 5 3 . 1 ( 7 2 . 5 ) * 5 3 4 . 0 ( 1 0 8 . 8 ) * 4 5 3 . 7 ( 1 4 8 . 8 ) * Corn meal 2 0 7 . 2 ( 3 1 . 5 ) 1 5 3 . 3 ( 7 . 7 ) 1 3 4 . 9 ( 3 3 . 0 )

5 X None 6 2 . 0 ( 2 0 . 4 ) 5 7 . 1 ( 6 . 4 ) 7 3 . 2 ( 6 . 8 ) Sewage sludge 6 3 7 . 1 ( 3 0 1 . 9 ) * 6 8 3 . 4 ( 5 6 . 2 ) * 5 3 1 . 6 ( 2 7 . 5 ) * Corn meal 1 6 5 . 8 ( 8 . 2 ) 8 0 . 5 ( 1 4 . 5 ) 1 4 3 . 0 ( 4 0 . 3 )

1 OX None 8 2 . 1 ( 2 9 . 4 ) 8 0 . 6 ( 3 1 . 3 ) 6 2 . 7 ( 3 1 . 1 ) Sewage sludge 3 5 3 . 9 ( 1 3 0 . 9 ) * 5 3 9 . 3 ( 1 5 0 . 8 ) * 4 7 9 . 8 ( 1 8 . 7 ) * Corn meal 2 2 1 . 2 ( 8 2 . 6 ) 1 5 9 . 2 ( 1 1 . 5 ) 1 4 4 . 9 1 5 1 . 7 )

a. See text for treatment level designations.

b. Values are means of nine replicates per treatment followed by standard deviations in parentheses; means with asterisks are significantly different from corresponding control (none) treatments according to Duncan's multiple range tests ( p = 0 . 0 5 ) .

Table 4a. Recovery of herbicides 60 days after landfarming of contaminated soil and biostimulation

% of initial recoveryb

Treatment ~ e v e l ~ Amendment Alac. Meto. Trif. Atra.

1 X None 29.0(11.0) 41.6(14.1) 34.2(11.0) 28.7(18.6)

Sewage sludge 20.5(6.6) 73.1(23.2) 60.3(21.3) 27.5(18.7)

Corn meal 19.3(3.3) 33.8(10.6) 20.1(6.0)* 41.2(20.6) .................................................................. None 32.6(7.8) 89.0(53.5) 46.3(18.6) 115.8(53.8)

Sewage sludge 41.6(8.7) 114.2(4.6) 132.5(7.9)* 80.1(27.7)

Corn meal 15.5(4.2)* 28.0(7.6)* 26.7(4.6) 110.7(110.6) .................................................................. None 37.8(13.2) 67.1(17.9) 60.1(29.0) 63.8(39.5)

Sewage sludge 22.1(5.3) 61.6(5.2) 58.1(7.7) 27.8(2.3)

Corn meal 16.8(3.6) 31.5(10.7)* 29.5(8.5) 29.0(12.9)

a. See text for treatment level designations.

b. Values are means generated from nine replicates followed by standard deviations in parentheses; means with asterisks are significantly different from their corresponding control (none) treatments according to Duncan's multiple range tests (p=0.05).

Table 4b. Recovery of herbicides 60 days after application of fresh spray mixture and biostimulation

% of initial recoveryb

Treatment ~ e v e l ~ Amendment Alac. Meto. Trif. Atra.

1 X None 17.7(14.8) 61.1(27.4) 57.8(51.3) 45.7(21.4)

Sewage sludge 12.7(17.7) O.O(O.O)* 36.6(27.4) 4.4(3.2)*

Corn meal O.O(O.0) O.O(O.O)* 61.1(50.0) 10.2(3.2) .................................................................. None 15.9'(3.0) 50.6(6.6) 34.8(5.5) 21.8(3.3)

Sewage sludge 7.1(2.4)* 91.0(20.4) 79.5(27.2)* 23.8(7.3)

Corn meal 1.9(1.9)* 9.4(12.2)* 28.1(10.4) 6.9(1.9)* .................................................................. None 33.5(9.7) 83.2(13.6) 62.9(10.2) 25.9(2.2)

Sewage sludge 9.6(5.9)* 97.1(50.8) 69.8(43.7) 28.8(18.7)

Corn meal 1.8(0.9)* 9.0(4.5)* 29.5(3.0) 6.3(0.7)

a. See text for treatment level designations.

b. Values are means generated from nine replicates followed by standard deviations in parentheses; means with asterisks are significantly different from their corresponding control (none) treatments according to Duncan's multiple range tests (p=0.05).

Current Approaches to Development of Pesticide Rinsate Disposal Technology

Cathleen J. Hapeman-Somich, Ph.D. Pesticide Degradation Laboratory Agricultural Research Service U.S. Department of Agriculture

Abstract

Economic and regulatory issues have prompted waste minimization and reuse of pesticide rinsate, yet the need for disposal methodology remains. Unlined evaporation pits, once considered an attractive option, transfer the pesticide to another environmental ntatni. Concentration or carbon filtration under controlled situations reduce the volume of waste requiring disposal. Microbial degradation is a viable method for biolabile compounds. Chemical pretreatment of rinsate with oxidizing agents has been shown to enhance microbial nt ineralization of more persistent pesticides. Preliminary field tests of a binary process, successive chemical and microbial treatment, revealed several significant challenges including high ferfilizer concentratiotts, the presence of surfactants and adjuvants and substantial fluchtations in the types and concentrations of pesticides.

Introduction

Increased awareness of the environmental risks associated with pesticide rinsate has prompted applicators to minimize the quantity of waste generated and to seek appropriate methods for disposition of unusable materials. If rinsate is to be reused, the total applied pesticide cannot exceed product label requirements. In addition, the recycled material cannot contain pesticide residues or cleaning materials that will harm crops. The vast majority of disposal processes and concepts that have been presented over the past two decades (Bridges, 1985; Bridges, 1986) involve transfer of the potential pollutant to another matrix and/or some detoxification technique. The immediate threat to the environment is removed in some of these detoxification processes. However, total mineralization, breakdown of a material into its elemental forms, such as carbon dioxide, water, ammonia or nitrates, inorganic salts and other innocuous compounds, may be required if the products of these procedures are to be rendered harmless and non-polluting.

The composition of the rinsate can vary among pesticide applicator situations and regions of the country. For example, a large variety of insecticides,

nematicides and fungicides are prevalent in an orchard situation whereas, in the corn belt, the predominant chemicals are herbicides. In addition, pesticide concentrations differ as do the amounts of surfactants, adjuvants, formulations and fertilizers. Rinsate also contains particulate matter such as the clay base of wettable powders and soil from application equipment. Thus, the effectiveness of a simple and universal treatment strategy to dispose of all rinsate is uncertain. Rinsate disposal techniques, in addition to cost, must consider the types of compounds presents, the level of treatment desired and the environmental matrix used for final disposition. The ultimate goal is to treat this waste possibly where it is generated so that it becomes nonhazardous and presumably nonregulated.

Physical Methods

In the past, pesticide rinsates been deposited on soil surfaces, in lined evaporation pits or in above- ground containment bins (Hodapp; Junk; Wiltterlin, 1984). This mechanism relied on concentration and adsorption of the pesticides to soil, compost, etc. reducing the total volume of material requiring disposal. Carbon filtration, a more controlled process can also provide a means of concentrating the pesticides of waste requiring disposal. The spent carbon and the sludge from the evaporation systems must be treated further either in a R C M approved hazardous waste landfill or a licenced incinerator. Alternatively, chemical or biological methods could be developed to completely degrade these pesticide sludges.

Chemical and Biological Methods

An alternative waste treatment scheme for the inherently biolabile pesticides is microbial degradation. This technique has been successfully applied to the organophosphate, coumaphos, at the bench-scale reactor level (Sheltort). Some microbial activity has been indicted in a number of evaporation beds (Hodapp; Junk; Wi,tterlitt, 1984). Unfortunately, microbial degradation of many pesticides is slow; the half life of the parent materials can be greater than several months (Winterlin, 1989). Metabolism can be completely inhibited if pesticide concentrations are too high or if inhibitory compounds, such as soil, rinsate components or toxic degradation products, are present.

Alkaline hydrolysis has also been examined in pesticide containment units but the application of this procedure is limited due to its dependence on the pesticide chemical structure. Pesticide formulations

may also suppress hydrolysis by buffering the system (Hemley; Lande; Schmidt).

Most of these studies have focused on the disappearance of parent materials but the nature and the fate of product residues must be considered. Some products are actually more toxic than the parent substrate. And as with the parent materials, compouncfs that are mineralized too slowly can contaminate water supplies.

Laboratory Investigations

A more promising strategy, yet also more capital intensive, is a combined approach where unusable rinsate is chemically treated using ultraviolet light or oxidizing agents to give rise to products that are more readily degraded by indigenous soil microflora than parent materials (Hapeman-Sor7ticlt, 1991). Irradiation of some pesticides with ultraviolet light yields compounds that are dealkylated and/or dechlorinated (Crosby and re$ tlterei~t; Somich, 1988). When the same compounds are treated with ozone, the alkyl side chains are oxidized and sometimes removed, but chlorine is usually not displaced (Hapentart-Somich et al., 1991; Keamey, 1985; Sontich, 1988). During ozonation, simple aromatic rings are also cleaved and portions mineralized, presumably to CO, or short chain carboxylic acids.

When either irradiated or ozonated solutions were placed on soils, recoveries of 80-90% 14c0, were observed within several days, whereas untreated labelled parent material was rarely mineralized beyond a few percent after several weeks (Keamey, 1988; Somich, 1988; Somiclt, 1990). In addition to this enhanced microbial mineralization of more persistent pesticides, bioassays of the process residues using soybean and wheat indicated that herbicidal activity was eliminated; Ames assays showed no mutagenic effects (Sonticlt, 1990).

Onsite Testing

Experiments using formulated pesticides at concentrations typically encountered in rinsates showed that photolysis was not always effective (Keanley, 1987). Subsequent laboratory tests revealed that UV light was principally responsible for initial degradation in both pure photolysis and photolytic ozonation (Hape171m1- Sontich, 1991). Typical field waste, however, was too opaque for effective light penetration. Consequently, UV light was abandoned in favor of ozone for chemical pretreatment. A pesticide disposal unit (PDU), initially consisting of an ozonation chamber and a soil column with organic rich soil as a source of microorganisms, was examined for effectiveness in the field.

First Year Field Tests: PDU-I

Pesticide waste was obtained from a small research farm in Maryland. Atrazine, cyanazine,

metolachlor and paraquat were the only detectable pesticide components during the first year. Initial laboratorv studies showed that the rate of ozonation was slower for paraquat and the s-triazines, atrazine azd cyanazine, as compared to metolachlor. In addition the rate was not ~seudo-first order as had been observed in previous studies using pure con~pounds. This was the first indication that other components in the waste could compete for the ozone (or hydroxy radical). Enhanced mineralization of the ozonated '4~-labelled-pesticide solutions was achieved using organic rich soil, although the s-triazines were shown to be less amenable to biodegradation (Somiclt, 1990).

Field experiments with PDU-I were fairly successful although difficulties arose in determining an appropriate ozonation time in the field. Rinsate was treated with ozone for 18 hours and then circulated through the soil column for 2 days. Parent material concentrations in the final effluent were reduced 45 to 97% from initial concentrations which ranged from 17 to 82 ppm. Incomplete oxidation of parent materials occurred and were then passed through the soil column. Although some of the parent pesticide bound to the column, a significant amount of untreated pesticide still present in the column effluent (Somiclt, 1990). Thus for overall effectiveness. ozonation must be continue until all parent materials are depleted.

Second Year Field Tests: PDU-II

Atrazine, cyanazine, dicamba, metolachlor and paraquat were detected in the pesticide waste from the second year. Concentrations of parent material were considerably higher, 70 to 300ppm. The process was monitored more frequently and onsite, allowing more timely processing of data and near complete oxidation was carried out. Biomineralization, on the other hand, could not easilv be determined since the soil contained a high amount'of organic matter which masked the peaks of the ozonation products (Hapernart-So171ic11, 1992); however, this monitoring dilemma was not addressed during this period.

The principle mechanisms in aqueous ozonation are direct reaction with ozone or reaction with hvdroxv radical, which is generally the most prevalent oxidation pathway (Peyton). Previous work had shown that raising the pH and addition of hydrogen peroxide increased the ozonation rate, implying an hydroxy radical mechanism (So~?tich, 1990). The buffer system used to maintain pI-I 10 was examined during the second year in an attempt to improve the ozonation efficiency. Carbonate buffer, which was the buffer of choice in nrevious studies because it is easily removed, is a known radical scavenger, whereas borate buffer is not (Glaze). Laboratory studies with farm generated rinsate indicated that these was no significant difference between the two buffers; however, borate was used during the second year because ACS grade borate is less than ACS grade carbonate. -

Longer ozonation time was required in these

second year experiments, even though the ozone delivery rate remained constant between the first and second years. Furthermore, the overall ozonation efficiency, as measured by the amount of ozone required to oxidize a known quantity of parent material, decreased 50%. This decrease may have been the result of design changes in PDU-I1 .and/or the increase in pesticide concentrations. Presumably the concentrations of formulating agents, emulsifiers surfactants and fertilizers were higher as well. These compounds are thought to decrease ozonation efficiency since they can also compete for oxidizing agents.

Third Year Trials

Pesticide waste examined in the third season contained atrazine, cyanazine, dicamba, metolachlor and paraquat. The concentration of ammonia, from the fertilizers mixed into the pesticide solutions, was also determined and values of ca. 1% obtained. Laboratory studies had implicated high ammonia concentrations in the growth inhibition of an organism, PSA, known to degrade s-triazines (Leeson). Ammonia can also compete for hydroxy radicals in the ozonation process.

Thus, nitrogen removal was attempted by increasing the pH to 10, which is above the pK, of ammonia, and vigorously aerating the solution. A tall column was needed to prevent volatilization of the pesticide, but more importantly, considerable foaming occurred even in the presence of significant concentrations (>5%) of antifoaming agent (Hapentail- Somich, 1992). While removal of some ammonia was achieved, this approach was obviously not useful or practical.

Reevaluation and Redesign

The ozonation products of the s-triazines were examined initially as these had been shown, in the first year tests, to be the more recalcitrant. The final ozonation products of atrazine were determined to be 2- chloro-4,6-diamino-s-triazine (CAAT) and 6-acetamido- 4-amino-2-chloro-s-triazine (CDAT) (Hapet~tart-SonticlIz et al., 1991). Thus, ozonation must continue not only after all parent material is depleted but until only CAAT and CDAT remain. Because the s-triazine ring of CAAT and CDAT cannot be used as a source of carbon, as it is at the oxidation state of carbon dioxide, microorganisms can utilize these compounds only as nitrogen sources in the presence of carbon substrate. Indeed, PSA was reexamined and was found to mineralize CAAT only when CAAT was the sole nitrogen source; ammonia was con~pletely inhibitory lo CAAT degradation (Leesoil).

A gram positive bacterium (DRS-I) was subsequently isolated from activated sewage sludge which could mineralize CAAT to carbon dioxide, ammonia, and chloride when additional carbon (corn syrup) was added. Further experiments, some using ' 4 ~ - l a b e l l e d - ~ A A ~ , demonstrated that DRS-1 utilized

CAAT as a nitrogen source for growth even in the presence of inorganic nitrogen. Kinetic constants for optimal growth of DRS-1 were determined using a bench-scale continuous-flow stirred tank reactor. Additional studies using an upflow fixed-film column bench-scale reactor, packed with Celite Biocatalyst Carrier, demonstrated the ability of DRS-1 to perform as a biofilm and its resiliency to sudden fluctuations in the waste stream and nutrient supplies (Leeson).

PDU-I11 is currently under construction and includes a more efficient ozone delivery unit in the ozonation reactor and several stages of biomineralization. The first bioreactor is a simple fermentation tank to remove any readily degradable carbon. The second bioreactor is an upflow column reactor packed Celite Biocatalyst impregnated with DRS-1 to remove CAAT. Interferences from soil components will be precluded by using this new support matrix for DRS-1.

Conclusions and Future Direction

While enhanced biodegradation of dilute pesticide solutions subsequent to UV irradiation or treatment with ozone was easily accomplished in the laboratory studies, considerable differences were observed between laboratory tests and individual field trials as is usually the case with environmental or real world samples. Uncontrollable factors such as precipitation events, increased applications of pesticides and fertilizers, and evaporation and concentration all contributed to the variability. Concentrations of pesticides remained relatively similar within a given application season but between years concentrations and the types of pesticides were different. Thus, direct comparisons of experimental data and conclusions between years is not always possible.

The results of these trials also demonstrated that significant optimization would be required before commercialization of this technique is possible. Research is continuing to further define the ozonation process and optimize the conditions for microbial activity. Eventually, this scheme of preoxidation and microbial mineralization may prove useful in remediating pesticide laden soils found at applicator operation sites.

References

Bridges, J.S. 1985. Proceedittgs: Natiotlal Workshop on Pesticide Disposal. EPA/600/9-85/030.

Bridges, J.S. 1987. Proceeditlgs: Natiottal Workshop or1 Pesticide Disposal. EPA/600/9-87/001.

Crosby, D.G. 1976. Herbicide photodecomposition. In: Herbicides. Cllet?tist~, Degradation, ajtd Mode of Actior~; Kearney, P. C.; Kaufman, D. D., Eds.; Marcel Dekker: New York, New York; Vol 2 pp 825-890.

Glaze, W. H. 1987. Drinking-water treatment with ozone. Etiviron. Sci. Technol. 19:224-230.

Food Clteni. 1992).

Hapeman-Somich, C. J. 1991. Mineralization of pesticide degradation products. In: Pesticide Transfonnatioti Products. Fate artd Sigt ificance in tlze Ettvironnzettt; Somasundaram, L.; Coats, J.R., Eds.; ACS Symposium Series No. 459; American Chemical Society: Washington, DC, 1991; pp 133-147.

Hapeman-Somich, C.J., Zong, G.-M., Lusby, W.R., Muldoon, M.T., Waters, R. Ozonation of atrazine. Description of the degradation pathway and product identification. (Manuscript submitted to J. Agn'c. Food C\ieni. 1991).

Hapeman-Somich, C.J., Shelton, D.R., Leeson, A., Muldoon. M.T. and Rouse, B.J. Field studies using ozonation and biomineralization as a disposal methodology for pesticide wastes. (Manuscript to be submitted to Clienzosphere 1992).

Hemley, A.T, Zhong, W.Z., Janauer, G.E. and Rossi, R. 1984. Investigation of degradation rates of carbamate pesticides. In: Treatment atid Disposal of Pesticide Wastes. Kruger, R.F., Seiber, J.N., Eds.; ACS Symposium Series No. 259; American Chemical Society: Washington, DC. pp 245-259.

Hodapp, D.M., Winterlin, W. 1989. Pesticide degradation in model soil evaporation beds. Bull. Etiviron. Contam. Toxicol. 43:36-44.

Junk, GA., Richard, J.J. and Dahm, P A . 1984. Degradation of pesticides in controlled water-soil systems. In: Treatnzent and Disposal of Pesticide Wastes. Kruger, R.F., Seiber, J.N., Eds.; ACS Symposium Series No. 259; American Chemical Society: Washington, DC. pp 37-67.

Kearney, P.C., Ruth, J. R., Zeng, Q. and Mazzocchi, P. 1985. UV-Ozonation of paraquat. J. Agric. Food Cltent. 33:953-957.

Kearney, P.C., Muldoon, M.T. and Somich, C.J. 1987. UV-Ozonation of eleven major pesticides as a waste disposal pretreatment. C/ieniosphere 16:2321-2330.

Kearney, P.C., Muldoon, M.T., Somich, C.J., Ruth, J.R. and Voaden, D.J. 1988. Biodegradation of ozonated atrazine as a wastewater disposal system. J. Agric. Food Clteni. 36:1301-1306.

Lande, S.S. 1978. Identification and description of chemical detoxification methods for the safe disposal of selected pesticides. NTIS PB-285208, Springfield, VA.

Peyton, G.R. and Glaze, W.H. 1987. Mechanism of photolytic ozonation. In: Photoclientistry of Erivironntental Aquatic Systents. Zika, R.G., Cooper, W.J., Eds.; ACS Symposium Series No. 327; American Chemical Society: Washington, DC; pp 76-88.

Schmidt, C., Klubek, B. and Tweedy, J. 1987. Biological and chemical disposal systems for waste pesticide solutions. In: Proceedings: National Workshop on Pesticide Disposal. Bridges, J.S., Ed.; EPA/600/9- 871001. pp 45-55.

Shelton, D.R. and Hapeman-Somich, C.J. 1991. Use of indigenous microorganisms of the disposal of cattle dip waste. In: On-Site Bioreclaniatiort. Processes for Xetiobiotic and Hydrocarbon Treattnent. Hinchee, R.E., Olfenbuttel, R.F., Eds.; Butterworth-Heinemann: Boston, MA; pp 313-323.

Somich, C.J., Kearney, P.C., Muldoon, M.T. and Elsasser, S. 1988. Enhanced soil degradation of alachlor by treatment with ultraviolet light and ozone. J. Agric. Food Cltem. 36: 1322-1326.

Somich, C.J., Muldoon, M.T. and Kearney, P.C. 1990. On-Site treatment of pesticide waste and rinsate using ozone and biologically active soil. Enviroti. Sci. Techtiol. 24:745-749.

Winterlin, W., Shoen, S.R. and Mourer, C.R. 1984. Degradation of pesticides in controlled water-soil systems. In: Treatntent and Disposal of Pesticide Wastes. Kruger, R.F., Seiber, J.N., Eds.; ACS Symposium Series No. 259; American Chemical Society: Washington, DC. pp 97-116.

Winterlin, W., Seiber, J.N., Craigmill, A., Baier, T., Woodrow, J. and Walker, G. 1989. Degradation of pesticide waste taken from a highly contaminated soil evaporation pit in California. Arch Ettviron. Contant. Toxicol. 18:734-747.

Leeson, A., Hapeman-Somich, C.J. and Shelton, D.R. Biomineralization of atrazine ozonation products. Application to the development of a pesticide waste disposal system. (Manuscript to be submitted to J. Agn'c.

Disposal Of Pesticides By Microbial Degradation

Glen H. Hetzel, Ph.D. Agricultural Engineering Department Virginia Tech

D. E. Mullins, Ph.D. Department of Entomology Virginia Tech

R. W. Young, Ph.D. Department of Biochemistry and Nutrition Virginia Tech

D. F. Berry, Ph.D. Department of Crop and Soil Environmental Sciences Virginia Tech

Abstract

Work being done at Virginia Tech has shown that it is possible to reduce pesticides to harmless substances by subjecting them to microbial degradation. The pesticides contained in rinsate are removed through a sorption process involving an organic sorbent. After filtration, the water is free of pesticide to the extent that the water can be reused for later mixes or can be discarded safely. The sorbent is then placed in a bioreactor where microbial degradation occurs. The sorbent may be amended with a hydro-carbon source to enhance the degradation process. The process should prove to be economical and easily managed.

Introduction

Pesticides are used extensively in U. S. agriculture. Because the use of pesticides is extensive two major concerns have come to the forefront. 1. the effect of pesticide residues on the environment and 2. how can unwanted pesticides and dilute pesticide formulations be safely removed or destroyed (Bird, 1985; Bridges, 1985; Cohen, et al., 1984; Pye and Patrick, 1983). Both the inappropriate disposal of pesticides and other indiscriminate use have led to increasing concern on the part of private applicators and chemical manufacturers (Alford and Ferguson, 1982; Anonymous, 1983, 1986; Bridges, 1985, 1987; Bridges and Dempsey, 1986, 1988; Hall, 1984).

Unwanted pesticide products and rinsate from chemical application equipment have posed a disposal problem for many years. More recently, regulatory efforts by the EPA have created additional concern

regarding the disposal of rinsates. With these concerns in mind, an interdisciplinary team of faculty within the College of Agriculture and Life Sciences at Virginia Tech began to search for a means to safely dispose of pesticide containing waste water. The team has focused on using microorganisms as pesticide degrading agents.

Most rinsate contains only water with small amounts of pesticide necessitating the processing of relatively large volumes of liquid. In order to more efficiently handle the hazardous material, a technique has been developed whereby the pesticide is sorbed to lignocellulosic materials (concentration phase) resulting in a dramatic reduction in pesticide concentration. Research carried out at Virginia Tech has shown that various lignocellulosic materials, such as peat moss and steam-exploded wood fibers will sorb pesticides from the rinsate. This sorption is nearly as effective as using activated carbon.

A major advantage of using organic materials as the sorbent for capturing pesticide from rinsate is that pesticides are subject to biodegradation. Work at Virginia Tech has proven this to be a safe and effective method for disposing of certain pesticides. (Collins, et al., 1984; Mullins, et al., 1981, 1986, 1989-Appendix 11; Mullins and Young, 1985; Nicholson, 1981; Petruska et al., 1985).

Currently, materials being tested as sorbents include peat moss, pine bark dust, steam-exploded wood fibers and chopped straw. Diazinon has been successfully sorbed onto peat moss at relatively high loading rates ranging from 0.05-0.40 g diazinonlg peat moss. These loading rates are similar to rates of adsorption for other common pesticides onto activated carbon (Dennis and Kobylinski, 1983). There appears to be differing rates of sorbency for the various types of sorbent when used with a variety of pesticides. Some of this variation occurs because many pesticides are formulated as emulsions. Treating emulsified pesticides with a demulsifying agent has proven to be helpful in removing pesticide from rinsate. However, sorption rates of various formulations will vary.

Procedure

The model initially utilized for disposing of pesticides contained in rinsates is shown in Figure 1. It is a single step process in which demulsification and sorption occur in a single step batch type reaction (Hetzel, et al., 1991). Rinsate and lignocellulosic sorbent were placed in a basket contained within a 55

gallon barrel. A motor driven stirrer was used to mix the rinsate and sorbent for approximately 4 hours to ensure good wetting of the sorbent particles. A demulsfying chemical, like calcium hydroxide [Ca(OH),] was added to the rinsate while mixing with the sorbent (steam exploded wood or peat moss). Following the demulsification-sorption phase the liquid was drained from the sorbent by raising the basket and allowing the liquid to drain from the sorbent for at least 4 hours. The liquid was allowed to settle for 12 hours or more to provide additional time for fines to settle. Following this settling period, the liquid was passed through two or more filters to remove fines left in suspension. Filters capable of removing particles of 3 microns were used for the final filtration. Good filtration was essential, because particles of the cellulosic material remaining in suspension had sorbed some pesticide from the mixture. Additionally, during demulsification, some flocculation may have occurred. Any flocculate present in the solution was also removed during filtering.

For the pesticides tested, it was possible to filter the solids from the mixture and reduce residual levels in the water to very low parts per million. It is likely that levels as low as parts per billion can be achieved. Further work will be carried out to improve the filtering process.

Figure 2 represents the pesticide disposal scheme currently being used. It is a two-step process in which demulsification and sorption occur as in the single-step process. The same equipment is utilized to mix the rinsate, the sorbent and the demulsifying agent Ca(OH),. The liquid is drained from the sorbent, but is not allowed to settle as in the single step system. After draining the liquid from the mixture, the liquid is cycled through a column packed with the same kind of sorbent as was used in the initial demulsification and sorption phase. Recycling the liquid through the column results in additional time to sorb any pesticide remaining in solution after the mixing phase. Some fines remaining in the mixture at the end of the first phase will be removed as the liquid is cycled through the column.Before disposal, the liquid is passed through a final disposable filter to remove remaining fines.

The system described can handle 132.5 - 151.4 L (35- 40 gal) of rinsate. Between 2-3 ft3 of lignocellulosic material is mixed with the rinsate. The column was constructed from a piece of 90 cm long by 20.3 cm in diameter (35.5 in long by 8 in diameter) PVC pipe with a 45 mesh stainless steel screen in the lower end. A float switch was installed to control the pump used in recycling the liquid through the column. Approximately .014m3 (.5 cu ft) of sorbent was placed in the

column.After the solids of the sorbent are separated from the rinsate solution, the sorbent is then placed into a bioreactor where solid-state fermentation occurs.

Results and Discussion

Pesticides can be removed from aqueous solutions using both the single step process of demulsification and sorption in a batch-type procedure and in a two-step process involving the use of a column following the batch-type procedure. A column was utilized as a means of overcoming limitations found in filtering the solution by conventional methods.

A high percentage of fines (dust) is desirable in lignocellulosic materials used to sorb pesticides from rinsates. A high percentage of fines increases the available surface area, enhancing sorption. However, as the amount of fines increases, the load imposed on the filters also increases. This poses a problem in getting complete removal of the pesticide from the aqueous solution. Several techniques were tested to find an acceptable way to remove fines from the mixture.

A procedure was developed to mix a lignocellulosic material, like peat moss or steam exploded wood fibers, with rinsate, When the pesticide formulation was an emulsion, it was necessary to break the emulsion before good sorption could occur. Calcium hydroxide [Ca(OH),] was found to be effective in breaking the emulsion of some formulations. The calcium hydroxide would be added to the mixture of rinsate and sorbent while mixing. Four hours of mixing gave good results for both the emulsified formulations and those not in an emulsion.

A batch type process required that 2-3 cu. ft. of the lignocellulosic material, such as peat moss or steam exploded wood products be used per 35 gallon of rinsate. After a 4 hour mixing period, the liquid was then separated from the solids. After allowing the fines to settle for 10-1 2 hours, the liquid was passed through a series of filters to remove the fines held in suspension. Fines in the 1 micron range were difficult to remove without clogging filters. When all fines are removed from the liquid, residue levels of pesticide were almost non-detectable.

A second approach was utilized to overcome the problem of clogged filters. After mixing the rinsate and sorbent in a batch process, as previously described, and allowing the liquid to drain from the sorbent, the liquid was then circulated through a column packed with approximately .5 cu. ft. of the same sotbent as used in the batch mixing. The liquid

was recycled through the column until the fines were retained in the column. This also provided an opportunity for further sorbtion of any pesticide not sorbed during the batch mixing.

Following the sorptionlfiltration process, sorbent can be placed in a bioreactor where the pesticide can be degraded during the process of solid state fermentation. After the pesticide has been sorbed onto the lignocellulosic matrix it is in a non-leachable state and becomes less a threat to the environment.

Monitoring of the degradation progress in the bioreactor has shown that for some pesticides, such as diazinon, mineralization will occur with 6-8 weeks. However other formulations may require more than 12 months. It is desirable to amend the sorbent with a carbon and energy source to enhance microbial activity. Ground cornmeal has proven to be effective as an enrichment for this purpose.

Results of this procedure have shown that it is possible to remove pesticides from rinsates economically. It is also possible to degrade most pesticides down into non-active chemicals using a microbial consortia. Results from our studies have shown that it is possible to remove pesticides from rinsate economically.

References

Alford, H. C. and M. P. Ferguson (eds.) 1982. pesticides in Soil and GroundlVater. Proc. Pest. Assess. Prog. University of California, California, Davis. 182 pp.

Anonymous. 1983. Pesticide waste disposal, problems of farmers explored. Chem. Eng. News Sept. 19, p. 43-45.

Anonymous. 1986. Pesticides in Ground Water: Backmound Document. USEPA. Washington, D.C. EPA WH-550G. 72 pp.

Bird, J. C. 1985. Groundwater Protection: Emerging Issues and Policy Challenges. Environment and Energy Study Institute, Washington, DC. 42 pp.

Bridges, J. (ed.) 1985. Proceedings: National Workshop on Pesticide Waste Disposal. denver, CO. Jan. 28-29. EPAl60019-851030. 155 pp.

Bridges, J . (ed.) 1987. Proceedings: National Workshop on Pesticide Waste Disposal, Denver, CO. Jan. 27-29, 1986. EPAl60019-87-001. 174 pp.

Bridges, J. S. and C. R. Dempsey (eds.) 1986. ~roceedinns: Research Workshop on the TreatmenWDisposal of Pesticide Wastewater. Cincinnati, OH. EPAl60019-861001. 55 pp.

Cohen, S. Z., S. M. Creeger, R. F. Carsel and C. G. Enfield. 1984. Potential for pesticide contamination of groundwater resulting from agricultural uses. In: Treatment and Disposal of Pesticide Wastes. Amer. Chem. Soc. S m p . Series. 259:297-325.

Collins, E. R., Jr., J. A. Petruska, D. E. Mullins, R. W. Young, and R. W. Nicholson. 1984. Livestock lagoon systems for disposal of pesticide wastes. Trans. MAE. 27:755-761.

Dennis, W. H. and E. A. Kobylinski. 1983. Pesticide-laden wastewater treatment for small waste generators. J. Environ. Sci. Health 18:317- 33 1.

Hetzel, G. H. D. E. Mullins, R. W. Young and D. F. Berry. 1991. A means of separating pesticides from rinsate. American Society of Agricultural Engineers. Paper 91-1070, 7 pp.

Mullins, E. R., J. A. Petruska, R. W. Nicholson, E. R. Collins, and R. W. Young. 1981. Preliminary studies evaluating composting as a means for pesticide disposal. In: Land Disposal: Hazardous Waste. Proc. 7th Ann. Res. Symp. EPA-60019-81- 006. Philadelphia, PA pp. 238-290.

Mullins, D. E. and R. W. Young. 1985. A model system for development and implementation of pesticide disposal using composting. Abstract of a poster presentation made a t the National Workshop on Pesticide Waste Disposal. Denver, CO. Jan. 28- 29.

Mullins, D. R., R. W. Young, G. H. Hetzel, and D. L. Paulson, J r . 1986. Treatment of dilute and concentrated pesticide formulations using absorption and microbial degradation. Proceedings. Symposium: Emerging Biological Treatment Processes for Leachate Including Genetic Engineering Issues. Nat. Meet. American Institute of Engineers. Boston. Aug. 24-27, 1986. Paper No. 86D.

Mullins, E. R., R. W. Young, C. P. Palmer, R. L. Hamilton and P. C. Shertz. 1989. Disposal of concentrated solutions of diazinon using organic absorption and chemical and microbial degradation. Pest. Sci. 25:241-254.

Nicholson, R. W., J r . 1081. An Evaluation of Composting as a R!Icans of Diazinon Disposal. Masters Thesis. Virginia Polytechnic Institute and State University, Blacksburg, VA. 96 pp,

Petruska, J. A., D. E. NIullins, R. W. Young and E. R. Collins, J r . 1985. A benchtop system for evaluation of pesticide disposal by composting. Nuclear and Chem. Waste Manag. 5:177-182.

Pye, V. I. and R. Patrick. 1983. Groundwater contarnillatioil in the United States. Science 221:713-718.

r WASTE:

Pestlclde-Laden Waste Solutlon s DEMULSIFICATION & SORPTION:

Llgnocelluloslc Matrlces

... ............................. . . . . .

FILTRATION

Dlsposal

Phase

DISPOSAL:

Purlfled Solution Pestlclde Degradation

Mlcroblal Bloreactor

Figure 1: One-Step Sorption Process

I WASTE: 1 I Pestlclde-Laden Waste Solutlon 1 ........................................................................

- . . .. - . . - t .......

BATCH DEMULSlFlCATlON & SORPTION:

Llgnocellulosic Matrices Sorptlon ........ ....

-. -- - Phase

COLUMN SORPTION &

FILTRATION

i DISCARD/RECYCLE: DISPOSAL:

Purified Solutlon Pesticide Degradation

Microbial Bioreactor

Figure 2. Two-step Sorption Process

-1 42-

MANAGEMENT AND DISPOSAL 0% F9ES"TI@liDE SPRAY TANK WASTES

F, R, Hall, R. A. Downer? A. C. Chapple Laboratory for Pest Control Application Techriology, The Ohio State University, Wooster, OH 44691.

ABSTRACT

The presence of pesticides in the environinent i s being given much attention by world socieiy. New technology pesticides will require increased care in rinsing spray tanks. In addition, current sprayers typically have 8-10 gallons left in the system when tanks are empty. Disposal of rinsates thus becomes critical for pesticide users. The CARBO-FLOB water effluent treatment process [an ICI/Allman Co., (UK) system now licensed to AgChem Equipment Co., Minn] uses a simple flocculation and filtration system which requires no specialist personnel for its effective use. The flocculation and settlement process takes a minim~lm of 1 hour. Filtration through one course gravel and two fine carbon filters takes approximately 2 hours. Water t l ~us treated can be recycled for subsequent use as rinse water. Simulated rinsates containing an array of fruit and vegetable pesticides were processed through the Sentinel@ plant. Analysis of treated water using GC technology showed 99.99% of pesticides were removed from the treated output rinsate. The system, combined with new application equipment and in-field user strategies, are being proposed for custom operators as part of the technology designed to prevent pesticide contamination near mixer/loader sites.

INTRODUCTION

Pesticides in the environment is the hot topic for discussion by the public and society in general. Recent surveys have revealed the presence of a number of pesticides in groundwater and well water (Moody 1990, Bridges & Dempsey 1985). Amendments to the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA-88) propose to revise the current regulations on transportation, storage, use and disposal of containers, and pesticide wastes. This is likely to entail greater control of pesticide rinsate disposal. The lack of proper containment at pesticide mixing/loading facilities has resulted in an increased potential for point source contamination of soil and groundwater surrounding these sites. Where these facilities are utilized by commercial applicators, the potential for contamination of surrounding ground becomes tnore serious as rinsing operations become more frequent. Innovative new technologies combined with long term

management practices and increased operator awareness will irltirnately determine the qirality of the environment near agricultural pesticide mixing/loading sites.

P:evention of pesticide pollution in agriculture depends greatly on good management practices. Spillage of agrichernicals in the fill-up areas near to wells can contribute to the presence of pesticide residues in drinking water. The movement of pad sites away from wells will reduce the likelihood of contamination from spillage. In additicn, NACA proposes the following "rules": (1) strict adherence to label instructions, (2) proper use of calibrated eqilipment, (3) prevention of back-siphoning into water sources, (4) proper pesticide and container disposal, (5) proper timing of irrigation and (6) proper well location and construction gc~idelines to be followed (Bridges & Dempsey 1985).

There are obvious "blueprint" plans for protecting groundwater from pesticides used in agricultural practices (Fawcett 1988, Logan 1990, U.S. Congress 1990). Many of them are common sense and require minimal labor. Prevention of application site contamination is more cost-effective than clean-up procedures. Accurate calibration and the use of spray monitors could allow farmers to arrive at the last row in the "last field" to be treated with no left-over materials. Rinsing of the tanks and disposal of the tank mixture has to be a priority item with new herbicides which are active at low rates (2g ha.').

In the past, common practice has been to wash down the sprayers, and rinse the left-over 7-1 0 gallons of spray (in the system) down the drain or allow it to run off into adjacent "drain" areas. All sprayers have the problem of being unable to completely pump out the entire spray mixture in the system. While it is technically possible to solve this problem, there also remains the necessity of rinsing out the tank, lines and nozzles in order to change pesticides. This is especially true with tlie new highly effective herbicides and the on-corning practice of treating each field for its own problem. Therefore, the need to irtilize a wider variety of cotnbinations is emphasized with best management practices (BMP) and conservation set- aside programs. On sotne crops, even a small amount of the newer herbicides left over from tlie previous field treatment can result in either phytotoxicity on a sensitive crop or result in inappropriate and illegal residues. Thus we are left with an increasingly important problem of how to best manage pesticide

rinsates. Efforts to reduce and/or eliminate point- source pollution need to be given a strong emphasis if we are to retain the use of the agrichemical tools -- pesticides (Fawcett 1988).

Current efforts in treating rinsate wastes at the farm level include an array of cleaning agents (Obrigawitch & Pugh 1992), chemical injection to reduce the amount of leftover tank mixes (Bridges & Dempsey 1985), and enzyme oxidation (Montgomery, et al.) oxidation, microbial and UV techniques (U.S. Congress 1990). Recently, Allman and Co., Ltd. (of U.K) in conjunction with ICI Agrochemicals (U.K.) recently developed the Sentinel Water Effluent Treatment Plant for use in small- scale industrial operations, as well as agricultural and other areas where environmental concerns are important. The Carbo-Flo Treatment (ICI) removes organic substances from the water via a series of steps. ICI brought this merged technology to the U.S. for evaluation trials and LPCAT was chosen for this initial research study. This paper reviews the research conducted by LPCAT at The Ohio State University at Wooster, Ohio, in the first pesticide waste treatment plant delivered to the U.S.

MATERIALS AND METHODS

The Sentinel Plant consists of a mairi tank (ca. 1000 I), a sludge tank, a gravel filter and 2 carbon filters (Figure 1). In addition, a centrifugal pump driven by a 3 HP gasoline engine allows the transfer of fluids throughout the system. Tank mix rinsates are pumped into the treatment plant through 5m of suction hose and filter, can extract rinsatelwaste from a holding tank. It is considered a fully portable system.

The Carbo-Flo treatment removes most unwanted organic substances from waste water via two main stages: (1) flocculation and sedimentation of suspended solids; the sludge produced is then further concentrated prior to disposal, and (2) filtration through gravel and carbon modules to remove dissolved organic matter. There are two main end products from each batch: (1) cleaned water which is clear, colorless and virtually odorless, and (2) solid sludge which is easily collected for storage and disposal. The cleaned water which is non-toxic may be discharged direct to a soil soakaway -- away from water to ensure safety to fish. The sludge and carbon may be stored in a secure place until sufficient is available for disposal to land fill via a waste contractor. About 3kg (dry weight) of sludge is produced per batch treated. The process is monitored via a coloring agent which is incorporated into the treatment materials. This is removed by the second stage while the carbon is still active. The life of the carbon depends upon the amount of dissolved

material which is treated. The total capacity of one carbon module is up to 20 batches of dilute pesticide or other equivalent effluent. This is half the installed adsorption capacity.

Priming of the system was carried out by half filling the main tank with clean water and then opening the liquid take-off valve, with the outlet valve at filter #3 closed. Water flowing into the filter elements forces air out of the air bleed valves and charges the filters, at which point the outlet valve at filter #3 was opened and the tank drained. Initially the water was colored with carbon fines but cleared quickly. While the tank was draining, the system was checked for leaks and the flow rate checked. This was found to be within the manufacturer's specifications of 4-6 liters per minute.

For initial evaluation of the system's efficiency in removing certain pesticides, permethrin, alachlor and atrazine were evaluated as single products and later as a three-way tank mix combination. A batch (500 1) of simulated spray tank waste rinsate was made up in the main tank by adding the pesticide(s) to the water while running the agitator paddle. The resultant rate of dilution was intended to simulate a field rate mixture diluted with water as should be the case when returning from routine spray operations and washing out a sprayer. When the tank contents were suitably mixed, a sample of the tank mixture (approx. 100 ml) was removed for later analysis. In addition, 100 ml samples were also taken at 15 min, intervals from points A, B, C, and D (Figure 1).

All samples were analyzed for pesticide content by using standard gas chromatography techniques. Extraction of pesticide from the aqueous samples was achieved as per standard GC procedures and as reported by Hall et al., 1991.

RESULTS AND DISCUSSION

The quantity of permethrin (ppm) detected in samples of effluent over the two and a half hour sampling period is shown in Figure 2, Initial concentrate contained 237.5 pprn and the detection limit was 0.01 ppm. The quantity of atrazine (ppm) detected in samples of effluent over the two hour sampling period, is shown in Figure 3. The initial concentrate contained 5100 ppm and the detection limit was 0.004 ppm. The quantity of alachlor (ppm) detected in samples of effluent over the two hour sampling period is shown in Figure 4. The initial concentrate contained 795 ppni and the detection limit was 0.0004 ppm. The three way tank mix of permethrin, atrazine and alachlor also showed excellent results with significant reductions in all 3 chemicals in

the effluent water (Table 1).

There is continuing research effort to expand the chemistry of pesticide treatment with the Carbo-Flo process. The waste treatment process is currently being examined in over 40 countries world-wide. As seen in Table 2, although data from ADAS (U.K.) and LPCAT indicate excellent efficacy in rinsate clean-up of various chemicals, it is clear that additional product/combinations will need to be evaluated. Future considerations of the system by LPCAT include:

1. Exploration of the efficiency against a ranue of the major high pollution pesticides identified in recent groundwater studies (Farm Chemicals 1989, Valiulis 1986).

2. Can the system be integrated with an in-field dilution strategy?

3. Can immunoassay kits be utilized as an easy, practical, cost-effective check (for use by farmer clientele) on the treatment efficacy of water effluent? Validity of such kits is being checked by USGS (Nov. 1989).

4. Establish the cost-benefit effectiveness of the treatment system for each run including rinse pad modifications, carbon placement strategies, holding tanks, and labor.

5. Establish the safety guidelines for system operation, dilution, holding, and transfer operations.

6. Establish the pollution/toxic hazard of sludge and its disposal.

7. Integrate the system into a state-wide water quality monitoring project(s).

Other simulations now under evaluation by LPCAT include a fruit/vegetable rinsate collection (Table 3). Initial results from this mixture show treatment residues of <5ppb for products thus far evaluated.

(5) appears to represent an important economic and practical step forward in the prevention of environmental pollution (point source) associated with the agricultural use of pesticides.

TABLE 1. THE WATER QUALITY FROM A RINSATE SAMPLE CONTAINING A THREE-WAY TANK MIX OF PERMETHRIN, ATRAZINE AND ALACHLOR.

1990 Waste Treatment Concentration at Sample Point D (ppb)

Tank Minutes from start Mix 30 60 90 120

Permethrin 2.2 <0.4 <0.4 ~ 0 . 4 Atrazine 84 3 1 1 0 9 Alachlor 26 < 4 <4 9

TABLE 2. SUMMARY OF DATA GENERATED FROM EXPERIMENTS CONDUCTED WITH THE ICIIALLMAN SENTINEL.

Before After Floccu- Filtra-

Pesticide lation ppm tion ppb

Demeton-S-methyl* 250 gamma-HCH* 530 Pirimicarb* 180 Propiconazole* 100 Cypermethrin* 25 2,4-D* 61 Mecoprop* 119 Paraquat* 580 Permethrin 238 Atrazine 51 00 Alachlor 795

CONCLUSIONS *Data generated in 1987 by ADAS Research and Development Services, Harpenden, Herts, UK.

These LPCAT studies show that the Carbo-Flo treatment is a simple batch system which: (1) uses measured and pre-packaged materials, (2) does not require technical staff to operate or monitor, (3) produces cleaned water, which can be discharged into a soakaway, plus small quantities of sludge, (4) uses technology that has been widely used in ICI agrochemical factories in the U.K. and overseas, and

TABLE 3. FRUIT/VEGETABLE PESTICIDE RINSATE SIMULATIONS.

Cygon Sevin Kelthane Manzate Guthion lmidan Benlate Captan Bayleton

dimethoate carbaryl dicofol dithiocarbamate azinphos-methyl phosmet benomyl captan triadimefon

REFERENCES

Bridges, J. S. and C. R. Dempsey, Eds. 1985. Pesticide Waste Disposal Technology, Noyes Data Corp., Park Ridge, ILL.

Brown, K. W. 1986. What's the best way to get rid of pesticide waste? Agrichemical Age. Jan. 1986. p. 14 + 44.

Farm Chemicals. 1989. Special Issue: A blueprint for protecting the groundwater. Farm Chemicals, ed. C. Sine, Meister Publishing, Willoughby, OH. Summer, 1989, pp. 70.

Fawcett, R. 1988. Excess spray mix seen as a major contamination source. Pesticide and Toxic Chemical News, Vol. 16(29).

Hall, F. R., R. A. Downer, and A. C. Chapple. 1990. Evaluation of the Carbo-Flo Pesticide Waste Management System. I 1 th Symposium on Pesticide Formulations and Application Systems, San Antonio, TX. ASTM STP 11 12, Phila, PA. In press.

Logan, T. J. 1990. Agricultural pest management practices and groundwater protection. Jnl. Soil and Water Conservation. Vol. 45(2): 201 -206.

Obrigawitch and Pugh. 1992. Decontamination of herbicide application equipment. Weed Technology. In press.

J. S. Bridges and C. R. Dempsey, Eds. 1985. Pesticide Waste Disposal Technology, Noyes Data Corp., Park Ridge, ILL.

U. S. Congress, Office of Technology Assessment. 1990. Beneath the bottom line: Agricultural approaches to reduce agrichemical contamination of groundwater. Wash. Printing Office. Nov. 1990. OTA-F-418.

Valiulis, D. 1986. Groundwater contamination and the fate of agrichemicals. Agrichemical Age. Jan. 1986. p. 10-13.

Moody, D. W. 1990. Groundwater contamination in the United States. Jnl. Soil and Water Conservation. Vol. 45 (2) : 1 70-1 79.

Figi~re 1. Schematic of the Sentinel systetn

Decrease in detectable quantities

h

of permethrin in treated water. E Q. 2 4 0 a Y

Quantity of Perrnothnn detected c .- at point A after 45 minute. L ' 1 6 0 g L a, a

8 0

h c. .- 46 7 6 106 136 166

+ hs (mh) C a a 0

0 3 0 60 90 1 2 0 1 5 0

Time (min)

+ Point A A Point B

Figure 2. Decrease in detectable quantities of permethrin in treated water -147-

I Time (mid

I + Point A A Point B 0 Point D I I I Figirre 3. Decrease in detectable quantities of atrazine in treated water

Figure 4. Decrease in detectable quantities of alachlor in treated water.

-1 48-

Decrease in detectable quantities of alachlor in treated water.

E 7 0 - n

------*-----------------A

a 3 0

0

>, 2 0 + .- z 1 0 a

-

-

-

6 oc: m L'

m u 3

3 0 6 0 9 0 1 2 0 Time (min)

+ Point A A Point B 0 Point D

CLOSED MIXING/LBABIING SYSTEMS REVIEW

Ronald T. Noyes, P.E. Extension Agricultural Engineer Oklahoma State University

David E. Kammel, Ph.D. Extension Agricultural Engineer University of Wisconsin-Madison

Vern Hofman Extension Agricultural Engineer North Dakota State University

Edward Barnes Extension Engineer Oklahoma State University

Abstract

Closed mixing systems (CMS) designs have evolved during the past 25 years. In the early 1 9801s, California regulations requiring CMS spurred market development. Most early CMS' were not true closed systems as containers were opened to insert suction probes, exposing mixer l loaders to toxic vapors and splashes. Early CMS were cumbersome, complex, and slow.

Recent research has concentrated on a more economical and efficient vacuum closed mixing1 transfer system design using venturi injectors. Vacuum transfer CMS' are safer. Research on precision loadcell weighing integrated to mini- bulk and S V R containers is currently being investigated. Schematic plumbing diagrams illustrate basic 1 optional CMS designs.

Background Handling acutely toxic organophosphate and

carbamate pesticides can be extremely hazardous to mixinglloading personnel. Using open pesti- cide mixing systems, full strength pesticides are poured into mixing tanks. Operators splash pes- ticide on themselves, and inhale toxic vapors and dust. Although several closed mixing systems and components are available, a simplified modular vacuum transfer CMS design is needed to minimize hazards to aerial and ground pesti- cide applicators. This design needs to be capable of handling liquid and diy flowable pesticides.

Research data indicates that both ground and aerial application mixerlloader personnel have a much greater risk for pesticide poisoning than all other agricultural pesticide application workers. The reasons are simple--they work with full strength liquid and dry pesticide concentrates. They seldom wear prescribed protective clothing and equipment while pouring full strength acutely toxic pesticides into open mixing tanks. They are exposed to splashing or blowing of liquid or dry chemicals onto their bodies, especially hands and face, inhaling toxic vapors or dust, or absorbing them through their eyes which circulates the chemicals directly to the brain.

According to Criswell (1991), recent EPA regulations have cancelled some uses of parathion and placed severe restrictions on other parathion applications. Aerial applicators are still allowed to apply parathion to certain crops but the use of closed mixing systems is mandated. Future restrictions may be applied to other pesticides.

Literature Review The major problem of mixerboader pesticide

poisoning is transfer of pesticides from open containers -- either by hand pouring during open transfer, or installing or removing suction probes in open or partially closed mixing systems where splashes and vapors are a common problem. EPA statistics show that a completely closed liquid transfer and mixing system reduces the risk of dermal absorption by up to 90% and vapor inhalation by up to 85%, compared to con- ventional open systems. FIFRA (Federal Insec- ticide Fungicide Rodenticide Act) states that applicator mixing and loading personnel using closed pesticide mixing systems are exempt from stringent clothing requirements listed on pesticide container labels.

Tighter pesticide regulations in California, including mandatory use of closed mixing systems for Class I pesticides (signal word "DANGER) were reported by Smith (1974), Kahn (1976), Akesson et al. (1978), and Houston (1980) to have caused gradual declines in illnesses of mixing personnel and other applicators. California regu- lations effective December 31, 1977, required closed mixing systems for all applicators using Class I pesticides, and prohibited aerial applicator pilots from mixing and loading pesticides.

Although California mandated closed mixing systems 14 years ago, many problems still remain. All "closed systems" are not designed to meet the letter or intent of the California regula- tion. Many private operators still use open sys- tems for general mixing of lower toxicity materi- als, and hire commercial operators using closed systems to mix and/or apply Class I chemicals.

As an indication of the magnitude of the pes- ticide mixing problem, Yates et al. (1974) reported that 63.5 million kilograms (140 million pounds) of actual ~esticide concentrates were used in Cali- fornia in i972. Collins (1986) found that a total of 454 million kilograms (1.00 billion pounds) of pesticides are used annually in the U.S. Of this, 340 million kilograms (750 million pounds) are used on 114 million hectares (282 million acres) of U.S. agricultural land, an average of 2.98 kghectare (2.66 lblacre). Reviewing California closed mixing systems in 1978, Dewey (1982) found that all units had one or more major problems. He found closed systems:

(1) were too slow; (2) were too complex (one unit required 42

operations per mixing cycle); (3) had tank, piping, and fitting corrosion; (4) used improper hoses which ruptured; and (5) were not designed to properly rinse the

containers or the probes.

Jacobs (1982) described an ideal closed system as the transfer of pesticides from shipping con- tainer to application equipment (aircraft hopper or ground application sprayer tank) without exposure of chemicals to the atmosphere or per- sonnel while reusing container rinse water as part of the makeup water for field mixtures.

Jacobs (1984, b) stated that the National Agricultural Chemical Association (NACA) implemented a voluntary pesticide container closure design standard to reduce the number of container closures and standardize the designs. He reported that if the pesticide manufacturers did not adopt the NACA closure standard by December 31, 1988, EPA would write new container regulations based on FIFRA.

EPA's Office of Pesticide Programs Division is currently in the process of writing these "Container" regulations which will cover contain- ers, out of date pesticide disposal, and point- source ground water contamination. These regu- lations are expected to be released in sections between 1992 and 1994.

Barthel (1981) reported on cancer morbidity of 1,658 men who worked with pesticides for at least 5 years; 169 were diagnosed to have malig- nant tumors. Doherty (1986) stated that Kansas farmers who applied herbicides more than 20 days per year had 6 times greater risk of non- Hodgkin's limphomas than non-farmers; herbi- cide mixing personnel had 8 times the risk. Unprotected farmers had 40% higher risk than protected farmers. Jacobs (1984, a), an EPA biol- ogist, stated that 33-43% of California mixer load- ers who reported pesticide illnesses lost work time.

Kuhlman et al. (1981) and Dewey et al. (1984) reviewed California data showing the percent of dermal absorption of Parathion at 8 anatomy locations on male workers which were: scalp, 32.1%; ear canal, 46.5%; forehand, 36.3%; fore- arm, 8.6%; palm of hand, 11.8%; abdomen, 18.4%; scrotum, 100%; ball of feet, 13.5%. Kuhlman listed charts showing relative toxicity of pesti- cides by dermal or skin contact and by oral or ingestion for fungicides, herbicides, and insecti- cides.

Akesson et al. (1974) pointed out that closed system mixing offered much more protection for mixing personnel than open systems. Jacobs (1984, b) said that closed mixing systems which prevent toxic chemical escape was a much safer and more practical approach to mixing personnel safety than shielding them with protective clothing. Chemical manufacturers specifications of protective clothing requirements on pesticide container labels has not been highly effective. Much pesticide mixing takes place during warm or hot weather. Specified clothing is bulky and hot; lighter weight breathable clothing that's more comfortable is very expensive. Therefore, improved closed mixing systems are needed by chemical applicators.

Current CMS Technology Pesticide mixing technology advances in the

U.S. have been slow during the past twenty five years. Many "closed systems" being used are only partially closed. They include external probes attached to the suction side of pumps. Entry and removal of probes from containers after partial or complete pesticide withdrawal exposes workers to volatile vapors and toxic chemicals on probes. Some containers are tightly sealed by the probe, others are not. Sealed probes with inadequate venting create a serious potential container fail- ure problem (discussed later).

Simple closed mixingiloading systems are this valve and tank assembly up in size for faster designed to empty and rinse shipping containers, handling rates may prove expensive and limit its transferring both product and rinsate to applica- usefulness. Garnett (1991) reports the develop- tion equipment in a closed environment, prevent- ment and marketing of a new vacuum closed ing or minimizing exposure of workers to pesti- transfer system design in the United Kingdom cides. Sophisticated closed systems can transfer that he has developed during 5 years of research. and mix chemicals from two or more containers simultaneously prior to transfer to spray equipment.

Simplified CMS Designs - -

Jacobs (1984, a) stated that "although many of the closed systems now in use have been designed and built by their owners, complete closed systems and components for building closed systems a re commercially available. Most of the closed system equipment now on the mar- ket represents the commercial production of homemade devices found to be useful. The typical closed system manufacturer is, therefore, rooted in the pesticide application business. Larger cor- porations which manufacture agricultural equip- ment have not entered the closed system market to a significant degree." To date, that issue has not changed significantly.

In November, 1986, ASTM Committee E-35 on Pesticides, and ASTM Subcommittee E35.22 on Pesticide Formulation and Application Sys- tems sponsored the "Seventh Symposium on Pes- ticide Formulations and Application Systems" a t Phoenix, AZ. During this. symposium, six papers were presented in a program entitled "Special Session: Closed Mixing, Handling, and Applica- tions Systems". (Appendix I-Supplemental Refer- ences) That is the latest review of pesticide mix- ing and transfer technology and represented the current agricultural pesticide industry philosophy five years ago. Noyes (1987, a) reported on closed mixing system technology and developed a strategy for transfer/mixing/loading systems and (1987, b) research results from a prototype closed mixing system. A partial list of manufacturers of commercial pesticide mixing system components

Vacuum transfer of full strength chemicals greatly reduces risks of serious injury which can occur if a pressure transfer hose ruptures. If a vacuum hose leaks, outside air will be sucked into the hose, slowing the transfer process. The sim- plest vacuum powered closed systems are venturi injector (also called eductors or ejectors) systems "powered" by water pumps. Suction is generated by pressure drop between the inlet and outlet of the venturi, Figure 1, creating a suction in the narrow throat area where a side opening allows fluid or dry materials to be drawn into the flow.

Figure 2 shows a schematic plumbing dia- gram with vacuum filled metering tanks that pull chemicals from one or more pesticide containers and/or PDR units. Pesticides are then metered from vacuum tanks by suction into the venturi injector for direct mixing with the pump flow on the way to the applicator tank. Liquid pesticide can be metered from holding tanks with a visual sight tube using manual control systems, or by load cells using semi-automatic systems, Figure 3.

To facilitate mixing and transfer of low vol- umes of pesticides for small applications, and still be able to adequately rinse transfer hoses and tanks before the total mix volume has been transferred, a n optional auxiliary source of vacuum may be required to minimize the total amount of water transfer through the venturi. Figure 2 illustrates a plumbing diagram that uses a n auxiliary vacuum transfer source to augment the venturi injector.

for transfer/mixing/loading systems and some Small shipping container-mounted pressure vacuum closed/transfer/mixing system

pump systems are a second low pressure transfer components are listed in Appendix 11. alternative to vacuum filing of metering tanks. -

During the past five years, some limited Systems using auxiliary pressure pump systems, research work has been conducted by agricultural Figure 4, do not require vacuum designed me- engineers in Oklahoma, Wisconsin, and North tering tanks if the tank is vented a t all times. -

Dakota, but little reported research has been submitted since Noyes, e t al. (1987, b). A single A third alternative system would be to use a n

auxiliary vacuum pump or low pressure pump control, complex valvelmetering and tank arrangement to control all transfer and rinse transfer system to move pesticides from shipping

operations has been patented by Bleth (1987). containers to a n elevated metering tank. Then,

But, the flow rate of this valve is restrictive. Due pesticides could gravity flow directly into applicator tanks for mixing in the tank or hopper. to its design and operation complexity, scaling

Complexity of mixing systems increases the Jvleasurina or Meterinq risk of an incident or accident. Closed mixing systems need to be simple to operate for improved Measuring and metering approaches involve safety. Thus, functions to be performed by the the use of metering tanks with calibrated liquid CMS must be fully understood. sight gauges, andlor load cell weighing, liquid

flow meters (must be high quality units that can

Basic CMS Operating Functions be calibrated), or positive displacement metering pumps. Flow meters can be used on pressure - - flow plumbing; liquid meters do not meter

The basic task performance functions of a closed accurately on vacuum lines due to induced air mixing system are as follows: and changes in product density.

(1) safely emptying pesticide shipping containers;

(2) accurately measuring or metering pesticides;

(3) rinsing containers, metering tank and

plumbing;

(4) blending pesticides, water, rinsate, and other

additives to field mixtures;

(5) transfer of field mixtures and rinsate into

applicator tanks.

Container Rinsing

Two-way containers are returned unrinsed to the supplier or manufacturer for refilling of the same product on a continuous recycling basis. One-way containers must be rinsed for proper disposal. Power rinsing is recommended over "hand triple rinsing". Rinsing should be done as soon as the container is emptied -- neither method is very effective if pesticide dries inside on con- tainer walls. Self contained PDR or PDRC are the only closed system for draining and rinsing

Each of these functional areas have unique one-way containers and preparing them for safe operational problems as discussed below. disposal. Hand-held power rinsers with piercing

gm~tv ina Shimina Containers

Vacuum or direct mounted pump suction is used in closed systems to transfer pesticides from 400-1500 liter (110-400 gal.) mini-bulk and 57-114 liter (15-30 gal.) small volume returnable or "SVR" shipping containers from built-in probes. Closed systems can also incorporate one or more puncture/drain/rinse (PDR) or puncture1 drain/rinse/crush (PDRC) units for sealed han- dling of 3.8 to 208 liter (1 to 55 gal.) standard one-way shipping containers, with metered suction transfer to mixing or applicator tanks.

The closed system suction force that moves liquids or powders from shipping containers into metering, mixing, or applicator tanks is provided by either a vacuum pump, venturi injector, or pump suction. Vacuum systems can be used to incorporate dry formulations with liquid concen- trates in a common CMS. Built-in probes were evaluated by Ciba-Geigy Corporation for uses on a limited basis according to Reynolds (1986) and were being added to some shipping containers as part of closure mechanisms. Dry break connec- tors are an important component of the built-in probe concept.

tips are currently being marketed for rinsing one- way containers in open mixing systems.

Pesticide Blendinq

Blending involves:

(1) One or more pesticides transferred into small metering tanks, then metered into the venturi to mix with required makeup water on the way to the applicator tank is the recommended process.

(2) One or more pesticides can be sucked directly from shipping containers by venturi injectors as the makeup water is pumped directly into the applicator tank. However, metering accuracy may be a problem during direct transfers.

Transfer

Applicator tank loading involves standard high volume low pressure water pumps in line with venturi injectors to provide a high rate of pesticide and rinsate transfer that mixes pesti- cides with the water enroute to the applicator tank. A venturi bypass valve circuit, Figures 1 and 2, allows operators to switch from a low flow suction mode to high-flow bypass mode. The prototype 2 HP CMS pump system shown in Fig- ure 5 has 95 gpm bypass flow versus 35 gpm through the venturi.

SuctionIRinsing Probes

External suction/rinsing probes are not true closed mixingltransfer system technology. To use a rinsing probe, containers must be opened to insert the probe, exposing the operator to vapors and liquid splash. Probes that seal to the con- tainer opening, allowing the container to be pres- surized, create a major risk due to the possibility of rupture of the container due to accidental operation of the rinse water valve, or collapse of the container due to excessive evacuation with inadequate venting of the container during transfer of pesticides. Non-sealed probes that have space between the probe tube and the opening provide adequate venting, but expose operators to toxic vapors and splashes or sprays if probe suction and rinse water control valves are used improperly.

Shipping containers and closed system probes remain contaminated with full strength pesticide formulation until after rinsing. The safety of operators using closed systems is severely com- promised when contaminated probes are removed from a non-rinsed container. This approach allows liquid to drip from the probe tip and toxic vapors to escape into the work environment.

Future Closed Systems

To correct a problem that critically affects the health of thousands of agricultural workers, positive physical action must be taken. Spurrier (1986) indicated that a well coordinated research, development, and education program is needed to optimize closed mixing systems in the U.S. so that simpler, safer, durable, economical, high capacity closed mixing systems can be produced and placed in service.

Cooperative efforts are needed using the ex- pertise of key university, chemical industry, gov- ernment and agricultural pesticide applicator leaders to develop a n optimum closed mixing system design which, with modular options, can handle liquid solutions, emulsifiable concentrates, dry wettable powders, and flowable formulations. This modular field scale closed mixing system needs to be developed, fabricated, tested in laboratory and field conditions, then integrated into widespread public use through a n effective educational thrust.

CMS Design Objectives

The following design objectives are appropri- a te for development of a n optimum modular vacuum powered closed mixinglloading system:

(1) Develop a n optimum field scale vacuum pow- ered closed mixing system capable of trans- ferring liquid or dry formulated pesticides, from shipping container to holding, metering, mixing, or application tanks at suitable handling rates.

(2) Develop a closed mixing system that embodies complete premixing of multiple pesticides in liquid and/or dry formulations.

(3) Develop alternative precision measuring or metering components that can be used with manual or automatic controls for fast accurate field mixture formulation and loading.

(4) Develop modular pesticide handling subsys- tems, as part of the overall closed mixing sys- tem, that can be incorporated into alternative CMS designs based on operators performance needs.

(5) Develop vacuum powered closed mixing sys- tems that are simple to operate and maintain, safe to use, with built in "fail safe" control systems on automatic or semiautomatic controlled units.

Desirable CMS Design Characteristics

(1) simple construction and operation with mini mum valving;

(2) durable corrosion resistant materials for tanks, hose, seals, and valves;

(3) rapid transfer of viscous materials; (4) suitable design for mixing liquid and dry

formulations; (5) vacuum or low pressure transfer of full

strength chemicals; (6) enclosed punch/drain/rinse unit to empty

one-way containers; (7) dry-break hose connections directly to mini-

bulk and SVR containers; (8) precision load cell weighing for metering;

and (9) complete plumbing and tank rinsing after

each chemical transfer. (10) manual and/or semi-automatic loadcell and

electric valve control panel.

Needed CMS Equipment Components

Equipment components that should be eval- uated for inclusion in a state-of-the-art closed mixing system are:

vacuum or low pressure sources (to draw pesticides into meteringlmixing tanks); metering and mixing tanks for vacuum or low pressure; meteringlweighing equipment and control systems; adequatekfe tank venting system; suction/rinsing probes that can be safely used in closed/sealed systems; puncture, drain, rinse, (and crush) container processing modules; simple flexible pesticide and rinse water transfer plumbing and valving; manual and automatic controls integrated with precision weighing (load cells) and electrical plumbing controls and valves.

These are achievable design objectives that can be reached with adequate planning, coordi- nation, communication, cooperation, funding and research effort. The pesticide industry in concert with the university research community must commit and dedicate itself to continuing research and development of safe practical, economical closed mixing equipment systems technology until these goals are achieved. Pesticide poison- ing is a silent cumulative process. We must provide safe solutions.

APPENDIX I

Bibliography

Akesson, N.B., J . B. Bailey, W.F. Serat, and W.E. Yates. 1974. Health Hazards to Workers from Application of Pesticides, ASAE Pa- per No. 74-1007, University of California. 10 p.

Akesson, N.B., W.E. Yates, R.W. Brazelton. 1978. Monitoring Airborne Pesticide Chemical Levels and Their Efforts on Workers Mixing, Loading, and Applying or Enter- ing Treated Fields, ASAE Paper No. 78- 3565, Agr. Eng. Department, University of California, Davis, December, 18 p.

Bleth, J . 1987. "Fluid Inductor and Metering Device and Method of Use", U.S. Patent # 4690179, Issued Sept. 1, 1987, U. S. Patent Office, Washington, D. C., 16 p.

Collins, H. 1986. "Editorial", Agricultural Avia- tion, Vol. 13, No. 8, Nov./Dec., 5 p.

Criswell, J.T. (Ed.) 1991. "Pesticide Reports", Cooperative Extension Service, Oklahoma State University, November, pp. 1-2.

Dewey, J.E. 1982. "Some Observations on Closed Mixing Systems for Pesticides", Pesticide Tank Mix Applications: First Conference, ASTM STP 764, J.F. Wright, A.D. Lind- say, and E. Sawyer, Eds. American Society for Testing and Materials, 1982. pp. 58-67.

Dewey, J.E., N. Akesson, W. Betts, R.W. Brazel- ton, S . Dubelman, R.K. Houston, D.L. Reichard, R. Reynolds. 1984. Closed Systems for Handling Liquid Pesticides, Task Group on Closed Systems, Extension Committee on Organization and Policy, USDA Cooperative Extension Service and Cornell University. 17 p.

Doherty, J . 1986. Cancer and Agricultural Her- bicides, Journal Embargo, HHS News, Department of Health and Human Ser- vices, National Cancer Institute, September 4, 1986.

Garnett, R.H. 1991. The Wisdon Closed Transfer system. Marketing information packet, Wisdoln Agricultural Limited, Hereford, U.K., 21 p.

Houston, R.K. 1980. Status Report on the Task Force for Safer Handling of Restricted Use Pesticides, ASAEINAAA Paper No. AA-80-008, National Agricultural Aviation Association, Las Vegas, Nevada, December, 5 p.

Jacobs, W.W. 1982. "Closed Mixing and Loading Systems and Pesticide Containers", Pes- ticide Tank Mix Applications: First Con- ference. ASTM STP 764. J.P. Wright, A.D. Lindsay, and E. Sawyer, Eds. Ameri- can Society for Testing and Materials, 1982, pp. 58-67.

Jacobs, W.W. 1984. "Closed Systems for Mixing and Loading", Determination and As- sessment of Pesticide Exposure, Studies in Environmental Science 24, Proceedings of a Working Conference, Hershey, PA, October, 1980, The National Agricultural Pesticide Assessment Program, Sponsored by USDA, USEPA, and NJAES, Rutgers University, Marie Siewierski, Ed., Elsevier, New York.

Jacobs, W.W. 1984. "Closed System Packaging: Industry Plan for Standardization of Containers and Closures", Notices, EPA, Federal Register, Vol. 49, No. 212, October 31.

Kahn, E. 1976. "Pesticide Related Illness in Cali- fornia Farm Workers", Journal of Occu- pational Medicine, Vol. 18, No. 10, October.

Kuhlman, D.K.and D.C. Cress. 1981. "Aerial Application Handbook for Applicators, Cooperative Extension Service Publica- tion No. MF-622, Kansas State Uni- versity, December, 74 p.

Noyes, R.T. 1987. Vacuum System Design for Liquid Pesticide Mixing Safety, for Presentation at the Oklahoma Agricultural Chemicals Conference, Meridian Plaza Hotel, Oklahoma City, January 20-22, 19 p.

Noyes, R.T., J.B. Solie, R.W. Whitney. 1987. Precision Vacuum Mixing System for Im- proved Pesticide Safety, ASAE Paper No. 87-1068, Dept. of Agricultural Engineer- ing, Oklahoma State University, Stillwater, June, 12 p.

Reynolds, R. 1986. The Universal Closed System for Liquids, Seventh Symposiuin on Pes- ticide Formulations and Application Systems, ASTM Sub-committee E-35.22, Phoenix, AZ, November, 8 p.

Smith, P.W. 1974. Medical Problems in Aerial Application Diagnosis and Treatment of Poisoning, Aviation Toxicology Labora- tory, Civil Aeromedical Institute, FAA, Dept. of Transportation, June, 16 p.

Spurrier, E.C. 1986. Farm Chemical Handling, Mixing and Loading Safety and Environ- mental Concerns, Seventh Symposium on Pesticide Formulations and Application Systems, ASTM Sub-committee E-35.22, November, 7 p.

Yates, W.E., N.B. Akesson, R.W. Brazelton. 1974. Closed System Mixing and Handling of Pesticides in California, ASAE Paper No. 74-1538, Dept. of Agricultural Engineer- ing, Univ. of California, Davis, December, 11 p.

Supplemental CMS References

Akesson, N.B., W.E. Yates, S.W. Boos. 1976. Systems for Handling Toxic Liquid Pesti- cide Formulations, ASAE Paper No. 76- 1504, University of California, December, 16 p.

Anderson, D.L., J r . 1986. Development of De- vices Designed to Increase Safety During I n Field Handling of Pesticides, Seventh Symposium on Pesticide Formulations and Application Systems, ASTM Sub- Committee E-35.22, Phoenix, AZ, November, 9 p.

Bouse, L.F., D.K. Kuhlman, W.E. Yates, R.O. Roth and R.B. Ekblad. 1985. "Workshop 1: Technology Improvements Needed in the Aerial Application of Agrochemicals", Improving Agrochemical and Fertilizer Application Tech-nology, Agricultural Research Institute, April, 1985. pp. 85-94.

Brazelton, R.W.and N.B. Akesson. 1986. Princi- ples of Closed Systems for Handling of Agricultural Pesticides, Seventh Sympo- sium on Pesticide Formulations and Ap- plication Systems, ASTM Sub-committee E-35.22, Phoenix, AZ, November, 13 p.

Davies, J.E. 1984. "Epidemiologic Concerns for Exposure Assessment", Determination and Assessment of Pesticide Exposure, Studies Environmental Science 24, Pro- ceedings of a Working Conference, Her- shey, PA, October, 1980, The National Agricultural Pesticide Assessment Pro- gram, Sponsored by USDA, USEPA, and NJAES, Rutgers University, Marie Siewierski, Ed., Elsevier, NY.

Jacobs, W.W. 1986. Risk Reduction Through Use of Closed Systems: An Attainable Goal?, Seventh Symposium on Pesticide Formu- lations and Application Systems, ASTM Sub-committee E-35.22, Phoenix, AZ, November, 19 p.

Nigg, H.N., J.H. Stamper, and R.M. Queen. 1986. "Dicofol Exposure to Florida Citrus Applicators: Effects of Protective Cloth- ing", Archives of Environmental Con- tainment and Toxicology, 15:121-134.

Rutz, R. 1986. Closed System Acceptance and Use in California, Seventh Symposium on Pesticide Formulations and Application Systems, ASTM Sub-committee E-35.22, Phoenix, AZ, November, 17 p.

Barthel, E. 1981. Increased Risk of Lung Cancer in Pesticide Exposed Male Agricultural Workers, Journal of Toxicology and Envi- ronmental Health, 8:1027-1040.

APPENDIX II Partial List of Mixing System Equipment and Components

I.D.# Company Address

1 Agsco, Inc Box 458, Mill Road

2 Captain Crunch, Mid- Continent Aircraft Corp. Planemate Div., Draw. L

3 Cherlor Mfg. Co. P.O. Box 2174

4 Custom Farm Service P.O. Box 338

5 Cole-Fab Inc. 4413 W. Vandegrift

6 Dutch Industries 705 1st Ave

7 Emco Wheaton, Inc. 4001 Weston Pkwy.

8 Empty Clean Corporation PO Drawer 1077

9 Fox Valve Development Hamilton Business Pk, Unit 6A

10 Gilco Sales Inc. 3093 Flint Dr.

11 Great Plains Industries 1711 Longfellow Ln.

12 Hollingsworth Co. Industrial Park Rd.

13 J.E. Soares, Inc. 7093 Dry Creek Rd.

14 Load Safe Systems, Inc. P.O. Box 421

15 Mazzei Injector Corp. 11 10 1 Mountain View Rd., Rt 5

16 MP Pumps 34800 Bennett Dr.

17 Micro, Inc. P.O. Box 2074

18 Murray Equipment 3330 Taylor St.

19 Pacer Pumps 1 Lark Ave.

20 Protect-0-Mfg. Co. Star Rt. Box 8337, W Hwy 126

21 S&G Enterprises, Inc. 5626 N. 91 St.

22 S&R Speciality Equip. P.O. Box 505

23 Scienco, Inc. 5558 Federal Ave.

24 Wilbur-Ellis, AMC Custom Spray Equipment 2524 E. Jensen

City State ZIP Phone

Grand Forks ND 58206 (701) 775-5325

Hayti MO 63851 (314) 359-0500

Salinas CA 93902 (408) 422-5477

Stanfield AZ 85272 (602) 424-3322

Fresno CA 93722 (209) 432-1613

Regina, Sask. Canada SN4 4M4 (306) 949-9522

Cary NC 27513 (919)677-0777

Cordele GA 31015 (800) 833-0943

Dover NJ 07801 (201) 328-1011

Memphis TN 38115 (901) 365-7970

Wichita KS 67207 (316) 686-7361

Boone IA 50036 (515) 432-3717

Belgrade MT 59714 (406) 388-6069

Heber Springs AR 72543 (501) 362-8404

Bakersfield CA 93307 (805) 845-2253

Fraser MI 48026 (313) 293-8240

N. Mankato MN 56002 (507) 625-6426

Ft. Wayne IN 46804 (800)348-4753

Leola PA 17540 (717)656-2161

Redmond OR 97756 (503)382-6886

Milwaukee WI 53225 (414)464-5310

Corcoran CA 93212 (209)992-4191

Memphis TN 38118 (901)365-8804

Fresno CA 93706 (209)485-1662

25 Wisdom Agricultural Ltd. Opella Building, Twyford Rd. Ph. # [4410432 342101 Rotherwas Industrial Estate Hereford UK HR2 6JR

Components Offered by Above Companies

Component Company ID Component Company ID

Mixinflransfer Systems: 1, 4, 8, 10, 13, 14, 22, 24, 25 Transfer Pumps: 16, 17, 18, 19, 23

Closed Transfer Sys. (Vacuum): 5 ,14,22,25 Venturi Injectors: 5, 9, 15

ProbesProbe Transfer Systems: 3 ,5 , 6 , 8 , 2 0 Can Crushers: 2, 13, 14, 21

Dry Break Couplers and Valves: 7, 11, 18 Gravity System Comps.: 2, 4, 12, 13, 14

VARIABLE FLOW

Figure 1 : Venturi Injector and Bypass Valve Circuit

RINSE

RINSE

.p:::.ei:i:i:::::i:::::

. TARE 3 CONTROL PANEL w

-?P FROM L D CELL(S)

BULK 0 R

, SRV

Figure 3: Semiautomatic Load Cell System

SOURCE (OPTIONAL)

RINSE NOZZLE

A

Cn *

CHECK VALVES

3-WAY VALVE

-. -.....--

Figure 2: Manual Operation Vacuum Powered Closed Volumetric Metering/Mixing System

RINSE SPRAY

DRY BREAK CONNECTOR

JENTURI INJECTOR .&-n\-nn.\\\\\\\\nn-

LLL.2 8 8 n r -

SOLENOID MINI-BULK

\ m,,u, B

- .. . . . . -. . . . -. - . -. ..- .-. -. . - -. - --- --- -- -

Figure 4: Auxiliary Pressure Pump System with Vented Tank

Figure 5: Prototype 2 HP Pump Close Mixing System

-1 60-