Aquaculture Production Best Management Practices (BMPs )

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Aquaculture Production Best Management Practices (BMPs )

Transcript of Aquaculture Production Best Management Practices (BMPs )

Page 1: Aquaculture Production Best Management Practices (BMPs )

AQUACULTURE PRODUCTION BMPS 2003 1

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TABLE OF

CONTENTS

WHY BMPS ARE

IMPORTANT TO LOUISIANA

In Louisiana we are blessed with beautiful and abun-

dant waters to enjoy fishing, hunting, boating or just relaxingon the shore of a lake, river or bayou. Most of the water inLouisiana’s rivers and lakes comes from rainfall runoff. As thisrunoff travels across the soil surface, it carries with it soilparticles, organic matter and nutrients, such as nitrogen andphosphorus. Agricultural activities contribute to the amountof these materials entering streams, lakes, estuaries andgroundwater. In addition to assuring an abundant, affordablefood supply, Louisiana farmers must strive to protect theenvironment.

Research and educational programs on environmen-tal issues related to the use and management of naturalresources have always been an important part of the LSUAgCenter’s mission. Working with representatives from theagricultural commodity groups, the Natural Resources Con-servation Service (NRCS), the Louisiana Department ofEnvironmental Quality (LDEQ), the Louisiana Farm BureauFederation (LFBF) and the Louisiana Department of Agricul-ture and Forestry (LDAF), the LSU AgCenter has taken thelead in assembling a group of Best Management Practices(BMPs) for each agricultural commodity in Louisiana.

BMPs are practices used by agricultural producersto control the generation and delivery of pollutants fromagricultural activities to water resources of the state andthereby reduce the amount of agricultural pollutants enter-ing surface and ground waters. Each BMP is a culmination ofyears of research and demonstrations conducted by agricul-tural research scientists and soil engineers. BMPs and accom-panying standards and specifications are published by theNRCS in its Field Office Technical Guide.

Introduction ......................... 3

Finfish Productionin Ponds ................................ 4

Crawfish Productionin Ponds ................................ 9

Crawfish NutrientManagement ....................... 10

Intensive ProductionSystems ............................... 12

Soil and WaterManagement ....................... 14

Pesticide Management andPesticides ............................ 20

General Farm BMPs ......... 25

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aquacultureBMPs

INTRODUCTION

The production of seafoodfrom aquaculture businessesinvolves hundreds of producersin Louisiana and supports manyother industries such as transpor-tation, processing, marketing anddistribution. The feed and baitindustries that support aquacul-ture production in Louisiana alsoprovide substantial economicbenefits to rural communities.Louisiana has one of the mostdiverse aquaculture industries inthe nation. Farm-gate value offarmed crustaceans, molluscs,reptiles and finfish typicallyexceeds $100 million annually.Catfish, crawfish, soft-shellcrawfish, alligators, bait min-nows, tilapia, ornamental spe-cies, turtle hatchlings, hybridstriped bass, soft-shell crabs, reddrum and oysters are all pro-duced in the state. Oyster aqua-culture occurs in open waterswith no feeding and no dis-charges. For this reason, oysterproduction was excluded fromthis review.

Production technologiesvary within each species, as wellas among culture systems fordifferent species. Accordingly,this document addresses a num-ber of commercial aquacultureapproaches now used in Louisi-ana. Aquaculture productionsystems can be specialized

businesses or combined withconventional plant and animalagriculture. When combined withconventional agriculture, aqua-culture must be managed as partof a complex food productionsystem.

Although Louisiana is aleader in the production of wildcaught fish and shellfish, thedemand for these productscannot be met solely by naturalproduction. Populations of wildspecies continue to be affectedby fishing pressure, pollution,loss of critical habitat and saltwa-ter intrusion. Part of the demandfor seafood must be met byaquaculture if Louisiana is tocontinue as a national leader inseafood production.

Best Management Practices(BMPs) have been determined tobe an effective and practicalmeans of reducing point andnonpoint-source water pollutantsat levels compatible with envi-ronmental quality goals. Theprimary purpose for implementa-tion of BMPs is to conserve andprotect soil, water and air re-sources. BMPs for aquacultureoperations are a specific set ofpractices used to reduce theamount of soil, nutrients, pesti-cides and microbial contaminantsentering surface and groundwaterwhile maintaining or improving

the productivity of agriculturalland. This list of BMPs is a guidefor the selection and implementa-tion of those practices that willhelp producers to conserve soiland protect water and air re-sources by reducing pollutantsfrom reaching both surface andgroundwater.

The BMPs that apply mostdirectly to the aquaculture indus-try are included in this publica-tion. A brief description, purposeand conditions to which thepractice applies are given for eachof the BMPs listed.

References are made tospecific Natural Resources Con-servation Service (NRCS) pro-duction codes, which are ex-plained in the text of this docu-ment. More detailed informationabout these practices can befound in the NRCS Field OfficeTechnical Guide (FOTG). TheFOTG can be found in all Soiland Water Conservation districtoffices and all NRCS field officesor on the NRCS web page. Addi-tionally, under voluntary partici-pation by the producer, technicalassistance to develop and imple-ment a farm-specific conservationplan is available through theConservation Districts, NRCSfield offices and the LSUAgCenter parish offices.

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Finfish Production in Ponds

AQUACULTURE PRODUCTION

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Introduction andGeneralConsiderations

Ponds constructed forcommercial production of finfishgenerally fall into two categories:levee ponds or watershed ponds.Levee ponds are completelyenclosed by constructed embank-ments; watershed ponds usuallyrely on one embankment con-structed across an existing valleyto catch and hold runoff fromrainfall. Both types of construc-tion are associated with watercontrol structures, irrigation,drainage modifications, accessand storage facilities and otherconservation practices. Addition-ally, site selection for both typesof pond system should considerprevailing elevations and theneed to use natural drainage formanagement purposes.

While both systems rely onoccasional flushing or drainingof pond water, fish productionconverts raw feedstuffs intoedible protein more efficientlythan traditional animal industries,resulting in comparatively mini-mal amounts of waste. Also,ponds used for raising catfish,hybrid bass and other speciesoften remain filled for years at a

time, using the same naturalcycles as wetlands, lakes andoceans to biodegrade uneatenfeed and waste products. Interms of best managementpractices and potential environ-mental impacts, ponds used toculture turtle broodstock shouldprobably also be included in thiscategory of production systems.

In a typical catfish pondproducing 5,000 pounds of fishper acre annually (from 10,000pounds of feed), 400 pounds ofnitrogen, 80 pounds of phospho-rus and 3,000 pounds per acre oforganic matter are generated inaddition to the fish produced.But, because of the naturalbreakdown and cycling ofnutrients within pond systems

only 110, 7 and 1,500 pounds ofnitrogen, phosphorus and organicmatter, respectively, would bedischarged even if the pond weredrained at the end of each yearand no provisions were made tocapture rainfall. In contrast, ifstandard industry BMPs ofcapturing and storing rainfall anddraining ponds only every fiveyears are practiced, per-yeardischarges drop to only 30, 2 and400 pounds of nitrogen, phospho-rus and organic matter per acre,respectively, equating to wastereductions of 92 percent, 97percent and 87 percent. Clearly,pond-based aquaculture incorpo-rates efficient production ofanimal protein while minimizingenvironmental impacts.

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Production System-based BMPs

Operate Production Ponds for Several YearsWithout Draining

While some production ponds, such as fry and fingerling ponds,require annual draining and re-filling, most commercial ponds in thesoutheastern United States are operated for as long as possible with-out draining. While an average figure of 6.5 years between fillings istypical for catfish production, some commercial ponds have been leftundrained for as long as 15 years while still maintaining adequatewater quality for fish production. This re-use of water for multiplecrops reduces both effluent volume from draining and the need forpumped groundwater to refill ponds.

Install Drain Outlets to Draw Overflow Fromthe Pond Surface

Water from the lower layers of a pond is generally of poorerquality than that near the surface. This can be especially true in termsof suspended solids, oxygen demand and nutrients. Pond drainsshould be constructed to allow water to leave the pond from thesurface, not the bottom. Existing drains that draw from the pondbottom and incorporate external structures to regulate pond depthshould be modified, during regularly scheduled pond renovations, todraw water from near the pond surface.

Practice Water Detention When DrainingProduction Ponds

Eventually, most aquaculture ponds must be drained for inven-tory adjustments or to allow for levee repairs and restoration of depthand slopes. When ponds must be drained, avoid releasing water fromthe pond while it is being seined or immediately afterward. Holdingthe last 10 percent to 20 percent of the pond water for two to fivedays before discharge can significantly reduce nutrient loads ineffluents because many nutrients are bound to particles of sediment,which can settle out of the water column before discharge.

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Capture and Store Rainfall to Reduce EffluentVolume and Pumping Costs

Allowing the normal pond level to fall at least 4 to 6 inchesbelow the level of the standpipe (or more, depending on the season)without re-filling will greatly reduce the volume of water exitingproduction ponds during rainfall. In summer and fall, maintain 8inches of rainfall storage capacity if possible, since effluents will bemost concentrated during these months because of heavy feeding andhigher temperatures. Standpipes within ponds can be painted a brightcolor to indicate the target water depth at which pumping is needed.An added benefit of this practice is the reduced need for pumpinggroundwater to maintain ponds at or near maximum depths.

Use High Quality Feeds and MaximizeConversion of Feed to Fish

Pollutants in catfish pond effluents are generally the result ofuneaten feed and waste products from the fish being fed. The use ofhigh quality feeds improves not only feed conversion, but usuallyfeed consumption as well. It is also important to adjust the amount offeed provided each day to match the fish’s appetite. Water qualityconsiderations usually limit feeding rates to no more than 125-150pounds per acre per day. Fish must use their daily ration first andforemost to maintain their weight from one day to the next. Anyexcess feed provided can be used for growth, which from an eco-nomic standpoint is the equivalent of production.

Adopt Moderate Stocking LevelsWhen excessively high numbers of fish are stocked, most of the

daily feed allowance must be used for maintenance and little isavailable for fish production. This, of course, is an inefficient use offeed, fingerlings and pond space. Lower stocking rates allow moreefficient use of feed and ultimately reduce the cost of fish productionas well as the amount of waste generated per pound of fish produced.Excessively high stocking and feeding rates result in a deteriorationof water quality once the natural processes in a pond can no longerbreak down waste products as quickly as they are added. This in turnincreases disease losses, reduces feed conversion efficiency and canresult in fish kills caused by heavy algal blooms. Nutrient levels inany effluents that may leave the pond during these periods will reflectpoor water quality within the pond itself. Adhering to moderatestocking and feeding rates can reduce the cost of production throughreduced aeration costs, better water quality, higher survival, reducedmedication and chemical costs, and improved feed conversions.

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Maintain Adequate Aeration and CirculationKeeping oxygen levels up improves feed consumption and

conversion, and it enhances the natural processes responsible forbreaking down waste products and cycling nutrients within the pond.Organic matter will be more readily oxidized, the solubility of phos-phorus will be reduced and nitrogen losses will be increased, all ofwhich improve fish production and the quality of any effluents thepond may discharge. Aerators should be positioned and operated tominimize erosion of pond levees and bottoms.

Avoid FlushingThe use of pumping well water to flush ponds is becoming

increasingly costly, and research suggests this practice is usually oflittle benefit. Many well water supplies for commercial ponds areunable to add more than 5 percent of a pond’s volume on a dailybasis, and water exchange at these rates typically has little or noeffect on pond water quality. The water leaving the pond, however,represents an unnecessary pollution load in the receiving drainage.

Reuse Pond WaterTo save on pumping costs, conserve groundwater and reduce

effluents when draining must be accomplished, pond water can bepumped into surrounding adjacent ponds and then reused. Transfercan usually be accomplished with a low-lift pump, and water can bereplaced later by siphon. In some circumstances, it may be possibleto drain water directly into ponds with lower elevations.

Use Effluents for IrrigationUnder some conditions, pond water discharge can be used to

irrigate crops. Unfortunately, most pond overflow in Louisiana occursduring periods of high precipitation, when irrigation requirements arelow or non-existent. Additionally, the nutrient content of aquaculturepond water is too low to reduce appreciably the fertilizer require-ments of terrestrial crops. Under some circumstances, diverting ponddischarge can result in excessive erosion, so take care when consider-ing this practice.

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Consider the Use of Natural or ConstructedWetlands to Reduce Effluent Nutrients

Natural wetlands are an effective means of treating aquacultureeffluents, but care must be taken not to overload these systems.Effective treatment requires retention times of at least two days.Research suggests that constructed wetlands are not cost-effective fortreating the entire volume of an aquaculture pond, because of theneed to retain water for at least two days, but this option may beappropriate to treat the concentrated effluents typically associatedwith the final 10 percent to 20 percent of pond volume during drain-ing.

Consider Watershed IssuesAlthough levee ponds typically collect only that precipitation

that falls directly into the pond or on the inner levee slopes, water-shed or hillside ponds are subjected to heavy flushing during exces-sive or prolonged rainfall. Pond design and construction should takeinto account the overall size and hydrology of the surrounding water-shed. Means to divert excessively heavy or turbid runoff should beincorporated during construction or renovation.

Practice Erosion Control in Drained PondsWhen ponds are drained and idle, especially in the winter in

Louisiana, substantial erosion of the exposed pond bottom can occur,affecting both the serviceability of the pond and the receiving waterson the outside of the drain pipe. For this reason drains should alwaysbe closed when ponds sit empty, and ponds should be partially orcompletely refilled as quickly as possible.

Minimize Environmental Impacts DuringPond Renovation

Use sediment from within the pond to rebuild levees and fill inlow areas. Do not remove it from the pond unless absolutely neces-sary. During renovation, keep drains closed to minimize erosion anddischarge of sediment. Pond depth can usually be increased at thistime to allow more management flexibility in capturing and storingrainfall or water from surrounding ponds. In this way, effluents willbe further reduced.

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CrawfishProduction inPondsIntroduction andGeneralConsiderations

The development of craw-fish culture in the early 1960swas stimulated by the year-rounddemand for crawfish and by theseasonality of crawfish catchesfrom natural areas. Crawfishculture in Louisiana has devel-oped into a major aquacultureindustry, recognized throughoutthe world. Cultivation and pro-duction of crawfish in manmadeponds with controlled waterdepth, forage management(usually rice cultivation) andwater recirculation techniquesover the past several decadesprovided the groundwork for ascientifically managed produc-tion system.

Key considerations forcrawfish culture are the highvolumes of water (70-100 gpm/surface acre) required to maintainacceptable pond water quality,the high expense of harvesting,the length and frequency of theharvesting season, an expandingmarket and the need for contin-ued product development. His-torically, about 100,000 acres ofcrawfish production in Louisianahave yielded an average of 25million to 50 million pounds ofcrawfish a year. The crop has afarm value of $20 million to $35million annually.

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Crawfish ponds donot typically affect theenvironment negatively,but rather serve as favor-able habitat for manyspecies of waterfowl,wading birds and furbear-ers. Effluents from craw-fish ponds have not hadserious impacts on receiving waters, especially when compared withother agricultural and industrial activities. Often, marginal agricul-tural lands are used to produce crawfish. Integration of crawfishproduction with traditional land uses often provides a practical meansof both soil and energy conservation.

Production System-based BMPs

Reduce PumpingCosts and ImproveFlushing Efficiency

When flushing crawfishponds in the fall to improvewater quality, avoid pumping anddraining at the same time. Fillthe pond no more than 12 inchesbefore flushing, then shut off thepump. Open the drain and allowthe entire pond to drop to a depthof roughly 4 to 6 inches, then re-fill with fresh water, again to nomore than 12 inches. This type offlushing ensures that stale waterwill be diluted with fresh waterthroughout the entire pond,preventing the establishment of‘dead’ areas where water will notnormally flow with conventionalflushing. The pond can be filledto an optimum operating depth of14 to 18 inches during the winterwhen temperature drops andwater quality problems subside.

Alternately, baffle leveescan be used to direct water flowthrough the pond to eliminate

hypoxic areas and to allow forthe use of paddlewheel circula-tion or recirculating pumps. Inareas where the quality of surfacewater is occasionally unaccept-able or where well water must bepumped from great depths, waterrecirculation can be a cost-effective alternative.

Fertilize Forage CropsEfficiently

Nutrient application rateswill be based on the results of asoil analysis. Select only thosematerials recommended for useby qualified individuals from theLouisiana Cooperative ExtensionService, Louisiana AgriculturalExperiment Station, certifiedcrop advisors and certifiedagricultural consultants or pub-lished LSU AgCenter data.

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Minimize Discharges and Sediment LoadingWhen Draining

Recent research has shown that the totalvolume of discharge can be reduced consid-erably over the course of a season by main-taining a 2 to 6 inch water storage capacitywithin a crawfish pond whenever possible.This allows for rainwater to be capturedrather than be flowing out of the pond andcan help reduce pumping costs. Findingsalso suggest that replacing removable droppipes with vertically adjustable drainagestructures can significantly improve thequality of effluents leaving the pond by

allowing water to be drained from the surface rather than the pondbottom.

One aspect of crawfish pond production that is unique to thistype of aquaculture is the reliance on natural food chains to supportproduction of the crop. While vegetative forages such as rice areessential to crawfish production, these plants are not directly con-sumed by the crawfish. Instead, they serve as the basis of a complex,natural food chain supporting microorganisms, protozoans andvarious invertebrates which in turn serve as the principal food sourcefor the crawfish crop. One consequence of this natural productioncycle is the constant bottom foraging behavior of the crawfish, whichresults in the suspension of clay turbidity in the water column, espe-cially late in the season.

While this condition can bemitigated somewhat in crawfish-only ponds by postponing drain-ing until most of the crawfishpresent have burrowed in theearly summer, it poses problemsin ponds where draining must beaccomplished much earlier toallow for a commercial rice cropto be planted. In these instances,no specific recommendationshave been formulated to reducesuspended sediments in ponds oreffluents, but suspending harvestactivities for one to two weeksbefore draining should improvewater clarity prior to discharge.The use of filter strips and chan-nel vegetation will also probablybe beneficial in reducing thiscomponent of crawfish effluents.Other approaches, such as main-taining in-pond buffer zones ofnatural aquatic vegetation orconstructing gravel barriersaround pond drains, are beingevaluated.

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Crawfish NutrientManagement

AQUACULTURE PRODUCTION BMPS 2003

IntroductionA sound soil fertility program is the foundation upon which a

profitable farming business must be built. Agricultural fertilizers are anecessity for producing abundant, high quality food, feed and fibercrops. Using fertilizer nutrients in the proper amounts and applyingthem correctly are both economically and environmentally importantto the long-term profitability and sustainability of crop production.The fertilizer nutrients that have potential to become groundwater orsurface water pollutants are nitrogen and phosphorus. In general,other commonly used fertilizer nutrients do not cause concern aspollutants.

Because erosion and runoffare the two major ways nonpoint-source pollutants move intosurface water resources, practicesthat reduce erosion or runoff areconsidered Best ManagementPractices (BMPs). Similarly,practices that limit the buildup ofnutrients in the soil, which canleach to groundwater or be

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picked up in runoff, and practicesthat ensure the safe use of agri-cultural chemicals also areconsidered BMPs. In general,soil conservation and waterquality protection are mutuallybeneficial; therefore the BMPsdescribed here are the best meansof reducing agriculturalnonpoint-source pollution result-ing from fertilizer nutrients.

Nitrogen In aquaculture, conversion

of feeds and organic matterresults in simpler inorganicnitrogen forms such as ammo-nium (NH4+) and nitrate (NO3-).These are soluble in soil waterand readily available for plantuptake. The ammonium form isattracted to and held by soilparticles, so it does not readilyleach through the soil withrainfall or irrigation water.Nitrates, on the other hand, arenot attached to soil particles anddo move downward with soilwater and can be leached intogroundwater or run off intosurface waters.

Excessive nitrate concentra-tions in water can acceleratealgae and plant growth instreams and lakes, resulting inoxygen depletion. Nitrate con-centrations above a certain levelin drinking water may injureyoung animals or human infants.

algae bloom

AQUACULTURE PRODUCTION BMPS 2003

PhosphorusNaturally occurring phos-

phorus (P) exists in a phosphateform either as soluble inorganicphosphate, soluble phosphate,particulate phosphate or mineralphosphate. The mineral forms ofphosphorus (calcium, iron andaluminum phosphates) do notdissolve in water very easily. Theamount of these elements (cal-cium, iron and aluminum)present in reactive forms varieswith different soils and soilconditions.

Most phosphate is notreadily water soluble. Most ofthe ions are either used by livingplants or adsorbed to sediment,so the potential of their leachingto groundwater is low. Thatportion of phosphate bound tosediment particles is virtuallyunavailable to living organisms,but becomes available as itdetaches from sediment. Only asmall part of the phosphatemoved with sediment into sur-face water is immediately avail-able to aquatic organisms. Addi-tional phosphate can slowlybecome available through bio-chemical reactions. The slowrelease of large amounts ofphosphate from sediment layersin lakes and streams could causeexcessive algae blooms andexcessive growth of plants,thereby affecting water quality.

Soil testing is the founda-tion of a sound nutrient man-agement program.

A soil test is a series ofchemical analyses that determinethe levels of essential plantnutrients in the soil. When nottaken up by a crop, some nutri-ents, particularly nitrogen, can belost from the soil by leaching,runoff or mineralization. Others,like phosphorus, react with soilminerals over time to formcompounds that are not availablefor uptake by plants. Soil testingcan be used to estimate howmuch loss has occurred and topredict which nutrient(s) andhow much of that nutrient(s)should be added to the soil toproduce a particular crop andyield. Take soil tests at leastevery three years or at the begin-ning of a different croppingrotation.

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Intensive ProductionSystems

Intensive Production With Morethan 10 Percent Daily WaterExchange

Several examples of high-exchange intensiveaquaculture can be found in Louisiana. Production ofalligators for hides and meat is accomplished through anintensive production system with daily water exchangestypically exceeding 10 percent by volume. Eggs aregathered under permit from natural nests in marshes andswamps. Eggs are collected in June and July during theearly stages of incubation. Eggs hatch in late August.Grow-out technology of hatchlings generally involvesintensive indoor growing systems. Alligators are main-tained in buildings of rectangular or circular design.About 75 percent of the floor space is flooded. Thesloping floor has a water depth of 0 - 12 inches. Afterflushing, the compartments are reflooded with heatedwater to reduce thermal stress to the alligators. Thebuilding temperature is maintained by circulating warmwater in a closed loop system within the concrete floor.There are rigid regulations issued by the LouisianaDepartment of Wildlife and Fisheries (LDWF) as togrowing shed design, water temperature and growingdensities.

Alligator culture issomewhat atypical in itsdischarge of warm, nutrient-rich water. Culture practicesinvolve feeding the animalsdaily, maintaining watertemperature at a minimum of80 degrees F and changingwater daily. The high densityof one animal per square footinitially to about 3 square feetper animal at 4 feet longgenerates relatively concen-trated wastewater; however,shallow water depths (12inches or less) and allowances

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1. Soil test for nutrient statusand pH to:• determine the amounts of additionalnutrients needed to produce a forage cropfor crawfish and the amount of lime neededto correct soil acidity (ph) problems

• optimize farm income by avoidingexcessive fertilization and reducing nutrientlosses by leaching and runoff; and identifyother yield-limiting factors such as highlevels of salts or sodium that may affectsoil structure, infiltration rates, surfacerunoff and, ultimately, groundwater quality

2. Base fertilizer applicationson:• soil test results• realistic yield goals and moisture

prospects• crop nutrient requirements• past fertilization practices• previous cropping history

3. Time nitrogen applicationsto:• correspond closely with crop uptake

patterns• increase nutrient use efficiency• minimize leaching and runoff losses

4. Skillfully handle and applyfertilizer by:• properly calibrating and maintaining

application equipment• properly cleaning equipment and

disposing of excess fertilizers,containers andwash water

• storing fertilizers in a safe place

RecommendedCrawfishForage

Practices

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for dry areas in houses result in alow level of water use. Alligatorwastewater includes fecal mate-rial and remains of food. Manyalligator farmers use oxidationponds and lagoons to treateffluent. A common alternative isthe use of commercially availablesewage treatment packages.Depending on holding capacity,excess water from the lagoon island applied; however, it is rarefor wastewater to be disposed ofby land application.

Several finfish productionsystems operating in Louisianafall into this category. Thesesystems range from outdoorraceways made of concrete orearthen walls to indoor multi-pass tank facilities. Source watercan vary, from heated industrialeffluent to municipal supplies tosurface water from lakes andrivers. As a result, a number ofconservation practices must beincluded to address the multiplic-ity of possible configurations thatfall into this category. Effluentcharacteristics may vary signifi-cantly between similarly config-ured systems, depending on thespecies being cultured. Concernsfor preventing escape of exoticspecies may require removal anddisposal of all but the smallestsolids from effluents, while othertypes of high-turnover systemsmay rely solely on dilution todispose of dissolved and solidwastes in the effluent stream. Asthis sector of the industryevolves, economically successfulconfigurations will be moreeasily characterized and BMPscan be more directly applied.

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Intensive Production With Less Than 10Percent Daily Water Exchange

A number of systems operating in Louisiana fall into this cat-egory. These systems are typically indoor tank systems that replaceless than 10 percent of the system’s water volume daily. They havebeen used to culture soft-shell crawfish and soft-shell crabs, tilapia,red drum broodfish and striped bass broodfish. These species havethe high market value needed to cover the relatively high overheadcosts. Water sources range from municipal supplies to subsurfacewells.

Since the systems are completely enclosed, the effects of theproduction system on the environment are mainly limited to dis-charge of effluents. Effluent characteristics may vary significantlybased on the size of the system and the species being cultured.Concerns for preventing escape of exotic species, such as tilapia, willrequire removal and disposal of all but the smallest solids fromeffluents, while other systems may rely solely on dilution to disposeof dissolved and solid wastes in the effluent stream. Where possible,the producer should be encouraged to connect to municipal sewagesystems. When this is not practical, producers must design a wastetreatment system based on volume and concentration of the effluent.These treatment systems may range from a simple storage structurefor removal to off-site treatment to a series of treatment ponds forremoval of solids and nutrients. As this sector of the industry evolves,economically successful configurations will be more easily character-ized, and BMPs can be more directly applied.

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Sediment is the largestpollutant by volume of surfacewater in the Nation. Sedimentcomes from agricultural sources,construction sites and other soil-disturbing activities in urbansettings that leave the soil ex-posed to rainfall. Sedimentincreases the turbidity of water,thereby reducing light penetra-tion, impairing photosynthesis,altering oxygen relationships andmay reduce the available foodsupply for certain aquatic organ-isms. It can affect fish popula-tions adversely in areas wheresediment deposits cover spawn-ing beds. Increased sediment alsofills lakes and reservoirs.

SOIL AND WATER

MANAGEMENTSediment directly damages

water quality and reduces theusefulness of streams and lakesin many ways. These include:

Damaged fish spawningareas

Reduced light penetrationfor aquatic life

Increased water purificationcosts

Lower recreational value

Clogged channels andincreased flooding

Increased dredging to main-tain shipping channels

Reduced storage capacityfor reservoirs

In addition, sediment is oftenrich in organic matter. Nutrientssuch as nitrogen and phosphorusand certain pesticides may enterstreams with sediment. The detri-mental effects of these substancesaccompanying the sediment mayinclude:

Rapid algae growth

Oxygen depletion as organicmatter and algae decomposi-tion

Fish kills from oxygendepletion

Toxic effects of pesticides onaquatic life

Unsafe drinking water causedby nitrate or pesticide content

The following are production practices and the NRCSproduction code associated with each practice that applies toaquaculture production.

Field Borders (NRCS Code 386) andFilter Strips (NRCS Code 393)

These are strips of grasses or other close-growing vegetationplanted around fields and along drainageways, streams and otherbodies of water. They are designed to reduce sediment, organicmaterial, nutrients and chemicals carried in runoff.

In a properly designed filter strip, water flows evenly throughthe strip, slowing the runoff velocity and allowing contaminants tosettle from the water. In addition, where filter strips are seeded,fertilizers and herbicides no longer need to be applied right next tosusceptible water sources. Filter strips also increase wildlife habitat.

Soil particles (sediment) settle from runoff water when flow isslowed by passing through a filter strip. The largest particles (sandand silt) settle within the shortest distance. Finer particles (clay) arecarried the farthest before settling from runoff water, and they may

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remain suspended when runoffvelocity is high. Farming prac-tices upslope from filter stripsaffect the ability of strips to filtersediment. Fields with steepslopes or little crop residue willdeliver more sediment to filterstrips than more gently slopingfields and those with goodresidue cover. Large amounts ofsediment entering the filter stripmay overload the filtering capac-ity of the vegetation, and somemay pass on through.

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4. Uniformity of water flowthrough the filter strip

Shallow depressions or rills needto be graded to allow uniformflow of water into the filter stripalong its length. Water concentratedin low points or rills will flow at highvolume, so little filtering will takeplace.

5. Maintenance of the filterstrip

When heavy sediment loads aredeposited, soil tends to build upacross the strip, forming a miniatureterrace. If this becomes large enoughto impound water, water willeventually break over the top andflow will become concentrated inthat area. Strips should be inspectedregularly for damage. Maintenancemay include minor grading or re-seeding to keep filter strips effective.

In summary:Vegetative filter strips can reduce

sediment effectively if water flow is evenand shallow.

Filter strips must be properly designedand constructed to be effective.

Filter strips become less effective assediment accumulates. With slowaccumulation, grass regrowth betweenrains often restores the filtering capacity.

Filter strips remove larger sedimentparticles of sand and silt first. Smaller clay-sized particles settle more slowly and maybe only partially removed, depending onthe strip width and water flow rate.

Because soil-bound nutrients andpesticides are largely bound to clayparticles, filter strips may be only partiallyeffective in removing them.

Fewer dissolved nutrients andpesticides will be removed than thosebound to soil particles.

Filter strips are a complementaryconservation practice that should be usedwith in-field conservation practices such asconservation tillage, contour buffer strips,strip cropping and waterways.

Filter strip effectiveness depends on five factors:

1. The amount of sediment reaching the filter strip. This isinfluenced by:

type and frequency of tillage in cropland above the filter strip. The moreaggressive and frequent tillage is above filter strips, the more likely soil is toerode.

time between tillage and a rain. The sooner it rains after a tillageoperation, the more likely soil is to erode.

rain intensity and duration. The longer it rains, and thus the moresediment deposited, the less effective filter strips become as they fill withsoil.

steepness and the length above the filter strip. Water flows faster downsteeper slopes. Filter strips below steep slopes need to be wider in relationto the cropland drained above to slow water and sediment movementadequately.

In general, a wider, uniformly shaped strip is more effective at stopping orslowing pollutants than a narrow strip. As a field’s slope or watershed sizeincreases, wider strips are required for effective filtering. The table gives thesuggested filter strip width based on slope. For a more accuratedetermination of the size of filter strip you will need for your individualfields, consult your local NRCS or Soil and Water Conservation Districtoffice.

Suggested Vegetated Filter Strip Widths on Percent Slope

Land Slope, % Strip Width, Feet

0 - 5 20

5 - 6 30

6 - 9 40

9-13 50

13-18 60*Widths are for grass and legume species only and are not intended for shrub and tree species. Adaptedfrom the NRCS Field Office Technical Guide, 1990.

2. The amount of time that water is retained in the filter strip.This is influenced by:

width of the filter area. Filter strips will vary in width, depending on thepercent slope, length of slope and total drainage area above the strip.

type of vegetation and quality of stand. Tall, erect grass can trap moresediment than can short flexible grass. The best species for filter strips aretall perennial grasses. Filter strips may include more than one type of plantand may include parallel strips of trees and shrubs, as well as perennialgrasses. In addition to potential for improving water quality, these stripsincrease diversity of wildlife habitat.

3. Infiltration rate of the soilSoils with higher infiltration rates will absorb water and the

accompanying dissolved nutrients and pesticides faster than soils with lowinfiltration rates. Parish soil survey reports include a table listing theinfiltration rate group for the soils identified in each parish.

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Grassed Waterways (NRCS Code 412):These are natural or constructed channels that are shaped or

graded to required dimensions and planted in suitable vegetation tocarry water runoff. They are designed to carry this runoff withoutcausing erosion or flooding and to improve water quality by filter-ing out some of the suspended sediment.

Heavy Use Area Protection(NRCS Code 561):

This practice addresses the need to stabilize areas frequentlyand intensely used by animals or vehicles. Suggested practicesinclude establishing vegetative cover, installing suitable surfacematerials and constructing needed structures.

Roof Runoff Management(NRCS Code 558):

The practice addresses the collection, control and disposal ofrunoff water from roofs. It is used to prevent the runoff water fromroofs from flowing across animal waste areas and to reduce pollu-tion and erosion, improve water quality, improve drainage andprotect the environment. This practice applies where: (1) roofrunoff is included in an overall plan for a waste management sys-tem and (2) roof runoff water may come in contact with wastes orcause soil erosion.

Sediment Basin (NRCS Code 350):This is a basin constructed to collect and store manure and

sediment. Its purpose is to maintain the capacity of lagoons, toprevent deposition on bottom lands and to trap sediment, agricul-tural wastes and other debris. This practice helps prevent beddingmaterials, such as sand, hay or straw, from entering waste disposalsystems, and traps manure for hauling to fields.

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Waste Treatment Lagoon(NRCS Code 359):

This is an impoundment made by excavation or earthfill for thetemporary storage and biological treatment of animal or otheragricultural waste. The impoundment stores organic waste, reducespollution and protects the environment. This standard establishesthe minimum acceptable requirements for design, construction andoperation of waste treatment lagoons. Embankments are limited toan effective height of 35 feet or less. This practice applies where:(1) an overall waste management system has been planned, (2)waste generated by agricultural production needs treatment, (3) alagoon can be located near the source of the waste, (4) soils aresuitable for retaining the waste or can be sealed and (5) a watersupply is adequate to fill the lagoon to about 3 feet before operationand to maintain the design depth when the lagoon becomes fullyoperational.

Cover and Green Manure Crop(NRCS Code 340):

This is a crop of close-growing grasses, legumes or smallgrains grown primarily for seasonal soil protection and improve-ment. It is usually grown for one year or less, except where there ispermanent cover. It is designed to control erosion during periodswhen the major crops do not furnish enough cover. It also addsorganic material to the soil and improves infiltration capacity,aeration and tilth.

Critical Area Planting (NRCS Code 342):This involves the planting of vegetation, such as trees, shrubs,

vines, grasses or legumes, on highly erodible or critically erodingareas. This practice does not include planting trees for wood prod-ucts. The primary purposes are to stabilize the soil, reduce damagefrom sediment and runoff to downstream areas, and improve wild-life habitat and aesthetics. Examples of applicable areas are dams,dikes, levees, cuts, fills and denuded or gullied areas where vegeta-tion is difficult to establish by usual planting methods.

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Regulating Water in Drainage System(NRCS Code 554)

Controlling the removal of surface runoff, primarily throughthe operation of water control structures. It is designed to conservesurface water by controlling the outflow from drainage systems.

Riparian Forest Buffer (NRCS Code 391):This is an area of trees, shrubs and other vegetation located

adjacent to and uphill from water bodies. This practice may beapplied in a conservation management system to supplement oneor more of the following:

• To create shade to lower water temperature, which wouldimprove habitat for aquatic organisms.

• To remove, reduce or buffer the effects of nutrients, sedi-ment, organic material and other pollutants before entry intosurface water and groundwater recharge systems.

This practice applies on cropland, hayland, rangeland, forest-land and pastureland areas adjacent to permanent or intermittentstreams, lakes, rivers, ponds, wetlands and areas with groundwaterrecharge where water quality is impaired or where there is a highpotential of water quality impairment.

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For more information on thesepractices and how to implementthem, contact your local NRCS orConservation District office.

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Pesticides can directly entergroundwater by spills around poorlyconstructed or sealed wells, or wellswith improper casting, or by back-siphoning during spray tank filling.

Rainfall runoffwill also movepesticides acrossthe soil surface.

Rain or irrigationstarts pesticidesmoving into andthrough soil.

Soil-incorporatedsystemic pesticide

Pesticide is carriedinto and throughsoil. Movementthrough soil isaffected by soil andpesticideproperties andamount andtiming of water.Pesticide residueand by-productsnot absorbed arebroken down intothe groundwater.

WATER TABLE

Pesticide is taken upby plants, brokendown by organisms,sunlight or chemicalreactions.

Groundwater f low

Movement withgroundwater –additionalbreakdown generallyslowed, but dependson chemical natureand groundwater.

Pesticides can directly entergroundwater by spills around poorlyconstructed or sealed wells, or wellswith improper casting, or by back-siphoning during spray tank filling.

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IntroductionTo preserve the availability

of clean and environmentallysafe water in Louisiana, contami-nation of surface and groundwa-ter by all agricultural and indus-trial chemicals must be reduced.Some sources of contaminationare easily recognizable from asingle, specific location. Othersources are more difficult topinpoint. Nonpoint-sourcepollution of water with pesticidesis caused by rainfall runoff,particle drift or percolation ofwater through the soil. Pestmanagement practices will bebased on current research andextension recommendations. Byusing these recommendations,pesticide usage will followenvironmentally sound guide-lines.

Pest Management ProceduresPesticides will be applied

only when they are necessary toprotect the crop. The pesticidewill be chosen following guide-lines to assure that the onechosen will give the most effec-tive pest control with the leastpotential adverse effects on theenvironment.

Water quality, both surfaceand ground, will be protected byfollowing all label recommenda-tions and guidelines dealing withwater quality.

All label statements anduse directions designed specifi-cally to protect groundwater willbe followed closely.

Specific Best ManagementPractices designed to protectsurface water will be followedclosely.

Erosion control practices(such as pipe drops, etc.) will beused to minimize runoff thatcould carry soil particles withadsorbed pesticides and/or dis-solved pesticides into surfacewaters.

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Unsaturated zone

WATER TABLE

Rainfall runoff

The water tableseparates theunsaturated zonefrom the saturatedzone (groundwater)

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PesticideApplication

Management practices suchas the pesticide selected, theapplication method, the pesticiderate used and the applicationtiming influence pesticide move-ment. Pesticides should beapplied only when needed toprevent economic loss of a crop.

In pesticide application,“the label is the law.” Usingchemicals at rates higher thanspecified by the label is ILLE-GAL as well as an environmentalhazard because more pesticide isexposed to erosion, runoff orleaching. Poor timing of a pesti-cide application (application justbefore rain falls) can result inpesticide movement into watersources, as well as give littlecontrol of the targeted pest.

Certain areas on your farmsuch as streams and rivers,wellheads and lakes or ponds aresensitive to pesticides. Youshould create buffer zonesaround these areas where pesti-cide use will be reduced oreliminated. By buffering theseareas, you may reduce waterquality problems. Areas such asroads, off-site dwellings andareas of public gatherings shouldbe identified. You may want tolimit the use of pesticides nearthese types of areas, too.

These practices will befollowed:

Select the pesticide to givethe best results with the leastpotential environmental impactoutside the spray area.

Select application equip-ment with care and maintain itcarefully.

Carefully calibrate applicationequipment at the beginning of thespray season and periodically thereaf-ter. Spray according to recommenda-tions.

Minimize spray drift by follow-ing the label instructions and all rules and regulations developedto minimize spray drift (the physical movement of spray particlesat the time of or shortly after application).

Before applying a pesticide, make anassessment of all of the environmental factorsinvolved in all of the area surrounding theapplication site.

Carefully maintain all pesticide appli-cations, not just Restricted Use Pesticides.

Pesticide SelectionWhen selecting pesticides, consider chemical solubility,

adsorption, volatility and degradation characteristics. Chemi-cals that dissolve in water readily can leach through soil togroundwater or be carried to surface waters in rainfall orirrigation runoff. Some chemicals hold tightly to, or areadsorbed on, soil particles, and these chemicals do not leach asmuch. But even these chemicals can move with sediment whensoil erodes during heavy rainfall. Runoff entering surfacewaters may ultimately recharge groundwater reserves. Chemi-cals bound to soil particles and organic matter are subject tothe forces of leaching, erosion or runoff for a longer period,thus increasing the potential for water pollution.

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Pesticidestorage shed

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These practices will be followed:

Selection will be based upon recommendations by qualifiedconsultants, crop advisors and upon the published recommendationsof the LSU AgCenter, Cooperative Extension Service.

The selection of the pesticide to be used will be based upon itsregistered uses and its ability to give the quality of pest controlrequired.

The selection also will be based upon its impact onbeneficials, other non-target organisms and on the general environ-ment.

Pesticide Storage andSafety

Farmers and commercialpesticide applicators are subjectto penalties if they fail to store ordispose of pesticides and pesti-cide containers properly. Eachregistered pesticide product,whether general or restricted use,contains instructions for storageand disposal in its labeling. TheLouisiana Pesticide Law ad-dresses specific requirements forstorage and disposal. The appli-cator must follow these require-ments carefully and ensure thatemployees follow them as well.

The recommended proce-dures do not apply to the dis-posal of single containers ofpesticides registered for use inthe home and garden. Thesecontainers may be disposed ofduring municipal waste collec-tion if wrapped according torecommendations.

Storage sites should bechosen to minimize the chance ofpesticides escaping into the

environment. Pesticides shouldnot be stored in an area suscep-tible to flooding or where thecharacteristics of the soil at thesite would allow escaped chemi-cals to percolate into groundwa-ter. Storage facilities should bedry, well ventilated and providedwith fire protection equipment.All stored pesticides should becarefully labeled and segregatedand stored off of the ground. Donot store pesticides in the samearea as animal feed. The facilityshould be kept locked when notin use. Further precautionsinclude appropriate warningsigns and regular inspection ofcontainers for corrosion orleakage. Protective clothingshould be stored close by but notin the same room as the pesti-cides because they may becomecontaminated. Decontaminationequipment should be presentwhere highly toxic pesticides arestored.

Exceptions forFarmers

Farmers disposing of usedpesticide containers for their ownuse are notrequired tocomply with therequirements ofthe hazardouswaste regula-tions providedthey triple rinseor pressurewash each container and disposeof the residues on their ownfarms in a manner consistentwith the disposal instructions onthe pesticide label. Note thatdisposal of pesticide residuesinto water orwhere they arelikely to reachsurface orgroundwatermay be consid-ered a source ofpollution underthe Clean Water Act or the SafeDrinking Water Act and thereforeillegal.

After the triple rinse proce-dure, the containers are then“empty” and the farmer candiscard them in a sanitary wastesite without further regard to thehazardous waste regulations. Theempty containers are still subjectto any disposal instructionscontained within the labeling ofthe product, however. Disposal ina manner “inconsistent with thelabeling instructions” is a viola-tion of EPA guidelines and couldlead to contamination of water,soil or persons and legal liability.

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Agricultural Chemicals and Worker SafetyThe EPA has general

authority to regulate pesticideuse to minimize risks tohuman health and to theenvironment. This authorityextends to the protection offarm workers exposed topesticides. All employers mustcomply with ALL instructionsof the Worker ProtectionStandardconcern-ing workersafety orbe subjectto penal-ties. Labels may include, forexample, instructions requir-ing the wearing of protective

clothing,handlinginstructionsand instruc-tions setting aperiod of timebefore work-

ers are allowed to re-enterfields after the application ofpesticides (Restricted EntryInterval).

Employers should readthe Worker Protection Stan-dard regulations governing theuse of and exposure to pesti-cides. The regulations setforth minimum standards thatmust be followed to protect

farm workers and pesticidehandlers. The regulationsinclude standards requiringoral warnings and posting ofareas where pesticides havebeen used, training for allhandlers and early re-entryworkers,personalprotectiveequipment,emergencytransporta-tion anddecontamination equipment.

The EPA regulations holdthe producer of the agriculturalplant on a farm, forest, nurseryor greenhouse ultimatelyresponsible for compliancewith the worker safety stan-dards. This means the land-owner must ensure complianceby all employees and by allindependent contractors work-ing on the property. Contrac-tors and employees also maybe held responsible for failureto follow the regulations.

The OccupationalSafety and HealthAct (OSHA)

The federal govern-ment also regulates farmemployee safety under theOccupational Safety andHealth Act (OSHA).OSHA applies to allpersons (employers)engaged in businessaffecting interstate com-merce. The federal courtshave decided that allfarming and ranchingoperations, regardless ofwhere goods produced areactually sold or con-sumed, affect interstatecommerce in some re-spect, and thus are subjectto OSHA’s requirements.In general, every em-ployer has a duty toprovide employees withan environment free fromhazards that are causingor are likely to causedeath or serious injury.

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Wash pad with collection pond

This...backflowprotection

...Not Thischemicalssiphonedback intowater supply

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In summary: All label directions will be

read, understood and followed.

The Louisiana Departmentof Agriculture and Forestry(LDAF) is responsible for thecertification of pesticide applica-tors. All commercial and privatepesticide applicators applyingrestricted use pesticides mustsuccessfully complete a certifica-tion test administered by theLDAF. The LSU AgCenter con-ducts training sessions and pub-lishes study guides in variouscategories covered by the test.Contact your county agent fordates and times of these sessions.

All requirements of theWorker Protection Standard (WPS)will be followed, including, but notlimited, to:

Notifying workers of apesticide application (either oral orposting of the field), abiding by therestricted entry interval (REI).

Maintaining a centralnotification area containing thesafety poster; the name, addressand telephone number of thenearest emergency medical facility;and a list of the pesticide applica-tions made within the last 30 daysthat have an REI.

Maintaining a decontamina-tion site for workers and handlers.

Furnishing the appropriatepersonal protective equipment(PPE) to all handlers and earlyentry workers, and ensuring thatthey understand how and why theyshould use it.

Assuring that all employeesrequired to be trained under theWorker Protection Standard haveundergone the required training.

Pesticides will be stored ina secure, locked enclosure and in a

container free of leaks, abiding byany specific recommendations onthe label. The storage area must bemaintained in good condition,without unnecessary debris. Thisenclosure will be at least 150 feetaway and down slope from anywater wells.

All uncontained pesticidespills of more than one gallonliquid or four pounds dry weightwill be reported to the director ofPesticide and EnvironmentalPrograms, Louisiana Departmentof Agriculture and Forestry within24 hours by telephone (225-925-3763) and by written notice withinthree days. Spills on public road-ways will be reported to theLouisiana Department of Transpor-tation and Development. Spills intonavigable waters will be reportedto LDEQ, Coast Guard, USEPA.

Empty metal, glass orplastic pesticide containers will beeither triple rinsed or pressurewashed, and the rinsate will beadded to the spray solution todilute the solution at the time orstored according to the LDAF rulesto be used later. Rinsed pesticidecontainers will be punctured,crushed or otherwise renderedunusable and disposed of in asanitary landfill. (Plastic containersmay be taken to specific pesticidecontainer recycling events. Contactyour county agent for dates andlocations in your area.)

All pesticides will beremoved from paper and plasticbags to the fullest extent possible.

The sides of the container will becut and opened fully, without foldsor crevices, on a flat surface; anypesticides remaining in the openedcontainer will be transferred intothe spray mix. After this procedure,the containers will be disposed ofin a sanitary landfill.

Application equipment willbe triple rinsed and the rinsateapplied to the original applicationsite or stored for later use to dilutea spray solution.

Mix/load or wash pads(NRCS production code Interim)will be located at least 150 feetaway and down slope from anywater wells and away from surfacewater sources such as ponds,streams, etc. The pads will beconstructed of an imperviousmaterial, and there will be a systemfor collecting and storing therunoff.

Empty containers will notbe kept for more than 90 days afterthe end of the spray season.

Air gaps will be maintainedwhile filling the spray tank toprevent back-siphoning.

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Irrigation waterquality

Irrigation water (surfaceand/or well) should be tested inthe spring to determine thesalinity (salt) level before irrigat-ing a field or pasture. Takesamples to an approved labora-tory for analysis.

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Water wellprotection

Farm*A*Syst/Home*A*Systshould be usedevery three yearsto determinepotentialthreats to waterwells. Threatsidentified will beranked and mea-sured to correctthe most seri-ous.

Used engine oil,grease, batteries,tires, etc.

• Used engine oil shouldbe stored in a waste oil con-tainer (tank or drum) untilrecycled.

• Empty paint cans,antifreeze containers, usedtires, old batteries, etc., will bestored in a secure area untilthey can be disposed of prop-erly.

Fuel storage tanksAbove-ground fuel storage tanks in Louisiana are regulated by

the State Fire Marshal and by the EPA if surface water is at risk.Above-ground tanks containing 660 gallons or more require second-ary containment. The State Fire Marshal recommends that some sortof secondary containment be used with all fuel storage tanks. Thiscould include the use of double-walled tanks, diking around the tankfor impoundment or remote impoundment facilities.

These practices are to be followed:

Any existing above-ground fuel storage tank of 660 gallons ormore (1,320 gallons if more than one) must have a containment wallsurrounding the tank capable of holding 100 percent of the tank’scapacity (or the largest tank’s capacity if more than one) in case ofspillage.

The tank and storage area should be located at least 40 feetfrom any building. Fuel storage tanks should be placed 150 feet anddown slope from surface water and water wells.

It is recommended that thestorage tank be on a concreteslab to prevent any spillage fromentering surface and groundwa-ter.

The storage area should bekept free of weeds and othercombustible materials.

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This tank would be classified as anunderground fuel tank.

10 % of tank is belowground level

The tank should be conspicuously marked with the name ofthe product that it contains and “FLAMMABLE-KEEP FIRE ANDFLAME AWAY.”

The bottom of the tank should be supported by concreteblocks approximately 6 inches above the ground surface to protectthe bottom of the tank from corrosion.

If a pumping device is used, it should be tightly and perma-nently attached and meet NFPA approval. Gravity discharge tanks areacceptable, but they must be equipped with a valve that will auto-matically close in the event of a fire.

Plans for the installation of all storage tanks that will containmore than 60 gallons of liquid must be submitted to the State FireMarshal for approval.

All tanks that catch on fire must be reported to the State FireMarshal within 72 hours of the fire.

Underground storage tanks are defined as containing morethan 10 percent of their total volume beneath the soil surface. Under-ground tanks represent more of a problem than above-ground tanks,because leaks can often go for long periods without being detected.This poses a serious threat to groundwater sources in the vicinity ofthe tank. If you have an underground fuel storage tank, you need tocontact the State Fire Marshal’s Office for regulations affecting thesestorage tanks.

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Information in this publication was compiled by:C. Greg Lutz, Ph.D., Professor (Extension Aquaculture)

Fred S. Sanders, Ph.D., Associate Professor (Callegari Environmental Center)Robert P. Romaire, Ph.D., Professor and Resident Director, Aquaculture Research Station

Other LSU AgCenter contributors:Kenneth J. Roberts, Ph.D., Associate Vice Chancellor & Assistant Director,

Louisiana Cooperative Extension ServiceW. Ray McClain, Ph.D., Associate Professor, Rice Research StationJ. David Bankston, Jr., Ph.D., Professor (Food and Marine Engineer)

Louisiana Cooperative Extension ServiceMark G. Shirley, Louisiana Cooperative Extension Service

Thomas M. Hymel, Louisiana Cooperative Extension ServiceMary L. Grodner, Ph.D., Professor (Pesticide Safety), Louisiana Cooperative Extension Service

Natural Resources Conservation Service:Richard Aycock

Brad Sticker

Agricultural Research Service:Cade Carter

Louisiana Department of Natural Resources:Phil Pittman

Louisiana Department of Environmental Quality:Susan Vullo

Other Contributors:Jimmy L. Avery, Ph.D., Mississippi State University & National Warmwater Aquaculture Center

Jay V. Huner, Ph.D., University of Louisiana at Lafayette

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The complex nature of nonpoint pollution means programs designed toreduce its impact on the environment will not be easy to establish ormaintain. Controlling these contaminants will require solutions as diverseas the pollutants themselves. Through a multi-agency effort, led by theLSU AgCenter, these BMP manuals are targeted at reducing the impactof agricultural production on Louisiana’s environment. Agriculturalproducers in Louisiana, through voluntary implementation of theseBMPs, are taking the lead in efforts to protect the waters of Louisiana.The quality of Louisiana’s environment depends on each of us.

Visit our Web site:www.lsuagcenter.com

Louisiana State University Agricultural CenterWilliam B. Richardson, Chancellor

Louisiana Agricultural Experiment StationWilliam H. Brown, Vice Chancellor and Director

Louisiana Cooperative Extension ServicePaul D. Coreil, Vice Chancellor and Director

Pub. 2894 4/03 Online only

Issued in furtherance of Cooperative Extension work, Acts of Congress of May 8 and June 30, 1914, in cooperation with theUnited States Department of Agriculture. The Louisiana Cooperative Extension Service provides equal opportunities in

programs and employment.