THIRD FIVE-YEAR REVIEW REPORT FOR PERDIDO … Five-Year Review, Perdido Groundwater Contamination...

THIRD FIVE-YEAR REVIEW REPORT

FOR PERDIDO GROUNDWATER CONTAMINATION

SUPERFUND SITE OU-1, GROUNDWATER OPERABLE UNIT

PERDIDO,

BALDWIN COUNTY, ALABAMA EPA ID: ALD980728703

Approved by:

Prepared By:

U.S. Army Corps of Engineers Mobile District

109 Saint Joseph Street Mobile, Alabama 36602

Third Five-Year Review, Perdido Groundwater Contamination Site, Perdido, Alabama

Third 5-Year Review.doc i October 3, 2005

TABLE OF CONTENTS LIST OF ACRONYMS, SYMBOLS, AND ABBREVIATIONS iv EXECUTIVE SUMMARY v FIVE-YEAR REVIEW SUMMARY FORM vi I. INTRODUCTION 1 II. SITE CHRONOLOGY 2 III. BACKGROUND 3 PHYSICAL CHARACTERISTICS 3 LAND AND RESOURCE USE 4 HISTORY OF CONTAMINATION 5 INITIAL RESPONSE 5

BASIS FOR TAKING ACTION 6

Contaminants 6 Risk Assessment 7

IV. REMEDIAL ACTIONS 7 REMEDY SELECTION 7 REMEDY IMPLEMENTATION 8 Remediation System Components 9 OPERATION AND MAINTENANCE 9 Performance Monitoring 10 Remediation System Maintenance 11 Operation & Maintenance Costs 11 V. PROGRESS SINCE THE LAST FIVE-YEAR REVIEW 11 VI. FIVE-YEAR REVIEW PROCESS 12 ADMINISTRATIVE COMPONENTS 12 DOCUMENT REVIEW 13


Third 5-Year Review.doc ii October 3, 2005

DATA REVIEW 13 SITE INSPECTION 14 INTERVIEWS 14 VII. TECHNICAL ASSESSMENT 15

QUESTION A: IS THE REMEDY FUNCTIONING AS INTENDED BY THE DECISION DOCUMENTS? 15 Remedial Action Performance 15 System Operations 15 Opportunities for Optimization 15 Early Indicators of Potential Issues 15 Implementation of Institutional Controls and Other Measures 16 QUESTION B: ARE THE EXPOSURE ASSUMPTIONS, TOXICITY DATA, CLEANUP LEVELS, AND REMEDIAL ACTION OBJECTIVES USED AT THE TIME OF THE REMEDY STILL VALID? 16 Changes in Standards and TBCs 16 Changes in Exposure Pathways 16 Changes in Toxicity and Other Contaminant Characteristics 16 Changes is Risk Assessment Methods 16 Expected Progress Toward Meeting RAOs 16 QUESTION C: HAS ANY OTHER INFORMATION COME TO LIGHT THAT COULD CALL INTO QUESTION THE PROTECTIVENESS OF THE REMEDY? 17

TECHNICAL ASSESSMENT SUMMARY 17 VIII. ISSUES 17 IX. RECOMMENDATIONS AND FOLLOW-UP ACTIONS 17 X. PROTECTIVENESS STATEMENT 18 XI. NEXT REVIEW 18


Third 5-Year Review.doc iii October 3, 2005

LIST OF TABLES Table 1 - Chronology of Site Events 2 Table 2 - Performance Monitoring Program 10 Table 3 - Operation and Maintenance Costs 11 Table 4 - Recommendations and Follow-up Actions 17

LIST OF ATTACHMENTS Attachment 1 - Site Maps Al-1 Attachment 2 - List of Documents Reviewed A2-1 Attachment 3 - O & M Documents A3-1 Attachment 4 - Site Inspection Check List A4-1 Attachment 5 - Photographs Documenting Site Conditions A5-1 Attachment 6 - Interview Records A6-1


Third 5-Year Review.doc iv October 3, 2005

LIST OF ACRONYMS, SYMBOLS, AND ABBREVIATIONS ADEM Alabama Department of Environmental Management ADPHWS Alabama Department of Public Health, Division of Public Water

Supply ADSHW Alabama Department of Solid and Hazardous Wastes ARARs Applicable or Relevant and Appropriate Requirements CERCLA Comprehensive Environmental Response, Compensation, and Liability

Act COC Contaminant of Concern CDC Center for Disease Control CFR Code of Federal Regulations ESD Explanation of Significant Difference FIT Field Investigation Team FS Feasibility Study MCL Maximum Contaminant Level NCP National Contingency Plan NPDES National Pollutant Discharge Elimination System NPL National Priorities List O&M Operation & Maintenance PGCS Perdido Groundwater Contamination Site PPB Parts-per-billion PRP Potentially Responsible Parties RA Risk Assessment RAMP Remedial Action Master Plan RAO Remedial Action Objective RI Remedial Investigation RI/FS Remedial Investigation/Feasibility Study ROD Record of Decision TBC To be Considered TCL/TAL Target Compound List/Target Analyte List USAGE U.S. Army Corps of Engineers USEPA U.S. Environmental Protection Agency


Third 5-Year Review.doc v October 3, 2005

EXECUTIVE SUMMARY

The Perdido Groundwater Contamination Site was placed on the National Priority List in September 1983 following an accidental benzene spill in 1965. The selected remediation for the site is pump-and-treat with reinjection of the treated effluent into the groundwater aquifer and to surface water. Following issuance of a Record of Decision (ROD) in 1988, the selected groundwater remediation system construction was completed in 1992. There is one Explanation of Significant Difference (ESD) associated with the ROD which allows for the addition of treated effluent to be discharged to a single surface water discharge point. The remediation system consists of one operable unit (OU-1) that includes multiple withdrawal wells, injection wells, observation wells, and the recent addition of biosparge wells. There is no soil contamination associated with the ROD. Groundwater withdrawal and treatment has been successfully performed at the site since 1992. The remediation system has controlled the benzene contamination plume by hydraulically influencing the natural migration of groundwater and significantly reducing the levels of benzene concentrations by pumping and treating groundwater using conventional air stripping technology, and by biosparging the groundwater aquifer (since 1999) to enhance natural biogeochemical reduction of benzene in place. Operation and maintenance procedures are performed regularly, groundwater sampling is performed quarterly and the results reported semi-annually. This five-year review is performed in order to evaluate the effectiveness of the selected groundwater remediation system. According to the data reviewed, site inspection, and interviews, the remedy at Perdido Groundwater Contamination Site remains protective of human health and the environment. This is the third five-year review for the facility.


Third 5-Year Review.doc vi October 3, 2005

FIVE-YEAR REVIEW SUMMARY FORM

SITE IDENTIFICATION

Site name (from WasteLAN): Perdido Groundwater Contamination

EPA ID (from WasteLAN): ALD980728703

Region: 4 State: AL City/County: Perdido/Baldwin County

SITE STATUS

NPL status: [X] Final [] Deleted [] Other (specify)

Remediation status (choose all that apply): [] Under Construction [X] Operating [] Complete

Multiple OUs?* [] YES [X] NO Construction completion date: November 1992

Has site been put into reuse? [] YES [X] No

REVIEW STATUS

Lead agency: [X] EPA [] State [] Tribe [] Other Federal Agency

Author name: Rhonda Capes, P.G.

Author title: Geologist Author affiliation: U.S. Army Corps of Engineers

Review period: April 1, 2005 to October 3, 2005

Date(s) of site inspection: June 2, 2005

Type of review: [X] Post-SARA [] Pre-SARA [] NPL-Removal only [] Non-NPL Remedial Action Site [] NPL State/Tribe-lead [] Regional Discretion

Review number: [] (first) [] (second) [X] (third) []Other (specify)

Triggering action: [] Actual RA On-site Construction at OU #__ [] Actual RA Start at OU# NA [] Construction Completion [X] Previous Five-Year Review Report [] Other (specify)

Triggering action date (from WasteLAN): August 3, 2000

Due date (five years after triggering action date): August 3, 2005

* ["OU" refers to operable unit.] ** [Review period should correspond to the actual start and end dates of the Five-Year Review in WasteLAN.]


Third 5-Year Review.doc vii October 3, 2005

Five-Year Review Summary Form, cont'd.

Issues: 1. No issues were identified for this site during this five-year review

process. The system is operating as intended, the benzene concentrations are low and approaching the remediation level of 5 ppb, and the system maintains hydraulic control on the migration of groundwater in the area.

Recommendations and Follow-up Actions: 1. Recommendations for the site include submittal of an optimization plan

that considers the continued use of biosparging and a reduction of pump and treat.

Protectiveness Statement: 1. According to the data reviewed, site inspection, and interviews, the

remedy at Perdido Groundwater Contamination Site remains protective of human health and the environment. Levels in groundwater contamination have decreased significantly and further migration of the contaminant is being controlled. Domestic wells in the affected area are no longer used since residents were provided with potable water from the Atmore municipal supply system.

Other Comments: 1. A meeting between the USEPA, CSXT, and AMEC occurred in August, 2005.

The agenda for the meeting included proposed modifications to the system, including the possibility of discontinuing the pump-and-treat/biosparge system for a period of one year with the continuation of quarterly monitoring. A work plan proposing these modifications is anticipated after the submittal of this 5-year review.


Third 5-Year Review.doc 1 October 3, 2005

PERDIDO GROUNDWATER CONTAMINATION PERDIDO, ALABAMA

THIRD FIVE-YEAR REVIEW REPORT I. INTRODUCTION The Perdido Groundwater Contamination Site (PGCS) was placed on the National Priority List (NPL) in September 1983 following an accidental benzene spill in 1965 and the subsequent discovery of groundwater contamination in 1982. Following issuance of a Record of Decision (ROD) in 1988, the selected groundwater remediation system construction was completed in 1992. This five-year review is performed in order to evaluate the effectiveness of the selected groundwater remediation system known as Operable Unit One (OU-1). OU-1 consists of a groundwater pump-and-treat system with re-injection of the treated groundwater into the subsurface and local surface water. OU-1 is the only Operable Unit for this facility. The purpose of the five-year review is to provide an independent review of the site conditions and effectiveness of the remediation system to remain protective of human health and the environment. In addition to the finding and conclusions of the five-year review, deficiencies are identified and corrective actions are recommended. The United States Environmental Protection Agency (USEPA) is preparing this Five-Year Review report pursuant to CERCLA §121 and the National Contingency Plan (NCP). CERCLA §121 states:

If the President selects a remedial action that results in any hazardous substances, pollutants, or contaminants remaining at the site, the President shall review such remedial action no less often than each five years after the initiation of such remedial action to assure that human health and the environment are being protected by the remedial action being implemented. In addition, if upon such review it is the judgment of the President that action is appropriate at such site in accordance with section [104] or [106], the President shall take or require such action. The President shall report to the Congress a list of facilities for which such review is required, the results of all such reviews, and any actions taken as a result of such reviews.

The USEPA interpreted this requirement further in the NCP; 40 CFR §300.430(f)(4)(ii) states:

If a remedial action is selected that results in hazardous substances, pollutants, or contaminants remaining at the site above levels that allow for unlimited use and unrestricted exposure, the lead agency shall review such action no less often than every five years after the initiation of the selected remedial action.



This is the third five-year review for PGCS since initiation of the selected remedial action. The triggering action for this statutory review is the second five-year review that was completed on August 3, 2000. The U.S. Army Corps of Engineers, Mobile District, at the request of the USEPA conducted this third five-year review during the period April 1, 2005 to October 3, 2005. This report documents the results of the review. II. SITE CHRONOLOGY Table 1 presents the chronology of events for the Perdido Groundwater Contamination Site.

Table 1 Chronology of Site Events

EVENT DATE

Train Derailment and Benzene Spill 5/17/1965

Alabama Department of Health (ADPH) confirms odor in well water near the site 12/1981

ADPH confirms groundwater contamination in two wells 2/1982

Alabama Department of Solid and Hazardous Wastes (ADSHW) samples 27 additional wells and confirms contamination in 6 wells

Aug. & Sept. 1982

Center for Disease Control tests urinary phenol levels of 30 residents, no elevated levels were detected 9/1982

ADSHW and USEPA sample 49 wells, confirm contamination in 9 wells 10/1982

Proposed NPL listing under CERCLA 12/1/1982

USEPA provides Immediate Removal Funds to furnish city water to residents 2/1983

Seaboard System RR (CSXT) provides funding and the water line installations were completed 7/1983

Field Instigation Team (FIT) contractors develop Remedial Action Master Plan (RAMP) 9/1983

Finalized NPL listing 9/1/1983

P.E. LaMoreaux & Associates (PELA) conduct field investigation Late 1983

Administrative Order on Consent to perform RI/FS 10/11/1985

USEPA performs solute transport model and soil vapor study recommending additional downgradient wells 3/1987

RI completed 11/1987

Supplemental RI report and FS submitted 5/1988



ROD 9/30/1988

Consent Decree 7/19/1990

Begin remediation system construction 5/1992

Remediation system completed 11/1992

ESD approved and surface water discharge installed 6/1993

USEPA approval to eliminate effluent-air treatment 9/8/1997

Pneumatic pumping system was replaced with an electric submersible pumping system 11/1997

Original Hazelton Stripper is replaced with a shallow tray air stripper 4/1998

USEPA approves installation of 2 additional groundwater wells and 3 biosparge wells 11/1998

Installation of new wells and air compressor complete 1/1999

Plan submitted for 2 new withdrawal wells, 9 biosparge wells and 1 source area observation well 10/1999

USEPA approves installation of new wells 12/1999

New wells installed 12/1999-2/2000

Reporting frequency changed from quarterly to semi-annually 12/2001

Proposal for 14 additional biosparge wells 4/2003

USEPA approves plan for additional biosparge wells 7/2003

Biosparge wells and new air compressor installations complete 10/2003

Effluent discharge pipe was pressure washed to remove sediment and iron scale deposits 2/2005

First Five May

Second Five August 3

Third Five October 3

III. BACKGROUND The purpose of this section is to provide a baseline description of the site and contaminant release in order to evaluate the current effectiveness of the remedy selection. The following subsections present background information for the PGCS including physical characteristics, land and resource use, history of contamination, initial response, and the basis for taking action. PHYSICAL CHARACTERISTICS The Perdido Groundwater Contamination Site is located in the Town of Perdido, Alabama near the intersection of State Roads 47 and 61 (Figure 1). In 1965, a



train derailment occurred approximately 200 yards east of this intersection spilling benzene into the drainage ditches along Highway 61. As a result of the spill, an unknown quantity of benzene leached into the groundwater aquifer used by the area residents for their domestic well water. The total area investigated during the Remedial Investigation in 1987 covered an area of approximately 125 acres and centered the groundwater contamination approximately 300 yards downgradient from the derailment site. Currently the groundwater remediation system consisting of the treatment facility, 25 observation wells, 10 injection wells, 16 withdrawal wells, 24 biosparge wells, 3 temporary wells, and all associated piping, is incorporated in an area of approximately 110 acres (Figures 1 and 2). Several of these wells are used for multiple purposes. All components of this system are either located on a CSX Transportation, Inc. (PRP) property, a property in which the PRP maintains a leasing agreement, or within the right-of-way of the railroad or highways. LAND AND RESOURCE USE The Town of Perdido is located approximately 10 miles southwest of the city of Atmore, Alabama. According to the 2000 census, the population of Perdido includes approximately 1,600 persons with 100 percent listed in the rural population category. The area immediately surrounding the PGCS is heavily wooded with several residences located along McCoy Road and a few commercial businesses located along HWY 47 (Figure 3). There are no land restrictions identified within the ROD which would prohibit land development of this area. Currently, the major resource of concern for this site is the Miocene groundwater aquifer. The Miocene aquifer is the uppermost aquifer at the site and is the source of domestic and public potable water for many Alabama residents, including the city of Bay Minette located approximately 12.5 miles southwest of Perdido. At the time of the train derailment in 1965, area residents used the Miocene aquifer as their sole source of drinking water. Following confirmation of groundwater contamination in these domestic wells, the Seaboard System Railroad (now CSXT) provided residents, within a one-mile radius of the site, access to the Atmore public water supply system. Currently, all nearby residents remain on this supplied water system. Migration of the existing groundwater benzene plume to domestic water well users is the principal human health concern for this site. It is noted that without the implementation of any enhanced remediation, the groundwater benzene plume slowly migrated over a period of 23 years, to an area centered approximately 300 yards from the derailment site. The average rate of groundwater flow at the site has been estimated as 0.23 ft/day. Since the implementation of the selected remediation alternative in 1992, the benzene concentrations in the groundwater have significantly reduced and are currently limited to only three areas on the site (Figure 4). With the current hydraulic controls and remediation activities in place, it is unlikely that the remaining groundwater contamination will further affect the use of the Miocene aquifer as a resource.



HISTORY OF CONTAMINATION The source of the contamination at the Perdido Groundwater Contamination Site is attributed to a single benzene release. On May 17, 1965, a train derailment occurred in which 21 cars of the 122 cars in the train derailed. The rail cars left the track near the intersection of County Highway 61 and Railroad Street, along the eastern portion of a curve in the track (Figure 1). Approximately 75% of the benzene contents (estimated 7,575 gallons) of the ruptured car were spilled. On the morning of May 19, 1965 the derailed cars were accidentally ignited by a cutting torch. The fire consumed the remaining benzene. Benzene is the only contaminant of concern (COC) at the PGCS. Another chemical which spilled as a result of the derailment, hexamethylene diamine, was never detected in any groundwater sampling event. The area of the train derailment and the drainage ditches along HWY 61 was investigated in 1983 and again in 1986 to determine the area and vertical extent of soil contamination. It was concluded that benzene was no longer present in the soils or was present at very low concentrations and therefore not considered to be a significant source contributor. INITIAL RESPONSE It was not until December 1981 that the Alabama Department of Public Health, Division of Public Water Supply (ADPWS) first documented reports of taste and odor problems in the Perdido residents' domestic water supply wells. Two wells were sampled in February 1982 that showed benzene contamination. In August and September 1982, the Alabama Department of Solid and Hazardous Waste (ADSHW) sampled 27 additional wells and found 6 of these contaminated with benzene. As a result of the benzene contaminated wells, the Baldwin County Health Officer recommended that residents within a one mile radius of the derailment stop drinking or bathing with their well water. This affected approximately 250 residents in the area and over 300 students attending the Perdido Junior High School. The National Guard provided two water tanks to a central location and the affected residents transported water to their homes. In September 1982, the Center for Disease Control (CDC) tested the urinary phenol levels of 30 residents whose wells were being tested for benzene. None of the residents tested showed an elevated level of urinary phenol, consequently none could be shown to have had benzene exposure at the time of the testing. Most of the people tested for urinary phenols had stopped drinking their well water long before the urine sampling took place. Following the determination of the contaminated wells, the ADSHW requested support from the U. S. Environmental Protection Agency (USEPA) to determine the extent of the groundwater contamination. During October 1982, ADSHW and the USEPA conducted groundwater sampling of 49 domestic water wells. A total of nine wells were determined to be contaminated in the Perdido area. As a result of the findings of contaminated groundwater in Perdido, the USEPA proposed on December 1, 1982 that the site be placed on the National Priorities List (NPL) under the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA) otherwise known as



Superfund. Placement of the Perdido site on the NPL became final on September 1, 1983. In early 1983, state and county officials requested that USEPA provide the Town of Perdido with funding assistance under Superfund so that an alternate supply of drinking water could be provided to the community. Immediate removal funding was provided by EPA in February 1983 and at the suggestion of EPA Region IV, Seaboard System Railroad (now CSXT) voluntarily provided funds for construction of a water line extending six miles from the nearby Town of Atmore, Alabama. Approximately 150 Perdido homes within a one mile radius of the derailment site were connected to the water system. The water line was completed in July 1983. BASIS FOR TAKING ACTION As a result of the determination of benzene contamination in the Perdido groundwater, several studies were initiated to define the extent of contamination. Contaminants Geophysical surveys were performed by the USEPA's Field Investigation Team (FIT) contractors in 1982 and 1983. FIT also developed the Remedial Action Master Plan (RAMP) in September 1983. CSX Transportation's contractor, P.E. LA Moreaux (PELA), conducted a field investigation in late 1983. On October 11, 1985, CSXT executed an Administrative Order on Consent (Docket No. 86-02-C) 1 with the USEPA to conduct a Remedial Investigation and Feasibility Study (RI/FS) on the site. The RI was begun in 1986 and completed in November 1987. In March of 1987, USEPA’s Groundwater Technology Unit and the Environmental Response Group conducted a solute transport model and a soil vapor survey respectively. Based on review of the data, USEPA requested that additional monitoring wells be installed further downgradient of the derailment area. The supplemental report was completed in May 1988. The RI confirmed the presence of benzene in the groundwater and led to the following conclusions:

• Leaching of contaminants from the surface and subsurface soils to the groundwater is no longer occurring or is insignificant;

• Volatilization of benzene from contaminated surface soil is no longer

occurring; • The current impact to surface water is not a concern, but future

contaminated groundwater discharge to surface water is a concern; • Subsurface migration of the contaminated groundwater plume to domestic

water well users is the principal human health concern.



Risk Assessment The contaminant of concern (COC) identified for the Perdido Site is benzene which is a known human carcinogen. The current and future risk to human health and the environment includes several exposure pathways. The potential exposure pathway identified for humans is ingestion and dermal contact of the groundwater, and ingestion of surface water for cattle. Additional pathways were deleted from consideration due to the facts that the release occurred in 1965, that benzene is highly volatile, and that benzene was only detected in the groundwater. IV. REMEDIAL ACTIONS The following subsections present the remedial actions for the Perdido Groundwater Contamination Site including remedy selection, remedy implementation, and operation and maintenance. REMEDY SELECTION The USEPA determined that continued migration of contaminated groundwater is a major threat to the public health and the environment in the area surrounding and downgradient of the contaminant plume. In 1988, USEPA selected groundwater extraction, on-site treatment, and reinjection of the effluent as the remedial action for the site. In 1993, USEPA subsequently approved the addition of an Explanation of Significant Difference (ESD) to include treated effluent discharge to surface water. The remedy was selected to protect the public health and the environment by imposing hydraulic controls on the migration of contaminated groundwater in the Miocene Aquifer, the primary source for domestic users in the Perdido area. The major components of the selected remedy are:

• Recovery of the contaminated groundwater by means of a recovery well field;

• Treatment of the recovered contaminated groundwater, by air stripping,

to achieve the 5 ppb cleanup levels established for benzene, and; • Injection of the treated groundwater back into the aquifer and into the

surface water. The ESD allows for treated water from the system to be discharged to a surface water location only after the reinjection system has reached its capacity. Since the National Contingency Plan (NCP) exempts Superfund sites from the requirement to obtain permits for actions occurring on-site, PGCS was not required to apply for a National Pollutant Discharge Elimination System Permit (NPDES). However, PGCS must meet the substantive requirements of the permitting program through the Alabama Department of Management (ADEM). These requirements as stipulated by ADEM are as follows:

• Monitor and report flow;



• Measure influent and effluent bi-weekly for Iron, Benzene, pH,

Suspended Solids, and flow during the first month; weekly for the second and third months; and monthly thereafter;

• Discharge limits:

pH 4.5-7.5 Benzene 5.0 ppb TSS 50 ppm Iron 1 ppm

• Installation of a control valve between the injection pump and the

filters; • Installation of a water level recorder in well OW-6 or OW-1; • Abandon and plug old wells that are not currently in use; • Submit site map that identifies the exact location of the discharge

point. REMEDY IMPLEMENTATION The Remedial Design Report for the PGCS was submitted in December 1991 and construction of the treatment system was accomplished from May 1992 through November 1992. The treatment system was initially comprised of twelve ground water extraction wells that supplied the contaminated groundwater to a Hazleton Maxi-Stripper System equipped with nine hydraulic venturi modules to supply outside air into the stripper. The effluent air was fed through a carbon adsorption tank prior to release to the atmosphere and the treated water was sent through a bag filter unit prior to being pumped to the injection wells. During start-up of the system it was discovered that the injection wells were unable to inject the volume of water passing through the treatment system. The excess water flooded the injection system and activated a high level cut off switch that shut down the entire system. To alleviate this problem and to allow the groundwater remediation to start, a surface water discharge system was proposed to handle the excess water. In June 1993, a surface water discharge to Perdido Creek was installed (Figure 1). Since the start-up of the remediation system in 1992, additional modifications have been necessarily implemented in order to optimize performance of the system. Originally the extraction wells were installed with pneumatic pumps which tended to vibrate the wells and cause an influx of sand into the system. These pumps were replaced with electric submersible pumps manufactured by Grundfos. Additionally, because of the high levels of iron and sand content in the influent groundwater, the small orifices in the original Hazelton Air Stripper would become plugged. Considerable maintenance efforts were required to clean each of the orifices of the stripper by hand using a small drill. The Hazelton Stripper was subsequently replaced with a New England Environmental Products shallow tray air stripper. Maintenance efforts and costs have significantly reduced since these changes were implemented.



Remediation System Components At the time of this review, the remediation system at PGCS consists of the following components: Groundwater Withdrawal System The current system consists of 17 wells located within the area of the former benzene plume limits (Figure 2). These wells include WW-1 through WW-16, and well IW-6. IW-6 was originally utilized as an injection well but is presently being used for both monitoring and withdrawal purposes. Seven of these withdrawal wells have been shut-off due to laboratory results of less than 1 ppb indicated in several quarterly sampling events. Groundwater extracted from the operating wells is delivered by underground piping to the groundwater treatment system located within a covered facility building. The withdrawal wells are located parallel to the long axis of the areas containing benzene. Groundwater Treatment System Groundwater extracted by the withdrawal wells enters the treatment system into a cone bottom sand separator. After separation, the groundwater is piped into the gravity fed shallow tray air stripper where a blower unit discharges the effluent air through an air stack installed in the treatment building. The effluent water is pumped to a two unit bag filter system. Each unit contains eight one micron bag filters. Treated Water Reinjection System Ten injection wells (IW-1 through IW-10) were originally completed in the aquifer but two (IW-5 and IW-6) have been converted for other purposes. The injection wells are located on either side of the benzene plume axis to increase the hydraulic gradient. After leaving the filter system, the treated water is pumped to the eight injection wells for infiltration into the aquifer. Overflow from the injection system is diverted to the surface water discharge point at Perdido Creek. Biosparge Wells Twenty-four biosparge wells have been installed at PGCS since 1999. The intent of the biosparge wells is to provide dissolved oxygen to areas of the plume that have exhibited decreased levels, subsequently increasing the natural degradation of the benzene. The biosparge wells are located along the benzene plume axis where dissolved oxygen is depleted. Photographic documentation of these remediation system components is provided within Attachment 5. OPERATION AND MAINTENANCE Operation and maintenance activities required to ensure the continued effectiveness of the selected remedy include:



• Periodic groundwater monitoring to ensure that long term performance

goals are being achieved; • Periodic monitoring of the pump and treat system to ensure continued

effectiveness in attaining the cleanup standard of 5 ug/1 (ppb) of benzene in the groundwater.

At the time of this review, on-site O & M services are being provided by United State Environmental Services, L.L.C., a subcontractor of AMEC Earth & Environmental, Inc. Groundwater sampling activities are provided by RDH Environmental. All services are performed as specified in the USEPA approved O & M Manual dated April 26, 1999 and as described below. Performance Monitoring The following table provided by AMEC summarizes the sampling and monitoring program.

Table 2 Performance Monitoring Program

Medium Type Monitoring Location (s) Frequency Analytical

Parameters

Sampling

OW-23, -26, -30, -33, -36, -37, -38, -39, -40, including trip, equipment, and duplicate blanks

Quarterly Benzene, pH Groundwater

Water Levels

Same as above Quarterly NA

Influent Groundwater Sampling

Inlet pipe to air stripper (downstream of settling tank) Monthly

Benzene, Iron, pH, Total

Suspended Solids

Effluent Groundwater Sampling

Sampling port downstream of the bag filters Monthly

Benzene, Iron, pH, Total

Suspended Solids

Effluent Air Sampling Prior to release to atmosphere Monthly Benzene

Solid Wastes Sampling Accumulated solid wastes within various components of the treatment system

As needed Benzene

Additional monitoring and sampling events not required by the performance monitoring program are occasionally performed in order to support operational needs and to re-evaluate the effectiveness of the remediation system. All seventeen withdrawal wells were included in the sampling event for the 1st quarter of 2005. Groundwater sampling is performed quarterly and the results presented semi-annually.



Remediation System Maintenance Inspection of the entire remediation system is performed on a weekly basis by Mr. D.C. Harville (USES). Mr. Harville has provided the on-site operations and maintenance of the facility since construction of the system in 1992. His duties entail inspection of the withdrawal, biosparge, and injection wells, noting any repairs that may be required, and documenting the volume of flow and pressure readings where applicable. These readings are compiled on a weekly log, faxed to AMEC, and included within the semi-annual monitoring reports. Additional duties performed by Mr. Harville include monitoring the pressure gauges on the filter bags and replacing the bags as necessary, cleaning the air stripper with an internal wand on an average of once per month, and completely dismantling the air stripper for cleaning annually. Mr. Harville also notes any system downtime due to power outages or mechanical breakdowns. Mr. Harville is available to attend to system repair requirements noted during his weekly inspection of the remediation system and on an emergency basis. An example of the Treatment Plant Weekly Log prepared by Mr. Harville is provided in Attachment 3. Operation & Maintenance Costs AMEC has provided the following O&M expenditures for the period 2000 through April 2005.

Table 3 Annual Operation and Maintenance Costs

2000-2005 (ytd)

Dates From To

Total Cost rounded to the nearest $100

2000 2001 $241,060 2001 2002 $225,758 2002 2003 $169,591 2003 2004 $246,450 2004 2005 $159,651 1/2005 4/2005 $63,330

A breakdown of the O& M expenditures is provided within Attachment 3. V. PROGRESS SINCE THE LAST FIVE-YEAR REVIEW The Statement on Protectiveness from the First Five-Year Review (1995) states:

"Based upon the groundwater monitoring results, the remedial action appears to be performing as intended. Benzene concentrations have declined from high values of 28.5 ppm (28,500 ppb) to 9.3 ppm (9,300 ppb) in the most recent quarterly sampling data.



Since there are no domestic water wells currently in use within a one-mile radius, there is no threat to public health (this has been confirmed by ADPH). Review of the effluent data indicate that vapor discharge to the atmosphere as well as injected water and surface water is clean. So long as the system is maintained, the treatment system will function to reduce levels of contaminants below cleanup standards. Handling and manifesting of contaminated media is being properly shipped off-site reducing any potential exposure to the local community."

The Statement on Protectiveness from the Second Five-Year Review (2000) states:

"The remedy at OU-1 currently protects the human health and the environment because the groundwater remediation system prevents the uncontrolled migration of contaminants by maintaining an inward gradient and remediates the groundwater concurrently. Domestic wells in the affected area are no longer used because the affected residents were placed on a municipal water system."

No deficiencies were noted in either of the previous five-year reviews that required follow-up actions. Improvements to the remediation system since the last five-year review include the installation of additional biosparge wells. At the close of the last five-year review, the remediation system included only three biosparge wells. Twenty-one additional biosparge wells have been installed and brought on-line since the beginning of 2000. Concurrently, a new Atlas Copco air compressor was installed at the treatment facility to supplement the existing air supply. Maintenance improvements to the system included the pressure washing of 2,500 linear feet of effluent discharge pipe. The effluent pipeline, which transfers treated water to the injection wells and Perdido Creek broke due to blockage within the pipe. It was determined that the blockage was a build-up of silt, very fine sand and iron scale deposits, which had significantly reduced the pipe capacity. On February 14-16, 2005, the effluent discharge pipe was pressure washed and the build-up successfully removed. Photographs of this effort were provided by AMEC and are included within Attachment 5. VI. FIVE-YEAR REVIEW PROCESS The third five-year review was conducted by the USAGE under guidance from the USEPA Remedial Project Manager for the PGCS. The five-year review process consisting of administrative components, document review, data review, site inspection, and interviews is described in the following subsections. ADMINISTRATIVE COMPONENTS The Perdido Groundwater Contamination Site, Third Five-Year Review was performed by Rhonda Capes of the USAGE at the request of USEPA. Potentially interested parties, including USEPA, ADEM, CSXT, and AMEC were notified of the initiation of the review and schedules were established thereafter.



DOCUMENT REVIEW This third five-year review consisted of a review of relevant documents including decision documents, semi-annual and quarterly monitoring reports, previous five-year review documents, weekly inspection checklists, and miscellaneous file correspondence. Attachment 2 provides a list of all documents reviewed for this effort. The following applicable or relevant and appropriate requirements (ARARs) were identified in the ROD and initial five-year review and were reviewed as a part of this five-year review:

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

• Resource Conservation and Recovery Act (RCRA) • Occupational Safety and Health Act (OSHA) • Federal Maximum Contaminant Levels (MCL's) under the Safe Drinking

Water Act • National Pollutant Discharge Elimination System (NPDES)

The MCL for benzene has remained unchanged at .005 mg/L (5 ppb) and benzene is the only contaminant of concern at the PGCS. DATA REVIEW The summary for the March 2005 Semi-Annual report states that the system has successfully treated over 613,217,643 gallons of contaminated water since system start-up in November 1992 (Figure 4). The report also states that the influent benzene concentration for the reporting period averaged 3.5 ppb and benzene concentrations in the effluent water and air samples were non-detectable. The initial five-year review reported benzene levels in the observation wells varying from 1,800 ppb in well OW-28 to < 1 ppb in several wells, with the total system influent varying from 140 ppb to 330 ppb at the treatment plant. During the most recent sampling event (March 2005), benzene was detected in only three site monitoring wells (OW-27, OW-31, and OW-4) at concentrations of 12 ppb, 5.9 ppb, and 9.6 ppb, respectively. All seventeen withdrawal wells were also sampled during this sampling event and exhibited concentrations of 1 ppb (WW-4), 26 ppb (WW-12), and 21 ppb (WW-14). All other withdrawal wells exhibited non-detectable concentrations. Figures 4 and 5 provide a comparison of benzene isopleths for the periods December 1994 and March 2005, respectively. In 1994, benzene concentrations in excess of 10 ppb extended from approximately 400 ft. south of the derailment area to approximately 2800 ft. south of the derailment area. In comparison, the 2005 isopleth shows the majority of the remaining benzene plume centered just south of the treatment facility with the highest benzene concentration of 26 ppb. Two additional areas near the derailment (source) area showed levels of 21 ppb and 9.6 ppb. A review of the water level data indicates that the groundwater extraction system is maintaining hydraulic control on the benzene plume (Figure 6).



SITE INSPECTION The site inspection was conducted at 10: 00 AM on June 2, 2005. Individuals in attendance included: Rhonda Capes (USAGE), Stephen Blair (AMEC), Bob Bamwell (ADEM), Sarah Gill (ADEM), Charles Anderson (USES), and D.C. Harville (USES). USEPA representative Michael Amett and CSXT representative Matt Adkins were not able to attend the site inspection. The purpose of the inspection was to assess the protectiveness of the remedy. Notes and observations from the site inspection were recorded on the Site Inspection Check List provided in Attachment 4. Photographic documentation is provided in Attachment 5. The attendees met at the treatment building where Mr. Harville began a brief explanation of the treatment process. Mr. Harville discussed the influent entering the building, desanding, air-stripping, filtering, and pumping of the treated water to the injection wells and surface water discharge point. From the treatment building, the group moved outside to inspect several wells nearest the treatment building. Biosparge well BS-1 was opened for inspection and Mr. Blair explained the air supply valving and piping layout. Extraction well WW-12 was also opened for inspection. Both wells were in good condition. Other wells inspected near the building included BS-5 and OW-26. BS-5 was missing a lock and Mr. Harville took note to perform an inspection of all the wells and replace locks as necessary. The group left the treatment building area by car and inspected the discharge point at Perdido Creek. The treatment system was not turned on at the time of inspection and subsequently no flow was evident. The discharge pipe was inconspicuous from the road. The group continued to withdrawal well WW-1 located at the former wood yard area. WW-1 was in good condition. Other than the absence of a lock on BS-5, no other physical deficiencies were noted. The treatment facility is secure from trespassers by the chain link fence and marked with the appropriate signage. All pertinent documents, including O&M records and a safety manual were readily available for inspection. INTERVIEWS During the five-year review process, several individuals were interviewed concerning the Perdido Groundwater Contamination Site with regard to activities over the last five years. The following individuals were interviewed:

• Mr. Stephen Blair (AMEC) on June 2, 2005 during the site visit. • Mr. D.C. Harville (USES) on June 2, 2005 during the site visit and

during multiple phone conversations during the review period. Interview comments are provided with Attachment 6.



VII. TECHNICAL ASSESSMENT The following Questions A, B, and C are answered to provide a technical assessment of the site remedy. Question A: Is the remedy functioning as intended by the decision documents? Yes, the remedy is functioning as intended by the decision documents. Support of this statement is described in the following subsections: Remedial Action Performance The construction of OU-1 is complete and functioning as intended in the ROD. Results of the groundwater monitoring program are reviewed thoroughly and measures are taken to optimize the system. Benzene concentrations in the groundwater have continued to decrease and are rapidly approaching the target level of 5 ppb. The withdrawal and reinjection system continues to adequately control the migration of groundwater. System Operations The O& M activities for the site are functioning well. The treatment system is well maintained and repairs are implemented expediently. Very little downtime of the system has occurred since it came online other than from occasional power outages due to storms or during cleaning of the system. Opportunities for Optimization The introduction of biosparging into the remediation process at PGCS has made a significant and measurable impact on the degradation of the benzene plume. These positive results present an opportunity to re-evaluate the current groundwater pump and treat system and the current performance monitoring program. Preparation of an optimization plan is recommended. A meeting between the USEPA, ADEM, and the PRP was held on August 2, 2005, to discuss ways to evaluate the area and extent of the remaining groundwater plume and ways o optimize the use of biosparging in the remediation process. Early Indicators of Potential Issues No issues were identified during this five-year review.



Implementation of Institutional Controls and Other Measures The institutional controls in place at the site provide adequate protection. The remediation system is monitored weekly and any necessary repairs are implemented. Question B: Are the exposure assumptions, toxicity data, cleanup levels, and remedial action objectives used at the time of the remedy still valid? Yes, the exposure assumptions, toxicity data, cleanup levels, and remedial action objectives used at the time of the remedy are still valid. Support of this statement is described in the following subsections: Changes in Standards and TBCs The only COC identified for PGCS is benzene. The drinking water MCL for benzene remains at 5 ppb. No changes have occurred to the standards which would affect the protectiveness of the remedy. According to ADEM and USEPA, there are no plans to change this standard. Changes in Exposure Pathways The pathways of exposure identified for PGCS are through ingestion and dermal contact of the groundwater to humans and through ingestion to livestock. No changes have occurred at the site to affect the exposure pathways. The hydraulic controls imposed on the groundwater aquifer prevent the migration of the remaining benzene contamination to any point of exposure. Area residents are provided with public municipal water from an upgradient source. The contaminants of concern remain the same, as well as the land usage and human usage of resources. The protectiveness of the remedy is still valid. Changes in Toxicity and Other Contaminant Characteristics Toxicity factors and other characteristics for contaminants of concern have not changed at the site to affect the protectiveness of the remedy. Changes is Risk Assessment Methods Standardized risk assessment methodologies have not changed to affect the protectiveness of the remedy. Expected Progress Toward Meeting RAOs The ROD estimated the aquifer cleanup would be completed in seven years and that continued groundwater monitoring would be required for five additional years to ensure the effectiveness of the cleanup. Remediation of the< benzene plume has been active for approximately 13 years with the most significant impact taking place within the last five-years following the implementation of biosparging. It is anticipated that a revised groundwater remediation and monitoring plan will be submitted following the meeting with the USEPA and PRP in early August, 2005.



Question C: Has any other information come to light that could call into question the protectiveness of the remedy? No information was discovered during this five-year review that questions the protectiveness of the remedy. TECHNICAL ASSESSMENT SUMMARY According to the data reviewed, site inspection, and interviews, the remedy is functioning as intended by the ROD. VIII. ISSUES No major issues were identified during this five-year review. IX. RECOMMENDATIONS AND FOLLOW-UP ACTIONS The limits of the benzene plume at PGCS have been significantly reduced and the threat to the environment remains minimal. It is recommended that the current remediation process be re-evaluated, taking the following into consideration:

• The optimization of benzene reduction that has been realized by biosparging the groundwater aquifer in place,

• Potential reduction/elimination of pumping and treating, • And a possible revision to the number and frequency of sampling

events at the site. It is further recommended that consideration be given to the abandonment of non-essential monitor wells. Until a revision to the remediation plan has been approved by the USEPA, the current remedial actions at the site should continue.

Table 4 Recommendations and Follow-Up Actions

Affects Protectiveness?

(Yes/No) Issue Recommendations/ Follow-up Actions

Party Responsible

Oversight Agency

Milestone Date

Current Future

Need for a plan to optimize the remedy.

• Evaluate enhancing the use of biosparging to optimize benzene reduction.

• Evaluate the need for continued operation of the pup and treatment process.

PRPs EPA March 2007 No No



• Need to change sampling frequency.

Need to abandon certain monitoring wells.

• Plan for conducting well abandonment. PRPs EPA May 2007 No NO

X. PROTECTIVENESS STATEMENT According to the data reviewed, site inspection, and interviews, the remedy at Perdido Groundwater Contamination Site remains protective of human health and the environment. Levels in groundwater contamination have decreased significantly and further migration of the remaining contaminated groundwater is being controlled. Local residents are supplied with water from an upgradient municipal supply system and there is little threat of contaminated groundwater migrating to surface water. XI. NEXT REVIEW The next five-year review for the PGCS is required to be conducted within five years of the approval date of this review

ATTACHMENTS

ATTACHMENT 1

SITE MAPS

Al-lThird 5-Year Review.doc October 3, 2005

ATTACHMENT 2

LIST OF DOCUMENTS REVIEWED

A2-1Third 5-Year Review.doc October 3,2005

Documents Reviewed(chronological order)

Responsiveness Summary, Perdido Groundwater Contamination Site,U.S. Environmental Protection Agency, July 14, 1988.

EPA Superfund Record of Decision, Perdido Groundwater Contamination Site,U.S. Environmental Protection Agency, September 30, 1988.

Record of Decision, Summary of Remedial Alternative Selection, Perdido GroundwaterContamination Site, Perdido, Baldwin County, AlabamaU.S. Environmental Protection Agency, September 30, 1988.

Consent Decree, United States of America vs. CSX Transportation, Inc.,July 19, 1990.

Superfund Program, Explanation of Significant Differences Fact Sheet,U.S. Environmental Protection Agency, May, 1993.

September 1994 Quarterly Report on the Treatment System Operation and Maintenance andPerformance Monitoring for the Perdido Groundwater Contamination Site, Perdido, Alabama,ENSR Consulting and Engineering, November, 1994.

Five-year Review Report. Perdido Groundwater Contamination Site, Perdido, Baldwin County,Roy F. Weston, Inc., May, 1995.

Hydrogeology and Vulnerability to Contamination of Major Aquifers in Alabama: Area 13Geological Survey of Alabama, 2000.

Perdido Groundwater Contamination Site, 2" Five- Year Review,U.S. Army Corps of Engineers, August 3, 2000.

March 2001 Quarterly Report, Treatment System Operations, Maintenance and PerformanceMonitoring, Perdido Remediation Site - Perdido, AlabamaAMEC, April 24, 2001.

March 2002 Semi-Annual Report, Treatment System Operations, Maintenance and PerformanceMonitoring, Perdido Remediation Site - Perdido, AlabamaAMEC, June 5, 2002.

March 2003 Semi-Annual Report, Treatment System Operations, Maintenance and PerformanceMonitoring, Perdido Remediation Site - Perdido, AlabamaAMEC, May 14, 2003.


September 2004 Semi-Annual Report, Treatment System Operations, Maintenance andPerformance Monitoring, Perdido Remediation Site - Perdido, AlabamaAMEC, November 12, 2004.

March 2005 Semi-Annual Report, Treatment System Operation, Maintenance, and PerformanceMonitoring, Perdido Remediation Site - Perdido, AlabamaAMEC Earth & Environmental, Inc., May 20, 2005.

A2-3Third 5-Year Review.doc October 3, 2005

ATTACHMENT 3

OPERATION & MAINTENANCE DOCUMENTS


TREATMENT PLANT WEEKLY LOG EMF-4

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Treatment Plant Weekly Log

A3-2Third 5-Year Review.doc

October 3,2005

Itemized O & M ExpensesPerdido Groundwater Contamination Site

2000-2005

ItemPowerTelephoneLaboratoryFeesLand LeasesO & MContractorO & MSupport(additionalwells/biospargepoints)ConsultantsOther (EPAOversight)Yearly ProjectTotals

2000$18,083$400$20,956

$6,500$122,101

$36,862

$36,158

$241,060

2001$18,106$400$16,031

$6,500$122,258

$34,375$28,088

$225,758

2002$24,139$400$23,928

$6,500$81,332

$33,292

$169,591

2003$15,580$400$20,860

$6,500$117,190

$32,428

$45,174$8,318

$246,450

2004$16,439$400$18,344

$6,500$81,102

$36,866

$159,651

2005 (a)$5,995$150$5,864

$6,500$33,760

$11,061

$63,330

(a) Through April 2005Does not include attorney fees

Third 5-Year Review.docA3-3

October 3,2005

ATTACHMENT 4

SITE INSPECTION CHECK LIST

A4-1Third5-YearReview.doc Octobers, 2005

I. SITE INFORMATION

Site Name: Perdido GroundwaterContamination

Date of Inspection: June 2, 2005

Location and Region: Perdido, AL EPA ID: ALD980728703Agency, office or company leading thefive-year review:U.S. Army Corps of Engineers

Weather/temperature:85°F Partly Cloudy/Rain

I I Monitored natural attenuationI I Groundwater containmentI | Vertical barrier walls

Remedy Includes (Check all that apply)I I Landfill cover/containmentI I Access controlsI | Institutional controlsIXI Groundwater pump and treatmentI I Surface water collection and treatmentIXI Other - Biosparging was voluntarily added by the PRP in 1999 for in placebiogeochemical treatment of groundwater.

I I Inspection team roster attached I I Site map attached

II. INTERVIEWS (Check all that apply)

1. O&M Site Manager

Interviewed IXI at site 1 1 at office I I by phone Phone no.Problems, suggestions; 1X1 Report attached

2. O&M Staff

Interviewed [>3 at site I I at office 1 1 by phone Phone no.Problems, suggestions; D^ Report attached

3. Local regulatory authorities and response agencies (i.e., State andemergency response office, police department, office of public health orhealth, zoning office, recorder of deeds, or other city and county offices,that apply.

Tribal Offices,environmentaletc.) Fill in all

4. Other Interviews:


III. ON-SITE DOCUMENTS & RECORD VERIFIED (Check all that apply)

1. O&M DocumentsE3 O&M ManualIXI As-built drawings£3 Maintenance Logs

Readily availableReadily availableReadily available

] Up to date D N/AUp to date D N/A

] Up to date Q N/A

2. Site Specific Health and Safety Plan ^ Readily available [X] Up to date D N/AContingency Plan/Emergency Response Plan ^ Readily available ^ Up to dateQ N/A

3. O&M and OSHA Training Records £3 Readily available Q Up to dateRemarks: Tlie O&M Manager is up to date on all OSHA certifications.

N/A

4. Permits and Service Agreements

D Air Discharge PermitI I Effluent dischargeD Waste disposal, POTWQOther permits __

Remarks:

Q Readily availableF1 Readily availableD Readily available

I I Readily available

Up to dateUp to dateUp to dateUp to date

N/AN/AN/A

N/A

5. Gas Generation RecordsD Readily available Up to date £<] N/A

6. Settlement Monument RecordsI I Readily available I I Up to date N/A

7. Groundwater Monitoring Records^ Readily available £<] Up to date Q N/A

Remarks: Groundwater monitoring is performed quarterly and reported semi-annually.8. Leachate Extraction Records

I I Readily available I I Up to dateRemarks

N/A

9. Discharge Compliance RecordsIE1 Air£3 Water (effluent)

E3 Readily available^ Readily available

Up to dateUp to date

N/AN/A

Up to date D N/A10. Daily Access/Security Logs DXJ Readily availableRemarks: Visitor Sign-in Logs are maintained on-site.


IV. O&M COSTS

1. O&M OrganizationI I State in-house I I Contractor for StateD PRP in-house E3 Contractor for PRPPI Other

2. O&M Cost Records^ Readily available 1X1 Up to dateI I Funding mechanism/agreement in placeI I Original O&M cost estimate:IXI Breakdown attachedRemarks: See Attachment 3

3. Unanticipated or Unusually High O&M Costs During Review PeriodDescribe cost and reasons: Additional O&M Costs were incurred during the

review period for cleaning of the effluent pipe.

V. ACCESS AND INSTITUTIONAL CONTROLS

A. Fencing

1. Fencing |~~l Location shown on map ^Gates secured I I N/ARemarks: The groundwater treatment facility and storage area are surrounded byfencing and locked for security.

B. Other Access Restrictions

1. Signs and other security measures I I Location shown on map I I N/ARemarks: The front gate and fencing are clearly marked "No Trespassing".

C. Institutional Controls (ICs)1. Implementation and enforcement

Site conditions imply ICs not properly implemented E^YES E3 NO I I N/ASite conditions imply ICs not fully enforced DYES E3 NO D N/A


Type of monitoring (e.g., self-reporting, drive by): Self-ReportingFrequency: Monitoring of the facility is mostly daily but no less than once/weekResponsible Party/Agency: USESContact: Mr. D.C. Harville Site Manager 251-656-0078

Reporting is up-to-date ^YES D NO D N/AReports are verified by the lead agency ^YES I I NO I I N/A

2. Adequacy ICs are adequateD. General

1. Vandalism/trespassing I I Location shown on site map IXI No vandalism evidentRemarks: No vandalism has been reported by the on-site manager.

2. Land use changes on site [XI N/A

3. Land use changes off site [XJ N/A

VI. GENERAL SITE CONDITIONS

A. Roads IXI Applicable I I N/ARemarks: The roads are in good condition.

B. Other Site Conditions Q Applicable Q N/ARemarks: The treatment facility building and surrounding yard are well maintained.

VII. LANDFILL COVERS Q Applicable g|Not Applicable

VIII. VERTICAL BARRIERS D Applicable ^ Not Applicable

IX. GROUNDWATER/SURFACE WATER REMEDIES^ Applicable I I Not Applicable

A4-5Third5-YearReview.doc October 3, 2005

A. Groundwater extraction wells, pumps and pipelinesIXI Applicable I I Not Applicable

1. Pumps, Wellhead Plumbing, and Electrical[X] Good Condition1X1 All required wells properly operatingI I Needs Maintenance I I N/A

Remarks; Each well is in good condition and repairs are made as necessary.2. Extraction System Pipelines, Valves, Valve Boxes, and Other Appurtenances

[XI Good ConditionI I Needs Maintenance I I N/A

3. Spare Parts and EquipmentIXI Readily Available^ Good Condition D N/A

B. Surface water collection structures, pumps and pipelinesI I Applicable [^ Not Applicable

C. Treatment System IXI Applicable I I Not Applicable

1. Treatment Train (Check Components that apply)I I Metal Removal [^Oil/Water Separation£3 Air Stripping QCarbon AdsorbersIXI Filters QAdditivie (e.g., chelation agent, flocculent)^Sampling/maintenance log displayed and up to date^Sampling Ports properly marked and functional^Equipment properly identified^Quantity of groundwater treated annually: Approximately 44 million gallons

2. Electrical Enclosures and Panels (properly rated and functional)I I N/A IXI Good condition QNeed Maintenance

IT Tanks, Vaults, Storage Vessels |^

4. Discharge Structures and Appurtenances 1X1 Good condition I I N/A~5. Treatment Building (s) IXI Good condition I I N/A~6. Monitoring Wells (pump and treat remedy) IXI Good condition

E3 Properly secured and locked


D. Monitoring Data 1X1 Applicable I I Not Applicable

1. Monitoring DataIXI Is routinely submitted on time IXI Is of acceptable quality

2. Monitoring Data suggestsIXI Groundwater Plume is effectively contained[^ Contaminant concentrations are declining

X. OTHER REMEDIES

XL OVERALL OBSERVATIONS

A. Implementation of the RemedyThe remedy is being implemented as designed and functioning successfully. Thebenzene levels are decreasing and the groundwater plume is contained. The remedy atthe site is protective of human health and the environment.

B. Adequacy of O&MThe remediation system is well maintained and all wells are in good condition. The on-site manager performs a thorough inspection of the system weekly and attends to anyissues noted at that time. Maintenance logs are completed regularly and submitted in thesemi-annual reports.

C. Early Indicators of Potential Remedy ProblemsThere were no potential remedy problems evidenced during this five-year review. Theremedy is functioning well and as designed.


D. Opportunities for OptimizationThe introduction of biosparging into the remediation system appears to have had a moresignificant contribution to benzene reduction in groundwater than pump and treat.Biosparging may be a potential replacement for pump and treat based on the decliningextent and concentrations of benzene and is an opportunity for optimization. Anotheropportunity for optimization is a revision to the current groundwater sampling plan.


ATTACHMENT 5

PHOTOS DOCUMENTING SITE CONDITIONS

A6-1Third 5-Year Review.doc ' October 3,2005

ATTACHMENT 6

INTERVIEW RECORDS


Site Name: Perdido Groundwater Contamination

Subject: 3rd Five- Year Review

Type: ^Telephone ^Visit DOtherLocation of Visit: Perdido Groundwater Contamination Site

EPA ID No.: ALD980728703

Time: 10:00 Date:6/02/05

[~] Incoming |~~| Outgoing

INTERVIEW RECORD

Contact Made By:

Name: Rhonda Capes Title: Geologist Organization: USAGE

Individual Contacted:

Name: Mr. D.C. Harville Title: On-Site Manager

Telephone No: 251-656-0078Fax No: 251-662-3400E-Mail Address:

Organization: USES

Street Address: 4230-A Halls Mill RoadCity, State, Zip: Mobile, AL, 36693

Summary Of Conversation

Mr. Harville is a resident of Perdido, AL and has been an employee at the site sinceconstruction of the treatment facility. Mr. Harville believes that the remedy system isworking well and that all necessary maintenance requirements are attended to in anexpedient manner by AMEC and USES.

Mr. Harville stated that the community is aware of the work that is being done to clean upthe site and that he has not had any problems with trespassers or anyone complaining of theactivities at the site.

Mr. Harville stated that he visits the facility most days just to make sure the system isrunning properly. He normally performs his weekly inspections on Fridays and does anyrepairs/maintenance the following Monday.


Site Name: Perdido Groundwater Contamination

Subject: 3rd Five- Year Review

Type: DTelephone ^Visit QOtherLocation of Visit: Perdido Groundwater Contamination Site

EPA ID No.: ALD980728703

Time: 10:00 Date:6/02/05

l~l Incoming fj Outgoing

INTERVIEW RECORD

Contact Made By:

Name: Rhonda Capes Title: Geologist Organization: USAGE

Individual Contacted:

Name: Mr. Stephen Blair Title: Project Manager

Telephone No: 865-986-4338Fax No:E-Mail Address:

Street Address:City, State, Zip:

Organization: AMEC

10239 Technology DriveKnoxville, TN 37932

Summary Of Conversation

Mr. Blair attended the site visit and assisted in providing a tour of the facility. Mr. Blairexplained the treatment process, discussed the installation of the biosparge wells, andcleaning of the effluent pipeline. Mr. Blair's overall impression of the remedy is that it isfunctioning as designed. He stated that AMEC will be meeting with USEPA in the nearfuture to discuss the additional usage of the biosparging wells and possible revisions to themonitoring plan.

Mr. Blair was not aware of any complaints, violations, or other incidents related to the sitethat required a response by his office.


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