RECORD OF DECISION (RODS) - Records Collections · Appendix A Public Announcement . Glossary of Terms _____ Located at the end of this Record of Decision . TERC Contract No.DACA56-94-D-0020

FINAL RECORD OF DECISION

LHAAP-32, FORMER TNT WASTE DISPOSAL PLANT LONGHORN ARMY AMMUNITION PLANT

KARNACK, TEXAS

Prepared for U.S. Army Corps of Engineers

Tulsa District 1645 South 101st Avenue

Tulsa, Oklahoma

Prepared by Shaw Environmental, Inc. 3010 Briarpark, Suite 400

Houston, Texas 77042

Contract Number DACA56-94-D-0020 Task Order No. 0109

August 2008

Table of Contents________________________________________________

List of Figures .................................................................................................................................................ii List of Appendices ..........................................................................................................................................ii Glossary of Terms ..........................................................................................................................................ii Acronyms and Abbreviations ......................................................................................................................... iii

1.0 Declaration...................................................................................................................................... 1-1 1.1 Site Name and Location ....................................................................................................... 1-1 1.2 Statement of Basis and Purpose .......................................................................................... 1-1 1.3 Description of the Selected Remedy .................................................................................... 1-1 1.4 Statutory Determinations ...................................................................................................... 1-2 1.5 Authorizing Signatures ......................................................................................................... 1-2

2.0 Decision Summary.......................................................................................................................... 2-1 2.1 Site Name, Location, and Description .................................................................................. 2-1 2.2 Site History and Enforcement Activities................................................................................ 2-2

2.2.1 Site History .............................................................................................................. 2-2 2.2.2 Enforcement Activities ............................................................................................. 2-2

2.3 Community Participation....................................................................................................... 2-3 2.4 Scope and Role of Operable Unit or Response Action......................................................... 2-4 2.5 Site Characteristics............................................................................................................... 2-4

2.5.1 Physical Characteristics .......................................................................................... 2-4 2.5.1.1 LHAAP-32 ................................................................................................. 2-4

2.5.2 Nature and Extent of Contamination........................................................................ 2-5 2.6 Current and Potential Future Site and Resource Uses......................................................... 2-6

2.6.1 Current and Future Land Uses ................................................................................ 2-6 2.6.2 Current and Future Surface Water Uses ................................................................. 2-7 2.6.3 Current and Future Groundwater Uses ................................................................... 2-7

2.7 Summary of Site Risks ......................................................................................................... 2-8 2.7.1 LHAAP-32 ............................................................................................................... 2-9

2.7.1.1 Human Health Risks ................................................................................. 2-9 2.7.1.2 Ecological Risks...................................................................................... 2-10

2.8 Documentation of Significant Changes............................................................................... 2-11 3.0 Responsiveness Summary ............................................................................................................. 3-1 4.0 References ..................................................................................................................................... 4-1

TERC Contract No.DACA56-94-D-0020 , TO No. 109 Shaw Project No. 845714 Longhorn Army Ammunition Plant, Karnack, Texas i August 2008

List of Figures __________________________________________________

Figure 2-1 Location of Longhorn AAP Figure 2-2 Site Location Map LHAAP-32 at Longhorn AAP Figure 2-3 Installation-Wide Groundwater Elevation Map (Shallow Zone)

List of Appendices_______________________________________________

Appendix A Public Announcement

Glossary of Terms _______________________________________________

Located at the end of this Record of Decision

TERC Contract No.DACA56-94-D-0020 , TO No. 109 Shaw Project No. 845714 Longhorn Army Ammunition Plant, Karnack, Texas ii August 2008

Acronyms and Abbreviations ______________________________________

BERA baseline ecological risk assessment bgs below ground surface CERCLA Comprehensive Environmental Response, Compensation, and Liability Act cm/sec centimeters per second COPC chemical of potential concern FFA Federal Facility Agreement HHRA human health risk assessment HI hazard index Jacobs Jacobs Engineering Group, Inc. LHAAP Longhorn Army Ammunition Plant MCL maximum contaminant level MOA Memorandum of Agreement NCP National Oil and Hazardous Substances Pollution Contingency Plan NPL National Priorities List RAB Restoration Advisory Board RCRA Resource Conservation and Recovery Act RFA RCRA Facility Assessment ROD Record of Decision SARA Superfund Amendments and Reauthorization Act Shaw Shaw Environmental, Inc. TCEQ Texas Commission on Environmental Quality TNT Trinitrotoluene USAEHA U.S. Army Environmental Hygiene Agency USATHAMA U.S. Army Toxic and Hazardous Material USEPA U.S. Environmental Protection Agency USFWS U.S. Fish and Wildlife Service

TERC Contract No.DACA56-94-D-0020 , TO No. 109 Shaw Project No. 845714 Longhorn Army Ammunition Plant, Karnack, Texas iii August 2008

Final Record of Decision, LHAAP-32 Shaw Environmental, Inc.

1.0 Declaration

1.1 Site Name and Location Site LHAAP-32, Former TNT Waste Disposal Plant.

Longhorn Army Ammunition Plant Karnack, Texas

Comprehensive Environmental Response, Compensation, and Liability Information System, U.S. Environmental Protection Agency (USEPA) Identification Number: TX6213820529.

1.2 Statement of Basis and Purpose This document presents the no action decision for Site LHAAP-32 located at the former Longhorn Army Ammunition Plant (LHAAP) in Karnack, Texas. The decision was chosen in accordance with the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) of 1980, as amended by the Superfund Amendments and Reauthorization Act (SARA) of 1986, and to the extent practicable, the National Oil and Hazardous Substances Pollution Contingency Plan (NCP), 40 CFR Part 300.

The decision was based on the Administrative Record file for this site, including the remedial investigation and baseline risk assessment reports (Jacobs Engineering Group, Inc. [Jacobs] 2001, 2002), the Final Site Evaluation Report (Shaw Environmental, Inc.[Shaw], 2005), the installation-wide baseline ecological risk assessment (BERA) report (Shaw, 2007b), the Proposed Plan (U.S. Army, 2008), and other related documents contained in the Administrative Record for site LHAAP-32.

This document is issued by the U.S. Army, the lead agency for this installation. USEPA Region 6 and the Texas Commission on Environmental Quality (TCEQ) are the regulatory agencies providing technical support, project review and comment, and oversight of the U.S. Army cleanup program. The USEPA and TCEQ concur with the selected No Action decision.

1.3 Description of the Selected Remedy The lead agency has determined that no CERCLA action is necessary to protect public health or welfare or the environment. The recommendation for no action is consistent with the criteria required under CERCLA.

Risk evaluation conducted for LHAAP-32 determined that the site was suitable for unrestricted use.

TERC Contract No.DACA56-94-D-0020 , TO No. 109 Shaw Project No. 845714 1-1Longhorn Army Ammunition Plant, Karnack, Texas August 2008

Final Reooro Of DeCIsion. LHAAP·32 Shaw EnwQnmenlal Inc,

1.4 Statutory Determinations one of the C RCLA : 121 slalutory determinarion. are necessary in thi adion inee no remedy

is. b~ing scJccred. J \ remedial aClion i nccess. ry 10 ensure protection of human health and the environment.

1.5 Authorizing Signatures

-v~~ 7Jt-I.!'1~ (Name) .rnlre

Thomas E. Lederle SarnueJ Coleman, P.E. lndustriHI Branch Chief Director BRAC Division, CSIM Superfund Division United States Arm U.S. Environmental Protccrion gency,

Rl.:gion 6

(Ny,me)

NJRC COOlf.l(1 tit> 1JACASS-94'i).lX),iO, ro ,'I.'l, 109 ':in.II,PI<!«f /{o ;;<51141·2t~nNmyAil~_'tMFIilr.1,K<!rtli-:;.. i"'J~ JWy2li\,"t1


2.0 Decision Summary

2.1 Site Name, Location, and Description LHAAP-32, Former TNT Waste Disposal Plant

Longhorn Army Ammunition Plant, Karnack, Texas

Comprehensive Environmental Response, Compensation, and Liability Information System USEPA Identification Number: TX6213820529

Lead Agency: U.S. Army, Department of Defense

Source of Cleanup Money: U.S. Army, Department of Defense

The former LHAAP is an inactive, government-owned, formerly contractor-operated and -maintained Department of Defense facility located in central east Texas in the northeast corner of Harrison County. As shown on Figure 2-1, LHAAP is approximately 14 miles northeast of Marshall, Texas. The facility is approximately 40 miles west of Shreveport, Louisiana. The former U.S. Army installation occupied 8,416 acres between State Highway 43 at Karnack, Texas, and the southwestern shore of Caddo Lake and is accessed by State Highways 43 and 134.

LHAAP was placed on the Superfund National Priorities List (NPL) on August 9, 1990. Activities to remediate contamination began in 1990. After its listing on the NPL, the U.S. Army, the USEPA, and the Texas Water Commission (currently known as the TCEQ) entered into a CERCLA Section 120 Federal Facility Agreement (FFA) for remedial activities at LHAAP. The FFA became effective December 30, 1991. LHAAP operated until 1997 when it was placed on inactive status and classified by the U.S. Army Armament, Munitions, and Chemical Command as excess property.

The site addressed in this ROD is LHAAP-32 shown in Figure 2-2 and is discussed below.

LHAAP-32 is a nine-acre site located in the west-central portion of LHAAP. The site entrance is at Avenue C, approximately 0.2 miles northwest of its intersection with Zeugner Drive. LHAAP-32 was the former TNT Waste Disposal Plant that operated from 1942 to 1945. The plant treated wastewater generated at the nearby TNT Production Area (LHAAP-29).

The site is surrounded by an area (approximately 7,000 acres) that was transferred by the U.S. Department of the Army to the U.S. Fish and Wildlife Service (USFWS) for management as the Caddo Lake National Wildlife Refuge. The U.S. Army, the lead agency for environmental



response actions at LHAAP, is acting in partnership with USEPA Region 6 and TCEQ in planning and implementing remedial action at LHAAP-32.

2.2 Site History and Enforcement Activities 2.2.1 Site History LHAAP was established in December 1941 with the primary mission of manufacturing trinitrotoluene (TNT). Production of TNT began at Plant 1 in October 1942 and continued through World War II until August 1945, when the facility was placed on standby status until February 1952. In 1952, the facility was reactivated and production of pyrotechnic ammunition, such as photoflash bombs, simulators, hand signals, and tracers for 40 mm ammunition continued at Plant 2 through 1956.

In December 1954, a third facility, Plant 3, began production of solid-fuel rocket motors for tactical missiles. Rocket motor production at Plant 3 continued to be the primary operation at LHAAP until 1965 when Plant 2 was reactivated for the production of pyrotechnic and illuminating ammunition. In the years following the Vietnam conflict, LHAAP continued to produce flares and other basic pyrotechnic or illuminating items for the U.S. Department of Defense inventory. From September 1988 to May 1991, LHAAP was also used for the static firing and elimination of Pershing I and II rocket motors in compliance with the Intermediate-Range Nuclear Forces Treaty in effect between the United States and the former Union of Soviet Socialist Republics.

LHAAP-32: Wastewater generated from the TNT Waste Disposal Plant was transferred to the disposal area through a 6-inch wooden pipeline and stored in holding tanks until treated. Wastewater was neutralized with sodium hydroxide and evaporated. Condensate was collected, stored, and released via a ditch to Goose Prairie Creek. The thickened and neutralized wastes were stored until burned at an incinerator facility at LHAAP-32. The remaining ashes were disposed at the Old Landfill (LHAAP-16) until early 1944, when an ash sluicing system was added to the LHAAP-32 treatment plant to dispose of the solids. A ditch to Goose Prairie Creek conveyed the resultant solids. This ditch also carried acidic cooling water from the TNT waste disposal plant to the Neutralizing Plant next to the Bulk Toluene Storage Area in LHAAP-29. In 1959, most of the buildings and tanks used in the disposal process were removed and the debris burned at Burning Ground No. 2/Flashing Area (Site 17).

2.2.2 Enforcement Activities Due to the release of hazardous substances, pollutants, and contaminants from operation and maintenance activities at the facility, the USEPA placed LHAAP on the Superfund NPL on August 9, 1990. LHAAP-32 was one of the sites identified as having a potential release of hazardous substances. Activities to remediate contamination associated with the listing of



LHAAP as a Superfund site began in 1990. After the listing on the NPL, the U.S. Army, the USEPA, and the Texas Water Commission (currently known as the TCEQ) entered into a CERCLA Section 120 FFA for remedial activities at LHAAP. The FFA became effective December 30, 1991.

2.3 Community Participation The U.S. Army, USEPA, TCEQ and the LHAAP Restoration Advisory Board (RAB) have provided public outreach to the surrounding community concerning LHAAP-32 and other environmental sites at LHAAP. The outreach program has included fact sheets, media interviews, site visits, invitations to attend quarterly RAB and regulatory review meetings, and public meetings consistent with its public participation responsibilities under Sections 113 (k)(2)(b), 117(a), and 121(f)(1)(g) of CERCLA.

The Proposed Plan (U.S. Army, 2008) for the decision of No Action Necessary for LHAAP-32 was released to the Administrative Record file and made available to the public for review and comment on January 10, 2008. A notice of availability of the Proposed Plan and other related documents in the Administrative Record file was published in The Shreveport Times and the Marshall News Messenger on January 13, 2008. A 30-day public comment period for the Proposed Plan began on January 13, 2008. The public meeting was held on January 29, 2008. No written comments were received from the USEPA, the TCEQ, or the general public.

Previously, copies of Administrative Record documents were made available to the public at several information repository locations, including LHAAP, USEPA Region 6 Library, TCEQ, and Marshall Public Library. Currently, the Administrative Record may be found at the information repositories maintained at the following locations:

Public Library

Location: Marshall Public Library 300 S. Alamo Marshall, Texas 75670

Business Hours: Monday – Thursday 10:00 a.m. – 8:00 p.m. Friday – Saturday 10:00 a.m. – 5:00 p.m.

Longhorn Army Ammunition Plant

Location: U.S. Army Office Trailer Longhorn Army Ammunition Plant, Karnack, Texas 75670



2.4 Scope and Role of Operable Unit or Response Action The land on which this site is located is excess to the Army’s needs and is intended for transfer to the USFWS for incorporation into the Caddo Lake National Wildlife Refuge. Future anticipated use is consistent with an industrial/recreational level of exposure. This site is being addressed independent of response actions at other environmental sites at LHAAP.

2.5 Site Characteristics This section of the ROD presents an overview of LHAAP-32 site characteristics with respect to physical site features, known or suspected sources of contamination, types of contamination, and affected media. Known or potential routes of contaminant migration are also discussed.

2.5.1 Physical Characteristics 2.5.1.1 LHAAP-32 The former TNT Waste Disposal Plant is a nine-acre site situated in the west-central portion of LHAAP (Figure 2-2). The topography is relatively flat and sparsely to heavily wooded. There are no major watercourses or surface water bodies at the site. Most of the buildings and tanks used in the disposal process have been removed, leaving only the concrete foundations, access roads, underground utilities and constructed surface water drainage ways remaining. Runoff from the site eventually enters Caddo Lake approximately two miles from the site via Goose Prairie Creek. Runoff from the northwestern and north-central portions of the site is generally toward the north. The runoff is collected by three ditches that merge near the northern site boundary into a single ditch that conveys the runoff northward into Goose Prairie Creek. In the eastern and southeastern portions of the site, runoff is overland and is captured by small tributaries of Goose Prairie Creek to the east of the site. Runoff from the south-central and southwestern portions of the site is generally to the south or southeast. The runoff is collected by a ditch along the south boundary of the site and carried to Goose Prairie Creek. The total distance from the site to Caddo Lake is approximately 2.3 miles (Jacobs, 2001).

At LHAAP, groundwater occurs within thin silty and clayey sands that are interbedded with clayey silt and silty and sandy clays. To approximately 100 feet below ground surface, three water-bearing zones are typically encountered and described as shallow, intermediate and deep.

Boring logs indicate that LHAAP-32 is situated on an outcrop of the Wilcox formation, overlain by a few feet of fill materials. Below the fill, silty clay and clayey silt is encountered from ground surface to depths ranging from approximately 38 feet at well 32WW01 to 41 feet at well 32WW02. Within this silty clay and clayey silt is the shallow groundwater zone which occurs within lenses of fine silty sand. Four wells were installed at LHAAP-32, all four within this interval. Shallow groundwater flow at this site is generally northeast (Figure 2-3). Hydraulic



conductivity determined by rising head slug tests performed on three wells installed in the shallow zone ranges from 1.34E-06 cm/sec to 9.89E-04 cm/sec (Jacobs, 2001).

2.5.2 Nature and Extent of Contamination As part of the Installation Restoration Program, the U.S. Army began an environmental investigation in 1976 at LHAAP followed by installation wide assessments/investigations that included the following:

• Record Search – In 1980, U.S. Army Toxic and Hazardous Material (USATHAMA, 1980) conducted a record search to assess the impact of the LHAAP installation activities including usage, storage, treatment, and disposal of toxic and hazardous materials on the environment, and define conditions that may have adversely affected human health and the environment.

• Contamination Survey – In 1982 as part of the LHAAP contamination survey, Environmental Protection Systems collected six groundwater samples for laboratory analyses. Subsequently in 1987, as part of the Resource Conservation and Recovery Act (RCRA) permit application process, and as a continuation of the contamination survey, U.S. Army Environmental Hygiene Agency (USAEHA) identified, described, and evaluated all solid waste management units at LHAAP (USAEHA, 1987). Units requiring further sampling, investigation and corrective action were delineated.

• RCRA Facility Assessment (RFA) – In 1988, a preliminary RFA was conducted by the U.S. Army (Maley, 1988). Waste at the various sites was characterized but no samples were collected.

In addition to the installation-wide investigations, site-specific investigations were conducted in a phased approach between 1982 and 2005, to establish the nature and extent of contamination at LHAAP-32. Media investigated included soil, groundwater, surface water, and sediment.

Surface Water and Sediment. Compounds that were detected in sediment and surface water were within acceptable levels.

Soil. Results of the initial investigations indicated elevated levels of metals at one soil sampling location and high levels of explosive constituents in the upper 0.5 feet of soil at another sampling location.

A human health risk assessment (HHRA) conducted in 2002 indicated unacceptable risk to a maintenance worker primarily from a high concentration of TNT detected in the former settling pond (Jacobs, 2002). Because the unacceptable risk was caused by a single high detection of TNT at a concentration of 57,000 milligrams per kilogram at boring 32SS03, the Army decided to resample that location and the area around it.



In 2004, the additional sampling of soil was conducted within the former settling pond where the high level of TNT was previously detected, to confirm and delineate the high TNT concentration (Shaw, 2007a). Soil samples were also collected from the former treatment facility building to determine if a release occurred in the past.

The high detection of TNT in the soil was not replicated during the 2004 re-sampling. Results of the investigations indicated that only one soil sample located within the former settling pond had a low detection of TNT. The TNT concentration was three orders of magnitude lower than previously detected in the area.

One subsurface soil sample collected from the northeastern corner of the former treatment building showed a detection of lead above the action level. Migration of the soil contaminants at these isolated locations would be impeded due to the lithology of the soil at the site, which consists of stiff clay with thin, isolated sand units (Shaw, 2007a).

Groundwater. Initial groundwater sampling results indicated that antimony, arsenic, and lead were detected above maximum contaminant levels (MCLs) in groundwater. These chemicals are not related to past operations at LHAAP-32. Instead, they were suspected to be related to the turbidity of the groundwater samples. In order to determine whether the chemicals were related to sample turbidity, Shaw re-sampled the wells using low-flow methods. Groundwater samples were collected from three monitoring wells at the site in May 2005. Re-sampling results confirmed that elevated metal levels were associated with high turbidity and not representative of groundwater conditions at the site. No explosives were detected in any of the groundwater samples.

2.6 Current and Potential Future Site and Resource Uses 2.6.1 Current and Future Land Uses LHAAP is located near the unincorporated community of Karnack, Texas. Karnack is a rural community with a population of 775 people. The incorporated community of Uncertain, Texas, population 205, is located to the northeast of LHAAP on the edge of Caddo Lake and is a resort area and an access point to Caddo Lake. The industries in the surrounding area consist of agriculture, timber, oil and natural gas production, and recreation.

LHAAP has been an industrial facility since 1942. Production activities and associated waste management activities continued until the facility was determined to be in excess of the Army’s needs in 1997. The plant area has been relatively dormant since that time. LHAAP is surrounded by a fence (except on the border with Caddo Lake), and current security measures at the LHAAP preclude unlimited public access to areas within the fence. The fence now represents the Refuge boundary. Approved access for hunters is very limited.



The reasonably anticipated future use of LHAAP-32 is as a national wildlife refuge. This anticipated future use is based on a Memorandum of Agreement (MOA) (U.S. Army, 2004) between the USFWS and the U.S. Army. That MOA documents the transfer process of the LHAAP acreage to USFWS to become the Caddo Lake National Wildlife Refuge. Presently the Caddo Lake National Wildlife Refuge occupies approximately 7,000 acres of the 8,416-acre former installation. A change in use from wildlife refuge requires an act of Congress.

2.6.2 Current and Future Surface Water Uses Streams on LHAAP currently support wildlife and aquatic life. While humans may have limited access to some streams during annual hunts, there is no routine human use of streams on LHAAP. The streams do not carry adequate numbers and size of fish to support either sport or subsistence fishing. During the summer months, the streams cease flowing and/or dry up. The streams discharge into Caddo Lake. Caddo Lake is a large recreational area that covers 51 square miles and has a mean depth of 6 feet. The watershed of the lake encompasses approximately 2,700 square miles. It is used extensively for fishing and boating. Caddo Lake is a drinking water supply for multiple cities in Louisiana including Vivian, Oil City, Mooringsport, South Shore, Blanchard, Shreveport, and Bossier City.

The anticipated future uses of the streams and lake are the same as the current uses.

2.6.3 Current and Future Groundwater Uses Groundwater in the deep aquifer (250-430 feet bgs) near LHAAP is currently used as a drinking water source. There are currently five active water supply wells near LHAAP. One well is located in and owned by Caddo Lake State Park. The well is completed to a depth of 315 feet and has been in use since 1935. A second well owned by the Karnack Water Supply Corporation services the town of Karnack and is located approximately 2 miles southeast of town. This well is approximately 430 feet deep and has been in use since 1942. The Caddo Lake Water Supply Corporation has three wells located both north and northwest of LHAAP. These wells are identified as Caddo Lake Water Supply Corporation Wells 1, 2, and 3 and are all hydraulically upgradient of LHAAP. These wells are completed deeper in the Wilcox than the deepest zone of contamination at LHAAP. Because of this and the large distance between these wells and LHAAP, water removal from these wells is not expected to affect groundwater flow at the site. In addition, there are several livestock and domestic wells located in the vicinity of LHAAP with depths averaging approximately 250 feet.

Three water supply wells are located within the boundary of LHAAP itself. One well is located at the Fire Station/Security Office approximately 0.1 miles north of LHAAP-32. The second well is located approximately 0.35 miles southwest of the Fire Station/Security Office and 0.14 miles southwest of LHAAP-32. The third well is located north of the administration building, near the entrance to LHAAP approximately 1.13 miles southwest of LHAAP-32. All



three water supply wells were completed within a deeper groundwater zone which is not associated with LHAAP-32. Two additional wells previously supplied water to the installation, but these have been plugged and abandoned. Although all three provide water at the tap, none are used for drinking water. None of the water supply wells are associated with the site addressed by this ROD.

Based on the anticipated future use of the facility (i.e., a wildlife refuge), the groundwater at the site will not be used in the future as a drinking water source. However, to be conservative, it is assumed that an industrial use scenario, though less likely, is possible. The future industrial scenario for LHAAP conservatively assumes limited use of groundwater as a drinking water source.

2.7 Summary of Site Risks This section summarizes the results of the baseline human health and ecological risk assessments conducted for LHAAP-32 (Jacobs, 2002; Shaw, 2007b). The risk assessments consist of an HHRA and a screening ecological risk assessment performed by (Jacobs, 2002) as well as an installation-wide BERA performed by Shaw (Shaw, 2007b).

The NCP, 40 Code of Federal Regulations Part 300, established a range of acceptable levels of cancer risk for Superfund sites. These values range between a higher risk of one in 10,000 and a lower risk of one in 1 million additional cancer cases if cleanup action is not taken at a site. Expressed in scientific notation, this translates to an acceptable risk range of 1 × 10-4 to 1 × 10-6

over a defined period of exposure to site-related contaminants.

In addition to a cancer risk, chemical contaminants that are ingested, inhaled, or dermally absorbed may present non-cancer hazards to different organs of the human body. The noncancer hazard or toxic effect is expressed as a hazard index (HI). USEPA considers an HI exceeding 1.0 to be an unacceptable non-cancer hazard.

The screening ecological risk assessments for LHAAP are provided in the Final Baseline Human Health and Screening Ecological Risk Assessment (Jacobs, 2002).

The ecological risk for site LHAAP-32 was addressed in the installation-wide BERA (Shaw, 2007b) and is noted in the subsections below. The BERA concluded that no unacceptable risk was present in the Industrial Sub-Area (Shaw, 2007b), the area in which the site is located. Therefore, no action is needed at LHAAP-32 for the protection of ecological receptors.



2.7.1 LHAAP-32 2.7.1.1 Human Health Risks An HHRA is based on a conservative estimate of the potential cancer risk or non-cancer hazard from potential exposure. The following three factors were considered in the evaluation:

• Nature and extent of contamination at LHAAP-32

• Exposure pathways through which human receptors are or may be exposed to those contaminants at the site

• Potential toxic effects of those contaminants.

The assessment of potential risks to current trespassers and future maintenance workers at LHAAP-32, and ecological receptors have been previously reported (Jacobs, 2002). During the risk assessment conducted by Jacobs, cancer risk and the non-cancer HI were calculated for a current trespasser scenario and a future industrial worker scenario. The trespasser was assumed to encounter surface soil only (0 to 0.5 feet bgs). The industrial maintenance worker was assumed to encounter both surface soil and subsurface soil (0 to 2 feet bgs). The baseline HHRA calculated the HI for the soil to be 35 for the current trespasser, and 230 for the future maintenance worker. The cancer risk for the soil was 9.2 × 10-5 and 1.2 × 10-3 for the trespasser and maintenance worker, respectively. Both the HI and cancer risk were unacceptable for the future maintenance worker, due to the one high detection of TNT. Non-cancer hazard and cancer risk were acceptable for groundwater (Jacobs, 2002). Additional sampling performed to replicate and delineate the high TNT detection revealed very low or nondetected concentrations of TNT, indicating that the detection was isolated and was not considered in the later risk assessment described below.

Shaw conducted the baseline HHRA for residential uses of LHAAP-32 (Shaw, 2005) to supplement the information presented in the industrial baseline HHRA (Jacobs, 2002) and provide risk managers information about whether the site can be released for unrestricted use. The residential baseline HHRA largely uses the same methods employed for the industrial baseline HHRA so that the two risk assessments are consistent. Some adjustments in the methods used for the industrial baseline HHRA were made, as appropriate, to present a residential assessment that is consistent with other risk assessments being conducted for LHAAP sites and with current regulatory guidance. The assessment of potential risks to residents at LHAAP-32 was based on TCEQ Risk Reduction Rules (TCEQ, 1998 and 2004a) and USEPA guidance (1989).

The residential baseline HHRA summarized below included data evaluation in which chemicals of potential concern (COPCs) were identified by comparison of results to LHAAP background concentrations and risk-based screening criteria; exposure assessment, which describes land use



assumptions, plausible human exposure scenarios and receptors, and quantitative estimates of their potential exposure; toxicity evaluation that briefly describes the adverse health effects associated with each COPC and provides references for further details; risk characterization that qualitatively describes cancer risk and non-cancer hazard to human receptors; and uncertainty analysis, which describes the uncertainties associated with the components of the risk assessment and their impact on the conclusions and future decisions regarding the site. The total cancer risk from exposure to soil (calculated 2.0 x 10-5) is within the acceptable range of 1.0 x 10-6 to 1.0 x 10-4. Potential ingestion of arsenic in soil is the major contributor to the estimated risk. The noncancer hazard (total HI) to children from exposure to soil (3.0 x 10-1) is less than 1 and is, therefore, below acceptable limits (USEPA, 1994). These chemicals are not of concern for exposures of potential residents to soil at LHAAP-32 and, therefore, no action for soil is necessary at LHAAP-32.

Metals including antimony, arsenic, and lead were detected in groundwater at levels above their respective MCL values, however, as indicated earlier, these chemicals are not related to past operations at LHAAP-32. Instead, they are suspected to be related to the turbidity of the groundwater samples.

Additional groundwater sampling conducted at LHAAP-32 confirmed that metals concentrations were elevated due to the high turbidity of groundwater samples collected from well 113. This monitoring well is located in the northwest corner of the site, in an area that does not appear to be affected by site activities. The other two monitoring wells are located in the main part of the site, with chemical concentrations undetected or below screening levels. The soil and groundwater data, thus, suggest the absence of a release at LHAAP-32. No action is recommended for the site.

A detailed account of the residential baseline HHRA process is included in Attachment 1 of the Final Site Evaluation Report (Shaw, 2005). The Army submitted the draft version of the Final Site Evaluation Report to USEPA Region 6 in October 2005, and received written concurrence with the recommendation of no action in November 2005. The letter of concurrence from USEPA Region 6 to the Army was received November 21, 2005 (USEPA, 2005).

2.7.1.2 Ecological Risks The ecological risk for site LHAAP-32 was addressed in the installation-wide BERA (Shaw, 2007b). For the BERA, the entire Installation was divided into three large sub-areas (i.e., the Industrial Sub-Area, Waste Sub-Area, and Low Impact Sub-Area) for the terrestrial evaluation. The individual sites at LHAAP were grouped into one of these sub-areas, which were delineated based on commonalities of historical use, habitat type, and spatial proximity to each other. The conclusions regarding the potential for chemicals detected at individual sites to adversely affect

TERC Contract No.DACA56-94-D-0020 , TO No. 109 Shaw Project No. 845714 2-10 Longhorn Army Ammunition Plant, Karnack, Texas August 2008


the environment must be made in the context of the overall conclusions of the sub-area in which the site falls. Site LHAAP-32 lies within the Industrial Sub-Area.

The BERA concluded that no unacceptable risk was present in the Industrial Sub-Area (Shaw, 2007b). Therefore, no action is needed at LHAAP-32 for the protection of ecological receptors.

2.8 Documentation of Significant Changes The Proposed Plan for LHAAP-32 was released for public comments in January 2008. The Proposed Plan documents the decision of No Action Necessary for the site. No significant changes have been made to the proposed plan for the site. No written or verbal comments were received during the public comment period. It was determined that no significant change to the decision, as originally identified in the Proposed Plan, was necessary or appropriate.

TERC Contract No.DACA56-94-D-0020 , TO No. 109 Shaw Project No. 845714 2-11 Longhorn Army Ammunition Plant, Karnack, Texas August 2008

~Stiaw®

Loui siana Texas

Loui siana Texas

Marion County

CaddoCounty

Longhorn ArmyAmmunition PlantFIL

E PAT

H OF

FICE

CHEC

KED

BYAP

PROV

ED B

YDR

AWN

BYHo

uston

, TX

P.Pac

e 02

/27/04

M

ayi

A.la

12/22

/04

Sriv

asP.

tav

06/30

/05

X:\Lo

ngho

rn\GI

Swork

spac

e\BLu

\MXD

\Tran

sfer1.

mxd

Marion County

CaddoCounty

Longhorn ArmyAmmunition Plant

Rusk County Panola County

Rusk County Panola County

0 2.5 5 10 Miles

Texas

U.S. ARMY CORPS OF ENGINEERS TULSA DISTRICT

TULSA, OKLAHOMA

FIGURE 2-1

LOCATION OF LONGHORNARMY AMMUNITION PLANT, HARRISON COUNTY, TEXAS

LONGHORN ARMY AMMUNITION PLANT KARNACK, TEXAS

Marshall

Harrison County

Marshall

Harrison County

FM 2198

FM 134

PLANT RD

29TH S

T.

AVE "N"

28TH S

T.

6TH S

T.

24TH S

T 2

. 5TH S

T.

18TH S

T.

20TH S

T.

27TH S

T.

23RD S

T.

AVE "Q"

21ST S

T.

19TH S

T.

48TH S

T.

4TH S

T.

LONG POINT RD

MAR

SHAL

L AV

E

32ND ST.

AVE "E"

ZEUGNER DR

RICE AVE

AVENUE "P"

AVE "C" AVE "D"

59TH ST.

COOK RD. FI

RE

LAN

E

KARN

ACK AVE

11TH

ST.

34TH ST

HAYSTAC

K RD

.

51ST ST.

TYLER AVE

KELLY AVE

37TH ST.

60TH ST.

70TH ST.

62ND ST.

56TH ST. AVE "F

"

STA

RR

RA

NC

H R

D

IGN

ATIUS AVE

AVE "C"

6TH ST.

4TH ST.

AVE "D" ZEUGNER DR

LHAAP-32

FILE P

ATH

OFFIC

ECH

ECKE

D BY

AP

PROV

ED B

YDR

AWN

BYT:\

GIS\

Long

horn

\MXD

\ST08

3248

35C\

ROD\

SiteL

oc32

.mxd

Hous

ton,

TX

Lu

B.10

/12/07

Ol

sN.

on

02/19

/08

Sri

P.va

stav

02/19

/08 0 300 600 1,200

Feet

LHAAP-32

U.S. ARMY CORPS OF ENGINEERSTULSA DISTRICT

TULSA, OKLAHOMARoad

LEGEND

Approximate LHAAP Boundary FIGURE 2-2

Stream LHAAP Water Supply Well SITE LOCATION MAP

LHAAP-32Site

LONGHORN ARMY AMMUNITIKARNACK, TEXAS

ON PLANT

Central Creek

Caddo Lake

Goo

se P

rairi

e C

reek

Har

rison

Bay

ou S

aund

ers B

ranch

LHAAP-47

LHAAP-35A(58)

LHAAP-48LHAAP-04 LHAAP-35B(37)

LHAAP-32

LHAAP-35C(53)LHAAP-50

LHAAP-67LHAAP-29

LHAAP-18/24

LHAAP-17

FILE

PATH

OFFIC

E CH

ECKE

DBY

APPR

OVED

BYDR

AWN

BYP

lotD

ate:

02/0

8 Ho

uston

,TX

02/14

/08B.

Lu

04/20

/05

N.Ol

son

10/26

/07

P.Sr

ivasta

v T:\

GIS\L

ongh

orn\M

XD\ST

0832

4835

C\ROD

\LHAA

P_GW

_SH.m

xd

170

180

210

210 21

0

190

200

180

170

160

170

LHAAP-08

Legend Shallow Groundwater Monitoring Well

Newly Installed Shallow GroundwaterMonitoring Well

180 Approximate Groundwater Elevation Contour

Stream

Road

Building, Known to Exist

Site

Lake

Longhorn Base Boundary

Notes:1. All contours were generated using ArcGIS 8.3

(Spline as interpolation algorithm).2. Groundwater contour elevations reported in feet.3. Groundwater elevation data collected during data

gaps investigation in August -- September, 2004.

0 1,250 2,500 5,000Feet

U.S. ARMY CORPS OF ENGINEERSTULSA DISTRICT

TULSA, OKLAHOMA

FIGURE 2-3

INSTALLATION-WIGROUNDWATER ELEVAT

DEION MAP

(SHALLOW ZONE)LONGHORN ARMY AMMUNITI

KARNACK, TEXAS ON PLANT


3.0 Responsiveness Summary

No comments were received from the regulatory agencies or the general public during the public comment period and Proposed Plan meeting in January 2008. The Proposed Plan was finalized without revision. Appendix A contains the public announcement for the Proposed Plan meeting.



4.0 References

Jacobs Engineering Group (Jacobs), 2001, Final Remedial Investigation Report (Volume 1-3) for the Group 2 Sites: 12, 17, 18/24, 29, and 32, at the LHAAP, Karnack, Texas, April.

Jacobs, 2002, Final Baseline Human Health and Screening Ecological Risk Assessment for the Group 2 Sites, Sites 12, 17, 18/24, 29, 32, and 49, Harrison Bayou and Caddo Lake, LHAAP, Karnack, Texas, August.

Maley, Don, 1988, Potential Hazardous Waste Site Preliminary Assessment, EPA Form 2070-12, April.

Shaw, 2005, Final Site Evaluation Report, LHAAP-32, Former TNT Waste Disposal Plant, Longhorn Army Ammunition Plant, Karnack, Texas, November, Shaw Environmental, Inc.

Shaw, 2007a, Final Data Gaps Investigation Report, Longhorn Army Ammunition Plant, Karnack, Texas, April.

Shaw, 2007b, Installation-Wide Baseline Ecological Risk Assessment, Longhorn Army Ammunition Plant, Karnack, Texas, Volume I: Step 3 Report; Houston, Texas, November.

Texas Commission on Environmental Quality (TCEQ) 1998, Interoffice Memorandum from Ronald R. Pedde to Remediation Division Staff regarding implementation of the existing risk reduction rules (a.k.a. TNRCC Consistency Memorandum), July.

TCEQ, 2004a, Texas Risk Reduction Rules (30TAC§335) as updated through April 2004.

TCEQ, 2004b, Texas Risk Reduction Rules (30TAC§335) as updated through March 2006.

U.S. Army, 2004, Memorandum of Agreement Between the Department of the Army and the Department of the Interior for the Interagency Transfer of Lands at the Longhorn Army Ammunition Plant for the Caddo Lake National Wildlife Refuge, Harrison County, Texas, signed by the Department of the Interior on April 27, 2004 and the Army on April 29, 2004.

U.S. Army, 2008, Final Proposed Plan for LHAAP-32, Former TNT Waste Disposal Plant, Longhorn Army Ammunition Plant, Karnack, Texas.

U.S. Army Environmental Hygiene Agency, (USAEHA), 1987, Final Groundwater Contamination Survey No. 38-26-0851-89, Evaluation of Solid Waste Management Units, Longhorn Army Ammunition Plant, Karnack, Texas, May.

U.S. Environmental Protection Agency (USEPA), 1989, Risk Assessment Guidance for Superfund, Volume I, Human Health Evaluation Manual (Part A), Interim Final, EPA/540/1-89/002, U.S. Environmental Protection Agency, Office of Emergency and Remedial Response, Washington, DC.



USEPA, 1994, National Oil and Hazardous Substances Pollution Contingency Plan, 40 Code of Federal Regulations Part 300, 59 Federal Register 47384, October 10.

USEPA, 2005, Letter to Army Referencing Longhorn Army Ammunition Plant (LHAAP) Final Site Evaluation Report, LHAAP-32, Former TNT Waste Disposal Plant, November.


Final Record of Decision, LHAAP-32 Shaw Environmental, Inc. Glossary of Terms

Glossary of Terms

Administrative Record File – The body of reports, official correspondence, and other documents that establish the official record of the analysis, clean up, and final closure of a site.

ARARs – Applicable or relevant and appropriate requirements. Refers to the federal and state requirements that a selected remedy (a no action decision) will attain.

Background Levels – Naturally-occurring concentrations of inorganic elements (metals) that are present in the environment and have not been altered by human activity.

Characterization – The compilation of all available data about the waste unit to determine the rate and extent of contaminant migration resulting from the waste site, and the concentration of any contaminants that may be present.

Chemicals of Concern (COC) – Those chemicals that significantly contribute to a pathway in an exposure model of a hypothetical receptor (e.g., a child that resides on a site). They exceed either the calculated numerical limit for cumulative site cancer risk (1 in 10,000 exposed individuals) or the calculated numerical limit of 1 for non-cancer effects, a value proposed by the USEPA.

Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) – CERCLA was enacted by Congress in 1980 and was amended by the Superfund Amendments and Reauthorization Act in 1986. CERCLA provides federal authority to respond directly to releases or threatened releases of hazardous substances that may endanger public health or the environment. CERCLA established prohibitions and requirements concerning closed and abandoned hazardous waste sites and established the Superfund Trust Fund.

Exposure – Contact of an organism with a chemical or physical agent. Exposure is quantified as the amount of the agent available at the exchange boundaries of the organism (e.g., skin, lungs, gut) and available for absorption.

Federal Facility Agreement – A legal binding agreement among USEPA, TCEQ, and U.S. Army that sets the standards and schedules for the comprehensive remediation of Longhorn Army Ammunition Plant.

Groundwater – Underground water that fills pores in soil or openings in rocks to the point of saturation.

Human Health Risk Assessment – A study conducted as part of a remedial investigation to determine the risk posed to human health by site-related chemicals.

TERC Contract No.DACA56-94-D-0020 , TO No. 109 Shaw Project No. 845714 1Longhorn Army Ammunition Plant, Karnack, Texas August 2008


National Priorities List (NPL) – The USEPA’s list of the most serious uncontrolled or abandoned hazardous waste sites identified for possible long-term remedial action under Superfund. USEPA is required to update the NPL at least once a year. A site must be on the NPL to receive money from the Trust Fund for remedial action.

Record of Decision – A legal document presenting the remedial action selected for a site or operable unit. It is based on information and technical analyses generated during the remedial investigation/feasibility study and consideration of public comments on the statement of basis/proposed plan and community concerns.

Remedial Investigation – A study designed to gather data needed to determine the nature and extent of contamination at a Superfund site.

Resource Conservation and Recovery Act (RCRA) – Gives USEPA the authority to control the generation, transportation, treatment, storage, and disposal of hazardous waste. RCRA focuses only on active and future facilities and does not address abandoned or historical sites.

Responsiveness Summary – A summary of oral and/or written comments received during the proposed plan comment period and includes responses to these comments. The responsiveness summary is a key part of a ROD highlighting community concerns.

Screening-Level Ecological Risk Assessment – The initial phase of a baseline ecological risk assessment in which conservative concentrations of site chemicals are quantitatively compared to chemical- and media-specific generic effect levels. Those chemicals selected as chemicals of potential ecological concern are further refined through quantitative comparison to chemical- and species-specific effect doses, as well as qualitative examination. Those chemicals identified as chemicals of concern may be investigated further, remediated, or left in place per the decision of the risk managers.

Proposed Plan – A plan for a site cleanup that proposes a recommended or preferred remedial alternative. The Proposed Plan is available to the public for review and comment and the preferred alternative may change based on public and other stakeholder input.

Superfund Amendments and Reauthorization Act (SARA) – Amended CERCLA in 1986. SARA resulted in more emphasis on permanent remedies for cleaning up hazardous waste sites, increased the focus on human health problems posed by hazardous waste sites, and encouraged greater citizen participation in making decisions on how sites should be cleaned up.

Surface Media – The soil (surface or subsurface), surface water, and sediment present at a site as applicable. The source material in the surface media may be contributing to groundwater contamination.



Superfund – The common name used for CERCLA; also referred to as the Trust Fund. The Superfund Program was established to help fund cleanup of hazardous waste sites. It also allows legal action to force those responsible for sites to clean them up.


AAppppeennddiixx AA

PPuubblliicc AAnnnnoouunncceemmeenntt

PUBLIC NOTICE OPEN HOUSE ON TUESDAY, JANUARY 29, 2008

THE UNITED STATES ARMY INVITES PUBLIC COMMENT ON THE PROPOSED PLANS FOR ENVIRONMENTAL SITES LHAAP-08, -32, -48,

and -35C (53), LONGHORN ARMY AMMUNITION PLANT, TEXAS

The U.S. Army, as lead agency for environmental response actions at Longhorn Army Ammunition Plant (LHAAP), in partnership with Texas Commission on Environmental Quality and the U.S. Environmental Protection Agency Region 6, has developed Proposed Plans for the following sites: LHAAP-08, -32, -48, and -35C (53). An open house forum for the public to view information and ask questions will be held on Tuesday, January 29, 2008 from 6:30 to 8:30 p.m. at the Karnack Community Center, Highway 134 and Spur 449, Karnack, Texas. The meeting will be an open house format with no set or formal presentations.

LHAAP-08, a former sewage treatment plant, is located in the central portion of LHAAP and covers an area of approximately 1 acre. LHAAP-08 operated from 1942 to 1997. The plant was modified over time to handle hydraulic capacity of 0.5 million gallons per day. The plant received domestic wastewater through 6-inch and 15-inch pipelines.

LHAAP-32, a former TNT waste disposal plant, is a 9-acre site located in the west-central portion of LHAAP. The TNT waste disposal plant operated from 1942 to 1945. The plant also treated wastewater generated at the nearby TNT production area.

LHAAP-48 is the former igniter production area, otherwise known as the “Y-Area” located in the eastcentral portion of LHAAP. LHAAP-48 covers an area of approximately 16 acres. The “Y-Area” was used for the production of igniters and illumination devices and was active until about 1997.

LHAAP-35C (53) covers an area of approximately 40.3 acres in the east-central portion of LHAAP. Known as the former static test area, LHAAP-35C (53) was used for testing of illumination devices and static test firing of rocket motors. Structures for this site included a test tunnel and a data acquisition system for flares, rocket motor test stands of earth and concrete, and conditioning facilities for reproducing arctic and tropical temperatures. The site was active through 1998.

The Proposed Plans identify the recommendation of No Action Necessary for LHAAP-08, -32, -48, and 35C (53) which is based on the existing data and determination of no unacceptable risk to human health and the environment.

The U.S. Army is soliciting public review and comment on the recommendation of No Action Necessary for LHAAP-08, -32, -48, and -35C (53). Copies of the Proposed Plans and supporting documentation are available for public review at the Marshall Public Library, 300 S. Alamo, Marshall, Texas, 75670.

The U.S. Army encourages the public to participate in the decision-making process by offering comments on the Proposed Plans. Public comment period begins January 13, 2008 and concludes February 14, 2008. The public information forum will be held on Tuesday, January 29, 2008 from 6:30 – 8:30 p.m. at the Karnack Community Center, Highway 134 and Spur 449, Karnack, Texas 75661. Interested parties are invited to attend. For further information, contact: Dr. Rose M. Zeiler, Longhorn Army Ammunition Plant, P.O. Box 220, Ratcliff, Arkansas, 72951; phone number 903-679-3192 or e-mail [email protected].

Documents

RECORD OF DECISION (RODS) - Records Collections · Appendix A Public Announcement . Glossary of Terms _____ Located at the end of this Record of Decision . TERC Contract No.DACA56-94-D-0020