Fort Chaffee, Arkansas · In this document, Fort Chaffee is considered to consist of the geographic...

RECORD OF DECISION FOR THREENO FURTHER ACTION

GROUP IV ENVIRONMENTAL SITES

Fort Chaffee,Arkansas

920699

RECORD OF DECISION FOR THREE NO FURTHER ACTIONGROUP IV ENVIRONMENTAL SITES

FORT CHAFFEE, ARKANSAS

1.0 DECLARATION

This Record of Decision (ROD) document addresses three environmental sites at Fort Chaffee,Arkansas for which the United States Army has been identified as the lead agency forComprehensive Environmental Response, Compensation, and Liability Act (CERCLA) responseactions. The United States Army Fort Chaffee Base Transition Team (FCBTT) is the on-siteorganization responsible for the response actions. The three No Further Action Group IVEnvironmental Sites (Group IV Sites) at some point have been included in lists of sites that havesome potential to require a response under CERCLA. The Proposed Plan of Action forGroup IV Environmental Sites (Fort Chaffee, 2000a) issued for public review on August 23,2000, proposed the three Group IV Sites for no further action and summarized information fromvarious environmental site evaluations that were conducted.

Areas that are to be transferred from the United States Army for reuse are referred to as theExcess Area. The area retained by the United States Army is referred to as the Enclave Area, ofwhich most is licensed to the Arkansas National Guard. The three Group IV Sites beingaddressed by the FCBTT and addressed in this ROD are located in the Excess Area or EnclaveArea as noted below:

Site List - Fort Chaffee Group IV Sites

SiteNumber

FTCH-022

'FTCH-043

FTCH-046

Site Name

Fire Training Pit

East Land Application Area

Oil House Ditches, Excess Area

Excess or Enclave Area

Excess

Enclave

Excess

The three Group IV Sites addressed in this ROD require no further action for protection ofhuman health and the environment and can be transferred without CERCLA land use restrictions.As referred to in this document, Fort Chaffee is considered to consist of the geographic extent ofthe Fort Chaffee Military Reservation at the time it was closed in October 1997 (Figure 1).

The FCBTT encourages the public and other interested parties to review relevant information to-gain -a better understanding -of these environmental -sites. -All -sampling results used for siteevaluations of the current environmental condition at Fort Chaffee are part of the information inthe Administrative Record for Fort Chaffee. The Administrative Record for Fort Chaffeeenvironmental compliance efforts can be viewed at either of the following two locations:

Record of DecisionNo Further Action Group IV Environmental SitesUnited States Army Fort Chaffee Base Transition TeamFort Chaffee, Arkansas

Page 1 of 12 November 1,2000Revision 2

|Fort Chaffee Base Transition Team.Environmental Compliance Office^Building 2033,1st AvenueBarling, Arkansas 72923

" "

•'Fort Smith Public Library

1.1 Site FTCH-022: Fire Training Pit

This site is located at Fort Chaffee, Arkansas as shown in Figure 2.

1.1.1 Statement of Basis and Purpose

This decision document presents the selected remedial action for the site listed above. Theselected remedy was chosen in accordance with CERCLA, as amended by the SuperfundAmendment and Reauthorization Act (SARA), United States Army Regulation 200-1, and to theextent practicable, the National Contingency Plan. This decision is based on the AdministrativeRecord for this site.

1.1.2 Description of the Selected Remedy

No further action will be taken at this site. Selection of this remedy is based on knowledge ofsite history and site operation. Evaluation of current site conditions including surface soilsampling, subsurface soil sampling, and groundwater sampling supports the selected remedy ofno further action.

J.I.3 Declaration Statement

No further remedial response action is required to ensure protection of human health and theenvironment, and no CERCLA-related restriction on land uses is required.

1.2 Site FTCH-043: East Land Application Area

This site is located at Fort Chaffee, Arkansas and is shown in Figure 2.


This decision document presents the selected remedial action for the site listed above. Theselected remedy was chosen in accordance with CERCLA, as amended by SARA, United StatesArmy Regulation 200-1, and to the extent practicable, the National Contingency Plan. Thisdecision is based on the Administrative Record for this site.

Record of DecisionNo Further Action Group IV Environmental SitesUnited Slates Army Port Chaffee Base Transition TeamFort Chaffee, Arkansas

Pase2of 12 November 1.2000Revision 2


No further action will be taken at this site. Selection of this remedy is based on knowledge ofsite history and site operation. Evaluation of current site conditions including surface soilsampling, subsurface soil sampling, and groundwater sampling supports the selected remedy ofno further action.

1.2.3 Declaration Statement

No further remedial response action is required to ensure protection of human health and theenvironment, and no CERCLA-related restriction on land uses is required.

1.3 Site FTCH-046: Oil House Ditches, Excess Area

This site is located at Fort Chaffee, Arkansas as shown in Figure 2.


This decision document presents the selected remedial action for the site listed above. Theselected remedy was chosen in accordance with CERCLA, as amended by SARA, United StatesArmy Regulation 200-1, and to the extent practicable, the National Contingency Plan. Thisdecision is based on the Administrative Record for this site.


No further action will be taken at this site. Selection of this remedy is based on knowledge ofsite history and site operation. Evaluation of current site conditions including surface soilsampling supports the selected remedy of no further action.

1.3.3 Declaration Statement.'

/'No* further remedial response action is required to ensure protection of human health and theenvironment, and no CERCLA-related restriction on land use is required.

barren L. JohnsonSite ManagerUnited States Army Fort Chaffee Base Transition TeamFort Chaffee, Arkansas

Date


Page 3 of 1 2 November 1 , 2000Revision 2

2.0 DECISION SUMMARY

This decision document addresses three environmental sites (Group IV Sites) at Fort Chaffee,Arkansas for which the United States Army has been identified as the lead agency forComprehensive Environmental Response, Compensation, and Liability Act (CERCLA) responseactions. The United States Army Fort Chaffee Base Transition Team (FCBTT) is the on-siteorganization responsible for these actions. The three Group IV Sites have at some point beenincluded in lists of sites at Fort Chaffee that have some potential to require a response underCERCLA. The three sites required no further action for protection of human health and theenvironment. All sampling results and referenced documents used to characterize the three sitesin Section 2.0 are found in the Administrative Record for Fort Chaffee located at the Fort SmithPublic Library and the FCBTT-Environmental Compliance Office.

In this document, Fort Chaffee is considered to consist of the geographic extent of theFort Chaffee Military Reservation at the time of closure. As part of the Base Realignment andClosure (BRAC) process, Fort Chaffee was closed in October 1997. Fort Chaffee, Arkansas isapproximately seven miles east-southeast of Fort Smith, Arkansas. The military reservationconsisted of over 71,000 acres. Most of the land became part of the Fort Chaffee ManeuverTraining Center operated by the Arkansas Army National Guard for reserve component training.The area retained by the United States Army is referred to as the Enclave Area, of which most islicensed to the Arkansas National Guard. The remaining 7,000 acres, or Excess Area, will bedisposed by the United States Army and is available for community reuse. Figures 1 and 2 showthe location of the sites discussed in this decision document. The proposed future use of thesites, the human health screening/cleanup levels achieved through the environmental restorationprogram, and the previous uses by the military are presented in Table 1. The ecological status ofthe sites is summarized in Table 2.

2.1 Site FTCH-022: Fire Training Pit

2.1.1 Site Location and Description

' Site FTCH-022 is located south of Custer Boulevard in the Excess Area (Figure 2). The siteconsisted of a shallow open pit that was dug into clayey soils and shale and measuredapproximately 100 feet by 50 feet and 2-feet deep. Although historically the land use for SiteFTCH-022 has been industrial, the planned future use for the land is residential.

2.1.2 Site History and Enforcement Activities

The pit was used for fire training exercises from 1980 to 1990. Water-contaminated fuels, usedoils, and solvents were poured into the pit before each training exercise, ignited, thenextinguished. The water and fire suppression chemicals were left in the pit to evaporate or seepinto the soil.

In 1990, an organic vapor analyzer was used as a field-screening device to delineate the extent ofobvious soil contamination. This soil (estimated at 200 to 400 cubic yards) was then removed aspart of a source removal action from the pit and taken to the West Land Application Site forRecord of Decision Page 4 of 12 November 1, 2000No Further Action Group IV Environmental Sites Revision 2United States Army Fort Chaffee Base Transition TeamFort Chaffee, Arkansas

landfarming. The pit was then backfilled. The site was inspected in 1995 as part of anenvironmental baseline survey. At that time grasses covered the site and no environmentalconcerns were noted. Groundwater samples collected from monitoring wells in April 1988 andagain in January 1995 did not detect any constituents at concentrations to indicate that groundwater had been impacted from site activities.

2.1.3 Site Characteristics

In December 1997, surface soil samples were collected in the pit area, at a former abovegroundstorage tank area, and at locations outside the pit. Subsurface soil samples were also takenwithin the pit, downgradient of the pit, and along a former buried fuel line. Samples wereanalyzed for volatile organic compounds (VOCs), semivolatile organic compounds (SVOCs),organochlorine pesticides, polychlorinated biphenyls (PCBs), and inorganics (metals). Theprocedures and results of this investigation were presented in a report entitled RemedialInvestigation Report, Fire Training Pit, Site FTCH-022 (Fort Chaffee, 2000b).

With the exception of low concentrations of methylene chloride and di-n-butylphthalate, noVOCs, SVOCs, or PCBs were detected in the surface soils. The presence of methylene chloride(VOC) and di-n-butylphthalate (SVOC) are attributed to laboratory contamination and not site-related. Although not site related, two pesticides were detected at low concentrations, wellbelow the residential soil screening levels. The concentrations of all organic constituents werebelow Environmental Protection Agency (EPA) soil screening levels for residential use. Metalconcentrations detected in surface soils were consistent with background with the exception ofcadmium. However, cadmium was detected at concentrations less than the residential medium-specific screening level.

Similarly, no organic contaminants of potential concern were reported above soil screeninglevels for residential use in the subsurface soil samples. No SVOCs or PCBs were detected insubsurface soils. Low concentrations of VOCs (acetone, benzene, methylene chloride, andtoluene) detected in subsurface soils were significantly less than the residential soil screeningJevels. Although not site related, pesticides were present in one subsurface soil sample from a

vdepth of 4 feet and were at concentrations significantly below the residential soil screeninglevels. Metal concentrations detected in subsurface soils were consistent with background withthe exception of cadmium. However, cadmium was detected at concentrations less than theresidential medium-specific screening level.

Groundwater samples were tested in December 1997 and October 1998 for the same parametersas soils. Low concentrations of VOCs (acetone, methylene chloride, tetrachloroethene andtoluene) in ground water were either slightly above detection limits (acetone, tetrachloroethene,and toluene) or attributed to laboratory contamination (methylene chloride).

The only SVOCs detected in grounSwater samples were di-n^utyl phthalate and phenol forwhich there are no maximum contaminant levels (MCLs) established, and bis (2-ethylhexyl)phthalate which is a common laboratory contaminant. The isolated occurrence of these organicconstituents and their presence in low concentrations, slightly above detection limits, does notindicate a release.

Record of Decision Page 5 of 12 November 1, 2000No Further Action Group IV Environmental Sites Revision 2United States Army Fort ChafTee Base Transition TeamFort Chaffee, Arkansas

Detected concentrations of metals in the ground water are considered to be caused by suspendedparticulates in the ground water that are naturally occurring and are not indicative of a release toground water. In addition, the upgradient monitoring wells, MW02 and MW04, both hadelevated-metals with no known upgradient source for the elevated metals.

In summary, based on the evaluation of the analytical results, there is no contamination insurface soils. This finding is consistent with the fact that the majority of surface soils wereidentified as backfill placed during the 1990 source removal activities. The subsurface soilanalytical results indicate some residual VOCs were detected in subsurface soils near the formerpit location. However, the surface soil, subsurface soil, and groundwater analytical datacollected in 1997 and 1998 indicate that the source removal action performed in 1990 wassuccessful and eliminated exposure pathways, although minor residual concentrations of VOCswere detected in subsurface soils. No further action is recommended for Site FTCH-022.

2.1.4 Summary of Site Risks

Source removal has eliminated the surface exposure pathway and minimized the potential forcontinued impact to ground water. The analytical results of samples obtained from the originalsoils remaining after source removal indicate that residual concentrations are less than residentialscreening levels and protective of human health.

This site can be considered ecologically irrelevant because residual contamination in subsurfacesoils is at low concentrations and is considered negligible to ecological receptors (Table 2). Thesite does not pose an unacceptable risk to human health or the environment and no CERCLA-related restrictions on land use are required. No further action is recommended.

2.2 Site FTCH-043: East Land Application Area


Jhe 5.3-acre area referred to as the East Land Application Area (FTCH-043), located east of 1st

'Avenue and north of Fort Smith Boulevard, was used to treat petroleum-impacted soils bylandfarming (Figure 2). The historical and planned future land use for Site FTCH-043 isindustrial and the land will remain as Enclave.


The landfarmed soil originated from underground storage tank (UST) excavations at FortChaffee. The site is part of the Enclave Area of Fort Chaffee that was retained by the UnitedStates Army. Most of the Enclave Area was licensed to the Arkansas National Guard.


In 1997, a remedial investigation was conducted at FTCH-043. This investigation included theanalysis of 24 surface soil samples (0.0- to 0.5-feet below ground surface [bgs]), five subsurfacesoil samples (greater than 0.5-feet bgs), and groundwater samples collected from five monitoringwells. An additional surface soil and three groundwater samples were collected in 1999.Record of Decision Page 6 of 12 November 1, 2000No Further Action Group IV Environmental Sites Revision 2United States Army Fort Chaffee Base Transition TeamFort Chaffee, Arkansas

Samples were analyzed for VOCs, SVOCs, and 25 metals. The procedures and results of thisinvestigation were presented in a report entitled Remedial Investigation Report, East LandApplication Area, Site FTCH-043 (Fort Chaffee, 2000c).

Metal concentrations in surface soils were consistent with background concentrations, except forcadmium, lead, molybdenum, and zinc which were detected at levels exceeding backgroundconcentrations, but were less than the residential medium specific screening levels (MSSLs)(USEPA, 1999). No VOCs were detected. Polynuclear aromatic hydrocarbons (PAHs) weredetected in two of 24 surface soils samples collected during 1997. Industrial MSSLs wereexceeded in one of the two surface soil samples. During 1999, an additional sample wascollected adjacent to the original sampling point identified with elevated PAH concentrations.This additional sampling effort was performed to determine if the PAH exceedances were anindication of significant area contamination or an isolated incident. The additional work wasscoped by the Base Realignment and Closure (BRAC) Cleanup Team (BCT) during a meetingheld on July 21, 1999. The BCT is comprised of representatives from the Fort Chaffee BaseTransition Team, Arkansas Department of Environmental Quality, and U.S. EPA Region 6. NoPAHs were detected in the additional surface sample collected during 1999. Therefore, thedetection of PAHs in 1997 may be an isolated presence of PAH-containing material fromanthropogenic sources such as landfarmed UST excavation debris.

SVOCs and VOCs were not detected in the subsurface soil samples. Metals in the subsurfacesoil samples were consistent with background concentrations.

No VOCs were detected in the groundwater samples. Metals detected during the 1997 samplingwere found to be within levels observed as naturally occurring at Fort Chaffee. Two SVOCs (di-n-butylphthalate and phenol) were detected in one upgradient monitoring well in 1997. Groundwater was subsequently obtained in 1999 from downgradient wells and analyzed for SVOCs. NoSVOCs were detected. Analytical data from both groundwater-sampling events indicate that nosite-related release of inorganic or organic constituents to the ground water has occurred.


Analytical results for metals in subsurface soils and ground water at this site are within the rangeof expected background concentrations and are considered to be naturally occurring. There is noindication that a release to subsurface soils or ground water from site-related activities hasoccurred at this site.

Metals were detected in surface soils that exceeded background, but were less than residentialMSSLs. The metals concentrations in surface soils do not pose an unacceptable risk to human orecological receptors.

This site is ecologically irrelevant ^because oT the low contaminant concentrations, limitedpathway, and minimal potential for transport. In addition, the detection of low-level PAHs insurface soils is isolated and is considered negligible to ecological and human receptors. This sitepresents no unacceptable risk to human health or the environment and no CERCLA-relatedrestrictions on land use are required. No further action is recommended.

Record of Decision Page 7 of 12 November 1,2000No Further Action Group IV Environmental Sites Revision 2United States Army Fort Chaffee Base Transition TeamFort Chaffee, Arkansas

2.3 Site FTCH-046: Oil House Ditches, Excess Area


This site consists of ditches associated with 31 oil houses located in the Excess Area upgradientof Grayson Creek and the vehicle wash rack areas (FTCH-017) (Figure 2). The oil houses aregrouped in six east-west trending rows, each consisting of two to six oil houses, with theexception of one outlying oil house in the southernmost part of the Excess Area. Unused oil andother forms of hydrocarbons were stored in drums and other containers in the oil houses. Eachoil house is a small structure (typically 14 feet by 16 feet) associated with an adjacent vehiclemaintenance shop. Inside the oil house was a concrete floor with a grate-covered sump used tocollect and contain spills. If the sump capacity was exceeded, the material would overflow viaan overflow pipe into nearby drainage ditches. The site is part of the Excess Area of FortChaffee that will be disposed of by the United States Army and will be available for communityreuse. The historical land use was industrial and the planned future land use is light business,industrial, commercial, and retail.


Prior to 1999, no investigations have been performed at these oil houses or associated ditches inthe Excess Area and there are no records of releases to the environment. However, the oil houseditches in the nearby Enclave Area have been investigated and incorporated into the Record ofDecision for No Further Action Group II Sites (Fort Chaffee, 1999). The investigation of SiteFTCH-046 in 1999 (Fort Chaffee, 2000d), was intended to identify a release to surface soil fromthe oil house ditches in the Excess Area, upgradient of Grayson Creek and the wash rack area.


Investigation activities included sampling and analysis of 13 surface soil samples. Samples wereanalyzed for VOCs, SVOCs, and 25 metals (inorganics). The procedures and results of thisinvestigation were presented in a report entitled Site Investigation Report, Oil House Ditches,Excess Area, Site FTCH-046 (Fort Chaffee, 2000d).

The only VOCs detected were acetone and toluene. However, the low concentrations of acetoneand toluene detected are attributed to laboratory contamination and not a site-related release.

Detected metal concentrations were consistent with background concentrations with theexceptions of barium, cadmium, copper, lead, silver, and zinc. The metals detected in surfacesoil above background may be the result of anthropogenic sources such as metal siding(cadmium, copper, and zinc) or paints (barium, cadmium, lead, and zinc) but may also be a site-related release. Nevertheless, the detected concentrations of metals in surface soil are notexpected to "have an ecological impact and are well below the residential MSSLs protective ofhuman health.

Several SVOCs were detected in one or more surface soil samples but were less than theresidential MSSLs with one exception. The residential MSSL, a conservative screening level

Record of Decision Page 8 of 12 November 1,2000No Further Action Group IV Environmental Sites Revision 2United States Army Fort Chaffee Base Transition TeamFort Chaffee, Arkansas

biased to be the most protective of human health, was exceeded in one sample for benzo(a)pyrene. However, benzo(a)pyrene was detected in only one of thirteen surface soil samples,and was at a concentration below the industrial MSSL. The SVOCs detected in surface soilsmay be associated with anthropogenic sources such as asphalt runoff but may also be a site-related release. Nevertheless, the detected SVOC concentrations in surface soil are not expectedto have an ecological impact and are at levels considered protective of human health.


This site is considered an ecologically irrelevant site, presents no unacceptable risk to humanhealth or the environment, and no CERCLA-related restrictions on land use are required. Nofurther action is recommended.

3.0 COMMUNITY PARTICIPATION

The Proposed Plan for the three sites in this ROD was summarized in a public notice publishedin local newspapers as noted below. The notice also announced the availability of the ProposedPlan of Action for Group IV Environmental Sites for three sites, the location of supportingdocuments and the public open house held on August 30, 2000. All three of these sites areaddressed in this Record of Decision (ROD) for no further action. The proposed plan has alsobeen presented to and discussed with the Fort Chaffee Restoration Advisory Board (RAB). Thepublic forum included informational displays and afforded an opportunity for interestedstakeholders to ask questions and/or comment to United States Army personnel. The publiccomment period ended on September 21, 2000. No written or verbal comments concerning theProposed Plan have been received.

NewspaperArkansas Democrat

Gazette

Charleston Express

Little River NewsSouthwest Times

Record

LocationLittle Rock, AR

Charleston, AR

Ashdown, ARFort Smith, AR

Publication DatesAugust 23, 2000August 27, 2000August 30, 2000August 16, 2000August 23, 2000August 30, 2000August 24, 2000August 23, 2000August 27, 2000August 30, 2000

Record of Decision Page 9 of 12 November 1, 2000No Further Action Group IV Environmental Sites Revision 2United States Army Fort Chaffee Base Transition TeamFort Chaffee, Arkansas

4.0 SCOPE AND ROLE OF RESPONSE ACTION

This document is the fifth in a series of decision documents for Fort Chaffee that document thecompletion of required CERCLA response activities for the installation. The United StatesArmy (lead agency), in cooperation with other members of the BRAC Cleanup Team, hascooperatively developed a plan to periodically document attainment of all requirements for thesites at Fort Chaffee. This decision document will record in the administrative record,concurrence between the lead and support agencies that CERCLA response actions, required bythe United States Army relative to Fort Chaffee, have been completed for the included sites.

5.0 EXPLANATION OF SIGNIFICANT CHANGES

The decisions presented in this document do not differ significantly from those presented in theProposed Plan of Action for Group IV Environmental Sites issued for public review August 23,2000.

6.0 RESPONSIVENESS SUMMARY

No verbal or written comments concerning the proposed decision were received during thepublic comment period.

7.0 REFERENCES

Fort Chaffee, 1999. Record of Decision for No Further Action Group II Sites, Fort Chaffee,Arkansas,

USEPA, 1999. Region 6 Human Health Medium-Specific Screening Levels (MSSLs). June4999.

Fort Chaffee, 2000a. Proposed Plan of Action for Group IV Environmental Sites. Revision 2,August 23, 2000.

Fort Chaffee, 2000b. Remedial Investigation Report, Fire Training Pit, Site FTCH-022, FortChaffee, Arkansas. Revision 1, May 2000.

Fort Chaffee, 2000c. Remedial Investigation Report, East Land Application Area, Site FTCH-043, Fort Chaffee, Arkansas. February 2000.

Fort Chaffee, 2000d. Site Investigation Report, Oil House Ditches, Excess Area, SiteFTCH-046, Fort Chaffee, Arkansas. January 2000.

Record of Decision Page 10 of 12 November 1, 2000No Further Action Group IV Environmental Sites Revision 2United States Army Fort Chaffee Base Transition TeamFort Chaffee, Arkansas

Table 1Land Use Summary

Site

FTCH-022FTCH-043FTCH-046

Description

Fire Training Pit. East Land Application Area

Oil House Ditches, Excess Area

Proposed Use

ResidentialEnclave

Light Business/IndustrialCommercial/Retail

Human HealthScreening/Cleanup

LevelResidentialResidentialResidential8

HistoricalUse

IndustrialIndustrialIndustrial

Single occurrende of benzo (a) pyrene exceeded the residential screening level but was less than the industrial screening level



Table 2Ecological Risk Summary

Site

FTCH-022

FTCH-043

FTCH-046

RemedialStatus

Rla

Rl

Slb

EcologicalStatus

EcologicallyIrrelevant



Decision

NFAC, NLURa

NFA, NLUR

NFA, NLUR

Comments

Removal of impacted soils and placement of clean backfill in excess of two feeteliminates the surface exposure pathway and minimizes the continued impact toground water. Residual contamination in subsurface soils is at low concentrationsand is considered negligible to ecological receptors.The limited occurrence of metals exceeding background and PAHs in surface soilminimizes the exposure potential. The impact of metals and low level PAHs areconsidered negligible to ecological receptors.Although both PAHs and metals were detected, neither can be attributedexclusively to site activities and are believed to be related to asphalt runoff, metalsiding, and painted surfaces. Nonetheless, because of limited occurrences andlow levels, the potential impact to ecological receptors is considered negligible.

a Remedial Investigationb Site Investigation0 No Further Actiond No Land Use Restriction



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