Site Name: FORT LEWIS LOGISTICS CENTER

EPA ID: WA7210090067 EPA Region: 10 Metro Statistical Area: 8200

T19N R2E SECS 21,22,26,27, FORT LEWIS, WA 98433-5000

Operable Unit: 02

ROD ID: EPA/ROD/R10-93/072 ROD Date: 09/24/93

Contaminant: VOCs; Other Organics

Keys: Carbon Adsorption (GAC); Carcinogenic Compounds; Chromium; Direct Contact; Excavation; Filling; Ground Water; Ground Water Monitoring; Ground Water Treatment; Institutional Controls; Lead; MCLGs; MCLs; Metals; O&M; Offsite Disposal; Onsite Containment; Onsite Discharge; Onsite Disposal; Onsite Treatment; Organics; PAHs; PCE; RCRA; Safe Drinking Water Act; Soil; Soil Washing/Flushing; Solvents; State Standards/ Regulations; TCE; Toluene; Treatability Studies; Treatment Technology; Vacuum Extraction; VOCs; Wetlands.

Abstract:

The Fort Lewis Logistic Center site is part of a 650-acre military storage and maintenance facility in Pierce County, Washington. Land use in the area is mixed residential, military, and recreational. The site overlies a surficial aquifer and a deeper, bedrock aquifer that is used as a water supply and contains several lakes, a creek, a marsh, and a small, forested wetland. The Fort's primary water sources, Sequalitchew Springs and Sullivan Well, are located within a 1,800 foot-radius of the Fort's landfill. Two sites within a common area of the Fort, Landfill 4(LF4) and the Solvent Refined Coal Pilot Plant (SRCPP), have been contaminated by site operations, which primarily consisted of equipment repair and maintenance. LF4 occupies approximately 52 acres in the northern part of the Fort and was developed in 1951 by placing refuse in two gravel pits. Land filling was expanded to the south and west until 1967, when the landfill was closed and covered with gravel. Although no landfill records exist, the waste materials likely consisted of domestic and light industrial solid waste. In 1988, a site investigation indicated that shallow ground water around the landfill was contaminated with chlorinated hydrocarbons, primarily TCE, and that treated water from Sequalitchew Springs and the Sullivan Well contained several VOCs. The SRCPP occupies approximately 25 acres between Sequalitchew Lake and Hamer Marsh and primarily is covered with a gravel or asphalt surface. From 1974 to 1981, the SRCPP operated as a production/research facility designed to develop a solvent extraction technology for deriving petroleum, hydrocarbon-like products from coal. The facility converted coal into a low-sulfur, low-ash solid product (SRC-I) by the solvent refined coal process. The process was later modified to distill the volatile fractions and produce liquid fuel products (SRC-II). Incoming coal was stored in uncovered piles, as were solid products awaiting shipment and sulfur. End products of the SRC-II process included light oil, wash solvents, recycled solvents, and solid, as well as byproduct solid, liquid, and gaseous waste. Liquid waste was directed to an onsite wastewater treatment plant or disposed of offsite through a system of subsurface drain lines that were later shown to be leaking, and solids reportedly were disposed of offsite. Treated wastewater was discharged to the wastewater lagoon, and overflow from the lagoon entered the adjacent Hamer marsh. Contaminants in the solid and liquid waste included PAHs, VOCs, SVOCs, and oils, and surface water runoff from onsite storm sewers contained PAHs, phenols, metals, coals, and other contaminants. In 1979, a 2,000gallon spill of liquid fuel from the SRCPP resulted in soil and ground water investigations. In 1980, a large volume of soil was removed from the spill area and, reportedly, a ground water extraction and treatment system was implemented to remediate the underlying aquifer. In 1982, sludge in the wastewater lagoon was excavated as part of facility decommissioning. The spill and decommissioning led to monitoring and investigations, conducted in 1991, which showed that soil and ground water had been contaminated by site activities and previous waste handling practices. A 1990 ROD addressed contaminated ground water in the surficial aquifer beneath the entire Fort and provided for further investigation of contaminants in the soil and deeper aquifer. This ROD addresses contaminated soil and deep, ground water at the LF4 and the SRCPP sites. The primary contaminants of concern affecting the soil and ground water are VOCs, including TCE and vinyl chloride; and other organics, including PAHs.

SELECTED REMEDIAL ACTION: The selected remedial action for this site includes installing and operating a network of vapor extraction wells along with an air sparging system to strip the contaminants from both soil and ground water at the LF4; using carbon adsorption to control air emissions; disposing of spent carbon at an offsite disposal or recycling facility; reinjecting treated water onsite; excavating and treating soil from the former process area at the SRCPP onsite using soil washing or thermal desorption; disposing of treated residuals at an offsite facility, if thermal desorption is used; backfilling the excavated areas with treated soil; allowing contaminant concentrations to naturally attenuate over a fifty-year period; monitoring ground water; and implementing institutional controls, including land use restrictions. The estimated present worth cost for this remedial action is $7,117,000.

PERFORMANCE STANDARDS OR GOALS: Chemical-specific soil cleanup goals for the SRCPP are based on MTCA Method B, and include PAHs 1 mg/kg. Chemical- specific ground water cleanup goals for the LF4 are based on MTCA Method B and SDWA MCLs and MCLGs, and include TCE 5 ug/l and vinyl chloride 1 ug/l. Chemical-specific soil and ground water cleanup goals for the LF4 and the SRCPP, respectively, were not provided. INSTITUTIONAL CONTROLS: Institutional controls, including land use restrictions, will be implemented to protect human health and the environment during the remedial activities.

Remedy:

The selected remedy for LF4 includes treatment of suspected sources of groundwater contamination, treatment of contaminated groundwater, groundwater monitoring, and implementation of institutional controls to protect human health and the environment during remedial action. Major components of the LF4 selected remedy include:

* Installing an active soil vapor extraction system (VES) in suspected groundwater contamination source areas. Vapors from the system will be treated in compliance with air quality regulations prior to discharge.

* Installing an in situ groundwater sparging system to remove volatile contaminants from groundwater. The sparging system will work in conjunction with the VES.

* Monitoring upper aquifer groundwater to determine the effectiveness of the selected remedy. As part of the monitoring program, the localized area of elevated manganese along the western borders of South and Northwest LF4 will be monitored to determine any changes in manganese concentrations. If the monitoring indicates that manganese concentrations are not declining, the need for remediation of the localized area will then be reevaluated. This reevaluation may include supplemental sampling, or additional source characterization.

* Maintaining institutional controls restricting access to and development at the site as long as hazardous substances remain onsite at levels that preclude unrestricted use.

The selected remedy for the SRCPP includes excavation and treatment of contaminated soils, groundwater monitoring, and institutional controls to protect human health and the environment during remedial action. Major components of the SRCPP selected remedy include:

* Excavating and treating contaminated soils. Soils will be treated using either soil washing or low temperature desorption to met cleanup levels.

* Monitoring upper aquifer groundwater beneath and adjacent to the site to determine the effectiveness of the selected remedy.

* Maintaining institutional controls restricting access to and development at the site as long as hazardous substances remain onsite at levels that preclude unrestricted use.

ASSESSMENT OF THE SITES

Actual or threatened releases of hazardous substances from these sites, if not addressed by implementing the response actions selected in this Record of Decision, may present an imminent and substantial endangerment to public health, welfare, or the environment.

STATUTORY DETERMINATIONS

The selected remedies are protective of human health and the environment, comply with Federal and State requirements that are legally applicable or relevant and appropriate to the remedial actions, and are cost effective. The remedies utilize permanent solutions and alternative treatment technologies to the maximum extent practicable, and satisfy the statutory preference for remedies that employ treatment that reduces contaminant toxicity, mobility, and volume as a principal element.

A review will be performed not less often than every five years after initiation of the final response actions, as long as hazardous substances remain onsite at levels that preclude unrestricted use.

Operable Unit:

ROD ID: EPA/ROD/R10-90/025 ROD Date: 09/25/90

Contaminant: VOCS; PCE; TCE; DCE

Keys: AIR STRIPPING; CARCINOGENIC COMPOUNDS; CLEAN WATER ACT; DIRECT CONTACT; DRINKING WATER CONTAMINANTS; GROUND WATER; GROUND WATER MONITORING; GROUND WATER TREATMENT; INSTITUTIONAL CONTROLS; MCLS; O&M; ONSITE DISCHARGE; ONSITE TREATMENT; PCE; RCRA; SAFE DRINKING WATER ACT; SOLVENTS; STATE STANDARDS/REGULATIONS; TCE; TREATABILITY STUDIES; VOCS

Abstract:

THE 650-ACRE FORT LEWIS LOGISTICS CENTER SITE IS A MILITARY STORAGE AND MAINTENANCE FACILITY IN PIERCE COUNTY, WASHINGTON. SURROUNDING LAND USE IS MIXED RESIDENTIAL AND COMMERCIAL. THE SITE OVERLIES A SURFICIAL AQUIFER, AND A DEEPER BEDROCK AQUIFER THAT IS USED AS A WATER SUPPLY TO OVER 85,000 PEOPLE IN THE AREA. THE LOGISTICS CENTER IS AN INDUSTRIAL COMPLEX, WHICH INCLUDES WAREHOUSES, MOTOR POOLS, MAINTENANCE FACILITIES, AND AN EQUIPMENT DISPOSAL YARD. FROM THE 1940S TO THE MID 1970S, SOLVENTS INCLUDING TCE AND PCE WERE USED AS DEGREASERS DURING MAINTENANCE ACTIVITIES. THE SOLVENTS WERE FREQUENTLY COMBINED WITH WASTE OIL AND DISPOSED OF AT SEVERAL LOCATIONS WITHIN THE LOGISTICS CENTER. SITE INVESTIGATIONS FROM 1985 TO 1988 DETECTED VOC CONTAMINATION IN ONSITE MONITORING WELLS AND OFFSITE PRIVATE WELLS. AS A RESULT OF THESE FINDINGS, AFFECTED RESIDENTS WERE CONNECTED TO A PUBLIC WATER SUPPLY. THIS RECORD OF DECISION (ROD) ADDRESSES RESTORATION OF THE CONTAMINATED SURFICIAL GROUND WATER AQUIFER, AND PROVIDES A FINAL REMEDY FOR THE SITE. CONFIRMATION SOIL SAMPLING AND FURTHER CHARACTERIZATION OF THE DEEP AQUIFER CONTAMINATION WILL BE EVALUATED AS PART OF THIS REMEDIAL ACTION. THE PRIMARY CONTAMINANTS OF CONCERN AFFECTING THE GROUND WATER ARE VOCS INCLUDING PCE, TCE, AND DCE.

THE SELECTED REMEDIAL ACTION FOR THIS SITE INCLUDES:

* PUMPING AND ONSITE TREATMENT OF GROUND WATER USING AIR STRIPPING TO REMOVE VOCS;

* DISCHARGING THE TREATED WATER ONSITE TO INFILTRATION TRENCHES, INCLUDING ONE TRENCH LOCATED UPGRADIENT TO FACILITATE FLUSHING OF SECONDARY CONTAMINANT SOURCES;

* LONG-TERM MONITORING OF GROUND WATER;

* CONDUCTING CONFIRMATION SOIL SAMPLING;

* INVESTIGATING THE DEEP AQUIFER CONTAMINATION FOR POSSIBLE REMEDIATION;

* AND IMPLEMENTING INSTITUTIONAL CONTROLS.

THE ESTIMATED PRESENT WORTH COST FOR THIS REMEDIAL ACTION IS $9,068,000, WHICH INCLUDES AN ANNUAL O&M COST (EXCLUSIVE OF MAINTENANCE) OF $517,000 FOR 30 YEARS.

PERFORMANCE STANDARDS OR GOALS; GROUND WATER CLEANUP STANDARDS ARE BASED ON FEDERAL MCLS AND INCLUDE PCE 5 UG/L TCE 5 UG/L, AND DCE 70 UG/L. INSTITUTIONAL CONTROLS; INSTITUTIONAL CONTROLS WILL BE IMPLEMENTED ONSITE AND IN DOWNGRADIENT OFFSITE AREAS AFFECTED BY THE CONTAMINANT PLUME.

Remedy:

THE SELECTED REMEDY FOR THE LOGISTICS CENTER OPERABLE UNIT ADDRESSES THE PRINCIPAL TREATING THE GROUNDWATER AND BY FLUSHING SECONDARY SOURCE RESIDUAL CONTAMINATION. THE REMEDY IS DESIGNED TO REDUCE EXPOSURE TO THE CONTAMINATED GROUNDWATER AND TO REMEDIATE THE GROUNDWATER TO LEVELS THAT ARE PROTECTIVE OF HUMAN HEALTH AND THE ENVIRONMENT.

THE MAJOR COMPONENTS OF THE SELECTED REMEDY INCLUDED:

* INSTALL GROUNDWATER EXTRACTION WELLS CAPABLE OF CAPTURING THE GROUNDWATER CONTAMINANT PLUME IN THE UNCONFINED AQUIFER.

* INSTALL ON-SITE GROUNDWATER TREATMENT FACILITIES TO REMOVE CONTAMINANTS FROM THE COLLECTED GROUNDWATER.

* TO EXPEDITE GROUNDWATER REMEDIATION, INSTALL GROUNDWATER EXTRACTION WELLS NEAR AREAS OF HIGHEST CONCENTRATION OF CONTAMINATION AND DISCHARGE TREATED GROUNDWATER UPGRADIENT OF THESE EXTRACTION WELLS TO FACILITATE FLUSHING SECONDARY SOURCES FROM THE GROUNDWATER.

* MONITOR THE GROUNDWATER CONTAMINANT PLUME AND THE EXTRACTION/TREATMENT SYSTEM DURING GROUNDWATER REMEDIATION ACTIVITIES TO ENSURE THAT BOTH GROUNDWATER AND SURFACE WATER REMEDIATION GOALS ARE ACHIEVED.

* IMPLEMENT ADMINISTRATIVE AND INSTITUTIONAL CONTROLS THAT SUPPLEMENT ENGINEERING CONTROLS AND MINIMIZE EXPOSURE TO RELEASES OF HAZARDOUS SUBSTANCES DURING REMEDIATION.

* INVESTIGATE THE LOWER AQUIFER(S) TO DETERMINE THE PRESENCE OF CONTAMINATION AND TO EVALUATE THE EXTENT OF CONTAMINATION, IF NECESSARY. IF CONTAMINATION IS FOUND, A GROUNDWATER EXTRACTION SYSTEM WILL BY INSTALLED WHICH IS CAPABLE OF CAPTURING THE CONTAMINANT PLUME WITH SUBSEQUENT TREATMENT OF THE EXTRACTED GROUNDWATER IN THE ON-SITE TREATMENT FACILITY. THE REMEDIATION GOALS SPECIFIED FOR THE UNCONFINED AQUIFER WILL ALSO APPLY TO ANY CONTAMINATED LOWER AQUIFERS.

* PERFORM CONFIRMATION SOIL SAMPLING TO ENSURE THAT ALL REMAINING SOURCES OF SOIL CONTAMINATION HAVE BEEN IDENTIFIED AND CHARACTERIZED.