Site Name: FAIRCHILD AIR FORCE BASE (4 WASTE AREAS)

EPA ID: WA9571924647 EPA Region: 10 Metro Statistical Area: 7840

US HWY 2 W OF SPOKANE, SPOKANE, WA 99011

Operable Unit: 02

ROD ID: EPA/ROD/R10-93/068 ROD Date: 07/14/93

Contaminant: VOCs, Other Organics, Metals

Keys: Alternate Water Supply; Benzene; Biodegradation/ Land Application; Carbon Adsorption (GAC); Carcinogenic Compounds; Chromium; Clean Air Act; Clean Water Act; Direct Contact; Drinking Water Contaminants; Excavation; Floodplain; Ground Water; Ground Water Monitoring; Ground Water Treatment; Institutional Controls; Lead; MCLs; Metals; O&M; Offsite Treatment; Onsite Discharge; Onsite Disposal; Onsite Treatment; Organics; PAHs; RCRA; Safe Drinking Water Act; Soil; Solvents; State Standards/Regulations; TCE; Toluene; Treatability Studies; Treatment Technology; VOCs; Xylenes.

Abstract:

The Fairchild Air Force Base 4 Areas (Operable Unit 2) site is part of the 4,300-acre Fairchild Air Force Base (AFB) located approximately 12 miles west of Spokane, Washington. Land use in the area is predominantly agricultural. In addition, a portion of the site may be within a floodplain, since it could be flooded during intense precipitation. Initially, in 1942, the Base was established as a U.S. Army repair depot. In 1947, it was transferred to the Strategic Air Command and renamed Fairchild AFB, in 1950. Since 1942, varying quantities of hazardous wastes from fuel management, industrial and aircraft operations, and fire training activities have been generated and disposed of onsite. The site consists of five separate Priority 1 (P1) OUs: SW-1 (Old Base Landfill northeast of Taxiway No. 7); IS-1 (Building 1034 French Drain System); OU1 (Flightline Sites PS-2, PS-6, PS-8); FT-1 (Fire Training Area); and WW-1 (Wastewater Lagoons). From about 1949 to 1958, the SW-1 landfill was the main disposal area for the base and received industrial wastes including plating sludge, solvents, and lubricating oils. The Building 1034 French drain system was constructed to dispose of wastewater from an inside sink and the roof runoff at Building 1034; however, it is believed that hazardous materials, including waste solvents, mineral spirits (PD-680), cleaning compounds, and acid solutions were washed into the drain system. In 1992, the Air Combat Command division of the Air Force assumed command of Fairchild AFB. Also, in 1992, the Air Force completed a non-time-critical removal action to remove and treat offsite the contaminated sediment and water from the manholes of the French drain system, in addition to, rerouting drainage from the sink and roof and sealing the manholes with water-tight gaskets. The flightline OU is comprised of three sites: PS-2, where approximately 5,120 gallons of JP-4 fuel leaked/spilled between 1984 and 1985; PS-6, where approximately 3,550 gallons of JP-4 fuel leaked in 1986; and PS-8, where petroleum vapors were attributed to leaks in the underground fuel lines. Until 1991, fire training exercises, which included burning approximately 300 gallons of JP-4 fuel and extinguishing the blaze with approximately 125 gallons of aqueous film-forming foam, were held two or three times a month at the Fire Training Area. The Wastewater Lagoons currently are used for disposal of industrial wastewater and storm water, but wastes such as JP-4 fuel, oil, industrial solvents, acids, and cleaning compounds are known to have been discharged previously into the lagoons. Until 1989, the lagoons periodically were dredged, and approximately 18 inches of the dredged material was spread over the lagoon banks. As part of the Department of Defense's Installation Restoration Program (IRP), onsite environmental investigations of past disposal practices were initiated that revealed onsite soil and ground water contamination. A 1993 ROD addressed the source contamination at the Craig Road Landfill and onsite and offsite ground water, as OU1. This ROD addresses soil and ground water contamination at the five P1 areas, as OU2. A future ROD will address the P2 OUs. The primary contaminants of concern affecting the soil and ground water are VOCs, including benzene, TCE, toluene, and xylenes; other organics, including PAHs; and metals, including chromium and lead.

SELECTED REMEDIAL ACTION: The selected remedial action for this site includes combining onsite in-situ bioventing of the contaminated soil in the FT-1 area with an in situ ground water air sparging treatment system to prevent continued movement of contaminated water from the FT-1 area; treating contaminated air vapors from both systems to comply with State air standards; collecting and treating floating product at the PS -2 area by either a passive or active removal system; transporting the collected product offsite to a recycling facility for reuse as a fuel source; extracting and treating contaminated ground water at the WW-1 area using an air stripping unit and/or a carbon adsorption unit; reinjecting the treated water into the aquifer or discharging it onsite either directly or indirectly to No Name Ditch; recycling spent carbon offsite; allowing contaminated ground water to naturally attenuate at SW-1, PS-2, and PS-8; conducting onsite ground water monitoring at SW-1, PS-2, PS-8, and FT-1 sites, and offsite ground water monitoring at SW-1, FT-1 and WW-1 areas; and implementing institutional controls, including deed restrictions, and site access restrictions at the SW-1 and the WW-1 areas, and ground water use restrictions at the SW-1, PS-2, PS-8, FT-1, and WW-1 areas. The estimated present worth cost for this remedial action is $5,816,000, which includes an estimated annual O&M cost of $340,000 for 30 years.

PERFORMANCE STANDARDS OR GOALS: Chemical-specific soil cleanup goals are based on the State Model Toxics Control Act (MTCA), which establishes maximum acceptable overall site risk for carcinogens of 1x10[-5], and for non-carcinogens as levels which the human population may be exposed during a 30-year period without adverse health effects, and include benzene 0.5 mg/kg and cadmium 2 mg/kg. Chemical- specific ground water cleanup goals are based on SDWA MCLs and the State (MTCA), and include benzene 5 ug/l; TCE 5 ug/l; and TPH 1 mg/l.

INSTITUTIONAL CONTROLS: Deed, ground water, and land use restrictions will be implemented to prevent the site from being used in the future for residential purposes, and to prevent the use of contaminated ground water at the Base.

Remedy:

This ROD addresses soil and groundwater contamination at five P1 operable units. This is the second of three RODs planned for Fairchild Air Force Base. The first ROD, signed in February 1993, addressed contamination at the Craig Road Landfill operable unit. The third ROD will address the Priority Two (P2) operable units.

The major components of the selected remedies for the five P1 operable units are highlighted below. Further explanations regarding the remedial alternatives and selected alternatives are located in sections VIII and X, respectively, of the ROD Decision Summary.

Old Base Landfill (SW-1)

The goals of the remedial action at SW-1 are to restore the groundwater to drinking water quality within a reasonable timeframe, and to prevent exposure to landfill materials. The selected remedy combines the soil alternative of Institutional controls (Alternative 2) with the groundwater alternative of Institutional controls and Point-of-Use Treatment/Alternate water supply (Alternative 2). This remedy consists of the following elements:

* Maintaining institutional controls restricting access to the site.

* Maintaining institutional controls, in the form of restrictions against on-base usage of TCE-contaminated groundwater associated with the site, until cleanup levels are achieved.

* Monitoring groundwater at the site to identify a trend in contaminant concentrations, estimating a timeframe for restoration by natural dispersion, dilution, and degradation, evaluating the acceptability of the estimated timeframe, and implementing a compliance monitoring program to estimate attainment of cleanup levels.

* Monitoring off-site water supply wells in the vicinity of the site and providing point-of-use treatment and/or alternate water supply, if necessary.

The estimated costs associated with this remedy are:

Capital Cost: $0;

O&M Costs: $40,000

Present Net Worth: $615,000

Building 1034 French Drain System (IS-1)

The USAF has determined that no further remedial action is necessary at the IS-1 site to ensure protection of human health and the environment. This decision is based on the results of the human health risk assessment, which determined that conditions at the site pose no unacceptable risks to human health or the environment. With the completion of the removal action at IS- 1 in December 1992, all conduits, including surface water drainage into the manholes, and potential sources of groundwater contamination have been eliminated at the IS-1 site. The TCE groundwater contamination detected upgradient of this site is believed to be associated with site PS10, a P2 operable unit, and will be addressed under the RI/FS for the P2 sites.

Flightline Site (OU-1) PS-2

The goal of the remedial action at PS-2 is to restore the groundwater to drinking water quality within a reasonable timeframe. The selected remedy combines the soil alternative of No Action (Alternative 1) with the groundwater alternative of Free Product Removal with Institutional Controls (Alternative 5). This remedy consists of the following elements:

* Remediation of the floating product through passive collection and treatment, and recycling of recovered product at an offsite facility.

* Maintaining institutional controls, in the form of restrictions against on-base usage of benzene- and TPH-contaminated groundwater associated with the site, until cleanup levels are achieved.

* Monitoring groundwater at the site to identify a trend in contaminant concentrations, estimate a timeframe for restoration by natural dispersion, dilution, and degradation, evaluating the acceptability of the estimated timeframe, and implementing a compliance monitoring program to estimate attainment of cleanup levels.

The estimated costs associated with this remedy are:

Capital Cost: $195,000

O&M Costs: $85,000

Present Net Worth: $447,000

Flightline site (OU-1) PS-6

The USAF has determined that no further remedial action is necessary at the PS-6 site to ensure protection of human health and the environment. This decision is based on the results of the human health risk assessment, which determined that conditions at the site pose no unacceptable risks to human health or the environment. The TCE groundwater contamination detected upgradient of this site is not believed to be associated with this site and will be addressed under the RI/FS for the P2 sites.

Flightline site (OU-1) PS-8

The goal of the remedial action at PS-8 is to restore the groundwater to drinking water quality within a reasonable timeframe. The selected remedy combines the soil alternative of No Action (Alternative 1) with the groundwater alternative of Institutional Controls (Alternative 2). This remedy consists of the following elements:

* Maintaining institutional controls, in the form of restrictions against on-base usage of benzene-contaminated groundwater associated with the site, until cleanup levels are achieved.

* Monitoring groundwater at the site to identify a trend in contaminant concentrations, estimating a timeframe for restoration by natural dispersion, dilution, and degradation, evaluating the acceptability of the estimated timeframe, and implementing a compliance monitoring program to estimate attainment of cleanup levels.

The estimated costs associated with this remedy are:

Capital Cost: $0

O&M Costs: $31,000

Present Net Worth: $477,000

Fire Training Area (FT-1)

The goals of the remedial action at FT-1 are to remediate soils to levels that are protective of groundwater, and to restore groundwater to drinking water quality. The selected remedy combines the soil alternative of In-situ Bioventing (Alternative 4) with the groundwater alternative of In situ Air Sparging with Institutional Controls (Alternative 4). This remedy consists of the following elements:

* Maintaining institutional controls, in the form of restrictions against on-base usage of benzene-contaminated groundwater associated with the site, until cleanup levels are achieved.

* Implementing an in-situ bioventing treatment system for benzene-contaminated soil.

* Implementing a pilot-scale in-situ air sparging system to evaluate the effectiveness of this technology for remediating benzene-contaminated groundwater, to be followed by implementation of a full-scale system if the pilot scale system is successful.

* Monitoring off-site water supply wells in the vicinity of the site and providing point-of-use treatment and/or alternate water supply, if necessary.

The estimated costs associated with this remedy are:

Capital Costs: $542,000

O&M Costs: $49,000

Present Net Worth: $785,000

Wastewater Lagoons (WW-1)

The goals of this remedial action are to restrict the site from future residential or agricultural uses, and to restore groundwater to drinking water quality. The selected remedy combines the soil alternative of Institutional Controls (Alternative 2) with the groundwater alternative of Groundwater Extraction and Treatment with Institutional Controls and Point-of-Use Treatment/Alternate water supply (Alternative 3). This remedy consists of the following elements:

* Implementing additional source investigation activities to identify the source of groundwater TCE contamination. If a source of TCE contamination is detected in soils, soil remedial alternatives will be evaluated at that time.

* Maintaining institutional controls restricting access to the site.

* Maintaining institutional controls, in the form of restriction against on-base usage of TCE-contaminated groundwater associated with the site, until cleanup levels are achieved.

* Implementing a groundwater extraction and treatment system, using air stripping and/or carbon adsorption.

* Monitoring off-site water supply wells in the vicinity of the site and providing point-of-use treatment and/or alternate water supply, if necessary.

The estimated costs associated with this remedy are:

Capital Cost: $1,442,000

O&M Costs: $135,000

Present Net Worth: $3,522,000

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 action, and are cost effective. Where practicable, the remedies utilize permanent solutions and alternative treatment technologies to the maximum extent practicable and satisfy the statutory preference for remedies that employ treatment which reduce contaminant toxicity, mobility, or volume as a principal element.

Because the remedial actions at sites SW-1, PS-2, PS-8, FT-1, andWW-1 may require five or more years to attain cleanup levels, a review of the selected remedies will be conducted for each of these sites within five years. The purpose of the five year review is to assure that the remedies remain protective of human health and the environment. A five year review is required at WW-1 because the selected remedy does not allow for unlimited use.