Site Name: HANFORD 1100-AREA (USDOE)
EPA ID: WA4890090075 EPA Region: 10 Metro Statistical Area: 6740
1100 AREA, RICHLAND, WA 99352
Operable Unit: 01
ROD ID: EPA/ROD/R10-93/063 ROD Date: 09/24/93
Contaminant: VOCs, Other Organics, Metals, Inorganics
Keys: Arsenic; Asbestos; Benzene; Capping; Carcinogenic Compounds; Chromium; Debris; Excavation; Filling; Ground Water; Ground Water Monitoring; Incineration/Thermal Destruction; Inorganics; Institutional Controls; Lead; MCLs; Metals; O&M; Offsite Disposal; Offsite Treatment; Onsite Disposal; Organics; PAHs; PCBs; PCE; Pesticides; RCRA; Safe Drinking Water Act; Soil; Solvents; State Standards/ Regulations; Toluene; Treatment
Technology; VOCs; Xylenes.
Abstract: The 5-square mile Hanford 1100-Area (DOE) site is located in the southern part of a 560-square mile Federal facility located along the Columbia River in southeastern Washington. The facility is located north and west of the cities of Richland, Kennewick, and Pasco, an area commonly known as the Arid Lands Ecology (ALE) Reserve. This area covers 120 square miles and is managed by DOE for ecological research. Land use in the area is predominantly agricultural. The Tri-Cities area is a major population center with 100,000 residents. In 1943, operations began at Hanford as part of the Army's "Manhattan Project" to produce plutonium for nuclear weapons; however DOE currently operates facilities throughout the site. The site contains the central warehousing, vehicle maintenance, transportation distribution center, and the ALE Reserve Headquarters, formerly a NIKE missile base and control center, located on the northern slope of Rattlesnake Hills. Historical documentation indicates that several individual waste units may have released a variety of contaminants onsite to the soil and ground water. During the detailed site investigations, quantitative evaluations of the waste units indicated that soil and ground water were contaminated by VOCs, PAHs, PCBs pesticides, metals, and other organics. The site has been divided into four OUs for remediation: 1100-EM- 1, 1100-EM-2, 1100-EM-3, and 1100-IU-1. The 1100-EM-1 OU consist of the Battery Acid Pit, Paint Solvent Pit, Antifreeze and Degreaser Pit, Antifreeze Tank Site, Discolored Soil Site, Horn Rapids Landfill (HAL), and Emphemeral Pool. This ROD addresses the risk associated with onsite contamination in the soil and ground water. The primary contaminants of concern affecting the soil and ground water are VOCs, including benzene, PCE, TCE; other organics, including PAHs, PCBs, and pesticides; metals; including arsenic, chromium, and lead; and other inorganics, including asbestos. SELECTED REMEDIAL ACTION: The selected remedial action for this site includes excavating approximately 840 tons of soil contaminated with bis (2-ethylhexyl) phthalate (BEHP) from the Discolored Soil Site, with offsite incineration at a RCRA-licensed facility; excavating approximately 636 yd[3] of PCB-contaminated soil from the Ephemeral Pool and the HRL, with offsite disposal in a TSCA-permitted landfill; removing more than 5,495 yd[3] of contaminated soil and debris from the 1100-EM-2, 1100-EM-3, 1100-IU-1 OUs, with offsite disposal; conducting soil sampling in excavations to determine if cleanup goals have been met; backfilling excavated areas with clean fill; capping the HRL to prevent contact with the contained asbestos; placing a notice on the deed identifying this area as an asbestos-containing landfill; allowing for natural attenuation of the TCE-contaminated ground water; monitoring ground water; and implementing institutional controls, including deed and ground water use restrictions. The estimated present worth cost for this remedial action is $10,840,000, which includes an estimated annual O&M cost of $65,300 for 30 years. PERFORMANCE STANDARD OR GOALS: The soil remedial action objectives are based on MTCA State standards, and include benzene 0.5 mg/kg; PCE 0.5 mg/kg; TCE 0.5 mg/kg; toluene 40 mg/kg; xylenes 20 mg/kg; PAHs 1 mg/kg; PCBs in Ephemeral Pool soil and soil from OUs 1100-EM-2, 1100-EM-3, and 1100-IU-1 1 mg/kg; PCBs in the HRL 5.2 mg/kg; hexavalent chromium 1,600 mg/kg; and lead 250 mg/kg. The objective for natural attenuation of ground water is TCE 0.5 mg/l, which is based on SDWA MCLs and is expected to be reached within 25 years. INSTITUTIONAL CONTROLS: Institutional controls, including deed and ground water use restrictions, will be implemented to notify the public that the HRL is an asbestos-containing landfill, and to prevent ground water use or drilling of new wells until cleanup goals are attained.
Remedy: The selected remedy for the 1100 Area NPL Site addresses actual or threatened releases at the four 1100 Area Operable Units: 1100-EM1, 1100-EM -2, 1100-EM-3, and 1100-IU-1.
The major components of the selected remedy include:
* 1100-EM-1 Operable Unit
* Capping the Horn Rapids Landfill.
* Offsite disposal of PCB contaminated soils.
* Offsite incineration of soils contaminated with bis (2-ethylhexyl)phthlalate.
* Natural attenuation of groundwater that currently exceeds MCL's and monitoring for compliance.
* Continuation of institutional controls for groundwater and land use at the Horn Rapids Landfill.
* 1100-EM-2, EM-3 and IU-1 Operable Units
* .Offsite disposal of soils, debris and structures contaminated with solvents, PCBs and other hazardous substances.
* Continuation and expansion of groundwater monitoring.
STATUTORY DETERMINATIONS
The selected remedy is protective of human health and the environment, will comply with federal and state requirements that are legally applicable or relevant and appropriate to the remedial action, and is cost effective. This remedy utilizes permanent solutions to the maximum extent practicable for this site, and satisfies the statutory preference for remedies that employ treatment that reduces toxicity, mobility, or volume as a principal element. Alternative treatment technologies were evaluated for this site, but are not included in the selected remedy.
Because this remedy will result in hazardous substances remaining on site above health-based levels, a review will be conducted within 5 years after commencement of remedial action to ensure that the remedy continues to provide adequate protection of human health and the environment.
Signature sheet for the Record of Decision for the USDOE Hanford 1100 Area Final Remedial Action between the United States Department of Energy and the United States Environmental Protection Agency, with concurrence by the Washington State Department of Ecology.