Hanford 1100-Area (USDOE)

Overview

The Hanford 1100-Area is a 120-square-mile federal facility site located one mile north of Richland, Washington. The U.S. Department of Energy owned and operated the site, which was listed on the National Priorities List in 1989 and later deleted in September 1996 after cleanup was finished. The site has since been redeveloped, with a portion now operating as the Port of Benton's Richland Innovation Center, home to nearly 20 companies.

Past waste disposal practices, including a landfill, drains, underground tanks, and a sand pit that may have received up to 15,000 gallons of waste battery fluids, left the soil and groundwater contaminated. Eight contaminants of concern were identified. Soil contaminants include arsenic, beryllium, bis(2-ethylhexyl)phthalate, chlordane, chromium, and polychlorinated biphenyls (PCBs). Groundwater contaminants include nitrate and trichloroethene. These substances posed unacceptable risks to human health or the environment through ingestion or skin contact.

The Department of Energy completed a site investigation and risk assessment by 1992. A Record of Decision signed September 30, 1993 approved removal of contaminated soils and closure of the landfill. Cleanup finished in 1995 and included removing about 130 cubic yards of soil containing bis(2-ethylhexyl)phthalate and 165 cubic yards of PCB-contaminated soil, both sent to incineration or permitted disposal facilities. The landfill was capped, and institutional controls such as fencing, signage, entry restrictions, and land use management were put in place to prevent exposure to buried asbestos. Groundwater now meets drinking water standards for trichloroethylene.

Human exposure is under control across the entire site, and groundwater migration is stabilized. Physical construction of cleanup work is complete, and the site is ready for its anticipated future uses. A 2010 Explanation of Significant Differences modified the remedy for Operable Unit 1 to focus on institutional controls. The site achieved ready-for-anticipated-reuse status in September 2010. EPA five-year reviews continue on a regular cycle, with the most recent completed in May 2022 and the next estimated between May and July 2027. The Department of Energy continues to monitor the site and maintain remedial protections.

Community members with questions can contact the EPA Remedial Project Manager. The Community Involvement Coordinator is also available for public outreach. The complete Administrative Record can be obtained by contacting the Department of Energy or the site's Public Information Repository.