The Colbert Landfill, also called Colbert Dump, sits about two miles north of Colbert, Washington. It operated from 1968 to 1986, accepting municipal, commercial, and industrial wastes across 40 acres. The site was added to the National Priorities List in 1983. Between 1975 and 1980, solvent and chemical waste disposed in open trenches spread contamination to the Little Spokane River and areas more than a mile south.
Six contaminants have been identified in groundwater at the site. They are 1,1,1-trichloroethane, 1,1-dichloroethane, 1,1-dichloroethene, chloromethane, tetrachloroethene, and trichloroethene. These are all volatile organic compounds. Organic solvent wastes came from an electronics manufacturing company and Fairchild Air Force Base. Workers poured spent solvents into open trenches mixed with soil and municipal refuse.
EPA selected a cleanup remedy in 1987. It covered installing groundwater interception and extraction wells, treating extracted groundwater, capping the landfill, and connecting affected homes to public water supplies. Spokane County began supplying bottled water to residents in 1984 and extended public water service to 26 homes in 1985. Remedy construction ran from 1989 to 1997. The groundwater extraction and treatment system operated from May 1995 to April 2014, and a shutdown test of that system that began in April 2014 remains ongoing. Treated groundwater discharges to the Little Spokane River through an underground pipeline. Restrictive covenants limiting groundwater use have been filed at the site.
Current assessments show human exposure is under control, with no unacceptable exposure pathways to people at this time. Groundwater migration remains uncertain due to insufficient data about how contaminated groundwater is moving. The site has not been deleted from the National Priorities List. Two five-year reviews have been referenced in source documents, one completed in 2014 and one in 2019, both finding the remedy protective of human health and the environment. A seventh five-year review was due in September 2024.
Community members can get involved by contacting the EPA Remedial Project Manager. For well water quality concerns, contact Spokane County. Site documents are available at the Spokane County Library's North Spokane Branch and the main Spokane Public Library. The EPA Region 10 Superfund Record Center in Seattle also holds administrative records and can be reached at 206-553-4494 or toll-free at 800-424-4372, extension 4494.
