EPA reviewing cleanup of contaminated Superfund site south of Chehalis

CHEHALIS, Wash. – The United States Environmental Protection Agency is conducting a five-year review of the cleanup at the Hamilton/Labree Roads Groundwater Contamination Superfund site near Chehalis, Washington.

The EPA is required to review all superfund sites every five years. Five-year reviews help ensure the selected cleanup actions effectively protect people’s health and the environment, according to a news release from the EPA.

The site, about 2 miles southwest of Chehalis, is contaminated with tetrachloroethene (PCE), also called PERC or perchloroethylene. It is a chemical used for dry cleaning, metal degreasing and other industrial processes.

The site is divided into two sections called Operable Unit 1 and Operable Unit 2. Unit 1 is known as the Hamilton Road Impacted Area (HRIA). Unit 2 includes all other areas outside of the 10-acre HRIA where impacted soil, sediment or groundwater have been detected. The five-year review is for OU1, or the HRIA.

In 2013, the EPA selected an interim cleanup plan for the HRIA. The cleanup plan is called “interim” because the EPA will propose and select other cleanup plans for the site after additional sitewide data is collected and evaluated. The interim cleanup began in 2020 and was completed in 2024.

The cleanup actions included thermal treatment, bioremediation and long-term monitoring, according to the EPA.

The Washington state Health Department first found contamination at the site in 1993. It came from a spill or direct release of 100 to 700 gallons of liquid PCE into Berwick Creek aquifer, according to previous Chronicle reporting.

In 1999, the EPA found 64 drums of PCE buried under a building owned by the S.C. Breen Construction Co. The barrels were removed and disposed of as hazardous waste. The S.C. Breen company signed an order as a “potentially liable party” and paid for testing and studies of how to clean up the area, but there were never any charges for the contamination of the now superfund site. The EPA and Washington state Department of Ecology conducted an investigation, but the source of the contamination was never found.