Sumner National Auto Parts

Environmental cleanup at the Sumner National Auto Parts site is completed. In 2022, Ecology determined that no further action is necessary because the cleanup meets state standards. 

Ecology held a public comment period from September 22 to October 23, 2022, on our proposal to remove the site from the Hazardous Sites List. Ecology received no comments during the comment period and we will remove the site from the list.

The site is about 1.5 acres in an area of mixed residential, commercial, and undeveloped properties. It was an auto supply store and an engine rebuild and metal machine shop. The building storage/warehouse was constructed in 1979. A portion of the property is paved with asphalt. Other areas are soil and gravel over soil.

Leaks of hazardous chemicals into the soil were likely caused by cleaning and refurbishing engines on a concrete pad, where fluids pooled and spread into the soil.

Contaminants in soil and groundwater included:

• Petroleum hydrocarbons.
• BTEX (benzene, toluene, ethylbenzene, and xylene).
• PAHs (polycyclic aromatic hydrocarbons).
• Metals.
• Organic solvents.

Soil excavations in 2017-2018 and 2021 removed about 513 tons of contaminated soil from the site. After the contaminated soil was removed, tests confirmed that contaminant concentrations were below state cleanup levels.

Groundwater monitoring wells were installed in and near areas where the contaminated soil was removed. Groundwater was tested periodically and results confirmed that contaminants were either not present in groundwater or present at concentrations below state cleanup levels.  

Household and public drinking water wells are not likely to have been affected by contamination at the site. 

The cleanup is effective in protecting the health of people and the environment. We determined that no further cleanup action is required.

Ecology held a comment before we considered removing the  site from the Hazardous Sites List.