A former refrigeration valve manufacturing plant sits on a 4-acre parcel at 611 E. Seventh Street in Washington, Missouri. The facility ran from 1939 until roughly 2003 to 2005, with operations that included plating, degreasing, and machining. The building and concrete slab were demolished in 2011. EPA added the site to the National Priorities List (NPL) in May 2019, which means it qualifies for the federal Superfund cleanup program.
The main contamination concern is trichloroethylene, or TCE, a chemical used in degreasing. TCE has spread in a groundwater plume that reaches beyond the property toward MacArthur Street to the east and Eighth Street to the south. Vapor intrusion sampling in 2015 found TCE concentrations in indoor air above screening levels at nearby homes. Volatile organic compounds (VOCs), a broader class of chemicals that includes TCE, continue to be tracked through quarterly groundwater sampling.
EPA conducted several removal actions between 2016 and 2019 to address immediate risks, and a remedial removal action ran from June 2022 to January 2023. Vapor mitigation systems have been installed in homes where indoor air contamination was identified. Six new groundwater monitoring wells were added along the plume perimeter in 2024. Sampling at those sentinel wells, completed in November 2024, showed no contamination above Safe Drinking Water limits. All homes in the area connect to the public water supply, and no private wells exist near the site, so there is no known immediate risk to residents. EPA states that human exposure is currently under control, though the agency notes that data on whether the groundwater plume has stopped moving is still insufficient to draw firm conclusions.
The site is still in the remedial investigation phase. That investigation is expected to finish between August and October 2026. A feasibility study examining cleanup options is estimated to wrap up between April and June 2028. No remedy has been selected yet, and physical construction of the final remediation has not been completed. A Remedial Investigation Report is being drafted and is scheduled for completion in 2026.
Community members who want to follow cleanup progress or ask questions can contact EPA's Community Involvement Coordinator or the Remedial Project Manager.
