Site Plain EPA Superfund sites near you, in plain language

EPA Superfund Site

FORMOSA MINE

OR | EPA ID ORN001002616

Human exposure is under control

About this site’s exposure pathways: There is currently insufficient data to determine the site-wide Human Exposure Control status at the Formosa Mine Superfund site. The site was added to the National Priorities List on September 19, 2007. Acid drainage from the mine has impacted 18 miles of river downstream of the Formosa Mine. Soils on the site are contaminated with copper, zinc and other heavy metals. Water quality data collected by the City of Riddle, Oregon (the nearest town downstream of the mine) indicates that downstream drinking water supplies have not yet been impacted by the acid mine drainage.

EPA is conducting a Remedial Investigation/Feasibility Study that will determine the nature and extent of contamination and enable us to propose a cleanup plan. In addition, EPA has taken two removal actions to address acid mine drainage. When the results of the investigation are complete, EPA will take appropriate cleanup action and adjust the human exposure determination for this site as appropriate.

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Data limitations: Proximity to a Superfund site boundary does not mean your property is contaminated. EPA site boundaries show the area designated for cleanup, not the full extent of contamination. Groundwater plumes can extend beyond site boundaries. This tool shows publicly available EPA federal data. It is not affiliated with or endorsed by EPA, and is not a substitute for a professional environmental assessment.

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