THE DALLES DISPOSAL SITE

The Dalles Disposal Site is a now-closed municipal landfill for the City of The Dalles, located in The Dalles, Oregon, on a portion of the former Golden Northwest Aluminum Company aluminum plant property. Plateau Geoscience Group provided field and documentation support for site investigation of The Dalles Disposal Site. Plateau staff conducted logging of soil borings and test pits, collected sediment samples from onsite wetland ponds, and collected soil gas samples from installed soil gas wells. In addition, Plateau prepared a Beneficial Water Use Determination as required by Oregon Department of Environmental Quality. Current beneficial uses of groundwater identified at the site included support of aquatic habitat, and potential future beneficial uses identified included drinking water, irrigation, and industrial.