PHASE II ESA SINGER CHEVRON STATION

Plateau Geoscience Group performed a Phase II ESA for the Singer Chevron gas station site located in Walla Walla, WA. A gas station has operated at this site since 1930. The Phase II ESA was to investigate whether petroleum hydrocarbons detected in shallow soil have impacted underlying groundwater. Three groundwater monitoring wells were installed on the site. The soil borings were logged, soil samples collected, and water table monitoring wells installed. Seven quarters of groundwater monitoring was performed to evaluate presence and potential migration of petroleum hydrocarbons that were detected in groundwater. The site has received a no further action determination from the Washington Department of Ecology.