Preliminary geospatial distribution of PFAS in the West Plains, Spokane County, Washington

Abstract

Groundwater samples collected in the West Plains, Spokane County by the EPA and EWU were analyzed for PFAS using EPA Method 533. An attempt was made to gather well depths and well logs from the wells sampled, but not all residences had a Water Well Report as many wells pre-date this regulation. Using PFAS results and well depths/aquifers concentration maps were made of the West Plains to show distribution of PFOS and PFHxS to see possible extents of contamination associated with high-temperature firefighting foam (AFFF) as well as PFOA, PFBS, and the PFAS Hazard Index (HI) for contamination associated with general commercial items, eg. automotive fluids, septic systems. Concentration maps were made for each aquifer, as well as a general HI distribution for all aquifers