PRELIMINARY GROUNDWATER MODELING OF THE WEST PLAINS, SPOKANE COUNTY, WA: DECIPHERING ERRATIC TRENDS OF PFAS CONTAMINATION

Located in eastern Washington, the West Plains is a plateau of Columbia River Basalt between Deep Creek, Hangman Creek, and south of the Spokane River. The quantity and quality of drinking water pumped from basalt aquifers has affected residents of the West Plains. The most recent issue is PFAS contamination found in drinking water wells across the West Plains, which likely has negative affects to human and environmental health. We interpret subsurface geology using well logs from the Palisades area in the eastern West Plains. Using ArcGIS PRO, well information interpolated to predict multiple geological horizons and can be used to estimate groundwater flow directions. Using PFAS results from across the West Plains the erratic contamination can be linked to possible sources, such as: airports, fire stations, car washing facilities, packaging plants or waste facilities. These models can help residences in the West Plains Region understand the possible sources of contamination as well as create a safer environment for themselves and their families.