On May 25, 2021 the US Geological Survey (USGS) and the State Water Resources Control Board (SWRCB) posted a Fact Sheet (USGS FS GAMA PFAS ) regarding USGS monitoring for PFAS in groundwater throughout California. The Groundwater Ambient Monitoring and Assessment Priority Basin Project (GAMA-PBP) began in 2004 as a collaboration between USGS and the SWRCB. The objective was to develop a representative assessment of the quality of groundwater used for the supply of drinking water. In 2019, USGS added PFAS to the list of chemicals monitored in the GAMA program.
From the USGS Fact Sheet:
“From May 2019 to September 2020, the GAMA-PBP collected PFAS samples from 107 public-supply wells and 104 domestic wells Statewide…. Results for GAMA-PBP PFAS sampling are available in a data release (Kent, 2021). At least one PFAS was detected in 49 of these 211 samples (23 percent). Total concentrations of PFAS in these samples ranged from 1 to almost 70 nanograms per liter (ng/L), and of the 49 samples with detections, 17 of them (35 percent) had concentrations greater than 10 ng/L.”
“This fact sheet presents preliminary results of PFAS sampling of public-supply and domestic wells by the GAMA-PBP between May 2019 and September 2020. GAMA-PBP sampling is ongoing and includes re-sampling a network of public-supply and domestic wells to monitor temporal variability (“trends” networks) and denser sampling of domestic wells in selected areas to assess the quality of groundwater resources used for domestic supply. Between October 2020 and September 2021, the GAMA-PBP plans to collect samples from 130 public supply wells and about 120 domestic wells.”