Several authors affiliated with the U.S. Geological Survey recently published the results of their testing for 24 PFAS (and various other potential contaminants such as tritium, volatile organic compounds (VOCs), and dissolved organic carbon (DOC)) in 254 groundwater samples collected in 2019. At least one PFAS chemical was detected in 54% of the samples tested, and at least two PFAS chemicals were detected in 47% of the samples tested. Overall, 60% of the public-supply samples were positive for at least one PFAS while 20% of the private wells were positive for at least one PFAS chemical. In addition, the study authors conducted boosted regression tree models in an effort to predict the presence of PFAS in groundwater using existing data such as the concentrations of tritium, VOCs, and DOC in groundwater as well as other data such as urban land use percentages and distance to nearest fire-training areas. The authors suggest continuing to develop targeted sampling related to PFAS to develop predictive models for identifying PFAS occurrence in U.S. groundwater.