Per- and polyfluoroalkyl substances (PFAS) concentration results in the Wanaque, Ramapo, Pompton, and Passaic River watersheds, New Jersey 2025

Beginning in January 2025, the U.S. Geological Survey (USGS) and the North Jersey District Water Supply Commission (NJDWSC) initiated a study to characterize the presence of per- and polyfluoroalkyl substances (PFAS) in four northern New Jersey watersheds. This study was designed to assess the occurrence and distribution of PFAS in the Passaic River Basin including 37 mainstem and tributary sites in the Wanaque, Ramapo, Pompton, and Passaic River watersheds. Results of this study can be used to help inform water-supply authorities (WSA) of PFAS surface-water concentrations as they begin to prepare to meet the newly established U.S. Environmental Protection Agency (EPA) drinking water Maximum Contaminant Level(s) (MCL) for perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) prior to their implementation. Additional information gathered and used in this study included potential sources (wastewater, industrial), landscape metrics, and an accumulated wastewater model. This information provides further insight into potential sources of PFAS contamination in rivers within the Passaic River Basin and is presented in this data release. In addition to PFAS, total organic carbon (TOC), water-quality field parameters (pH, specific conductance, water temperature, dissolved oxygen, and turbidity), and trace elements were also measured and (or) analyzed with each sample. Where possible, sites were chosen where streamflow gages were present. Where no streamflow gage was present, flow was measured and (or) calculated at each site for each sampling event. In March 2025, samples for 1,4-dioxane were collected. In January, March, July, and September 2025, four water-quality surface-water samples were collected during base-flow conditions at each of the 37 locations. In addition to the samples collected at base flow, in July 2025, one rain event sample was collected at 27 of the 37 tributary and mainstem river locations. In December 2025, samples were collected from 9 of the mainstem river locations on the rising limb of the surface-water hydrograph to determine if PFAS was entering the rivers from overland runoff. Analyses for PFAS were conducted by Eurofins Environmental Testing laboratory in Barberton, Ohio using the EPA Method 1633, revision A. Total organic carbon samples were analyzed at the NJDWSC using Standard Method 5310 B-14. Trace elements and mercury were analyzed at the NJDWSC laboratory using EPA Method 200.8 and 245.1, respectively. 1,4-dioxane was analyzed at ALS Laboratories, Middletown, Pennsylvania. Water-quality parameters were collected in situ using a multiparameter sonde.