Understanding the Occurrence and Distribution of Per- and Polyfluoroalkyl Substances (PFAS) in Surface Waters of the Nontidal Passaic River Basin

Scientific Investigations Report 2026-5018
Prepared in cooperation with the North Jersey District Water Supply Commission
By: , and 

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Abstract

This study, completed by the U.S. Geological Survey in cooperation with the North Jersey District Water Supply Commission (NJDWSC), was designed to characterize the occurrence and distribution of per- and polyfluoroalkyl substances (PFAS) in surface waters of the nontidal Passaic River Basin in New Jersey that have the potential to affect public-drinking-water quality. In 2025, 37 sites in the Wanaque, Ramapo, Pompton, and Passaic River watersheds were sampled in January, March, July, and September under base-flow conditions and a subset of sites was sampled during two rain events. Samples were analyzed for 40 individual PFAS and total organic carbon and a subset of samples was analyzed for 1,4-dioxane and trace elements. Fifteen PFAS were detected at least once, with individual concentrations ranging from 0.42 to 28 nanograms per liter (ng/L; median, 2.8 ng/L). Perfluorooctanoate (PFOA) and perfluorooctane sulfonate (PFOS) were widespread and detected in 100 and 97 percent of the samples, respectively. Concentrations of PFOA and PFOS ranged from 1.2 to 28 ng/L (median, 7.7 ng/L) and from 0.52 to 12 ng/L (median, 3.8 ng/L), respectively. Generally, concentrations were lower in the Wanaque and Ramapo River watersheds compared to the Pompton and Passaic River watersheds. Concentrations of PFOA and PFOS were highest in July and September when flows were low. During rain events, median concentrations of PFOS were elevated compared to those observed under base-flow conditions, indicating potential inputs from non-point sources. To understand potential drivers of PFAS concentrations, land cover and potential PFAS sources were summarized for each sampling site, and an accumulated wastewater model was used to estimate the percentage of wastewater from upstream municipal and industrial sources in all flowlines of the Passaic River Basin. Developed land, the number of potential sources, and the mean-annual accumulated wastewater percentage were highly correlated with PFAS concentrations and Deciduous Forests were negatively related to concentrations. Data provided by this study can be used by water purveyors and resource managers to make treatment and mitigation decisions to minimize PFAS in local surface waters used as drinking-water resources.

Plain Language Summary

U.S. Geological Survey researchers, in cooperation with the North Jersey District Water Supply Commission, determined that per- and polyfluoroalkyl substances (PFAS) are present in northern New Jersey rivers that are used as drinking-water sources. During their 2025 study, the researchers sampled 37 locations across the Wanaque, Ramapo, Pompton, and Passaic River watersheds. The researchers tested each sample for 40 types of PFAS. Of these, 15 were detected at least once. Two PFAS, perfluorooctanoate (PFOA) and perfluorooctane sulfonate (PFOS), were present in nearly every sample. PFAS concentrations varied by watershed and season. The lowest were detected in the Wanaque and Ramapo River watersheds, and the highest, in the Pompton and Passaic River watersheds. Concentrations of PFOA and PFOS were highest under base-flow conditions in July and September.

Suggested Citation

Schreiner, M.L., Romanok, K.M., Gray, J.T., Brown, E.J., Williams, B.M., Kneser, M., Capuzzi, A.J., Boerner, J., Giunta, L., Serillo, P., Trainor, J.J., and Smalling, K.L., 2026, Understanding the occurrence and distribution of per- and polyfluoroalkyl substances (PFAS) in surface waters of the nontidal Passaic River Basin: U.S. Geological Survey Scientific Investigations Report 2026–5018, 64 p., https://doi.org/10.3133/sir20265018.

ISSN: 2328-0328 (online)

Table of Contents

  • Introduction
  • Purpose and Scope
  • Methods
  • Results
  • Discussion
  • Summary and Conclusions
  • Appendix 1. Ancillary Study Results
  • Appendix 2. Presumptive Sources of Per- and Polyfluoroalkyl Substances
Publication type Report
Publication Subtype USGS Numbered Series
Title Understanding the occurrence and distribution of per- and polyfluoroalkyl substances (PFAS) in surface waters of the nontidal Passaic River Basin
Series title Scientific Investigations Report
Series number 2026-5018
DOI 10.3133/sir20265018
Publication Date April 30, 2026
Year Published 2026
Language English
Publisher U.S. Geological Survey
Publisher location Reston, VA
Contributing office(s) New Jersey Water Science Center
Description Report: ix, 64 p.; Data release
Online Only (Y/N) Y
Additional Online Files (Y/N) N
Additional publication details