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Contaminants of Emerging Concern: PFAS
Introduction
A photo of water and sediment samples on the Neshaminy Creek. Photo by the DRBC.
A photo of water and sediment samples collected from
the Neshaminy Creek. Photo by the DRBC.

What are PFAS?

Perfluoroalkyl and polyfluoroalkyl substances (PFAS) are a diverse group of >10,000 chemical compounds that have varying degrees of persistence, toxicity and bioaccumulation in the environment.

Known as "forever chemicals," they also do not easily degrade.

The most produced and studied of the PFAS are Perfluorooctanoic acid (PFOA) and Perfluorooctanesulfonic acid (PFOS).

PFAS have unique properties to repel both water and oil. They are found in a variety of industrial and household products, including:

  • Fire-fighting foams

  • Nonstick cookware, paper coatings & food packaging

  • Stain repellant & waterproof textiles (clothing, furniture, carpet)


Exposure to PFAS

In addition to direct human exposure pathways, PFAS can enter the environment through industrial outfalls, municipal treatment plants, firefighting foams, stormwater runoff and landfill leachate.

PFAS released into the environment can contaminate surface water, as well as groundwater, and can bioaccumulate in fish. Environmental releases expose wildlife and humans through direct (swimming, drinking water, etc.) and indirect (consumption of contaminated organisms, etc.) pathways.

With PFAS' ubiquitous nature, there is increasing evidence of its adverse effects on human health and the environment.


Setting PFAS Drinking Water Criteria: States and EPA

PFAS have been detected in drinking water. To manage and reduce PFAS exposure, the basin states and the EPA have implemented health advisories, drinking water standards and fish consumption advisories.

  • U.S. EPA: In April 2024, the EPA announced the final National Primary Drinking Water Regulation (NPDWR), setting maximum containment levels (MCL) for six target PFAS compounds. This rule requires public water systems to monitor these compounds, notify the public of their concentrations and reduce levels that exceed the proposed standards. Learn more about the final rule.

  • New Jersey, Pennsylvania and New York: These states have PFAS drinking water standards for two to three compounds, but are all two to three times higher than the proposed EPA limits.

  • Delaware: Delaware was developing PFAS drinking water standards but paused those efforts pending the outcome of the proposed EPA MCL drinking water standards.
PFAS Monitoring in the Delaware River Basin
DRBC staff pull a sediment sample from the Delaware River to monitor for PFAS. Photo by DRBC.
DRBC staff pull a sediment sample from the Delaware
River to monitor for PFAS. Photo by DRBC.

It is important to quantify PFAS occurrence and bioaccumulation to protect water resources that are vital to ecosystem and human health.

  • DRBC has investigated PFAS in Delaware River fish tissue since 2004, in surface water since 2007 and in sediment since 2016.

  • DRBC works with the Basin states, EPA and others to understand and manage these contaminants of emerging concern.

  • DRBC also works with its Toxics Advisory Committee (TAC), Monitoring and Advisory Coordination Committee (MACC) and Water Quality Advisory Committee (WQAC) to solicit input from experts and stakeholders in the Basin on how to improve its monitoring program.


Why does the DRBC Collect PFAS Data?

  • To identify occurrences and potential sources of PFAS;

  • To understand risks to designated uses (e.g., source water protection, fish consumption advisories, maintenance and propagation of fish and other aquatic life); and

  • To evaluate the efficacy of regulatory and reduction management strategies in reducing exposure and risks from PFAS.


DRBC Monitoring Efforts

  • The DRBC has performed PFAS monitoring of surface water, sediment, fish tissue and blue crab tissue under several different grant projects.

  • Fish species collected are channel catfish and white perch from the tidal Delaware River and white sucker and smallmouth bass from the non-tidal Delaware River.


Delaware River Conservation Fund (NFWF)

  • In 2021 and 2022, the DRBC collected samples of surface water, sediment, fish and blue crabs to monitor for 40 different analytes of PFAS in the mainstem Delaware River at seven locations from Lackawaxen, Pa. in the upper Delaware to Pea Patch Island, Del. Five tributaries were also sampled, including the Neshaminy Creek and the Lehigh, Schuylkill and Christina rivers.

  • Data collected show a general trend of increasing PFAS concentrations from upstream to downstream, likely due to increasing population, commercial and industry densities as you head towards Pea Patch Island in the Delaware Bay.

  • In July 2023, the DRBC published PFAS Water Quality and Fish Tissue Assessment Study: Year 1 (pdf).

  • In 2023, 15 main stem sites from Lackawaxen, Pa. to Pea Patch Island, Del. and 1 tributary (Schuylkill) were sampled for water and sediment and 9 sites for fish and 1 for blue crabs. Forty different analytes of PFAS were monitored for, and samples were collected in the spring and fall.

  • In March 2024, the DRBC published PFAS Water Quality and Fish Tissue Assessment Study: Year 2 (pdf).

  • The Year 3 study report under this grant is forthcoming, sometime in late 2024/early 2025.


PA Coastal Zone Management (PACZM)

  • This work was financed, in part, through a Federal Coastal Zone Management Grant, administered by the PADEP and funded by NOAA.

  • For Year 1 of this grant, the DRBC was able to monitor 17 total sites, 10 in the mainstem Delaware River Estuary bordering Pennsylvania and 7 in Pa. tidal tributaries, near their confluence with the Delaware River. Over 40 different PFAS compounds were monitored for. The same general trend of increasing PFAS concentrations from upstream to downstream, likely due to increasing population, commercial and industry densities, was seen.

  • In July 2023, the DRBC published PFAS in Surface Water, Sediment and Fish in the Pennsylvania Coastal Zone (pdf) for year 1 of the project.

  • In 2023, monitoring for Year 2 of this grant collected sediment and surface water samples at 12 sites in the tidal Delaware River and adjacent Pa. tributaries. Collection of fish tissue at 6 sites will occur in the spring 2024.

  • A final report is expected in late 2024/early 2025.


Partnership for the Delaware Estuary (Bipartisan Infrastructure Law)

  • In 2023, thanks to grant funding from the Bipartisan Infrastructure Law that came to the DRBC through the Partnership for the Delaware Estuary, surface water from 12 tidal tributaries were sampled from south of Trenton, N.J. to Delaware.}

  • Parameters sampled for included PFAS, PCBs, Dioxins, Furans, Organochlorine Insecticides, Neonicotinoid Insecticides, Pyrazole Pesticides and PAHs.

  • The goal is to track down sources of these pollutants in tributaries that contribute to pollutants in the mainstem Delaware River.

  • Enhanced Monitoring for Toxics and Emerging Contaminants in Delaware Estuary Tributaries (Final Report; pdf; April 2025)


N.J. Water Supply Authority: Delaware & Raritan Canal

  • In the spring 2024, the DRBC deployed passive samplers in the D&R Canal (in both the DRB and Raritan Basin) to help the N.J. Water Supply Authority determine sources of PFAS in the canal. The canal is a source of drinking water. Initial results show higher PFAS concentrations in the Raritan portion of the D&R Canal than in the DRB.


What Do the Data Show to Date?

  • PFAS concentrations generally increase from upstream to downstream, likely due to increasing population, commercial and industry densities.

  • Concentrations of PFAS in resident fish varied by species, sample location and sample year.

  • Surface water concentrations of PFAS appear to be below regional and national guidelines in areas designated as drinking water sources.

  • While significant decreases in some PFAS compounds have been observed in fish species, reduction in concentrations of other PFAS, such as PFOS, in fish tissue has been less substantial and has triggered fish consumption advisories in Basin states.

  • Sediment from the tidal main stem Delaware River have long-chain PFAS detected at low concentrations.

  • Further evaluation of risk to human health and wildlife is warranted in the Delaware River. 


Long-term Roadmap

  • With ~20 years of monitoring, the DRBC's PFAS dataset is extensive. Looking ahead, DRBC plans to go from basic monitoring to synthesizing our data to identifying hot spots in the Basin with a goal of identifying sources and reducing discharges.

DRBC staff collects a surface water sample from the Delaware River to monitor for PFAS. Photo by DRBC. DRBC staff collects a sediment sample from the Delaware River to monitor for PFAS. Photo by DRBC. DRBC staff collects a surface water sample from the Delaware River to monitor for PFAS. Photo by DRBC.
DRBC staff collects a surface water
sample from the Delaware River to
monitor for PFAS. Photo by DRBC.		 DRBC staff collects a sediment sample
from the Delaware River to monitor for
PFAS. Photo by DRBC.		 DRBC staff collects a surface water
sample from the Delaware River to
monitor for PFAS. Photo by DRBC.
DRBC staff collected several species of fish, including catfish, from the Delaware River to monitor for PFAS. Photo by DRBC. DRBC staff collected several blue crabs from the Delaware Bay to monitor for PFAS. Photo by DRBC. DRBC staff collected several species of fish, including catfish, from the Delaware River to monitor for PFAS.Photo by DRBC.
DRBC staff collected several species of
fish, including catfish, from the
Delaware River to monitor for PFAS.
Photo by DRBC.		 DRBC staff collected blue crabs from
the Delaware Bay to monitor for PFAS.
Photo by DRBC.		 DRBC staff collected several species of
fish, including catfish, from the
Delaware River to monitor for PFAS.
Photo by DRBC.
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