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Contaminants of Emerging Concern: PFAS
Introduction
Chemistry of PFOA, courtesy of the National Institute of Environmental Health Sciences.https://www.niehs.nih.gov/health/assets/images/pfoa.jpg

What are PFAS?

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

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 such as stain repellant textiles, fire-fighting foams, paper coatings and food packaging. 

Exposure to PFAS

In addition to direct human exposure pathways, PFAS can enter the environment through industrial outfalls, municipal treatment plants, usage of AFFF for firefighting, 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 Criteria: States and EPA

PFAS have been detected in drinking water wells. The Bains states have implemented initiatives to manage PFAS exposure, including setting fish consumption advisories.

Health advisories and standards have been developed by federal and Basin state agencies for some PFAS.

  • U.S. EPA: In March 2023, the EPA proposed National Primary Drinking Water Standards for six PFAS compounds that it anticipates finalizing by the end of 2023. If implemented this rule would set maximum containment levels (MCL) for the target PFAS compounds and require public water systems to monitor these compounds, notify the public of their concentrations, and reduce levels that exceed the proposed standards.

  • 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 has 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.

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

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

The DRBC also works with its various advisory committees (e.g., the TAC, MACC and 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 and fish tissue under several different grant projects.

Channel catfish and white perch are collected from the tidal Delaware River; 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 bluecrabs 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 the Delaware Bay.

In 2023, surface water, sediment and fish tissue samples are being collected at 16 total sites, 15 mainstem and one tributary (Schuylkill River). Forty different analytes of PFAS will be monitored for, and samples will be collected in the spring and fall.

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 will collect sediment and surface water samples at 12 sites and fish tissue at 6 sites.

Partnership for the Delaware Estuary (Bipartisan Infrastructure Law)

Thanks to grant funding from the BIL through the Partnership, surface water from 12 tidal tributaries will be sampled from south of Trenton, N.J. to Delaware. Parameters sampled for include PFAS, PCBs, Dioxins, Furans, Organochlorine Insecticides, Neonicotinoid Insecticides, Pyrazole Pesticides and PAHs. The goal is to track down sources of these pollutants in tributaries.

What Do the Data Show to Date?

•  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. 

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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