Hydrologic and Water Quality Studies of PFAS in Pennsylvania

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USGS is working with federal, state, and local partners to monitor and evaluate perfluoroalkyl and polyfluoroalkyl substances (PFAS) in Pennsylvania's groundwater and surface waters.

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Hydrologic Technician Collecting PFAS Surface Water Samples in Lake Erie, Pennsylvania

(Credit: Joe Duris, USGS Pennsylvania Water Science Center. Public domain.)

Per- and Polyfluorinated Alkyl Substances (PFAS) are emerging anthropogenic contaminants, classified as a water pollutant, manufactured and used commercially in the U.S. since the 1940s. As a group, PFAS contain more than 4,000 different compounds that are saturated with fluorine, some as carboxylic acids (perfluorooctanoic acid [PFOA]) and some as sulfonic acids (perfluorooctanesulfonic acid [PFOS]). The primary use of the chemicals is in firefighting foams for hydrocarbon fires with so called Aqueous Film Forming Foam (AFFF), the manufacture of non-stick coatings, the manufacture of stain resistant and waterproof fabric, metal plating, food packaging, paints, and surfactants. Scientific studies indicate PFAS can affect multiple systems in the human body and have effects such as hormone level interference, increased cholesterol levels and risks of certain cancers.

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PA Hydrologic Technician Preparing a Shipment of PFAS Samples for Laboratory Analysis

(Credit: Joe Duris, USGS Pennsylvania Water Science Center. Public domain.)


Pennsylvania Water Science Center is working with Pennsylvania Department of Environmental Protection and experts across the Nation to develop and implement rigorous and innovative techniques to detect PFAS at low levels and determine the magnitude and spatial distribution of environmental PFAS contamination. 

Current Pennsylvania PFAS Projects include: 


Current Pennsylvania PFAS Projects
Project Background Products
Standardization of PFAS Sampling Techniques for Surface Water As part of the USGS national goals to collect consistent and reliable data, the USGS Pennsylvania Water Science Center partnered with the USGS Water Mission Area and the USGS National Water Quality Laboratory (NWQL) to systematically test standard sampling equipment to determine existing equipment and cleaning procedures that can be used for PFAS sampling in Pennsylvania. We worked with our cooperators at the Pennsylvania Department of Environmental Protection (PDEP) Bureau of Clean Water and with collaborators at the Susquehanna River Basin Commission, to conduct an established PFAS sampling equipment cleaning procedure with an equipment blanking round-robin study, (results are available here) to ensure cleaning procedures met project specifications for sampling of PFAS in surface water.   Data from this study is pending release in USGS ScienceBase and will be used to inform new chapters in the USGS National Field Manual that will provide specific techniques related to PFAS sampling in surface water and groundwater.  
PFAS in Pennsylvania Streams and Lakes The first-of-its-kind PFAS reconnaissance to evaluate seasonal fluctuation and fate and transport of PFAS in Pennsylvania. The USGS has partnered with the Commonwealth of Pennsylvania to operate the Pennsylvania Surface Water Quality Network (WQN) since 2002. Pennsylvania uses information produced from this partnership to evaluate trends in water quality, collect data to inform current or future permitting, to assess water for the Federal Clean Water Act Sections 303(d) and 305(b), and to evaluate emerging science topics, such as PFAS contamination in water. This study used adapted USGS surface water sampling techniques to provide information on PFAS in surface water that is relevant to the cooperator, other state and federal agencies, local water resource managers, and the public. A total of 216 water samples (environmental and quality control) for PFAS were collected from 178 sites across the entire WQN. Samples were analyzed for 33 PFAS compounds and 19 PFAS precursor compounds (52 total PFAS-related analytes). 

Looking ahead, from October 2020 to September of 2021 the USGS PAWSC is cooperating with the PADEP to evaluate likely PFAS sources across the landscape of Pennsylvania and add to a growing body of PFAS data and information describing the occurrence, distribution, fate and transport of PFAS across the North Atlantic Appalachian Region of the USGS. This interpretive effort will result in at least one peer reviewed journal article. 

Per-and Polyfluorinated Alkyl Substances (PFAS) and associated ancillary data from the Commonwealth of Pennsylvania, USA, 2019: U.S. Geological Survey data release.

A companion USGS Data Series Report is in preparation to describe standard operating procedures for equipment selection, equipment cleaning, sampling, sample processing, and analysis.  

Seasonality of PFAS in Pennsylvania Surface Water In 2021 a new study designed to assess seasonal variation in the variety and concentrations of PFAS compounds in streams will be conducted. Sampling for 24 PFAS compounds will occur monthly at 20 WQN sampling locations from October 2020 to September 2021, in addition to our standard operation of the WQN network. There will be 10 locations sampled in the greater Pittsburgh area in the Ohio River Basin, 1 location near Harrisburg in the Susquehanna River Basin, and 9 locations in the Delaware River Basin. All PFAS samples will be collected by 2-person field crews using “clean-hands/dirty hands” protocols. Samples will be depth and width integrated and composited in an HDPE churn splitter. For the first three months of the study, split replicates will be collected to compare results between the standard EPA drinking water method (USEPA 537.1) and new external-standard calibration EPA validated method (USEPA SW-856-8327). Routine PFAS analysis of all samples will be conducted at the PaDEP Laboratory following USEPA method 537.1.   
Willow Grove and Warminster - Groundwater flow and PFAS in wells USGS is partnering with the U.S. Navy to study the effects of changing groundwater use on migration of groundwater and surface water containing PFAS from former naval facilities and other sources in southeastern Pennsylvania. USGS has investigated groundwater flow and contaminant transport in the vicinity of former Navy bases in Bucks and Montgomery Counties, southeastern Pennsylvania, (more information here) since the 1990's.  
Letterkenny Army Depot PFAS Monitoring Letterkenny Army Depot (LEAD), located near Chambersburg, Pennsylvania is under the command structure of the United States Army Aviation and Missile Life Cycle Management Command. Most of LEAD is an ammunition storage facility (16,614 acres), which is referred to as the Ammunition Area (AA). The Pennsylvania Department of Environmental Protection (PADEP) has required that LEAD perform chemical characterization and benthic macroinvertebrate sampling at selected locations within and near the AA at LEAD—open burning/open detonation (OB/OD) areas and the Flashing Furnace unit, also located in the OB areas—where thermal treatment occurs of various ammunition (up to 30 millimeter), propellants, explosives, pyrotechnics (PEP) and PEP-related materials. LEAD contracted Weston Solutions, Inc., to develop the environmental sampling plan, in coordination with the Pennsylvania Department of Environmental Protection (PADEP), as part of the required Resource Conservation and Recovery Act (RCRA) permitting process. LEAD has tasked the U.S. Geological Survey (USGS) with carrying out the PADEP-approved environmental sampling plan by conducting the environmental monitoring to document how activities conducted within the OB/OD and Flashing Furnace (FF) areas are impacting the surrounding environment. Environmental monitoring will be conducted quarterly for one year and annually thereafter to include sediment trap sampling, sedimentation basin sampling, soil sampling, surface-water sampling, groundwater sampling, and benthic macroinvertebrate sampling. USEPA Letterkenny Superfund Site Remedial Actions can be found here.

At the request of PADEP, during the first quarter of 2019, of groundwater sampling of the first year of sampling will include analysis for 12 PFAS compounds using EPA Method 537.

USGS National Water Quality Program  pending pending