Visit our PFAS page to read more about PFAS contaminants, and what Pennsylvania is doing on a state level.
Site facts
Municipality/County:
East and West Rockhill Townships, Bucks County
Hazardous Sites Cleanup Program Site (HSCA) Since:
2016
Primary contaminants of concern: Perfluorooctanoic acid (PFOA) and Perfluorooctanesulfonic acid (PFOS)
- Detected in:
Soil, Ground Water, and Surface Water - Impacting:
Drinking Water - DEP Response Actions:
Drinking Water (2019)
DEP Project Officer:
Colin R. Wade, 484-250-5722 or cowade@pa.gov
Background
- In September 2016, after a public supply well in the area was found to contain combined concentrations of PFOA and PFOS that exceeded the U.S. Environmental Protection Agency’s (EPA) 70 parts per trillion (ppt) Health Advisory Level (2016 HAL), and another public supply well was found to contain combined concentrations slightly below the HAL, DEP immediately took steps to begin a thorough investigation of the surrounding area.
- In January 2023, the Pennsylvania Environmental Quality Board amended the Pennsylvania Safe Drinking Water Act setting Maximum Contaminant Levels (PA MCLs) for PFOA (14 ppt) and PFOS (18 ppt). At that time, DEP expanded ongoing efforts regarding its investigation of the surrounding area and offered bottled water to residences known to be above the new PA MCLs.
- On April 10, 2024, EPA announced the National Primary Drinking Water Regulation (NPDWR) establishing new MCLs for six Per- and Polyfluoroalkyl Substances (PFAS) in drinking water, including PFOA and PFOS. EPA's PFAS site.
- DEP’s responsibility under the Hazardous Sites Cleanup Act (HSCA) is to select a remedy that is protective of human health and the environment and complies with all statutory and regulatory requirements.
- Since November 2016, DEP has tested over 170 private wells within the originally contaminated public water wells boundaries.
- DEP is currently evaluating residential well sampling data to propose a response action to provide an alternative source of potable water to impacted homes located within the area of concern that were not connected to the public waterline.
What are PFAS?
- Per- and polyfluoroalkyl substances (PFAS) are man-made chemicals, are resistant to heat, water, and oil, and persist in the environment and the human body. PFAS are not found naturally in the environment.
- They have been used to make cookware, carpets, clothing, fabrics for furniture, paper packaging for food, and other materials that are resistant to water, grease, or stains. They are also used in firefighting foams and in a number of industrial processes.
- More information about PFAS can be found at: PFAS in Pennsylvania and Our Current Understanding of the Human Health and Environmental Risks of PFAS | US EPA
Can I have my private well sampled by DEP for PFAS?
- Please contact the DEP Project Officer to see if you are eligible for DEP sampling. The area eligible for sampling by DEP is based on DEP’s current understanding of the contamination originating from the site. This area is routinely adjusted as DEP collects and evaluates data from the site.
- PFAS are unfortunately commonly found in drinking water in Pennsylvania. For several decades PFAS have been and continue to be used in a wide variety of common commercial products and industrial operations. DEP does not regulate private wells, but strongly recommends that well owners routinely sample their well for a number of contaminants including PFAS, bacteria, volatile organic compounds, and metals. More information on private well testing can be found at DEP's Private Wells webpage.
Additional Information
- Since November 2016, DEP has collected samples from more than 170 private wells within the area of interest surrounding the original contaminated public supply wells.
- Results of this sampling ranged from non-detect (ND) to 16,360 ppt combined for PFOA and PFOS.
- 15 homes were identified as having PFOA and PFOS levels above the 2016 HAL.
- The Administrative Record was open for public comment between June 2, 2018 and August 31, 2018. DEP held a public hearing on July 11, 2018.
- On April 18, 2019, DEP issued its Statement of Decision (SOD) and Response to Public Comments Document. In the SOD, DEP selected the Installation and Maintenance of Whole-House Filtration Systems (systems) to address the threats posed by exposure to PFOA and PFOS contamination above the 2016 HAL in residential privately-owned potable wells within the Site.
- Since the issuance of the SOD, DEP determined that the necessary circumstances already exist to allow its interim response to exceed 12 months in duration. Based on that determination, DEP no longer planned to transfer maintenance of the filtration systems to the residents after the 12-month period. Instead, DEP planned to monitor and maintain the systems to ensure that they are working properly for the duration of its investigation of the Site.
- As of March 2022, DEP had installed systems at 13 of the 15 homes with PFOA and PFOS levels above the 2016 HAL.
- In January 2023, DEP began to resample homes in the investigation area with prior detections below the 2016 HAL to determine whether they would exceed the lower PA MCLs of 14 ppt for PFOA and 18 ppt for PFOS.
- In February 2023, the Perkasie Regional Authority was awarded a $3.5M PENNVEST grant to extend a public waterline to the Site and connect homes at the Site, including those that were above the 2016 HAL.
- As of March 2024, 51 homes were connected to the waterline. DEP subsequently removed the treatment systems it installed from the homes.
- DEP is currently evaluating the data from residential well sampling to propose a response action to provide impacted homes located within the area of concern that weren’t connected to the public waterline with an alternative source of potable water.
- DEP is investigating groundwater, soil, and surface water in the area to determine the nature and extent of PFAS in the environment.
- A March 2020 Site Inspection Report (PDF), prepared by EnviroTrac, Ltd., on behalf of DEP, documents Site Investigation activities conducted between 2016 and 2020. Activities included:
- soil sampling,
- surface water sampling,
- sediment sampling, and
- the installation of monitoring wells at multiple depths.
- A September 2022 Technical Summary Report (PDF) and its Appendices (PDF), prepared by Tetra Tech, on behalf of DEP, documents Site activities conducted between 2019 and November 2021. Activities included:
- potable water treatment and monitoring,
- monitoring well installation,
- surface water / shallow groundwater sampling, and
- the in-situ remediation pilot study (described below).
- DEP performs routine sampling of the monitoring wells across the Site. The latest results can be found here:
- DEP and its contractors are installing monitoring wells at the Site at several locations in late October and November 2025.
In an attempt to prevent the further spread of PFOA and PFOS from the source area into nearby residential wells, DEP and its contractors are conducting a pilot study consisting of the use of a Regenesis product known as PlumeStop® to create a permeable, underground barrier, which will allow groundwater to flow through it, but not PFOA and PFOS.
- In January 2021, four injection wells and an additional monitoring well were drilled at the source area and sampled.
- Injections of PlumeStop® were successfully conducted in April 2021.
- The results of the post-injection sampling events show sustained and substantial reductions of PFOA and PFOS in monitoring wells within the study area. The latest results can be found here:
Timeline (October 2025)
● Completed steps, ^ Current step, ✚ Next steps
● | Public Water Supply Well detected PFOA and PFOS above HAL | 9/2016 |
^ | Drinking water sampling | 11/2016-Ongoing |
● | Drinking Water Interim Response Statement of Decision (SOD) and Response to Public Comments | 4/18/2019 |
● | Initiated a Suspected Source Property Investigation | 5/2019 |
● | Installation of Site Monitoring Wells | 10/2019 |
^ | Sampling of Monitoring Wells | 12/2019-Ongoing |
^ | Installation and maintenance of Whole-House Filtration Systems | 12/2019-Ongoing |
● | Completion of the Site Inspection Report | 3/2020 |
● | Expansion of the Monitoring Well Network | 10/2020 |
● | Initiation of a Pilot Study | 1/2021 |
● | PlumeStop® injections | 4/2021 |
● | Additional soil sampling | 3/2022 |
● | Technical Summary Report | 9/2022 |
✚ | Additional Expansion of the Monitoring Well Network | 10/2025 |
Community updates
To subscribe to updates, send an email to: RA-EP-SEROECB@pa.gov. Please indicate in the subject line or text of the email that you’d like to receive updates related to the Ridge Run PFAS HSCA Site.
Additional Contact Information
Please direct correspondence or inquiries to one of the following:
- Site Information: Colin R. Wade, Site Project Officer, at 484-250-5722 or cowade@pa.gov
- Community and Media Relations: Robyn Briggs, Regional Communications Manager, at 484-250-5965 or robbriggs@pa.gov
- Legislative Inquiries: Lisa Strobridge P.G., Local Government Liaison, at 484-250-5817 or lstrobridg@pa.gov
Municipality information
East Rockhill Township
(215) 257 -9156
staff@eastrockhilltownship.org
West Rockhill Township
(215) 257-9063
info@westrockhilltownship.org