What was found, and when
PFOA and PFOS are two of the compounds in firefighting foam that was used for decades at the former Naval Air Warfare Center in Warminster and at the Willow Grove and Horsham airfields on the county line. They moved into groundwater, and groundwater is where both townships drew their water.
The peak public-water readings in Warminster were 350 parts per trillion of PFOA and 1,100 ppt of PFOS, figures the Buxmont Coalition carried with a status date of March 2018. In the same account, more than 650 private wells in the area were sampled and 169 came back above the health advisory then in effect.
For scale: EPA’s drinking water limit, set in 2024, is 4 ppt each for PFOA and PFOS. The peak numbers above date from before the affected wells came off line and treatment went in, which is the next part.
What Warminster did
The Warminster Municipal Authority took its affected wells offline in 2016 and bought roughly three million gallons a day from North Wales Water Authority under a contract that ran to June 2026. That purchase cost about $2.5 million a year, and the rate customers paid went from $2.89 to $4.65 per thousand gallons in October 2016 (WHYY, May 10, 2019).
By 2019, four wells had been refitted with granular activated carbon and ion exchange, at a system cost of about $12 million. The state put $8 million toward the Warminster and Warrington work in 2019 (Philadelphia Inquirer, August 30, 2019). The authority’s own site, read in August 2026, says it is adding PFAS treatment at ten more wells. The system serves about 36,000 people and carries no health-based violations on record.
What the authority is buying or producing after the June 2026 contract date is not something we could confirm from a public page. That is a question for the authority, and a reasonable one to ask before you buy.
Picked up day and night, calls recorded. No credit pull, no application.
Say which township the house is in and whether it's on public water or a well, and a licensed Pennsylvania lender tells you what the loan will ask for on the water side. One call covers it.
The form takes about a minute and lands in the same place as the call.
What Warrington did
Warrington sold its water and sewer systems; water is now North Wales Water Authority and sewer is the Bucks County Water and Sewer Authority.
North Wales built dual-tank granular activated carbon treatment on the Warrington wells. The Costner wellfield was permitted in November 2020, and wells 3, 5, 8, 9 and 11 were permitted in September 2023, with quarterly finished-water testing reported as non-detect below 2.0 ppt.
The 2023 consumer confidence report for Warrington shows nearly all of the township’s water coming from North Wales’ Forest Park treatment plant, where PFOA averaged 2.2 ppt on a range of non-detect to 4.1, and PFOS averaged 1.1 ppt on a range of non-detect to 2.8. The Warrington wells themselves are listed as non-detect as of December 2023 and are used to supplement or for emergencies.
The Navy’s part
Two Superfund sites sit behind all of this. The Naval Air Warfare Center in Warminster, 840 acres in the township and Ivyland, went on the National Priorities List in October 1989; between 1993 and 1995 off-base private wells with solvent contamination got more than 40 home treatment units and about 60 homes were connected to public water, and the Navy later added carbon treatment for PFAS. Its last five-year review was in 2021 and the next was due in 2026.
The Willow Grove Naval Air Station and Horsham Air Guard Station site was listed in 1995. Its PFAS operable units are still under investigation, with the next five-year reviews scheduled for 2028.
If the house is on public water, ask these
Call the supplier before the inspection contingency runs out. For Warminster that’s the Warminster Municipal Authority; for Warrington it’s North Wales Water Authority.
- Which wells or which treatment plant serves this address?
- What did the most recent finished-water test show for PFOA and PFOS, and on what date?
- Is treatment in place at that source, and if it’s planned, when?
- May I have the current Consumer Confidence Report, and the one before it?
- What’s the current rate per thousand gallons, and is a rate change scheduled?
Those five answers, in writing, are worth more than any summary of the history, including this one.
If the house is on a private well
A private well has no annual report and nobody tests it for you. Put the test in the sale agreement or in your inspection period, and use a certified laboratory.
Ask for PFOA and PFOS specifically, since a standard well panel often skips them, alongside bacteria, nitrate, lead and whatever the inspector recommends for the area. Solvents are also part of the history near the Warminster base, so ask the lab what its volatile organic compound panel covers.
Who pays is negotiable, and in practice the buyer usually pays for inspections. If a result comes back high, treatment at the tap or at the point of entry is a known fix with a known cost, and that cost is something you can put in front of the seller while the inspection window is still open.
What the loan actually cares about
None of this by itself changes whether the mortgage happens. On public water, the lender is looking at the appraisal and the property’s condition, and public water and sewer are simply noted.
On a well, it’s more concrete. Government loan programs generally require a water test on a property served by a private well, and VA’s minimum property requirements include a safe water supply. The lender tells you which test it accepts and who may perform it, and the appraiser notes the well and any septic system.