PFAS in tap water, ZIP 19426 (Montgomery County)
4 of 5 water systems had PFAS-4 above our 0.5 ng/L benchmark at the latest sample. Highest: Collegeville Trappe Joint PWD, 253.1 ng/L. 4 had PFOA or PFOS above the 4 ng/L federal MCL in at least one sample.
5 community water systems report serving ZIP 19426 (Montgomery County, Pennsylvania) · 242,404 people served
Water systems serving ZIP 19426
| Water system | People served | PFAS-4 at the latest sample | Entry points | Latest sample |
|---|---|---|---|---|
| North Penn Water Authority reported by the system to EPA | 91,941 | 5.1 ng/L above the 2029 federal MCL | 5 | January 14, 2025 |
| PA American Norristown reported by the system to EPA | 88,885 | below the 3 to 4 ng/L reporting limit | 1 | October 9, 2024 |
| PA American Royersford reported by the system to EPA | 49,508 | 24.8 ng/L above the 2029 federal MCL | 5 | October 8, 2024 |
| Collegeville Trappe Joint PWD reported by the system to EPA | 8,470 | 253.1 ng/L above the 2029 federal MCL | 7 | September 20, 2023 |
| Aqua PA Perkiomen Township reported by the system to EPA | 3,600 | 18.2 ng/L above the 2029 federal MCL | 5 | July 8, 2024 |
Not sure which one is yours? The systems report their own ZIP lists to EPA. Check your water bill or your utility's Consumer Confidence Report.
Where this ZIP is
How to read these numbers
We compare PFAS-4 (PFOA + PFOS + PFNA + PFHxS) with this site's 0.5 ng/L benchmark, the same line as on the European pages. UCMR 5 reporting limits are 3 to 4 ng/L. So any quantified PFAS-4 compound is above the benchmark, and a clean result reads "below the 3 to 4 ng/L reporting limit", never zero. The US legal limit is the 4 ng/L federal MCL for PFOA and PFOS, which systems must meet from April 26, 2029 ("above the 2029 federal MCL").
EPA: "UCMR 5 results do not indicate compliance or noncompliance with the PFAS drinking water standards". Samples are taken where water enters the distribution system, not at your tap. A system may have changed sources or added treatment since. Source: U.S. Environmental Protection Agency (EPA), Office of Water, PFAS National Primary Drinking Water Regulation (NPDWR). Regulation details retrieved September 19, 2026. Every system page tracks the 2029 compliance date and the proposed rescission of the PFHxS, PFNA, HFPO-DA and Hazard Index limits.
This site is a data project, not an official source. If in doubt, check with your water supplier or local authority.