PFAS in tap water, Lehigh County, Pennsylvania
6 of 10 water systems had PFAS-4 above our 0.5 ng/L benchmark at the latest sample. Highest: Emmaus Borough Public Water, 213.2 ng/L. 5 had PFOA or PFOS above the 4 ng/L federal MCL in at least one sample.
10 community water systems · 237,036 people served · newest sample October 20, 2025
Water systems in Lehigh County
| Water system | People served | PFAS-4 at the latest sample | Entry points | Latest sample |
|---|---|---|---|---|
| Lca Allentown Division | 118,000 | 4.4 ng/L above the 2029 federal MCL | 2 | November 14, 2023 |
| Lca Wlsa Central Division | 47,693 | 4.3 ng/L above the 2029 federal MCL | 14 | January 31, 2024 |
| Swt Main System | 14,500 | below the 3 to 4 ng/L reporting limit | 9 | December 10, 2024 |
| Emmaus Borough Public Water | 14,000 | 213.2 ng/L above the 2029 federal MCL | 4 | February 11, 2025 |
| Whitehall TWP Authority | 13,063 | 16.1 ng/L above the 2029 federal MCL | 5 | May 1, 2025 |
| Salisbury TWP Water System | 8,522 | 8.7 ng/L above the 2029 federal MCL | 1 | October 20, 2025 |
| Upper Saucon TWP Water Supply | 7,300 | below the 3 to 4 ng/L reporting limit | 5 | November 20, 2023 |
| Catasauqua Mun Water Works | 6,598 | 4.2 ng/L | 1 | December 11, 2023 |
| Slatington Borough Water Sys | 4,450 | below the 3 to 4 ng/L reporting limit | 2 | October 15, 2024 |
| Lca North Whitehall Division | 2,910 | below the 3 to 4 ng/L reporting limit | 1 | November 13, 2023 |
| Creative Kids East Child Dev non-transient non-community water system | 175 | monitored under UCMR 5, no page | ||
1 system without a page is not a community water system (schools, workplaces, campgrounds). Nobody's home tap water.
Not sure which one is yours? The systems report their own service areas to EPA. Check your water bill or your utility's Consumer Confidence Report.
ZIP codes in Lehigh County
Census ZIP code tabulation areas that overlap the county. A ZIP served by one system opens that system's page; a ZIP shared by several systems lists them.
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.