PFAS in tap water, ZIP 15370 (Greene County and Washington County)

No serving system had a quantified PFAS-4 compound above the 3 to 4 ng/L reporting limits at its latest sample. That's below the lab limit, not zero.

2 community water systems report serving ZIP 15370 (Greene County and Washington County, Pennsylvania) · 44,400 people served

Water systems serving ZIP 15370

Water system	People served	PFAS-4 at the latest sample	Entry points	Latest sample
Southwestern PA Water Auth reported by the system to EPA	40,200	below the 3 to 4 ng/L reporting limit	1	February 13, 2024
PA American Dilliner System reported by the system to EPA	4,200	below the 3 to 4 ng/L reporting limit	1	November 19, 2025

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.