What the EPA limit means
No federal limit
The EPA has not set an enforceable numeric limit for this contaminant.
—
Health goal (MCLG) — the level with no known health effect. It is a goal, not a legal limit, and is often zero for carcinogens.
UCMR-5
Where these measurements come from. Hover the tag for the EPA programme and years.
Where PFOS was found
The water suppliers reporting the highest levels, worst first.
| Supplier | City | State | Level vs EPA limit |
|---|---|---|---|
| Nashville, Town of | Nashville | NC | 0.4900 µg/L No EPA limit set |
| Running Springs Water District | Running Springs | CA | 0.2365 µg/L No EPA limit set |
| Artondale | Tacoma | WA | 0.1536 µg/L No EPA limit set |
| Emmaus Borough Public Water | Emmaus | PA | 0.1530 µg/L No EPA limit set |
| Gwa Northern Water System | Tumon | GU | 0.1350 µg/L No EPA limit set |
| Yeshiva Farm Settlement | New Castle | NY | 0.1060 µg/L No EPA limit set |
| City of Grand Prairie | Grand Prairie | TX | 0.0820 µg/L No EPA limit set |
| Orangewood Water System | Holiday | FL | 0.0808 µg/L No EPA limit set |
| City of Oxford | Oxford | MS | 0.0722 µg/L No EPA limit set |
| Irondale Water System | Irondale | AL | 0.0594 µg/L No EPA limit set |
| Liberty Utilities - Bellflower-Norwalk | Downey | CA | 0.0590 µg/L No EPA limit set |
| Pa American Audubon | Norristown | PA | 0.0579 µg/L No EPA limit set |
| Lafayette | La Fayette | GA | 0.0560 µg/L No EPA limit set |
| Tempe City of | Tempe | AZ | 0.0558 µg/L No EPA limit set |
| Lake Panasoffkee Water Assn 2wps | Lake Panasoffkee | FL | 0.0530 µg/L No EPA limit set |
| Montebello Land & Water Co. | Montebello | CA | 0.0530 µg/L No EPA limit set |
| Moses Lake City of | Moses Lake | WA | 0.0522 µg/L No EPA limit set |
| Broken Arrow Municipal Authority | Broken Arrow | OK | 0.0513 µg/L No EPA limit set |
| Augusta-Richmond Co Ws | Augusta | GA | 0.0510 µg/L No EPA limit set |
| Dartmouth Water Division | Dartmouth | MA | 0.0506 µg/L No EPA limit set |
| Fkaa J. Robert Dean W.T.P. | Florida City | FL | 0.0503 µg/L No EPA limit set |
| Town of Thurmont | Thurmont | MD | 0.0480 µg/L No EPA limit set |
| Harrison Co Water Association | Cynthiana | KY | 0.0479 µg/L No EPA limit set |
| Aibonito La Plata | Aibonito C | PR | 0.0467 µg/L No EPA limit set |
| Barrow Utilities & Elec. Coop., Inc. (Bu | Barrow | AK | 0.0463 µg/L No EPA limit set |
Frequently asked questions about PFOS
What is PFOS in drinking water?
PFOS is monitored in US public drinking water under EPA rules. Each supplier's result is reported to the EPA and published here with its source and period.
Does the EPA limit PFOS?
The EPA has not set a numeric Maximum Contaminant Level for PFOS. It is still measured and reported, so levels can be compared between suppliers.
How common is PFOS in US tap water?
Of the 9,676 water suppliers with results on file, 1,290 detected PFOS — 13.3% of those tested.