PFOS in Treasure Valley drinking water
3 of 14 systems that tested for it in the last 36 months detected it; 3 are above the limit, elevated, or an aesthetic issue. PFOS is a PFAS compound. Some results are from EPA UCMR monitoring, not a claim it is in every tap. Certified filters are in the list.
| System | County | 36 mo max | Latest | Status | Last sample |
|---|---|---|---|---|---|
| Garden City Water and Sewer System | Ada | 28.2ppt | ND | Elevated | 2024-10-14 |
| Capitol Water Corp. | Ada | 9.8ppt | ND | Elevated | 2024-10-08 |
| Meridian Water Department | Ada | 4.9ppt | ND | Elevated | 2025-12-09 |
Limits
- Federal limit (MCL)
- 0.004 ug/L (4.0ppt)
- Health goal (MCLG)
- 0.0ppt
Exposure to PFOS over many years may result in adverse health effects including developmental effects, some cancers, immune effects, and thyroid effects.EPA, quoted.
Removal methods in the reference list: reverse osmosis, granular activated carbon, anion exchange. A method name is not a product certification.
By city: PFOS in Boise City drinking water, PFOS in Garden City drinking water, PFOS in Meridian drinking water.
Not enough groundwater samples in the region to estimate PFOS in private wells. A lab test is the only way to know.
Numbers are the system's samples at its taps and wells, not yours. Lead and copper are 90th percentiles from sampled homes. Well pages are nearby-sample estimates. Health text restates EPA and DEQ. Methodology.