County · Montana
Jefferson County, Montana: drinking water records
This overview covers 6 ZIP codes and 14 community water systems in Jefferson County. It also stands in for 1 ZIP codes whose utility has too little EPA data for a page of its own.
System population figures are summed from EPA registry records and can overlap where wholesalers and retail systems serve the same people. They are not a Census county-population estimate.
Water systems with the most complete records
| Water system | People served | PFAS survey results | PFAS found | Health-based violations | Lead, 9 in 10 homes at or below |
|---|---|---|---|---|---|
| Whitehall Town of MT0000359 | 1,500 | 0 | 0 | 51 | 2 ppb |
| Boulder City of MT0000158 | 1,400 | 0 | 0 | 1 | 0 ppb |
| Jefferson Hills Wua MT0002978 | 780 | 0 | 0 | 1 | 1 ppb |
| Basin County Water and Sewer Dist MT0000014 | 200 | 0 | 0 | 1 | 0 ppb |
| Saddle Mountain Corp Clancy MT0000057 | 350 | 0 | 0 | 0 | 6 ppb |
| Forest Park Water Users Association MT0000591 | 323 | 0 | 0 | 0 | 15 ppb |
| Blue Sky Heights Wua Clancy MT0000030 | 250 | 0 | 0 | 0 | 0 ppb |
| Hangmans Tree Wua MT0000128 | 158 | 0 | 0 | 0 | 5 ppb |
| Stoney Brook Village Condominium Assoc MT0004257 | 142 | 0 | 0 | 0 | 4 ppb |
| Elkhorn Health and Rehabilitation LLC MT0000618 | 89 | 0 | 0 | 0 | 0 ppb |
| Jefferson Tracts Assoc INC MT0003614 | 80 | 0 | 0 | 0 | 7 ppb |
| Sunnybrook Acres HOA MT0002482 | 50 | 0 | 0 | 0 | 1 ppb |
| Red Cliff Estates HOA MT0004268 | 48 | 0 | 0 | 0 | 4 ppb |
| Rocky Mountain Wua MT0000058 | 30 | 0 | 0 | 0 | 2 ppb |
ZIP reports in Jefferson County
No ZIP report in this county is published yet.
These ZIP codes are covered by this overview because their utility has too little EPA data for a separate page: 59721.
Sources and scope
EPA UCMR 5 occurrence data, samples collected 2023-01-03 – 2026-06-17, final release, August 2026 (file dated Aug 28, 2026); EPA SDWIS via ECHO, 2026Q2 extract (file dated Jul 9, 2026); EPA service-area boundaries v3.0; Census 2020 ZCTAs. Page generated 2026-09-03.
Counts cover the systems that report this county to EPA. A water system may cross county lines. "Found" means at least one result at or above the laboratory reporting level; it is not a compliance finding.