County · Washington
Okanogan County, Washington: drinking water records
This overview covers 19 ZIP codes and 46 community water systems in Okanogan County. It also stands in for 3 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 |
|---|---|---|---|---|---|
| Omak City of WA5363750 | 4,940 | 180 | 1 | 0 | 3 ppb |
| Progressive Flat Water Assn WA5369650 | 335 | 0 | 0 | 1 | 5.2 ppb |
| Paschal Sherman Indian School 105300009 | 220 | 0 | 0 | 5 | 2.2 ppb |
| River Road Mobile Home Park WA5317631 | 150 | 0 | 0 | 2 | 0 ppb |
| Olds Mobile Park OR4100392 | 60 | 0 | 0 | 1 | 0.6 ppb |
| Brewster City of WA5308300 | 3,843 | 0 | 0 | 0 | 1.7 ppb |
| Okanogan Water Department City of WA5363200 | 3,817 | 0 | 0 | 0 | 1.4 ppb |
| Oroville City of WA5364400 | 3,256 | 0 | 0 | 0 | 3.2 ppb |
| Tonasket Water System WA5388700 | 2,398 | 0 | 0 | 0 | 0 ppb |
| Coulee Dam Water Dept WA5315400 | 1,454 | 0 | 0 | 0 | 1.7 ppb |
| Winthrop Town of WA5397750 | 1,350 | 0 | 0 | 0 | 1 ppb |
| Twisp Town of WA5390050 | 1,173 | 0 | 0 | 0 | 1.1 ppb |
| Monse-Riggan Camp WA53AC141 | 1,165 | 0 | 0 | 1 | not reported |
| Pateros Water Department WA5366450 | 1,149 | 0 | 0 | 0 | 2.8 ppb |
| Jaw Farms INC WA5308246 | 636 | 0 | 0 | 0 | 0 ppb |
| Duck Lake Water Association WA5320200 | 635 | 0 | 0 | 0 | 0 ppb |
| Brewster Flat Domestic Water Assn WA5308290 | 542 | 0 | 0 | 0 | 3.6 ppb |
| Nespelem Water Dept WA5359000 | 510 | 0 | 0 | 0 | 0 ppb |
| P and G Orchards Camp 2 WA5307870 | 489 | 0 | 0 | 0 | 0 ppb |
| Riverside Town of WA5372850 | 429 | 0 | 0 | 0 | 0.2 ppb |
| Elmer City Water System WA5323120 | 368 | 0 | 0 | 0 | 0 ppb |
| Silver Spur RV Park LLC OR4195241 | 275 | 0 | 0 | 0 | 1.6 ppb |
| Sandflat Water Association WA5309064 | 260 | 0 | 0 | 0 | 0 ppb |
| Suncrest Plat Water System WA5385207 | 260 | 0 | 0 | 0 | 0 ppb |
| Coleman Butte Water Assn WA5313940 | 250 | 0 | 0 | 0 | 0 ppb |
ZIP reports in Okanogan 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: 98827, 98834, 98859.
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.