County · Oregon
Washington County, Oregon: drinking water records
This overview covers 23 ZIP codes and 30 community water systems in Washington 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 |
|---|---|---|---|---|---|
| West Slope Water District OR4100660 | 11,000 | 120 | 0 | 1 | 4.9 ppb |
| Tualatin Valley Water District OR4100665 | 224,600 | 300 | 0 | 0 | 4.5 ppb |
| Hillsboro, City of OR4101513 | 92,632 | 120 | 0 | 0 | 0 ppb |
| Beaverton, City of OR4100081 | 88,045 | 240 | 0 | 0 | 2.6 ppb |
| Tigard, City of OR4100878 | 62,500 | 420 | 0 | 0 | 0.9 ppb |
| Tualatin, City of OR4100906 | 28,106 | 174 | 0 | 0 | 4.9 ppb |
| Forest Grove, City of OR4100305 | 26,838 | 240 | 0 | 0 | 2.9 ppb |
| Sherwood, City of OR4100816 | 19,885 | 120 | 2 | 0 | 1.3 ppb |
| Cornelius, City of OR4100218 | 14,490 | 150 | 0 | 0 | 0 ppb |
| Raleigh Water District OR4100667 | 4,500 | 120 | 0 | 0 | 4.9 ppb |
| Banks Water Department OR4100076 | 2,070 | 0 | 0 | 1 | 3 ppb |
| Laurelwood Water Users OR4100315 | 200 | 0 | 0 | 4 | 1 ppb |
| Timber Water Association OR4100898 | 180 | 0 | 0 | 2 | 0 ppb |
| Heyburn Estates ID5340023 | 100 | 0 | 0 | 1 | 1 ppb |
| West Laurel Acres Water Co OR4100221 | 65 | 0 | 0 | 1 | 1 ppb |
| Laurel Acres Water Co INC OR4100217 | 50 | 0 | 0 | 3 | 0 ppb |
| Crown Mobile Home Park OR4101009 | 42 | 0 | 0 | 1 | 4 ppb |
| North Plains Water Department OR4100576 | 3,663 | 0 | 0 | 0 | 0 ppb |
| La Water Co-Op OR4100313 | 2,500 | 0 | 0 | 0 | 1.3 ppb |
| Hillsboro-Cherry Grove OR4100985 | 1,628 | 0 | 0 | 0 | 6.4 ppb |
| Gaston, City of OR4100312 | 625 | 0 | 0 | 0 | 0 ppb |
| Fir Grove Homeowners Assn OR4101441 | 450 | 0 | 0 | 0 | 0 ppb |
| Star Satellite Improv Dist OR4100077 | 400 | 0 | 0 | 0 | 0 ppb |
| South Hills Water System OR4100306 | 250 | 0 | 0 | 0 | 0 ppb |
| Westview Mobile Estates OR4100222 | 250 | 0 | 0 | 0 | 0 ppb |
ZIP reports in Washington 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: 97109, 97125, 97144.
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.