Water quality for ZIP code 97078
ZIP 97078 covers Aloha and Hillsboro in Washington County, Oregon, one of 23 ZIP codes in the county. 97 active public water systems serve the county; 70 had an EPA violation in the past three years.
Most likely your provider
Other community water systems in Washington County
28 systems, largest first| System | Serves | Status | Rules violated, 3 yr |
|---|---|---|---|
| Hillsboro, City of |
92,632 | 1 | |
| Beaverton, City of |
88,045 | 1 | |
| Tigard, City of |
62,500 | 2 | |
| Tualatin, City of |
28,106 | 1 | |
| Forest Grove, City of |
26,838 | 0 | |
| Sherwood, City of |
20,781 | 1 | |
| Cornelius, City of |
14,490 | 2 | |
| West Slope Water District |
11,000 | 2 | |
| Raleigh Water District |
4,500 | 1 | |
| North Plains Water Department |
3,663 | 1 | |
| LA Water Co-Op |
2,500 | 2 | |
| Banks Water Department |
2,070 | 0 | |
| Hillsboro-Cherry Grove |
1,628 | 3 | |
| Gaston, City of |
625 | 2 | |
| Fir Grove Homeowners Assn |
450 | 2 | |
| Star Satellite Improv Dist |
400 | 1 | |
| South Hills Water System |
250 | 0 | |
| Westview Mobile Estates |
250 | 2 | |
| Laurelwood Water Users |
200 | 6 | |
| Timber Water Association |
180 | 9 | |
| Parrett Mountain View Estates |
155 | 1 | |
| Wolsborn Farms Water District |
92 | 2 | |
| West Laurel Acres Water CO |
65 | 3 | |
| Laurel Acres Water CO INC |
50 | 4 | |
| Rainbow Ends Water System |
50 | 1 |
Non-community systems in Washington County (68: schools, campgrounds, workplaces, restaurants)
These systems serve places you visit rather than homes.
About this data
Water systems are matched to Washington County, the county this ZIP code lies in, largest first. Your exact provider depends on your address and connection; the largest community water system in a county is usually the city or town utility.
ZIP code areas and town boundaries come from the U.S. Census Bureau's 2020 ZCTA files.
Source: the U.S. EPA's Enforcement and Compliance History Online system (ECHO), which publishes the federal Safe Drinking Water Information System. EPA's terms and values are shown as published. The Oregon records are from EPA's data refresh of Oct 7, 2026; EPA refreshes this data quarterly, and states report to EPA with a lag of three to six months, so the newest violations may not appear yet. Retrieved from ECHO on Oct 11, 2026.