County · Oregon
Washington County, Oregon: drinking water records
Explore EPA records for 29 community water systems across 23 ZIP codes in Washington County, then find water-testing resources and available recent monitoring-station readings.
Data as of EPA UCMR 5 final release, August 2026 (file dated Aug 28, 2026) · EPA SDWIS 2026Q2 (file dated Jul 9, 2026). How we build these pages
Drinking-water records
EPA survey and compliance records are historical reports. UCMR 5 results are available for 10 of the 29 listed systems in this snapshot. A system with no reported PFAS detection is not a test of every tap or every contaminant.
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 in this county
All 29 active community systems in the available county records, sorted by record completeness. Scroll the table to explore more systems.
| 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 ppbbelow the action level |
| Tualatin Valley Water District OR4100665 | 224,600 | 300 | 0 | 0 | 4.5 ppbbelow the action level |
| Hillsboro, City of OR4101513 | 92,632 | 120 | 0 | 0 | 0 ppbbelow the action level |
| Beaverton, City of OR4100081 | 88,045 | 240 | 0 | 0 | 2.6 ppbbelow the action level |
| Tigard, City of OR4100878 | 62,500 | 420 | 0 | 0 | 0.9 ppbbelow the action level |
| Tualatin, City of OR4100906 | 28,106 | 174 | 0 | 0 | 4.9 ppbbelow the action level |
| Forest Grove, City of OR4100305 | 26,838 | 240 | 0 | 0 | 2.9 ppbbelow the action level |
| Sherwood, City of OR4100816 | 19,885 | 120 | 2 | 0 | 1.3 ppbbelow the action level |
| Cornelius, City of OR4100218 | 14,490 | 150 | 0 | 0 | 0 ppbbelow the action level |
| Raleigh Water District OR4100667 | 4,500 | 120 | 0 | 0 | 4.9 ppbbelow the action level |
| Banks Water Department OR4100076 | 2,070 | 0 | 0 | 1 | 3 ppbbelow the action level |
| Laurelwood Water Users OR4100315 | 200 | 0 | 0 | 4 | 1 ppbbelow the action level |
| Timber Water Association OR4100898 | 180 | 0 | 0 | 2 | 0 ppbbelow the action level |
| West Laurel Acres Water Co OR4100221 | 65 | 0 | 0 | 1 | 1 ppbbelow the action level |
| Laurel Acres Water Co INC OR4100217 | 50 | 0 | 0 | 3 | 0 ppbbelow the action level |
| Crown Mobile Home Park OR4101009 | 42 | 0 | 0 | 1 | 4 ppbbelow the action level |
| North Plains Water Department OR4100576 | 3,663 | 0 | 0 | 0 | 0 ppbbelow the action level |
| La Water Co-Op OR4100313 | 2,500 | 0 | 0 | 0 | 1.3 ppbbelow the action level |
| Hillsboro-Cherry Grove OR4100985 | 1,628 | 0 | 0 | 0 | 6.4 ppbbelow the action level |
| Gaston, City of OR4100312 | 625 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Fir Grove Homeowners Assn OR4101441 | 450 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Star Satellite Improv Dist OR4100077 | 400 | 0 | 0 | 0 | 0 ppbbelow the action level |
| South Hills Water System OR4100306 | 250 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Westview Mobile Estates OR4100222 | 250 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Parrett Mountain View Estates OR4101498 | 155 | 0 | 0 | 0 | 2.2 ppbbelow the action level |
| Wolsborn Farms Water District OR4100381 | 92 | 0 | 0 | 0 | 3 ppbbelow the action level |
| Rainbow Ends Water System OR4101350 | 50 | 0 | 0 | 0 | 1 ppbbelow the action level |
| Roth Development OR4100220 | 27 | 0 | 0 | 0 | 6 ppbbelow the action level |
| Joint Water Commission OR4100379 | 0 | 0 | 0 | 0 | 4 ppbbelow the action level |
USGS · Monitoring stations
The water, more recently.
Available station readings in Washington County, Oregon. Each measurement keeps its time, unit and original source.
These readings describe water at a monitoring station. They do not test your tap, measure PFAS or lead, or determine whether water is safe to drink or swim in.
Recent observations load when this section comes into view.
How these readings update
We check for updates every 10 minutes while this section is visible and show supported observations from the last 48 hours. The time beside a reading is when USGS measured it; the checked time is when our service retrieved the response. We mark a reading more than 6 hours old as older. Provisional observations can change after USGS review. A missing reading does not mean zero or clean water.
Temperature, pH, dissolved oxygen, turbidity, conductivity, streamflow and water level are shown only where a station reports them. Different measurements have different units and sampling intervals. USGS data and documentation.
Your next step
Water testing, reports & local help.
Use these official directories to find your drinking-water agency, a certified laboratory and public water records. We have not yet added an individually reviewed local resource list for this county.
Official national directories
Water testing
Find your state’s private-well program
EPA’s state directory points well owners to local program information. Services and eligibility vary by state and county.
Water testing
Find a certified drinking-water laboratory
Use EPA’s directory to reach your state’s laboratory certification program. EPA does not provide on-request testing of residential drinking water.
Public records
Find your utility’s Consumer Confidence Report
EPA links to community water-system reports and explains how to read them. Look for your actual supplier rather than assuming every address in a county shares one system.
Public records
Explore USGS water observations
Find current and historical observations from USGS monitoring locations, including available stream, lake, and groundwater data. Measurements vary by station and do not replace a test of your household water.
A county overview cannot identify every property’s water provider. If you use a public water system, confirm its name on your bill and request its annual Consumer Confidence Report. Private wells need their own testing; public-system records do not describe a private well.
Understand water testing and laboratory reportsResource descriptions are compiled by Tap Water Lookup. Review dates describe our source check, not a new water sample. How we review sources · Suggest a correction
Explore your area
Local coverage in Washington County
23ZIP areas in this overview
Explore the water-system records, recent station readings and testing resources on this county page. They describe the systems and stations identified in each section; they are not a separate water test for every community.
Towns and communities
- Aloha
- Banks
- Beaverton
- Bethany
- Cherry Grove
- Cornelius
- Forest Grove
- Hillsboro
- North Plains
- Sherwood
- Tigard
- Tualatin
View ZIP areas and understand coverage
- 97003Aloha
- 97005Beaverton
- 97006Beaverton
- 97007Beaverton
- 97008Beaverton
- 97062Tualatin
- 97078Aloha
- 97106Banks
- 97109
- 97113Cornelius
- 97116Forest Grove
- 97117
- 97119Cherry Grove
- 97123Hillsboro
- 97124Hillsboro
- 97125
- 97133North Plains
- 97140Sherwood
- 97144
- 97223Tigard
- 97224Tigard
- 97225Beaverton
- 97229Bethany
These Census ZIP Code Tabulation Areas are grouped here by their largest county overlap. A ZIP area can cross county lines and contain several water suppliers or private wells. Place labels reflect Census geography, not verified postal city names or utility service boundaries.
Records for these areas are currently presented in this county overview rather than individual ZIP reports. An unpublished report does not mean there are no water records. Confirm your supplier on your water bill; if you use a private well, testing your own well is the relevant next step.
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. Database prepared 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.
Compiled by Tap Water Lookup from the sources identified on this page. Read the methodology and review process.