Washington County, Oregon
27 ZIP codes · Avg score 74/100 · Grade B · Updated 2026-06-03
Based on current EPA data, Washington County's 27 ZIP codes maintain an above-average drinking water safety record.
How Washington County Compares
How Washington County Compares
Washington County scores 4 points below the Oregon state average (78/100) and 6 points above the national average (68/100).
Data: EPA SDWIS Last verified: 2026-06-03
ZIP Code Risk Map
Water Quality Map: Washington County, Oregon
Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.
Key Risk Factors
Health risk index: 11 (asthma 11.2%, diabetes 9.9%)
Estimated additional annual cost per homeowner: $1,031, driven primarily by flood
Infrastructure: 0.319% avg pipe failure probability, 15% of ZIPs at high risk
49.8% of homes built before 1978 (lead paint era)
Violation History (2021–2025)
↓ Improving trendEPA violation counts by year across Washington County water systems. Health-based shown in red, total in blue.
Peak year: 2022 with 10 violations. Past 5 years: 17 total (17 health-based). Health-based violations are declining versus the prior 2-year window.
Source: EPA SDWIS historical violations. Data may lag 6–12 months for the most recent year.
County Health Indicators vs National Average
Black markers indicate national averages. Source: CDC PLACES, Census ACS.
Infrastructure Overview
Sources: Census ACS (housing age), EPA SDWIS (infrastructure risk model), state bridge inspection data.
Compound Risk Breakdown
Estimated additional annual cost per homeowner: $1,031
Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).
Housing Age Distribution
242,825 housing units in Washington County
Source: U.S. Census Bureau ACS B25034 (Year Structure Built).
Water Safety Affordability
How much it costs to fix water issues relative to home values in Washington County
Remediation costs are relatively manageable for most homeowners in Washington County, representing a small fraction of property value.
Remediation includes water filtration, lead abatement, radon mitigation, and flood protection where applicable. Source: Census ACS, EPA SDWIS.
Health Outcomes vs National Average
CDC PLACES data for Washington County residents
Black markers = national averages. Red = above national avg. Green = below. Source: CDC PLACES, Census ACS.
Water Systems with Most Violations
Top 5 systems in Washington County ranked by EPA violation count.
| # | Water System | Population | Violations |
|---|---|---|---|
| 1 | Hillsboro-cherry Grove | 1,628 | 80 |
| 2 | South Hills Water System | 250 | 79 |
| 3 | Laurelwood Water Users | 200 | 72 |
| 4 | City of Forest Grove, | 26,838 | 66 |
| 5 | City of Hillsboro, | 92,632 | 57 |
33 total water systems serve Washington County.
All ZIP Codes in Washington County
27 ZIP codes tracked in Washington County.
| # | ZIP Code | City | Safety Score | Grade | Violations | Home Value |
|---|---|---|---|---|---|---|
| 1 | 97003 | Beaverton | 82 | B | 3 | $458K |
| 2 | 97006 | Beaverton | 82 | B | 3 | $536K |
| 3 | 97008 | Beaverton | 82 | B | 3 | $555K |
| 4 | 97075 | Beaverton | 82 | B | 3 | — |
| 5 | 97076 | Beaverton | 82 | B | 3 | — |
| 6 | 97077 | Beaverton | 82 | B | 3 | — |
| 7 | 97106 | Banks | 82 | B | 4 (1 health) | $513K |
| 8 | 97119 | Gaston | 82 | B | 29 (1 health) | $591K |
| 9 | 97207 | Portland | 82 | B | 2 | — |
| 10 | 97140 | Sherwood | 79 | B | 5 | $618K |
| 11 | 97116 | Forest Grove | 78 | B | 1 | $480K |
| 12 | 97007 | Beaverton | 77 | B | 3 | $583K |
| 13 | 97224 | Portland | 77 | B | 2 | $579K |
| 14 | 97225 | Portland | 77 | B | 2 | $710K |
| 15 | 97229 | Portland | 77 | B | 2 | $729K |
| 16 | 97113 | Cornelius | 76 | B | 36 (4 health) | $434K |
| 17 | 97123 | Hillsboro | 75 | B | 7 | $489K |
| 18 | 97124 | Hillsboro | 75 | B | 7 | $519K |
| 19 | 97005 | Beaverton | 72 | B | 3 | $476K |
| 20 | 97062 | Tualatin | 72 | B | 2 | $608K |
| 21 | 97223 | Portland | 72 | B | 2 | $578K |
| 22 | 97144 | Timber | 69 | C | 37 | $527K |
| 23 | 97109 | Buxton | 63 | C | 0 | $577K |
| 24 | 97117 | Gales Creek | 63 | C | 0 | $603K |
| 25 | 97133 | North Plains | 63 | C | 0 | $644K |
| 26 | 97078 | First Consumers Nat Bank | 55 | C | 0 | $463K |
| 27 | 97125 | Manning | 53 | D | 0 | — |
Recommended Buyer Guides for Washington County
Federal and certification sources drive the ordering: EPA monitoring data, NSF certifications, FEMA flood maps, and CDC lead guidance — guides surface only when county data warrants them.
- Best Under-Sink Reverse Osmosis Systems — Multi-contaminant removal at the kitchen tap
- Best Sump Pumps — Flood is the top compound risk factor
- Best Mold Test Kits — Flood-driven moisture and mold risk
Deep Dive Reports
Detailed analysis for Washington County, Oregon
Overview
Washington County in Oregon covers 27 ZIP codes with an average Home Safety Score of B (74/100).
22 of 27 ZIP codes have recorded EPA violations. 6 health-based violations have been documented.
← Back to Oregon water quality report
Data Sources
- Water quality: EPA Safe Drinking Water Information System (SDWIS)
- Home values: U.S. Census Bureau ACS (median estimates by ZCTA)
Updated daily.