Okanogan County, Washington
20 ZIP codes · Avg score 60/100 · Grade C · Updated 2026-06-03
Tracking 20 ZIP codes in Okanogan County reveals a mixed picture — tap water quality varies meaningfully by location.
How Okanogan County Compares
How Okanogan County Compares
Okanogan County scores 18 points below the Washington state average (78/100) and 8 points below the national average (68/100).
Data: EPA SDWIS Last verified: 2026-06-03
ZIP Code Risk Map
Water Quality Map: Okanogan County, Washington
Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.
Key Risk Factors
Health risk index: 14.1 (asthma 11.6%, diabetes 13.3%)
Estimated additional annual cost per homeowner: $2,008, driven primarily by wildfire
Infrastructure: 0.361% avg pipe failure probability, 30% of ZIPs at high risk
55.5% of homes built before 1978 (lead paint era)
Violation History (2021–2022)
→ Stable trendEPA violation counts by year across Okanogan County water systems. Health-based shown in red, total in blue.
Peak year: 2021 with 3 violations. Past 5 years: 5 total (5 health-based).
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: $2,008
Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).
Housing Age Distribution
22,661 housing units in Okanogan 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 Okanogan County
Remediation costs are relatively manageable for most homeowners in Okanogan 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 Okanogan 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 Okanogan County ranked by EPA violation count.
| # | Water System | Population | Violations |
|---|---|---|---|
| 1 | RIVERSIDE TOWN OF | 429 | 17 |
| 2 | Brewster Flat Domestic Water Assn | 542 | 16 |
| 3 | City of Brewster | 3,235 | 11 |
| 4 | Monse-Riggan Camp | 1,165 | 11 |
| 5 | P and G Orchards Camp 2 | 489 | 11 |
26 total water systems serve Okanogan County.
All ZIP Codes in Okanogan County
20 ZIP codes tracked in Okanogan County.
| # | ZIP Code | City | Safety Score | Grade | Violations | Home Value |
|---|---|---|---|---|---|---|
| 1 | 98841 | Omak | 70 | B | 0 | $288K |
| 2 | 98856 | Twisp | 70 | B | 1 | $398K |
| 3 | 98812 | Brewster | 69 | C | 11 (1 health) | $301K |
| 4 | 98834 | Methow | 69 | C | 2 | $539K |
| 5 | 98855 | Tonasket | 69 | C | 4 (1 health) | $230K |
| 6 | 98846 | Pateros | 67 | C | 4 | $315K |
| 7 | 98829 | Malott | 66 | C | 1 | $309K |
| 8 | 99116 | Coulee Dam | 66 | C | 0 | $213K |
| 9 | 99124 | Elmer City | 66 | C | 1 | $185K |
| 10 | 98844 | Oroville | 65 | C | 0 | $251K |
| 11 | 98862 | Winthrop | 64 | C | 9 | $695K |
| 12 | 99155 | Nespelem | 64 | C | 2 | $137K |
| 13 | 98840 | Okanogan | 63 | C | 2 | $252K |
| 14 | 98849 | Riverside | 59 | C | 17 | $242K |
| 15 | 98814 | Carlton | 53 | D | 0 | $512K |
| 16 | 98833 | Mazama | 53 | D | 0 | $604K |
| 17 | 98852 | Stehekin | 45 | D | 0 | $608K |
| 18 | 98819 | Conconully | 40 | D | 0 | $216K |
| 19 | 98827 | Loomis | 40 | D | 0 | — |
| 20 | 99140 | Keller | 40 | D | 0 | $139K |
Recommended Buyer Guides for Okanogan County
Editorial methodology pairs each documented risk in this county with the buyer category that addresses it, drawing on water-quality detections, housing-stock lead exposure, EPA Radon Zone designation, and FEMA flood and wildfire ratings. NSF-certified options surface where applicable, and products that match the specific contaminant take priority.
- Best Lead Paint Test Kits — 55.5% of homes built before 1978
- Best Radon Test Kits — EPA Radon Zone 1 (highest risk) dominant in county
- Best HEPA Air Purifiers for Wildfire Smoke — Wildfire is the top compound risk factor
Deep Dive Reports
Detailed analysis for Okanogan County, Washington
Overview
Okanogan County in Washington covers 20 ZIP codes with an average Home Safety Score of C (60/100).
11 of 20 ZIP codes have recorded EPA violations. 2 health-based violations have been documented.
← Back to Washington 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.