Island County, Washington
9 ZIP codes · Avg score 78/100 · Grade B · Updated 2026-06-03
Island County — 9 ZIP codes, above-average safety grade.
How Island County Compares
How Island County Compares
Island County scores 0 points above the Washington state average (78/100) and 10 points above the national average (68/100).
Data: EPA SDWIS Last verified: 2026-06-03
ZIP Code Risk Map
Water Quality Map: Island County, Washington
Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.
Key Risk Factors
Health risk index: 12 (asthma 10.5%, diabetes 10.1%)
Estimated additional annual cost per homeowner: $1,880, driven primarily by flood
Infrastructure: 0.341% avg pipe failure probability, 25% of ZIPs at high risk
44.7% of homes built before 1978 (lead paint era)
Violation History (2021–2025)
↑ Worsening trendEPA violation counts by year across Island County water systems. Health-based shown in red, total in blue.
Peak year: 2024 with 24 violations. Past 5 years: 46 total (46 health-based). Health-based violations are rising versus the prior 2-year window — worth closer monitoring.
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: $1,880
Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).
Housing Age Distribution
50,135 housing units in Island 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 Island County
Remediation costs are relatively manageable for most homeowners in Island 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 Island 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 Island County ranked by EPA violation count.
| # | Water System | Population | Violations |
|---|---|---|---|
| 1 | Rolling Hills-glencairn | 872 | 44 |
| 2 | Penn Cove Water and Sewer District | 460 | 44 |
| 3 | City of Oak Harbor | 23,767 | 38 |
| 4 | North Whidbey Water District | 568 | 38 |
| 5 | Dugualla Community Inc. | 459 | 38 |
38 total water systems serve Island County.
All ZIP Codes in Island County
9 ZIP codes tracked in Island County.
| # | ZIP Code | City | Safety Score | Grade | Violations | Home Value |
|---|---|---|---|---|---|---|
| 1 | 98239 | Coupeville | 94 | A | 6 (1 health) | $578K |
| 2 | 98249 | Freeland | 88 | A | 5 | $586K |
| 3 | 98282 | Camano Island | 85 | A | 1 | $600K |
| 4 | 98292 | Stanwood | 83 | B | 5 | $611K |
| 5 | 98260 | Langley | 80 | B | 15 | $646K |
| 6 | 98236 | Clinton | 71 | B | 1 | $611K |
| 7 | 98278 | Oak Harbor | 71 | B | 19 (6 health) | — |
| 8 | 98277 | Oak Harbor | 66 | C | 19 (6 health) | $455K |
| 9 | 98287 | Silvana | 65 | C | 0 | — |
Recommended Buyer Guides for Island County
Strictly editorial — no paid placements influence which guides appear; the selection draws on NSF certifications and EPA detection records for water systems serving this county.
- 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 Island County, Washington
Overview
Island County in Washington covers 9 ZIP codes with an average Home Safety Score of B (78/100).
8 of 9 ZIP codes have recorded EPA violations. 13 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.