San Juan County, Washington
9 ZIP codes · Avg score 74/100 · Grade B · Updated 2026-06-03
Across all 9 ZIP codes in San Juan County, tap water consistently meets or exceeds federal safety standards.
How San Juan County Compares
How San Juan County Compares
San Juan County scores 4 points below the Washington 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: San Juan County, Washington
Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.
Key Risk Factors
Health risk index: 12.2 (asthma 10.5%, diabetes 10.7%)
Estimated additional annual cost per homeowner: $597, driven primarily by energy_code_gap
Infrastructure: 0.428% avg pipe failure probability, 78% of ZIPs at high risk
55% of homes built before 1978 (lead paint era)
Violation History (2021–2025)
↓ Improving trendEPA violation counts by year across San Juan County water systems. Health-based shown in red, total in blue.
Peak year: 2022 with 31 violations. Past 5 years: 77 total (77 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: $597
Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).
Housing Age Distribution
13,362 housing units in San Juan 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 San Juan County
Remediation costs are relatively manageable for most homeowners in San Juan 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 San Juan 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 San Juan County ranked by EPA violation count.
| # | Water System | Population | Violations |
|---|---|---|---|
| 1 | Eastsound Water Users Association | 3,711 | 22 |
| 2 | Friday Harbor Town of | 3,543 | 19 |
| 3 | Roche Harbor Water System Inc. | 1,985 | 19 |
| 4 | Portland Fair Estates | 130 | 19 |
| 5 | Cape San Juan Water District | 158 | 19 |
16 total water systems serve San Juan County.
All ZIP Codes in San Juan County
9 ZIP codes tracked in San Juan County.
| # | ZIP Code | City | Safety Score | Grade | Violations | Home Value |
|---|---|---|---|---|---|---|
| 1 | 98261 | Lopez Island | 95 | A | 1 | $701K |
| 2 | 98245 | Eastsound | 93 | A | 10 (1 health) | $694K |
| 3 | 98222 | Blakely Island | 73 | B | 0 | $741K |
| 4 | 98297 | Waldron | 73 | B | 0 | $409K |
| 5 | 98250 | Friday Harbor | 70 | B | 19 (13 health) | $746K |
| 6 | 98243 | Deer Harbor | 66 | C | 12 (11 health) | $1044K |
| 7 | 98279 | Olga | 66 | C | 0 | $821K |
| 8 | 98280 | Orcas | 66 | C | 0 | $927K |
| 9 | 98286 | Shaw Island | 66 | C | 0 | $621K |
Recommended Buyer Guides for San Juan County
While many sites publish identical guide lists across every county they cover, the selection here changes by location — driven by the EPA, NSF, FEMA, and CDC datasets that describe the actual conditions documented for this jurisdiction in the federal record.
- Best Lead Paint Test Kits — 55% of homes built before 1978
- Best Under-Sink Reverse Osmosis Systems — Multi-contaminant removal at the kitchen tap
Deep Dive Reports
Detailed analysis for San Juan County, Washington
Overview
San Juan County in Washington covers 9 ZIP codes with an average Home Safety Score of B (74/100).
4 of 9 ZIP codes have recorded EPA violations. 25 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.