Snohomish County, Washington
34 ZIP codes · Avg score 83/100 · Grade B · Updated 2026-06-03
Within Snohomish County, all 34 tracked ZIP codes show above-average drinking water safety — violations are infrequent and typically minor.
How Snohomish County Compares
How Snohomish County Compares
Snohomish County scores 5 points above the Washington state average (78/100) and 15 points above the national average (68/100).
Data: EPA SDWIS Last verified: 2026-06-03
ZIP Code Risk Map
Water Quality Map: Snohomish County, Washington
Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.
Key Risk Factors
Health risk index: 10.7 (asthma 11.1%, diabetes 9.1%)
Estimated additional annual cost per homeowner: $1,784, driven primarily by flood
Infrastructure: 0.311% avg pipe failure probability, 23% of ZIPs at high risk
48.3% of homes built before 1978 (lead paint era)
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: $1,784
Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).
Housing Age Distribution
314,050 housing units in Snohomish 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 Snohomish County
Remediation costs are relatively manageable for most homeowners in Snohomish 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 Snohomish 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 Snohomish County ranked by EPA violation count.
| # | Water System | Population | Violations |
|---|---|---|---|
| 1 | Sno Pud 1 - Lake Stevens | 60,064 | 97 |
| 2 | Sno Pud 1 - May Creek | 1,364 | 73 |
| 3 | City of Everett Public Works Department | 215,774 | 71 |
| 4 | Sno Pud 1 - Warm Beach | 2,890 | 64 |
| 5 | Sno Pud 1 - Storm Lake Ridge | 786 | 64 |
48 total water systems serve Snohomish County.
All ZIP Codes in Snohomish County
34 ZIP codes tracked in Snohomish County.
| # | ZIP Code | City | Safety Score | Grade | Violations | Home Value |
|---|---|---|---|---|---|---|
| 1 | 98293 | Startup | 95 | A | 0 | — |
| 2 | 98270 | Marysville | 94 | A | 3 | $540K |
| 3 | 98291 | Snohomish | 92 | A | 4 | — |
| 4 | 98207 | Everett | 91 | A | 8 | — |
| 5 | 98213 | Everett | 91 | A | 8 | — |
| 6 | 98020 | Edmonds | 90 | A | 1 | $959K |
| 7 | 98026 | Edmonds | 90 | A | 1 | $759K |
| 8 | 98271 | Marysville | 89 | A | 3 | $483K |
| 9 | 98203 | Everett | 87 | A | 8 | $575K |
| 10 | 98204 | Everett | 87 | A | 8 | $386K |
| 11 | 98205 | Everett | 87 | A | 8 | — |
| 12 | 98206 | Everett | 87 | A | 8 | — |
| 13 | 98275 | Mukilteo | 87 | A | 0 | $830K |
| 14 | 98043 | Mountlake Terrace | 85 | A | 2 | $606K |
| 15 | 98241 | Darrington | 85 | A | 8 | $391K |
| 16 | 98253 | Greenbank | 85 | A | 8 | $710K |
| 17 | 98012 | Bothell | 84 | B | 4 | $812K |
| 18 | 98021 | Bothell | 84 | B | 4 | $903K |
| 19 | 98258 | Lake Stevens | 84 | B | 13 | $607K |
| 20 | 98252 | Granite Falls | 83 | B | 1 | $493K |
| 21 | 98046 | Lynnwood | 82 | B | 3 | — |
| 22 | 98201 | Everett | 82 | B | 8 | $477K |
| 23 | 98208 | Everett | 82 | B | 8 | $641K |
| 24 | 98256 | Index | 82 | B | 4 | $380K |
| 25 | 98296 | Snohomish | 82 | B | 4 | $868K |
| 26 | 98037 | Lynnwood | 81 | B | 3 | $684K |
| 27 | 98087 | Lynnwood | 81 | B | 3 | $633K |
| 28 | 98294 | Sultan | 80 | B | 1 | $463K |
| 29 | 98223 | Arlington | 78 | B | 1 | $557K |
| 30 | 98290 | Snohomish | 77 | B | 4 | $718K |
| 31 | 98036 | Lynnwood | 76 | B | 3 | $693K |
| 32 | 98272 | Monroe | 69 | C | 8 | $638K |
| 33 | 98259 | North Lakewood | 66 | C | 0 | — |
| 34 | 98251 | Gold Bar | 60 | C | 0 | $415K |
Recommended Buyer Guides for Snohomish County
Where county records show a lead exceedance or pre-1978 housing concentration, lead-specific filters and test kits move toward the top of the list.
- 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 Snohomish County, Washington
Overview
Snohomish County in Washington covers 34 ZIP codes with an average Home Safety Score of B (83/100).
30 of 34 ZIP codes have recorded EPA violations. All violations are monitoring/reporting type.
← 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.