Cowlitz County, Washington
9 ZIP codes · Avg score 76/100 · Grade B · Updated 2026-06-03
Tracking 9 ZIP codes in Cowlitz County shows a water safety record well above the national median — violations are isolated exceptions, not recurring patterns.
How Cowlitz County Compares
How Cowlitz County Compares
Cowlitz County scores 2 points below the Washington state average (78/100) and 8 points above the national average (68/100).
Data: EPA SDWIS Last verified: 2026-06-03
ZIP Code Risk Map
Water Quality Map: Cowlitz County, Washington
Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.
Key Risk Factors
Health risk index: 13.8 (asthma 12.3%, diabetes 11.4%)
Estimated additional annual cost per homeowner: $2,107, driven primarily by flood
Infrastructure: 0.388% avg pipe failure probability, 25% of ZIPs at high risk
56.5% 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: $2,107
Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).
Housing Age Distribution
46,054 housing units in Cowlitz 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 Cowlitz County
Remediation costs are relatively manageable for most homeowners in Cowlitz 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 Cowlitz 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 Cowlitz County ranked by EPA violation count.
| # | Water System | Population | Violations |
|---|---|---|---|
| 1 | Longview Water Department | 49,111 | 8 |
| 2 | Beacon Hill Water & Sewer District | 11,969 | 8 |
| 3 | WOODLAND CITY OF | 10,640 | 7 |
| 4 | Beacon Hill East | 190 | 7 |
| 5 | Clark Public Utilities | 116,876 | 7 |
17 total water systems serve Cowlitz County.
All ZIP Codes in Cowlitz County
9 ZIP codes tracked in Cowlitz County.
| # | ZIP Code | City | Safety Score | Grade | Violations | Home Value |
|---|---|---|---|---|---|---|
| 1 | 98611 | Castle Rock | 85 | A | 1 | $382K |
| 2 | 98625 | Kalama | 85 | A | 0 | $442K |
| 3 | 98626 | Kelso | 84 | B | 3 | $340K |
| 4 | 98632 | Longview | 83 | B | 4 | $355K |
| 5 | 98674 | Woodland | 82 | B | 7 | $481K |
| 6 | 98581 | Ryderwood | 66 | C | 0 | $200K |
| 7 | 98609 | Carrolls | 66 | C | 0 | — |
| 8 | 98645 | Silverlake | 66 | C | 0 | $467K |
| 9 | 98649 | Toutle | 65 | C | 0 | $287K |
Recommended Buyer Guides for Cowlitz County
If FEMA records flag flood-top-risk status or EPA samples show PFAS exceedances, the matching logic lifts emergency-water and PFAS-rated filtration into the recommendations — federal data drives the order, not retailer arrangements.
- Best Lead Paint Test Kits — 56.5% of homes built before 1978
- 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 Cowlitz County, Washington
Overview
Cowlitz County in Washington covers 9 ZIP codes with an average Home Safety Score of B (76/100).
4 of 9 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.