Columbia County, Washington
2 ZIP codes · Avg score 80/100 · Grade B · Updated 2026-07-19
ZipCheckup grade for Columbia: B.
This ZIP looks solid, with a few items worth a quick check.
Across Columbia County's 2 ZIP codes, EPA compliance data shows above-average performance - violation rates are minimal, none of the county's systems have triggered health-based MCL exceedances in recent cycles, and the county's scores have stayed above the national baseline across every recent reporting period.
How Columbia County Compares
How Columbia County Compares
Columbia County scores 2 points above the Washington state average (78/100) and 12 points above the national average (68/100).
Data: EPA SDWIS Last verified: 2026-07-19
Key Risk Factors
Health risk index: 13.5 (asthma 11.3%, diabetes 12.2%)
Estimated additional annual cost per homeowner: $2,315, driven primarily by flood
Infrastructure: 0.5% avg pipe failure probability, 100% of ZIPs at high risk
81% 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: $2,315
Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).
Housing Age Distribution
2,060 housing units in Columbia 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 Columbia County
Remediation costs are relatively manageable for most homeowners in Columbia 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 Columbia County residents
Black markers = national averages. Red = above national avg. Green = below. Source: CDC PLACES, Census ACS.
Water systems serving Columbia County
2 community water systems serving Columbia County.
- B
- B
Systems with the most violations in Columbia County
1 water system with recorded EPA violations.
- B
All ZIP Codes in Columbia County
2 ZIP codes tracked in Columbia County.
| # | ZIP Code | City | Safety Score | Grade | Violations | Home Value |
|---|---|---|---|---|---|---|
| 1 | 99359 | Starbuck | 82 | B | 2 | $133K |
| 2 | 99328 | Dayton | 78 | B | 0 | $252K |
Recommended Buyer Guides for Columbia 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 — 81% 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
Overview
Columbia County in Washington covers 2 ZIP codes with an average Home Safety Score of B (80/100).
1 of 2 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.