Lewis County, Idaho
3 ZIP codes · Avg score 98/100 · Grade A · Updated 2026-06-03
Tracking 3 ZIP codes in Lewis County shows a water safety record well above the national median — violations are isolated exceptions, not recurring patterns.
How Lewis County Compares
How Lewis County Compares
Lewis County scores 32 points above the Idaho state average (66/100) and 30 points above the national average (68/100).
Data: EPA SDWIS Last verified: 2026-06-03
Key Risk Factors
Health risk index: 15.6 (asthma 11.3%, diabetes 15.1%)
Estimated additional annual cost per homeowner: $1,157, driven primarily by energy_code_gap
Infrastructure: 0.43% avg pipe failure probability, 67% of ZIPs at high risk
74% 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: $1,157
Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).
Housing Age Distribution
981 housing units in Lewis 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 Lewis County
Remediation costs are relatively manageable for most homeowners in Lewis 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 Lewis County residents
Black markers = national averages. Red = above national avg. Green = below. Source: CDC PLACES, Census ACS.
Water Systems with Most Violations
Top 4 systems in Lewis County ranked by EPA violation count.
| # | Water System | Population | Violations |
|---|---|---|---|
| 1 | City of Kamiah | 1,495 | 4 |
| 2 | Nezperce Water Department | 460 | 4 |
| 3 | City of Craigmont | 501 | 2 |
| 4 | Winchester Water Department | 400 | 2 |
All ZIP Codes in Lewis County
3 ZIP codes tracked in Lewis County.
| # | ZIP Code | City | Safety Score | Grade | Violations | Home Value |
|---|---|---|---|---|---|---|
| 1 | 83543 | Nezperce | 98 | A | 4 (1 health) | $186K |
| 2 | 83555 | Winchester | 98 | A | 2 | $231K |
| 3 | 83523 | Craigmont | 97 | A | 2 | $194K |
Recommended Buyer Guides for Lewis County
Retailer arrangements don't shape what appears here — the selection logic is independent, filtered against EPA detections and the federal hazard data on file for this county.
- Best Lead Paint Test Kits — 74% of homes built before 1978
Overview
Lewis County in Idaho covers 3 ZIP codes with an average Home Safety Score of A (98/100).
3 of 3 ZIP codes have recorded EPA violations. 1 health-based violation have been documented.
← Back to Idaho 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.