Nez Perce County, Idaho
6 ZIP codes · Avg score 91/100 · Grade A · Updated 2026-06-03
Throughout Nez Perce County, the 6 monitored ZIP codes show low violation rates and healthy safety scores — a pattern that puts the county well above the state baseline for drinking water quality.
How Nez Perce County Compares
How Nez Perce County Compares
Nez Perce County scores 25 points above the Idaho state average (66/100) and 23 points above the national average (68/100).
Data: EPA SDWIS Last verified: 2026-06-03
ZIP Code Risk Map
Water Quality Map: Nez Perce County, Idaho
Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.
Key Risk Factors
Health risk index: 13.5 (asthma 11.4%, diabetes 10.8%)
Estimated additional annual cost per homeowner: $1,053, driven primarily by energy_code_gap
Infrastructure: 0.423% avg pipe failure probability, 33% of ZIPs at high risk
68.3% of homes built before 1978 (lead paint era)
Violation History (2021–2025)
↑ Worsening trendEPA violation counts by year across Nez Perce County water systems. Health-based shown in red, total in blue.
Peak year: 2024 with 3 violations. Past 5 years: 7 total (7 health-based). Health-based violations are rising versus the prior 2-year window — worth closer monitoring.
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: $1,053
Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).
Housing Age Distribution
18,319 housing units in Nez Perce 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 Nez Perce County
Remediation costs are relatively manageable for most homeowners in Nez Perce 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 Nez Perce 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 Nez Perce County ranked by EPA violation count.
| # | Water System | Population | Violations |
|---|---|---|---|
| 1 | New Hope Subd | 100 | 20 |
| 2 | Sunnyside Park | 40 | 20 |
| 3 | Lewiston Orchards Irrigation District | 20,000 | 9 |
| 4 | City of Lewiston | 15,001 | 9 |
| 5 | Red Pheasant Water Company Llc | 480 | 9 |
11 total water systems serve Nez Perce County.
All ZIP Codes in Nez Perce County
6 ZIP codes tracked in Nez Perce County.
| # | ZIP Code | City | Safety Score | Grade | Violations | Home Value |
|---|---|---|---|---|---|---|
| 1 | 83501 | Lewiston | 94 | A | 9 (1 health) | $297K |
| 2 | 83540 | Lapwai | 94 | A | 5 | $190K |
| 3 | 83548 | Reubens | 94 | A | 9 (4 health) | $153K |
| 4 | 83524 | Culdesac | 91 | A | 5 | $227K |
| 5 | 83545 | Peck | 91 | A | 2 | $250K |
| 6 | 83541 | Lenore | 84 | B | 20 (2 health) | $310K |
Recommended Buyer Guides for Nez Perce 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 — 68.3% of homes built before 1978
- Best Under-Sink Reverse Osmosis Systems — Multi-contaminant removal at the kitchen tap
Deep Dive Reports
Detailed analysis for Nez Perce County, Idaho
Overview
Nez Perce County in Idaho covers 6 ZIP codes with an average Home Safety Score of A (91/100).
6 of 6 ZIP codes have recorded EPA violations. 7 health-based violations 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.