Clark County, Idaho
2 ZIP codes · Avg score 53/100 · Grade D · Updated 2026-06-03
Clark County ranks below average for water safety, with health-based violations recorded across multiple of its 2 ZIP codes.
How Clark County Compares
How Clark County Compares
Clark County scores 13 points below the Idaho state average (66/100) and 15 points below the national average (68/100).
Data: EPA SDWIS Last verified: 2026-06-03
Key Risk Factors
Health risk index: 13.7 (asthma 10.4%, diabetes 13.8%)
Estimated additional annual cost per homeowner: $990, driven primarily by energy_code_gap
Infrastructure: 0.36% avg pipe failure probability
57.5% 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: $990
Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).
Housing Age Distribution
423 housing units in Clark 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 Clark County
Remediation costs are relatively manageable for most homeowners in Clark 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 Clark County residents
Black markers = national averages. Red = above national avg. Green = below. Source: CDC PLACES, Census ACS.
All ZIP Codes in Clark County
2 ZIP codes tracked in Clark County.
| # | ZIP Code | City | Safety Score | Grade | Violations | Home Value |
|---|---|---|---|---|---|---|
| 1 | 83423 | Dubois | 65 | C | 2 (1 health) | $200K |
| 2 | 83446 | Spencer | 40 | D | 0 | — |
Recommended Buyer Guides for Clark County
Methodologically, the recommendation order reflects severity in the federal record: contaminants flagged in EPA detection records for this county outrank generic water concerns, FEMA-confirmed hazard ratings shift emergency-related categories upward, and CDC lead-exposure markers govern when lead-test kits and certified filters appear at the top of the list.
- Best Lead Paint Test Kits — 57.5% of homes built before 1978
- Best Radon Test Kits — EPA Radon Zone 1 (highest risk) dominant in county
Overview
Clark County in Idaho covers 2 ZIP codes with an average Home Safety Score of D (53/100).
1 of 2 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.
What You Can Do
Clark County has a grade of D. Here are steps to protect your household.
Test your tap water
Order a certified lab test kit ($20-$50) to check for lead, bacteria, and other contaminants specific to your ZIP code.
Consider a certified water filter
NSF-certified filters can remove most common contaminants. Match the filter to your test results for best protection. Try our filter matcher
Contact your water utility
Request the latest Consumer Confidence Report (CCR) from your water provider. It details exactly what was found in your water supply.
Check for lead in your home
57.5% of homes in this county were built before 1978. Older plumbing and solder can leach lead into drinking water, especially in the morning.