Lemhi County, Idaho
9 ZIP codes · Avg score 46/100 · Grade D · Updated 2026-06-03
Across Lemhi County, EPA compliance records for 9 ZIP codes fall well below average — documented health-based violations affect multiple areas, and the county's sustained low grade points to structural rather than temporary shortfalls in the underlying water systems.
How Lemhi County Compares
How Lemhi County Compares
Lemhi County scores 20 points below the Idaho state average (66/100) and 22 points below the national average (68/100).
Data: EPA SDWIS Last verified: 2026-06-03
ZIP Code Risk Map
Water Quality Map: Lemhi County, Idaho
Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.
Key Risk Factors
Health risk index: 14.2 (asthma 10.8%, diabetes 12.7%)
Estimated additional annual cost per homeowner: $843, driven primarily by energy_code_gap
Infrastructure: 0.344% avg pipe failure probability, 13% of ZIPs at high risk
54.8% of homes built before 1978 (lead paint era)
Violation History (2021–2025)
↑ Worsening trendEPA violation counts by year across Lemhi County water systems. Health-based shown in red, total in blue.
Peak year: 2025 with 36 violations. Past 5 years: 58 total (58 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: $843
Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).
Housing Age Distribution
4,437 housing units in Lemhi 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 Lemhi County
Remediation costs are relatively manageable for most homeowners in Lemhi 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 Lemhi 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 Lemhi County ranked by EPA violation count.
| # | Water System | Population | Violations |
|---|---|---|---|
| 1 | SALMON CITY OF | 3,158 | 10 |
| 2 | Elk Bend Unit 1 | 200 | 10 |
| 3 | Sunset Heights Water District | 65 | 10 |
| 4 | Valley View Heights | 65 | 10 |
| 5 | Salmon River Meadows Mutual Water Compan | 47 | 10 |
All ZIP Codes in Lemhi County
9 ZIP codes tracked in Lemhi County.
| # | ZIP Code | City | Safety Score | Grade | Violations | Home Value |
|---|---|---|---|---|---|---|
| 1 | 83462 | Carmen | 53 | D | 0 | $367K |
| 2 | 83466 | North Fork | 53 | D | 0 | $384K |
| 3 | 83469 | Shoup | 53 | D | 0 | — |
| 4 | 83467 | Salmon | 52 | D | 10 (5 health) | $278K |
| 5 | 83229 | Cobalt | 40 | D | 0 | — |
| 6 | 83463 | Gibbonsville | 40 | D | 0 | $263K |
| 7 | 83464 | Leadore | 40 | D | 0 | $165K |
| 8 | 83465 | Lemhi | 40 | D | 0 | $238K |
| 9 | 83468 | Tendoy | 40 | D | 0 | $349K |
Recommended Buyer Guides for Lemhi County
Independent picks. EPA-grounded. Matched here.
- Best Lead Paint Test Kits — 54.8% of homes built before 1978
- Best Under-Sink Reverse Osmosis Systems — Multi-contaminant removal at the kitchen tap
- Best Radon Test Kits — EPA Radon Zone 1 (highest risk) dominant in county
Deep Dive Reports
Detailed analysis for Lemhi County, Idaho
Overview
Lemhi County in Idaho covers 9 ZIP codes with an average Home Safety Score of D (46/100).
1 of 9 ZIP codes have recorded EPA violations. 5 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.
What You Can Do
Lemhi 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
54.8% of homes in this county were built before 1978. Older plumbing and solder can leach lead into drinking water, especially in the morning.