Elmore County, Idaho
7 ZIP codes · Avg score 50/100 · Grade D · Updated 2026-06-03
Public water compliance in Elmore County is below average — 7 ZIP codes, elevated violation rates.
How Elmore County Compares
How Elmore County Compares
Elmore County scores 16 points below the Idaho state average (66/100) and 18 points below the national average (68/100).
Data: EPA SDWIS Last verified: 2026-06-03
ZIP Code Risk Map
Water Quality Map: Elmore County, Idaho
Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.
Key Risk Factors
Health risk index: 12.3 (asthma 10.7%, diabetes 10.5%)
Estimated additional annual cost per homeowner: $1,551, driven primarily by wildfire
Infrastructure: 0.339% avg pipe failure probability, 43% of ZIPs at high risk
44.7% of homes built before 1978 (lead paint era)
Violation History (2021–2025)
↑ Worsening trendEPA violation counts by year across Elmore County water systems. Health-based shown in red, total in blue.
Peak year: 2025 with 8 violations. Past 5 years: 17 total (17 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: $1,551
Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).
Housing Age Distribution
19,793 housing units in Elmore 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 Elmore County
Remediation costs are relatively manageable for most homeowners in Elmore 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 Elmore 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 Elmore County ranked by EPA violation count.
| # | Water System | Population | Violations |
|---|---|---|---|
| 1 | City of Mountain Home, | 14,651 | 23 |
| 2 | Trinity Estates Water Users Assn | 250 | 20 |
| 3 | Mellen Subd Water District | 250 | 20 |
| 4 | Summerwind Water Users | 192 | 20 |
| 5 | Sawtooth Estates Water Users | 175 | 20 |
14 total water systems serve Elmore County.
All ZIP Codes in Elmore County
7 ZIP codes tracked in Elmore County.
| # | ZIP Code | City | Safety Score | Grade | Violations | Home Value |
|---|---|---|---|---|---|---|
| 1 | 83647 | Mountain Home | 65 | C | 20 (2 health) | $284K |
| 2 | 83601 | Atlanta | 62 | C | 2 | — |
| 3 | 83623 | Glenns Ferry | 56 | C | 3 | $192K |
| 4 | 83716 | Boise | 55 | C | 17 (3 health) | $573K |
| 5 | 83203 | Fort Hall | 40 | D | 0 | — |
| 6 | 83627 | Hammett | 40 | D | 0 | $165K |
| 7 | 83633 | King Hill | 33 | F | 11 (8 health) | $423K |
Recommended Buyer Guides for Elmore 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 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
- Best HEPA Air Purifiers for Wildfire Smoke — Wildfire is the top compound risk factor
Deep Dive Reports
Detailed analysis for Elmore County, Idaho
Overview
Elmore County in Idaho covers 7 ZIP codes with an average Home Safety Score of D (50/100).
5 of 7 ZIP codes have recorded EPA violations. 13 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
Elmore 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
44.7% of homes in this county were built before 1978. Older plumbing and solder can leach lead into drinking water, especially in the morning.