Fremont County, Idaho
8 ZIP codes · Avg score 56/100 · Grade C · Updated 2026-06-03
Within Fremont County, 8 tracked ZIP codes reveal moderate water quality — national standards are generally met, with some documented exceptions.
How Fremont County Compares
How Fremont County Compares
Fremont County scores 10 points below the Idaho state average (66/100) and 12 points below the national average (68/100).
Data: EPA SDWIS Last verified: 2026-06-03
ZIP Code Risk Map
Water Quality Map: Fremont County, Idaho
Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.
Key Risk Factors
Health risk index: 12.2 (asthma 10.5%, diabetes 10.5%)
Estimated additional annual cost per homeowner: $960, driven primarily by energy_code_gap
Infrastructure: 0.366% avg pipe failure probability, 13% of ZIPs at high risk
65.5% 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: $960
Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).
Housing Age Distribution
8,511 housing units in Fremont 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 Fremont County
Remediation costs are relatively manageable for most homeowners in Fremont 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 Fremont 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 Fremont County ranked by EPA violation count.
| # | Water System | Population | Violations |
|---|---|---|---|
| 1 | City of Parker | 322 | 5 |
| 2 | City of Ashton | 1,129 | 2 |
| 3 | City of Newdale | 340 | 1 |
| 4 | City of Sugar City | 2,395 | 0 |
| 5 | City of Teton | 735 | 0 |
All ZIP Codes in Fremont County
8 ZIP codes tracked in Fremont County.
| # | ZIP Code | City | Safety Score | Grade | Violations | Home Value |
|---|---|---|---|---|---|---|
| 1 | 83420 | Ashton | 69 | C | 2 | $320K |
| 2 | 83451 | Teton | 66 | C | 0 | $289K |
| 3 | 83438 | Parker | 65 | C | 5 (1 health) | $231K |
| 4 | 83436 | Newdale | 64 | C | 1 | $288K |
| 5 | 83429 | Island Park | 53 | D | 0 | $473K |
| 6 | 83445 | Saint Anthony | 53 | D | 0 | $234K |
| 7 | 83421 | Chester | 40 | D | 0 | $264K |
| 8 | 83433 | Macks Inn | 40 | D | 0 | $278K |
Recommended Buyer Guides for Fremont County
Editorial methodology pairs each documented risk in this county with the buyer category that addresses it, drawing on water-quality detections, housing-stock lead exposure, EPA Radon Zone designation, and FEMA flood and wildfire ratings. NSF-certified options surface where applicable, and products that match the specific contaminant take priority.
- Best Lead Paint Test Kits — 65.5% of homes built before 1978
- Best Radon Test Kits — EPA Radon Zone 1 (highest risk) dominant in county
Deep Dive Reports
Detailed analysis for Fremont County, Idaho
Overview
Fremont County in Idaho covers 8 ZIP codes with an average Home Safety Score of C (56/100).
3 of 8 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.