COUNTY REPORT ID

Owyhee County, Idaho

5 ZIP codes · Avg score 77/100 · Grade B · Updated 2026-06-03

Covering 5 ZIP codes, Owyhee County earns a high grade for tap water — most systems report zero health-based violations, and the overall compliance rate comfortably exceeds federal benchmarks.

How Owyhee County Compares

Owyhee County77/100
Idaho avg66/100
National avg68/100

How Owyhee County Compares

B
County Grade
77/100
Avg Safety Score
5
ZIP Codes
9
Water Systems

Owyhee County scores 11 points above the Idaho state average (66/100) and 9 points above the national average (68/100).

Data: EPA SDWIS Last verified: 2026-06-03

B
County Grade
77
Avg Safety Score
5
ZIP Codes
Best ZIP: 83650 (83/100)
Lowest ZIP: 83628 (64/100)
$269K
Median Home Value
$640
Avg Remediation (24% of home value)

ZIP Code Risk Map

Water Quality Map: Owyhee County, Idaho

Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.

A B C D F

Key Risk Factors

Health risk index: 13.9 (asthma 11%, diabetes 13.4%)

Estimated additional annual cost per homeowner: $852, driven primarily by energy_code_gap

Infrastructure: 0.362% avg pipe failure probability

53.8% of homes built before 1978 (lead paint era)

Violation History (2021–2025)

↑ Worsening trend

EPA violation counts by year across Owyhee County water systems. Health-based shown in red, total in blue.

2021
1 (1 health)
2023
1 (1 health)
2024
2 (2 health)
2025
1 (1 health)

Peak year: 2024 with 2 violations. Past 5 years: 5 total (5 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

Asthma 11% (national: 8.9%)
Diabetes 13.4% (national: 10.5%)
Obesity 33.4% (national: 32.4%)

Black markers indicate national averages. Source: CDC PLACES, Census ACS.

Infrastructure Overview

1973
Median Build Year
53.8%
Pre-1978 Housing
36%
Pipe Failure Probability
0%
ZIPs at High Infra Risk
Low
Lead Pipe Risk

Sources: Census ACS (housing age), EPA SDWIS (infrastructure risk model), state bridge inspection data.

Compound Risk Breakdown

Estimated additional annual cost per homeowner: $852

Energy Code Gap $432/yr
Wildfire $300/yr
Water / Lead $120/yr

Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).

Housing Age Distribution

4,271 housing units in Owyhee County

Pre-1940 8%
1940–1959 16%
1960–1979 24%
1980–1999 26%
2000+ 26%

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 Owyhee County

$269K
Median Home Value
$640
Est. Remediation Cost
0.2%
of Home Value
Remediation as % of home value low burden

Remediation costs are relatively manageable for most homeowners in Owyhee 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 Owyhee County residents

Asthma 11% (US avg: 8.9%)
Diabetes 13.4% (US avg: 11%)
Obesity 33.4% (US avg: 32.4%)

Black markers = national averages. Red = above national avg. Green = below. Source: CDC PLACES, Census ACS.

Water Systems with Most Violations

Top 5 systems in Owyhee County ranked by EPA violation count.

# Water System Population Violations
1 City of Marsing 1,300 28
2 East Lizard Butte Water Corporation 95 21
3 Hope House (owyhee) 78 21
4 City of Grand View, 352 13
5 Simplot Livestock Company Grandview 100 13

9 total water systems serve Owyhee County.

All ZIP Codes in Owyhee County

5 ZIP codes tracked in Owyhee County.

# ZIP Code City Safety Score Grade Violations Home Value
1 83650 Murphy 83 B 0 $308K
2 83604 Bruneau 82 B 2 (1 health) $250K
3 83624 Grand View 79 B 13 (1 health) $269K
4 83639 Marsing 79 B 21 (3 health) $397K
5 83628 Homedale 64 C 7 $233K

Recommended Buyer Guides for Owyhee County

Below: editorial picks, no sponsored placements.

Overview

Owyhee County in Idaho covers 5 ZIP codes with an average Home Safety Score of B (77/100).

4 of 5 ZIP codes have recorded EPA violations. 5 health-based violations have been documented.

← Back to Idaho water quality report

Data Sources

Updated daily.

Frequently Asked Questions

Is water safe in Owyhee County?
Owyhee County receives a grade of B, indicating generally safe tap water across its 5 ZIP codes.
How many water systems serve Owyhee County?
Owyhee County is served by 9 public water systems that supply drinking water to residents across 5 ZIP codes.
What is the biggest environmental risk in Owyhee County?
The primary environmental risk factor in Owyhee County is energy_code_gap. This contributes to an estimated additional annual cost of $852 per homeowner.
How old are homes in Owyhee County?
The median home build year in Owyhee County is 1973. 53.8% of homes were built before 1978, which means they may contain lead-based paint and older plumbing materials.
How does Owyhee County compare to Idaho?
Owyhee County has an average water safety score of 77/100, which is above the Idaho state average of 66/100.

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