COUNTY REPORT MT

Petroleum County, Montana

1 ZIP code · Avg score 71/100 · Grade B · Updated 2026-06-04

Although county size varies, Petroleum County's 1 ZIP code share reliably safe tap water records and above-average compliance scores.

How Petroleum County Compares

Petroleum County71/100
Montana avg55/100
National avg68/100

How Petroleum County Compares

B
County Grade
71/100
Avg Safety Score
1
ZIP Codes
1
Water Systems

Petroleum County scores 16 points above the Montana state average (55/100) and 3 points above the national average (68/100).

Data: EPA SDWIS Last verified: 2026-06-04

B
County Grade
71
Avg Safety Score
1
ZIP Codes
Only ZIP: 59087
$167K
Median Home Value
$400
Avg Remediation (24% of home value)

Key Risk Factors

Health risk index: 14.3 (asthma 10.5%, diabetes 12.4%)

Estimated additional annual cost per homeowner: $800, driven primarily by wildfire

Infrastructure: 0.42% avg pipe failure probability, 100% of ZIPs at high risk

61% of homes built before 1978 (lead paint era)

County Health Indicators vs National Average

Asthma 10.5% (national: 8.9%)
Diabetes 12.4% (national: 10.5%)
Obesity 32.9% (national: 32.4%)

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

Infrastructure Overview

1989
Median Build Year
61%
Pre-1978 Housing
42%
Pipe Failure Probability
100%
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: $800

Wildfire $300/yr
Energy Code Gap $270/yr
Water / Lead $150/yr

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

Housing Age Distribution

262 housing units in Petroleum County

Pre-1940 23%
1940–1959 10%
1960–1979 17%
1980–1999 39%
2000+ 11%

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 Petroleum County

$167K
Median Home Value
$400
Est. Remediation Cost
0.2%
of Home Value
Remediation as % of home value low burden

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

Asthma 10.5% (US avg: 8.9%)
Diabetes 12.4% (US avg: 11%)
Obesity 32.9% (US avg: 32.4%)

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

All ZIP Codes in Petroleum County

1 ZIP code tracked in Petroleum County.

# ZIP Code City Safety Score Grade Violations Home Value
1 59087 Winnett 71 B 4 $167K

Recommended Buyer Guides for Petroleum County

Filtered against EPA monitoring data and CDC lead-exposure guidance, the guides below skip the generic catalog and connect directly to the contaminants and hazards on file here.

Overview

Petroleum County in Montana covers 1 ZIP code with an average Home Safety Score of B (71/100).

1 of 1 ZIP code have recorded EPA violations. All violations are monitoring/reporting type.

← Back to Montana water quality report

Data Sources

Updated daily.

Frequently Asked Questions

Is water safe in Petroleum County?
Petroleum County receives a grade of B, indicating generally safe tap water across its 1 ZIP codes.
How many water systems serve Petroleum County?
Petroleum County is served by 1 public water system that supplies drinking water to residents across 1 ZIP codes.
What is the biggest environmental risk in Petroleum County?
The primary environmental risk factor in Petroleum County is wildfire. This contributes to an estimated additional annual cost of $800 per homeowner.
How old are homes in Petroleum County?
The median home build year in Petroleum County is 1989. 61% of homes were built before 1978, which means they may contain lead-based paint and older plumbing materials.
How does Petroleum County compare to Montana?
Petroleum County has an average water safety score of 71/100, which is above the Montana state average of 55/100.

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