Custer County, Montana
5 ZIP codes · Avg score 45/100 · Grade D · Updated 2026-06-03
Compared to state averages, Custer County scores below the baseline — health violations appear more frequently than the norm across its 5 ZIP codes.
How Custer County Compares
How Custer County Compares
Custer County scores 10 points below the Montana state average (55/100) and 23 points below the national average (68/100).
Data: EPA SDWIS Last verified: 2026-06-03
ZIP Code Risk Map
Water Quality Map: Custer County, Montana
Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.
Key Risk Factors
Health risk index: 13.9 (asthma 11.8%, diabetes 11.7%)
Estimated additional annual cost per homeowner: $1,844, driven primarily by flood
Infrastructure: 0.458% avg pipe failure probability, 80% of ZIPs at high risk
78.4% of homes built before 1978 (lead paint era)
Violation History (2022–2024)
→ Stable trendEPA violation counts by year across Custer County water systems. Health-based shown in red, total in blue.
Peak year: 2022 with 14 violations. Past 5 years: 21 total (21 health-based).
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: $1,844
Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).
Housing Age Distribution
5,828 housing units in Custer 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 Custer County
Remediation costs are relatively manageable for most homeowners in Custer 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 Custer 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 Custer County ranked by EPA violation count.
| # | Water System | Population | Violations |
|---|---|---|---|
| 1 | City of Miles City | 9,565 | 15 |
| 2 | Custer Company Water and Sewer District | 480 | 15 |
| 3 | Pine Hills Youth Correct Facil | 193 | 15 |
| 4 | Shepherd Water Station | 100 | 15 |
| 5 | Palisades Apartments | 50 | 15 |
All ZIP Codes in Custer County
5 ZIP codes tracked in Custer County.
| # | ZIP Code | City | Safety Score | Grade | Violations | Home Value |
|---|---|---|---|---|---|---|
| 1 | 59301 | Miles City | 54 | D | 15 (3 health) | $202K |
| 2 | 59338 | Kinsey | 53 | D | 0 | $276K |
| 3 | 59312 | Angela | 40 | D | 0 | — |
| 4 | 59333 | Hathaway | 40 | D | 0 | $184K |
| 5 | 59336 | Ismay | 40 | D | 0 | $277K |
Recommended Buyer Guides for Custer County
Independent picks. EPA-grounded. Matched here.
- Best Lead Paint Test Kits — 78.4% 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
- Best Sump Pumps — Flood is the top compound risk factor
- Best Mold Test Kits — Flood-driven moisture and mold risk
Deep Dive Reports
Detailed analysis for Custer County, Montana
Overview
Custer County in Montana covers 5 ZIP codes with an average Home Safety Score of D (45/100).
1 of 5 ZIP codes have recorded EPA violations. 3 health-based violations have been documented.
← Back to Montana 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
Custer 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
78.4% of homes in this county were built before 1978. Older plumbing and solder can leach lead into drinking water, especially in the morning.