Lake County, Montana
12 ZIP codes · Avg score 49/100 · Grade D · Updated 2026-06-03
Across Lake County's 12 ZIP codes, EPA data shows a below-average compliance pattern — health-based violations are documented in several areas, and independent testing is a reasonable step for concerned households.
How Lake County Compares
How Lake County Compares
Lake County scores 6 points below the Montana state average (55/100) and 19 points below the national average (68/100).
Data: EPA SDWIS Last verified: 2026-06-03
ZIP Code Risk Map
Water Quality Map: Lake 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 12%)
Estimated additional annual cost per homeowner: $824, driven primarily by wildfire
Infrastructure: 0.333% avg pipe failure probability, 8% of ZIPs at high risk
56.3% 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: $824
Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).
Housing Age Distribution
11,383 housing units in Lake 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 Lake County
Remediation costs are relatively manageable for most homeowners in Lake 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 Lake 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 Lake County ranked by EPA violation count.
| # | Water System | Population | Violations |
|---|---|---|---|
| 1 | Pablo Lake County Water and Sewer District | 2,175 | 7 |
| 2 | Round Butte Water Company | 400 | 3 |
| 3 | Consolidated Charlo Lake Company W and S District | 450 | 3 |
| 4 | City of Polson | 5,300 | 2 |
| 5 | Jette Meadows Lake Company W and S District | 375 | 2 |
11 total water systems serve Lake County.
All ZIP Codes in Lake County
12 ZIP codes tracked in Lake County.
| # | ZIP Code | City | Safety Score | Grade | Violations | Home Value |
|---|---|---|---|---|---|---|
| 1 | 59860 | Polson | 69 | C | 2 | $386K |
| 2 | 59931 | Rollins | 65 | C | 2 | $1016K |
| 3 | 59855 | Pablo | 64 | C | 5 (2 health) | $127K |
| 4 | 59826 | Condon | 53 | D | 0 | $492K |
| 5 | 59824 | Charlo | 52 | D | 3 | $325K |
| 6 | 59831 | Dixon | 40 | D | 0 | $156K |
| 7 | 59863 | Ravalli | 40 | D | 0 | — |
| 8 | 59865 | Saint Ignatius | 40 | D | 0 | $310K |
| 9 | 59910 | Big Arm | 40 | D | 0 | $606K |
| 10 | 59914 | Dayton | 40 | D | 0 | $938K |
| 11 | 59915 | Elmo | 40 | D | 0 | — |
| 12 | 59929 | Proctor | 40 | D | 0 | $253K |
Recommended Buyer Guides for Lake 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.
- Best Lead Paint Test Kits — 56.3% of homes built before 1978
- 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 Lake County, Montana
Overview
Lake County in Montana covers 12 ZIP codes with an average Home Safety Score of D (49/100).
4 of 12 ZIP codes have recorded EPA violations. 2 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
Lake 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
56.3% of homes in this county were built before 1978. Older plumbing and solder can leach lead into drinking water, especially in the morning.