Harrison, MT: High Radon Risk — 40/100 (2026)
1 ZIP code · 1 water system · Updated 2026-06-03
A meaningful share of water systems in Harrison have recorded health-based violations in recent MT monitoring periods — placing the city in the lower tier for tap water safety.
How Harrison Compares
Data: EPA SDWIS Last verified: 2026-06-03
What You Should Know About Harrison Water
- Homes built before 1986: 38% — older plumbing may contain lead solder.
- Estimated remediation: $1,200 per household.
- CDC health risk index: 12.81 — above typical levels.
Who Supplies Your Water in Harrison
Supply infrastructure in Harrison, MT runs through a single dominant provider — the main entity among 1 tracked system through which rate decisions, infrastructure work, and federal compliance are managed.
Overview
We track water quality and home safety data for 1 ZIP code in Harrison, Montana (population ~391), covering 1 community water system serving approximately 1,500 people region-wide.
No EPA violations recorded across any ZIP codes in Harrison — an excellent indicator of water quality.
Home Safety Score
Average Home Safety Score for Harrison: D (40/100)
The score combines three factors:
| Factor | What It Measures |
|---|---|
| Water Quality | EPA violations and compliance history |
| Lead Levels | 90th percentile lead concentration vs EPA action level |
| Radon Risk | EPA radon zone classification |
Water Sources
Harrison water systems draw from: Groundwater.
Lead & Copper
- Lead data: not yet available for Harrison
- 0 ZIP codes exceed the EPA lead action level
Radon Risk
Dominant radon zone: Zone 1 (High Risk)
The EPA recommends testing homes in Zone 1 and Zone 2 areas for radon.
Areas with No Violations
| ZIP Code | Safety Score | System | Population |
|---|---|---|---|
| 59735 | D | WHITEHALL TOWN OF | 1,500 |
All ZIP Codes in Harrison
- 59735 [D]
Data Sources
- Water quality: EPA Safe Drinking Water Information System (SDWIS)
- Lead/copper: EPA Lead and Copper Rule sampling data
- Radon: EPA Map of Radon Zones
Updated daily.
Health Outcomes in Harrison
Source: CDC PLACES (County-level estimates). Water contamination can correlate with respiratory and chronic health conditions.
Compared to National Average
Vertical line = national average. ■ Above national · ■ Below national
Housing & Infrastructure in Harrison
Housing age data helps assess potential lead pipe and infrastructure risks. Newer housing stock generally means lower plumbing-related contamination risk.
Source: U.S. Census Bureau American Community Survey (ACS).
Housing Age Profile
Because Harrison's housing stock spans a wide range of construction eras, the median build year of 1997 lands in a zone where two distinct risk populations share the same residential market. Homes built before 1986 may have lead-soldered copper plumbing joints — that practice was federally prohibited in 1986 but remained standard until then. The fraction built before 1970 face an additional risk: lead pipes used for service line connections were common before that decade, meaning both the pipe and the solder may be lead-containing in the oldest structures. Residents in mid-century or earlier homes face a different risk environment than neighbors in houses built after 1986, even if they drink from the same utility's supply — and that property-level divergence is what makes the age distribution above more diagnostic than the city-wide median alone.
Most homes in Harrison were built after 1986, reducing the risk of lead contamination from plumbing. Older homes should still be tested.
Source: U.S. Census Bureau ACS B25034.
Cost Context: What Remediation Means for Harrison Homeowners
Equity impact data for Harrison lands in the favorable tier — remediation claims a small slice of what properties here are worth.
Remediation costs in Harrison are relatively low compared to home values. The $800–$1,500 estimated range is a small fraction of median property value. Home values are 42% above the Montana average.
Lead Exposure Risk for Children in Harrison
Why children are most at risk: The CDC states there is no safe level of lead exposure for children. Children under 6 absorb lead more readily than adults, and even low levels can cause developmental delays, learning difficulties, and behavioral problems.
38% — that captures the slice of Harrison housing dating from before the federal ban on solder containing lead. It pairs with aggregate utility readings that either approach or cross 0.015 mg/L, the benchmark set under the EPA Lead and Copper Rule. Together, the two figures shift one-home reads into a standard household-level confirmation, particularly for families with kids. A certified lead-removal filter is available through retailer-verified channels if a kit returns results that warrant additional measures.
Sources: EPA Lead and Copper Rule, U.S. Census Bureau ACS, CDC childhood lead poisoning prevention guidelines.
What You Can Do in Harrison
- Test your water at home. City-level data shows averages — your tap may differ. NSF-certified test kits cost $20-40 and give results in days.
- Install a certified water filter. An NSF-certified pitcher or under-sink filter removes most common contaminants.
- Check your home's plumbing. With 38% of homes built before 1986, lead solder is a real possibility.
- Review your water system's CCR. Your utility publishes an annual Consumer Confidence Report with detailed test results. Request it or find it online.
Deep Dive Reports
Detailed analysis for Harrison, MT