Troy, MT: High Radon Risk — 70/100 (2026)
1 ZIP code · 4 water systems · Updated 2026-06-03
Water systems serving Troy hold a strong EPA compliance record — the city places among the better-performing areas in MT with few health-based violations on file.
How Troy Compares
Data: EPA SDWIS Last verified: 2026-06-03
What You Should Know About Troy Water
- Average lead level: 0.002 mg/L.
- Homes built before 1986: 51% — older plumbing may contain lead solder.
- Estimated remediation: $2,400 per household.
- CDC health risk index: 15.86 — above typical levels.
Who Supplies Your Water in Troy
With 3 utilities splitting service in Troy, MT, water accountability is distributed across 4 systems on the federal record.
Overview
We track water quality and home safety data for 1 ZIP code in Troy, Montana, covering 4 community water systems serving approximately 3,359 people.
No EPA violations recorded across any ZIP codes in Troy — an excellent indicator of water quality.
Home Safety Score
Average Home Safety Score for Troy: B (70/100)
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
Troy water systems draw from: Groundwater.
Lead & Copper
- Average lead level (90th percentile): 0.0020 mg/L (EPA action level: 0.015 mg/L)
- 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 |
|---|---|---|---|
| 59935 | B | City of Troy | 2,100 |
All ZIP Codes in Troy
- 59935 [B]
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 Troy
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 Troy
With 51% of homes built before 1986, lead solder in plumbing is a potential concern. The EPA banned lead solder in 1986, but many older homes retain original plumbing.
Source: U.S. Census Bureau American Community Survey (ACS).
Housing Age Profile
Pre-1986 plumbing is not a rare legacy case in Troy — it's the dominant profile. The median build year of 1984 indicates a housing stock where lead-soldered copper joints are a common structural feature of residences across the city.
Over half of homes in Troy were built before 1986, when lead solder was banned. Older plumbing may leach lead into drinking water, especially with corrosive water chemistry.
Source: U.S. Census Bureau ACS B25034.
Cost Context: What Remediation Means for Troy Homeowners
While no remediation project is entirely without cost, the relationship between estimated remediation and property values in Troy is notably favorable — the equity share is small enough that the household financial perspective is one of proportionality rather than pressure, and most homeowners can treat it as routine planning rather than a significant financial event.
Remediation costs in Troy are relatively low compared to home values. The $1,600–$3,300 estimated range is a small fraction of median property value. Home values are 6% below the Montana average.
Lead Exposure Risk for Children in Troy
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.
In recent monitoring under the Lead and Copper Rule, citywide samples for Troy have approached or crossed the regulatory action level on multiple occasions. Combined with 51% of stock dating from the pre-rule era, the picture supports baseline single-tap reads as a standard household-level step.
Sources: EPA Lead and Copper Rule, U.S. Census Bureau ACS, CDC childhood lead poisoning prevention guidelines.
Flood & Climate Risk in Troy
The NFIP claim record for Troy — 3 filed incidents — reflects genuine, recurring flood exposure rather than an isolated event or two. When a community accumulates flood claims at this volume and carries 100% of its ZIP codes inside FEMA-designated zones, flood history starts to factor into water quality planning in ways it doesn't for lower-exposure areas. Flooding introduces specific contamination pathways — runoff overwhelming treatment facility intake, surface water infiltrating private wells, and pressure disruptions in distribution systems allowing backflow — all of which become more relevant as flood frequency increases.
Troy has a moderate flood history with 3 FEMA claims averaging $10,179 per payout. 100% of ZIP codes fall within FEMA flood zones. Flood events can contaminate drinking water and overwhelm treatment systems.
How flooding affects water quality: Flood events can introduce sewage, agricultural runoff, and industrial chemicals into water supplies. Even after floodwaters recede, contamination can persist in wells and aging infrastructure. Flood damage can add significantly to the estimated <strong>$2,400</strong> remediation cost per household.
Residents in flood-prone areas should consider flood insurance even outside FEMA zones — over 25% of flood claims come from low-to-moderate risk areas. After any flood event, test your water before drinking.
Source: FEMA National Flood Insurance Program (NFIP) claims data, FEMA flood zone designations.
Deep Dive Reports
Detailed analysis for Troy, MT