CITY REPORT
MT
Grass Range, MT Water Quality Report
1 ZIP code · 2 water systems · Updated 2026-03-16
Data: EPA SDWIS Last verified: 2026-03-16
1
ZIP Codes
2
Water Systems
1
ZIPs with Violations
Zone 1
Radon Risk (High)
Overview
We track water quality and home safety data for 1 ZIP code in Grass Range, Montana, covering 2 community water systems serving approximately 102 people.
1 of 1 ZIP code (100%) have recorded EPA violations. All violations are monitoring/reporting type.
Water Sources
Grass Range water systems draw from: Groundwater.
Lead & Copper
- Lead data: not yet available for Grass Range
- 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.
Top Contaminants
| Contaminant | Category | Violations | ZIPs Affected |
|---|---|---|---|
| Arsenic | Inorganic | 6 | 1 |
| Stage 1 DBP Rule | Treatment Technique | 4 | 1 |
| Surface Water Treatment Rule | Treatment Technique | 4 | 1 |
| Total Trihalomethanes (TTHM) | Disinfection Byproducts | 2 | 1 |
| Haloacetic Acids (HAA5) | Disinfection Byproducts | 2 | 1 |
Areas with Most Violations
| ZIP Code | Safety Score | Violations | Health-Based | System |
|---|---|---|---|---|
| 59032 | — | 9 | 0 | GRASS RANGE TOWN OF |
All ZIP Codes in Grass Range
- 59032 — 9 violations
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.