Hamilton, MT: 1 Violation — 70/100 (2026)
1 ZIP code · 5 water systems · Updated 2026-06-03
Unlike many cities its size in MT, Hamilton keeps health-based violation rates low — systems here score at or above the state average for tap water safety, with no systemic concerns flagged in the current data set.
How Hamilton Compares
Data: EPA SDWIS Last verified: 2026-06-03
Hamilton Water: The Quick Version
- Your city's water systems recorded 1 violation in the past 5 years.
- Average lead level: 0.001 mg/L.
- Homes built before 1986: 56% — older plumbing may contain lead solder.
- Estimated remediation: $2,900 per household.
- CDC health risk index: 12.93 — above typical levels.
Water Systems Serving Hamilton
Structurally, Hamilton, MT's water supply is divided. Federal data identifies 5 water systems in the area, with 3 providers serving the bulk of residential connections. These utilities operate independently, meaning rate-setting authority and EPA compliance accountability are distributed rather than centralized.
Overview
We track water quality and home safety data for 1 ZIP code in Hamilton, Montana, covering 5 community water systems serving approximately 14,775 people.
1 of 1 ZIP code (100%) have recorded EPA violations. All violations are monitoring/reporting type.
Home Safety Score
Average Home Safety Score for Hamilton: 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
Hamilton water systems draw from: Groundwater.
Lead & Copper
- Average lead level (90th percentile): 0.0010 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.
Top Contaminants
| Contaminant | Category | Violations | ZIPs Affected |
|---|---|---|---|
| Stage 1 DBP Rule | Treatment Technique | 2 | 1 |
Areas with Most Violations
| ZIP Code | Safety Score | Violations | Health-Based | System |
|---|---|---|---|---|
| 59840 | B | 1 | 0 | City of Hamilton |
All ZIP Codes in Hamilton
- 59840 [B] — 1 violation
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.
CDC Health Data for Hamilton
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
Key Contaminants Detected in Hamilton
Based on EPA violation records. Check your ZIP code report for system-specific contaminant data.
How Old Is Hamilton's Housing Stock?
With 56% 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
Because the majority of Hamilton's housing predates 1986, when lead solder was banned from new plumbing, the median build year of 1970 reflects a city where lead-era plumbing materials are common rather than exceptional.
Over half of homes in Hamilton 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.
Hamilton: Remediation Cost in Perspective
In Hamilton, property wealth outpaces what documented remediation typically demands — the equity burden lands well within the low tier.
Remediation costs in Hamilton are relatively low compared to home values. The $1,900–$4,100 estimated range is a small fraction of median property value. Home values are 35% above the Montana average.
Protecting Children from Lead in Hamilton
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.
Routinely in Hamilton, where 56% of housing predates the solder ban and aggregate utility readings hover near the federal threshold, a faucet-level draw functions as a standard household step for families with small kids.
Sources: EPA Lead and Copper Rule, U.S. Census Bureau ACS, CDC childhood lead poisoning prevention guidelines.
Climate-Related Water Risk for Hamilton
Flood risk in Hamilton occupies the middle ground: 3 NFIP claims and 100% of local ZIP codes within FEMA flood zones. At that level, the risk pathways connecting flooding to water quality — treatment system stress, well infiltration, distribution backflow — become relevant considerations during significant flood events, even if day-to-day water quality is unaffected by flood history.
Hamilton has a moderate flood history with 3 FEMA claims averaging $1,569 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>$2,900</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 Hamilton, MT