City of Boulder
EPA ID: MT0000158 · 1,400 people served · 1 ZIP code
EPA records: City of Boulder, 2 past violations, all resolved, 1,400 served.
Data: EPA SDWIS Last verified: 2026-04-02
Service Area Map
Coverage area for City of Boulder Source: EPA SDWIS service area boundaries.
Service area boundary — Grade D
Service Area Demographics
The City of Boulder serves a community with a median household income of $62,770 and an estimated 2,535 residents across its service area. Approximately 61% of housing stock was built before 1986, which increases the likelihood of lead service lines and older plumbing.
💧 Where Does Your Water Come From?
City of Boulder's water is pumped from underground aquifers. Groundwater is naturally filtered through rock and soil, but it can be vulnerable to PFAS contamination, nitrates from agriculture, and industrial chemicals that seep into the water table.
About 1% of homes in Jefferson County, Montana rely on private wells rather than public water systems. Private well owners are responsible for their own water testing and treatment.
Superfund Proximity Note: This service area ranks in the 60th percentile nationally for proximity to Superfund (NPL) sites. Groundwater sources near contaminated sites may face elevated risk from industrial chemicals.
Infrastructure Risk
Detected Contaminants
How City of Boulder compares to EPA limits
What This Means For You
Total Trihalomethanes (TTHM) at 1 mg/L exceeds the EPA maximum of 0.08 mg/L. Bladder & rectal cancer risk; reproductive concerns. Consider granular activated carbon (GAC) filtration.
E. coli at 1 Zero tolerance (any positive sample triggers immediate action) exceeds the EPA maximum of Zero tolerance (any positive sample triggers immediate action). Severe GI illness; potentially fatal kidney failure in children. Consider UV disinfection (99.99%) filtration.
Total Trihalomethanes (TTHM) was detected in this water system. granular activated carbon (GAC) filtration can reduce exposure.
Find a certified water filter →Comparable Water Systems
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Estimated Remediation Costs
Average estimated costs across ZIP codes served by this system
Based on national averages for common remediation projects. Actual costs vary by property. Only issues flagged by EPA, FEMA, or state data for each ZIP code are included.
System Overview
City of Boulder (EPA ID: MT0000158) is a community water system in Montana that serves approximately 1,400 people from groundwater sources.
This system serves ZIP code 59632 in Boulder.
Average Home Safety Score: D (54/100)
Based on water quality violations, lead levels, and radon risk across all ZIP codes served by this system.
Violation History
Recent Violations
| Date | Contaminant | Type | Status |
|---|---|---|---|
| January 1, 2024 | Total Trihalomethanes (TTHM) | Monitoring | Resolved |
Contaminants Detected
The following contaminants have been flagged in EPA records for this water system:
| Contaminant | Category | Violations | Health-Based |
|---|---|---|---|
| Total Trihalomethanes (TTHM) | Disinfection Byproducts | 1 | No |
| E. coli | Microbiological | 1 | Yes |
Health Risk Details
E. coli (EPA limit: Zero tolerance (any positive sample triggers immediate action))
Severe GI illness; potentially fatal kidney failure in children At-risk groups: children under 5, elderly, immunocompromised individuals, pregnant women.
Removal methods: UV disinfection (99.99%), chlorination, reverse osmosis. Find the right filter →
Lead & Copper
No Lead and Copper Rule sampling data available for this water system.
Radon Risk in Service Area
Dominant radon zone for ZIP codes served by this system: Zone 1 (High Risk)
The EPA recommends testing homes in Zone 1 and Zone 2 areas for radon.
Need help with your water quality?
Typical cost: Water test: typically $20–$50 (DIY kit) · Professional inspection: $150–$400
Find the Right Water FilterFree tip: Let cold water run for 2 minutes before drinking — this helps flush lead from your pipes.
ZIP Codes Served
- 59632 — Boulder
Data Sources
This report uses public data from the EPA Safe Drinking Water Information System (SDWIS). View the full compliance record for City of Boulder (MT0000158) on EPA.gov.
Frequently Asked Questions
Is City of Boulder water safe to drink?
City of Boulder has recorded 1 health-based violation in the past 5 years. While the system is required to treat water to meet federal standards, you may want to consider additional precautions such as a certified water filter.
How many people does City of Boulder serve?
City of Boulder serves approximately 1,400 people across 1 ZIP code in Montana.
Where does City of Boulder get its water?
The primary water source is groundwater.
Water Source & Treatment
Where this water originates and how it's treated before reaching your tap.
Source: BOULDER CITY OF Consumer Confidence Report.
ZipCheckup is not affiliated with this water utility. Treatment and source data are sourced from the utility's published CCR filings.
Source water assessment report available at: https://deq.mt.gov/water/Programs/dw-sourcewater
Treatment regime
How this utility classifies its treatment process and what each reported treatment chemical does.
Watershed exposure sources reported
Land-use and natural conditions identified in the utility's source-water assessment as potential contamination sources upstream of treatment.
Treatment classification and chemical list sourced from BOULDER CITY OF Consumer Confidence Report.
Treatment intensity is a ZipCheckup-derived classification based on the chemicals and processes the utility reports. Chemicals and contamination sources are taken verbatim from the utility's CCR filing. Routine federal monitoring and contaminant testing shown elsewhere on this page determine whether the water meets safety standards, not the treatment classification.
Lead Service Line Inventory
Service line breakdown reported under the federal Lead and Copper Rule Improvements (LCRI) inventory requirement:
This system reports zero confirmed lead service lines in its inventory. Unknown-material counts may still warrant verification.
Federal LCRI rule (effective October 2024) requires every public water system to inventory its service lines and complete lead-line replacement within 10 years.
Source: EPA SDWIS Federal Service Line Inventory (Phase 2) · Submitted 2026
ZipCheckup is not affiliated with the utility or state agency. Inventory figures render verbatim from the public LCRI submission cited above; ZipCheckup does not perform inspections or replacements.
Notable events and violations
This section summarizes events the utility chose to disclose in its most recent Consumer Confidence Report, plus any federal compliance violations the utility recorded against itself. Both lists are utility-authored — ZipCheckup does not audit, judge, or reorder them.
Federal compliance violations on record
These entries are taken verbatim from the utility's CCR violations section. EPA defines four broad violation categories: Maximum Contaminant Level (MCL), Treatment Technique (TT), Monitoring & Reporting (M&R), and Public Notification (PN).
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MONITORING, ROUTINE (DBP), MAJOR · Haloacetic Acids (HAA5)2024-01-01 to 2024-12-31
Failed to test drinking water for Haloacetic Acids (HAA5) during the period. Cannot be sure of water quality for the reported period.
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MONITORING, ROUTINE (DBP), MAJOR · Total Trihalomethanes (TTHM)2024-01-01 to 2024-12-31
Failed to test drinking water for Total Trihalomethanes (TTHM) during the period. Cannot be sure of water quality for the reported period.
Violations record from BOULDER CITY OF Consumer Confidence Report.
ZipCheckup note: items above reflect what the utility published in its most recent CCR. Federal violation records are also tracked separately by the EPA Safe Drinking Water Information System (SDWIS) — the SDWIS record is the authoritative federal source for any specific regulatory action.
Frequently Asked Questions
What You Can Do
Test your water
Home test kits can detect lead, bacteria, and other contaminants at your tap. Find the right filter →
Check your specific ZIP code
Water quality can vary within a system. View nearest ZIP report →
Contact your utility
City of Boulder (EPA ID: MT0000158) — request the latest Consumer Confidence Report or ask about specific contaminants.