F0/100
BOULDER CITY OF — Water Quality Report 2026
Serving 1,400 people · Montana
Water Source
Groundwater
County
—
System ID
MT0000158
Violations
87
Contaminant Test Results
1 contaminant above EPA health goals
| Contaminant | Detected | Limit (MCL) | Status |
|---|---|---|---|
Copper (90th percentile) | 1.40 mg/L | 1.30 mg/L | Over Limit |
EPA Violation History
3
Violations (last 5yr)
0
Unresolved
1
Health-Related
TIER 3Resolved
Failed Level 2 Assessment under Revised Total Coliform Rule
This is a paperwork/process violation — it does not mean a contaminant was detected at unsafe levels.
When: January 1, 2024 – December 31, 2024Rule: Stage 2 DBPREnforcement: Resolving — corrective action underway
TIER 3Resolved
Failed Level 2 Assessment under Revised Total Coliform Rule
This is a paperwork/process violation — it does not mean a contaminant was detected at unsafe levels.
When: January 1, 2024 – December 31, 2024Rule: Stage 2 DBPREnforcement: Resolving — corrective action underway
TIER 2Resolved
Violation related to Coliform (pre-2016 TCR)
When: July 1, 2022 – July 28, 2022Rule: Surface Water Treatment RuleEnforcement: Resolving — corrective action underway
Understanding violation severity
Tier 1Urgent health risk. Utility must notify all customers within 24 hours.Tier 2Important health or treatment issue. Customers notified within 30 days.Tier 3Administrative or monitoring issue. Reported in the annual water quality report.
Source: EPA Safe Drinking Water Information System (SDWIS) · Updated quarterly
Frequently Asked Questions About BOULDER CITY OF
Is BOULDER CITY OF water safe to drink?
BOULDER CITY OF water receives a grade of F (0/100), which is considered failing. 1 contaminant(s) exceed EPA legal limits and 87 violation(s) are on record. Customers may want to consider using a water filter.
What contaminants has BOULDER CITY OF detected?
2 contaminants were tested in BOULDER CITY OF's water. Notable contaminants include Copper (90th percentile). 1 exceed EPA legal limits (MCLs). 1 exceed EPA health goals (MCLGs).
Does BOULDER CITY OF have any EPA violations?
Yes, BOULDER CITY OF has 87 EPA violation(s) on record, with the most recent in 2024. Violation types include MR, TT, MON. 6 are health-based violations.
How many people does BOULDER CITY OF serve?
BOULDER CITY OF serves approximately 1,400 people, Montana. The system provides water to 1 community: Boulder.
What type of water does BOULDER CITY OF provide?
BOULDER CITY OF sources its water from groundwater. Groundwater is pumped from underground aquifers, which often provides natural filtration. The utility's system ID is MT0000158.
How does BOULDER CITY OF compare to other utilities in Montana?
BOULDER CITY OF scores 0/100 with a grade of F (failing). This score suggests significant water quality concerns relative to other utilities. Visit our Montana state page for a full comparison of water systems.