Community Water System · PWS MT0000158
Boulder City Of
Operator location Boulder, Montana - upper-third violation load (> 74 violations) with 376 EPA violations; groundwater source; 1,400 served (PWS-level, not municipal population).
- 1,400
- People served (this PWS)
- 376
- EPA violations (this PWS)
- 37
- Health-based (this PWS)
- Untested
- UCMR5 (this PWS)
Boulder City Of standing, high SDWIS violation third
376 EPA SDWIS violations on record - upper-third violation load (> 74 violations). Corpus terciles use 29,740 systems serving 500+ (the sitemap cohort). Health-based share 10% is middle-third health share (≤ 23%). Population rank #16,562 of 29,740 among systems serving 500+.
The verdict
Boulder City Of sits in the upper third of the sitemap cohort by violation count (376), so the tables below sample a dense compliance trail rather than a near-clean ledger. Population served is mid-pack at 1,400 (mid served population (≤ 3,309)). Health-based share is 10% (middle-third health share (≤ 23%)). No UCMR5 PFAS test appears for this system in this extract.
- #16,562 of 29,740
- Population · /systems
- #104 of 283
- Population · MT
- 376
- Total EPA violations on record
- 10%
- Health-based (MCL / treatment failure)
Population ordinals match the sitemap cohort (systems serving 500+, population_served DESC). See methodology · corpus placement.
System Details
- System Type
- Community
- Owner Type
- Local
- Connections
- 563
- County
- Jefferson
- School/Daycare
- No
- MCL Violations
- 29
- Monitoring Violations
- 339
- Treatment Tech Violations
- 8
Violation History
Contaminant violations recorded by EPA.
| Contaminant | Category | Count | Latest |
|---|---|---|---|
| Lead and Copper Rule | MR | 193 | 2007 |
| Coliform (TCR) | MCL | 29 | 2006 |
| Cadmium | MR | 12 | 2011 |
| Fluoride | MR | 12 | 2011 |
| Mercury | MR | 12 | 2011 |
| Nickel | MR | 12 | 2011 |
| Antimony, Total | MR | 12 | 2011 |
| Thallium, Total | MR | 12 | 2011 |
| Selenium | MR | 12 | 2011 |
| Barium | MR | 12 | 2011 |
| Chromium | MR | 12 | 2011 |
| Beryllium, Total | MR | 12 | 2011 |
| Coliform (TCR) | MR | 8 | 2005 |
| TTHM | MR | 6 | 2024 |
| Total Haloacetic Acids (HAA5) | MR | 6 | 2024 |
| Lead and Copper Rule | TT | 4 | 2006 |
| Surface Water Treatment Rule | TT | 4 | 2022 |
| Revised Total Coliform Rule | MON | 3 | 2018 |
| Asbestos | MR | 3 | 2011 |
Violation Count vs. the National Corpus
Boulder City Of has 376 recorded EPA violations, 93% of the 29,740 public water systems serving 500+ people nationwide carry fewer, and 7% carry more. 10% of this system's own violations are health-based (37 of 376), and it ranks #16,562 of 29,740 by population served among that same cohort.
EPA violations vs. the national water-system corpus
Public water systems serving 500+ people (EPA SDWIS)
376 Higher than most more violations than 93% of 29,740 water systems
the national water-system corpus, bucketed by value
Each bar is a band; taller bars hold more water systems. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count and share, and where it sits relative to this entry.
Source EPA SDWIS · 2026-05-15
SDWIS compliance record for Boulder City Of
376 violations on record for MT0000158; use EPA SDWIS to confirm return-to-compliance dates and monitoring categories.
Sources: EPA SDWIS
Nationwide peers
376 violations · 1,400 served: nearest cross-state SDWIS matches.
Cross-state systems with comparable violation load
Nearest cross-state community systems (500+ served) by total SDWIS violations on record.
Cross-state systems near this population served
Nearest cross-state systems by EPA SDWIS population_served (same 500+ sitemap gate).
What to do with Boulder City Of
Use this system's EPA-reported record as a starting filter, not a final verdict.
- See how every tracked system in Montana compares on the same EPA violation measures. Montana systems
- Check whether PFAS was detected at this system under UCMR5 testing. PFAS guide
- Find and compare another public water system by name or PWSID. Search systems
EPA SDWIS and UCMR5 figures are informational only, not a substitute for a certified lab test of your own tap water.