Community Water System · PWS MT0004249
Clarks Lookout
Operator location Dillon, Montana - 49% of 281 violations are health-based (upper-third health share (> 23%)); groundwater source; 62 served per SDWIS.
- 62
- People served (this PWS)
- 281
- EPA violations (this PWS)
- 139
- Health-based (this PWS)
- Untested
- UCMR5 (this PWS)
Clarks Lookout standing, high SDWIS violation third
49% of 281 recorded violations are health-based - upper-third health share (> 23%). Corpus terciles use 29,740 systems serving 500+ (the sitemap cohort). Health-based share 49% is upper-third health share (> 23%).
The verdict
Clarks Lookout sits in the upper third of the sitemap cohort by violation count (281), so the tables below sample a dense compliance trail rather than a near-clean ledger. Population served is smaller (62; smaller served population (≤ 999)), so each violation row represents a compact service footprint. Health-based share is 49% - most of this ledger is MCL or treatment-technique exceedance. No UCMR5 PFAS test appears for this system in this extract.
- 281
- Total EPA violations on record
- 49%
- Health-based (MCL / treatment failure)
- 62
- People served by this PWS (SDWIS)
- N/A
- PFAS compounds detected (UCMR5)
Population ordinals match the sitemap cohort (systems serving 500+, population_served DESC). See methodology · corpus placement.
System Details
- System Type
- Community
- Owner Type
- Private
- Connections
- 43
- County
- Beaverhead
- School/Daycare
- No
- MCL Violations
- 139
- Monitoring Violations
- 126
- Treatment Tech Violations
- 0
Violation History
Contaminant violations recorded by EPA.
| Contaminant | Category | Count | Latest |
|---|---|---|---|
| Arsenic | MCL | 139 | 2019 |
| Consumer Confidence Rule | Other | 16 | 2025 |
| Lead and Copper Rule | MR | 7 | 2012 |
| Di(2-ethylhexyl) adipate | MR | 4 | 2012 |
| Dinoseb | MR | 4 | 2012 |
| Hexachlorocyclopentadiene | MR | 4 | 2012 |
| Aldicarb | MR | 4 | 2012 |
| Atrazine | MR | 4 | 2012 |
| LASSO | MR | 4 | 2012 |
| Endrin | MR | 4 | 2012 |
| 2,4-D | MR | 4 | 2012 |
| 2,4,5-TP | MR | 4 | 2012 |
| HEXACHLOROBENZENE | MR | 4 | 2012 |
| Benzo(a)pyrene | MR | 4 | 2012 |
| Chlordane | MR | 4 | 2012 |
| Gross Alpha, Excl. Radon and U | MR | 4 | 2012 |
| Arsenic | MR | 4 | 2012 |
| Dalapon | MR | 4 | 2012 |
| Heptachlor | MR | 4 | 2012 |
| Di(2-ethylhexyl) phthalate | MR | 4 | 2012 |
| Pentachlorophenol | MR | 4 | 2012 |
| BHC-GAMMA | MR | 4 | 2012 |
| Combined Radium (-226 and -228) | MR | 4 | 2012 |
| Toxaphene | MR | 4 | 2012 |
| Picloram | MR | 4 | 2012 |
| Heptachlor epoxide | MR | 4 | 2012 |
| Aldicarb sulfoxide | MR | 4 | 2012 |
| Aldicarb sulfone | MR | 4 | 2012 |
| Simazine | MR | 4 | 2012 |
| Carbofuran | MR | 4 | 2012 |
Violation Count vs. the National Corpus
Clarks Lookout has 281 recorded EPA violations, 90% of the 29,740 public water systems serving 500+ people nationwide carry fewer, and 10% carry more. 49% of this system's own violations are health-based (139 of 281), and it ranks unranked by population served among that same cohort.
EPA violations vs. the national water-system corpus
Public water systems serving 500+ people (EPA SDWIS)
281 Higher than most more violations than 90% 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
Health-based violations on Clarks Lookout
139 health-based rows in the tables above map to MCL or treatment-technique exceedances, verify each contaminant code on the federal SDWIS report for MT0004249.
Sources: EPA SDWIS
Nationwide peers
281 violations · 62 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.
What to do with Clarks Lookout
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.