Community Water System · PWS MT0002514
Yellowtail Dam Gc System
Operator location Yellowtail, Montana - 0% of 226 violations are health-based (lower-third health share (≤ 1%)); groundwater source; 125 served per SDWIS.
- 125
- People served (this PWS)
- 226
- EPA violations (this PWS)
- 0
- Health-based (this PWS)
- Untested
- UCMR5 (this PWS)
Yellowtail Dam Gc System standing, high SDWIS violation third
0% of 226 recorded violations are health-based - lower-third health share (≤ 1%). Corpus terciles use 29,740 systems serving 500+ (the sitemap cohort). Health-based share 0% is lower-third health share (≤ 1%).
The verdict
Yellowtail Dam Gc System sits in the upper third of the sitemap cohort by violation count (226), so the tables below sample a dense compliance trail rather than a near-clean ledger. Population served is smaller (125; smaller served population (≤ 999)), so each violation row represents a compact service footprint. Health-based share is only 0% - almost all of this trail is monitoring or reporting. No UCMR5 PFAS test appears for this system in this extract.
- 226
- Total EPA violations on record
- 0%
- Health-based (MCL / treatment failure)
- 125
- 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
- Federal
- Connections
- 50
- County
- Big Horn
- School/Daycare
- No
- MCL Violations
- 0
- Monitoring Violations
- 214
- Treatment Tech Violations
- 0
Violation History
Contaminant violations recorded by EPA.
| Contaminant | Category | Count | Latest |
|---|---|---|---|
| Consumer Confidence Rule | Other | 12 | 2023 |
| Nitrate-Nitrite | MR | 11 | 2017 |
| Coliform (TCR) | MR | 9 | 2005 |
| Lead and Copper Rule | MR | 6 | 2024 |
| Selenium | MR | 5 | 2002 |
| Mercury | MR | 5 | 2002 |
| Cadmium | MR | 5 | 2002 |
| Arsenic | MR | 5 | 2002 |
| Barium | MR | 5 | 2002 |
| Antimony, Total | MR | 3 | 2002 |
| Chromium | MR | 3 | 2002 |
| Beryllium, Total | MR | 3 | 2002 |
| Toxaphene | MR | 3 | 2002 |
| Dalapon | MR | 3 | 2002 |
| Di(2-ethylhexyl) adipate | MR | 3 | 2002 |
| OXAMYL | MR | 3 | 2002 |
| Simazine | MR | 3 | 2002 |
| Hexachlorocyclopentadiene | MR | 3 | 2002 |
| Carbofuran | MR | 3 | 2002 |
| Aldicarb | MR | 3 | 2002 |
| Atrazine | MR | 3 | 2002 |
| HEXACHLOROBENZENE | MR | 3 | 2002 |
| Benzo(a)pyrene | MR | 3 | 2002 |
| Pentachlorophenol | MR | 3 | 2002 |
| cis-1,2-Dichloroethylene | MR | 3 | 2002 |
| Xylenes, Total | MR | 3 | 2002 |
| o-Dichlorobenzene | MR | 3 | 2002 |
| p-Dichlorobenzene | MR | 3 | 2002 |
| Vinyl chloride | MR | 3 | 2002 |
| 1,1-Dichloroethylene | MR | 3 | 2002 |
Violation Count vs. the National Corpus
Yellowtail Dam Gc System has 226 recorded EPA violations, 87% of the 29,740 public water systems serving 500+ people nationwide carry fewer, and 13% carry more. 0% of this system's own violations are health-based (0 of 226), 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)
226 Higher than most more violations than 87% 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 Yellowtail Dam Gc System
0 health-based rows in the tables above map to MCL or treatment-technique exceedances, verify each contaminant code on the federal SDWIS report for MT0002514.
Sources: EPA SDWIS
Nationwide peers
226 violations · 125 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 Yellowtail Dam Gc System
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.