Transient Non-Community Water System · PWS MT0002008
Hardin KOA Cistern
Operator location Hardin, Montana - smaller served population (≤ 999) at 100 people served; 41 SDWIS violations on record from surface water sources.
- 100
- People served (this PWS)
- 41
- EPA violations (this PWS)
- 5
- Health-based (this PWS)
- Untested
- UCMR5 (this PWS)
Hardin KOA Cistern standing, mid SDWIS violation third
100 people served (SDWIS) - smaller served population (≤ 999). Corpus terciles use 29,740 systems serving 500+ (the sitemap cohort). Health-based share 12% is middle-third health share (≤ 23%).
The verdict
Hardin KOA Cistern lands in the middle third by violation volume (41), large enough for peer comparisons without matching the fleet's heaviest ledgers. Population served is smaller (100; smaller served population (≤ 999)), so each violation row represents a compact service footprint. Health-based share is 12% (middle-third health share (≤ 23%)). No UCMR5 PFAS test appears for this system in this extract.
- 41
- Total EPA violations on record
- 12%
- Health-based (MCL / treatment failure)
- 100
- 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
- Transient Non-Community
- Owner Type
- Private
- Connections
- 49
- County
- Big Horn
- School/Daycare
- No
- MCL Violations
- 5
- Monitoring Violations
- 34
- Treatment Tech Violations
- 0
Violation History
Contaminant violations recorded by EPA.
| Contaminant | Category | Count | Latest |
|---|---|---|---|
| Revised Total Coliform Rule | MON | 20 | 2025 |
| Coliform (TCR) | MR | 10 | 2006 |
| Coliform (TCR) | MCL | 5 | 2006 |
| Nitrate | MR | 4 | 1983 |
Violation Count vs. the National Corpus
Hardin KOA Cistern has 41 recorded EPA violations, 51% of the 29,740 public water systems serving 500+ people nationwide carry fewer, and 48% carry more. 12% of this system's own violations are health-based (5 of 41), 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)
41 Around the middle fewer violations than 48% 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
Population served record for Hardin KOA Cistern
EPA SDWIS lists 100 people served and 49 connections for this PWS, confirm the service-area footprint on the federal report before comparing to municipal census totals.
Sources: EPA SDWIS
Nationwide peers
41 violations · 100 served: nearest cross-state SDWIS matches.
Cross-state systems near this violation count
Nearest cross-state community systems (500+ served) by total SDWIS violations on record.
What to do with Hardin KOA Cistern
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.