Community Water System · PWS MT0004802
Avalon Subdivision
Operator location Belgrade, Montana - 0% of 255 violations are health-based (lower-third health share (≤ 1%)); groundwater source; 135 served per SDWIS.
- 135
- People served (this PWS)
- 255
- EPA violations (this PWS)
- 0
- Health-based (this PWS)
- Untested
- UCMR5 (this PWS)
Avalon Subdivision standing, high SDWIS violation third
0% of 255 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
Avalon Subdivision sits in the upper third of the sitemap cohort by violation count (255), so the tables below sample a dense compliance trail rather than a near-clean ledger. Population served is smaller (135; 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.
- 255
- Total EPA violations on record
- 0%
- Health-based (MCL / treatment failure)
- 135
- 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
- 6
- County
- Park
- School/Daycare
- No
- MCL Violations
- 0
- Monitoring Violations
- 243
- Treatment Tech Violations
- 0
Violation History
Contaminant violations recorded by EPA.
| Contaminant | Category | Count | Latest |
|---|---|---|---|
| Revised Total Coliform Rule | MON | 42 | 2021 |
| Consumer Confidence Rule | Other | 12 | 2020 |
| OXAMYL | MR | 7 | 2013 |
| Simazine | MR | 7 | 2013 |
| Dinoseb | MR | 7 | 2013 |
| Carbofuran | MR | 7 | 2013 |
| Aldicarb | MR | 7 | 2013 |
| Atrazine | MR | 7 | 2013 |
| Heptachlor | MR | 7 | 2013 |
| Endrin | MR | 7 | 2013 |
| 2,4-D | MR | 7 | 2013 |
| 2,4,5-TP | MR | 7 | 2013 |
| Benzo(a)pyrene | MR | 7 | 2013 |
| Pentachlorophenol | MR | 7 | 2013 |
| BHC-GAMMA | MR | 7 | 2013 |
| Methoxychlor | MR | 7 | 2013 |
| Hexachlorocyclopentadiene | MR | 7 | 2013 |
| Aldicarb sulfone | MR | 7 | 2013 |
| Toxaphene | MR | 7 | 2013 |
| LASSO | MR | 7 | 2013 |
| Heptachlor epoxide | MR | 7 | 2013 |
| Chlordane | MR | 7 | 2013 |
| Dalapon | MR | 7 | 2013 |
| Lead and Copper Rule | MR | 7 | 2020 |
| HEXACHLOROBENZENE | MR | 7 | 2013 |
| Picloram | MR | 7 | 2013 |
| Aldicarb sulfoxide | MR | 7 | 2013 |
| Di(2-ethylhexyl) phthalate | MR | 7 | 2013 |
| Di(2-ethylhexyl) adipate | MR | 7 | 2013 |
| Asbestos | MR | 3 | 2011 |
Violation Count vs. the National Corpus
Avalon Subdivision has 255 recorded EPA violations, 88% of the 29,740 public water systems serving 500+ people nationwide carry fewer, and 11% carry more. 0% of this system's own violations are health-based (0 of 255), 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)
255 Higher than most more violations than 88% 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 Avalon Subdivision
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 MT0004802.
Sources: EPA SDWIS
Nationwide peers
255 violations · 135 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 Avalon Subdivision
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.