Transient Non-Community Water System · PWS CT1360154
Oneco Market
Operator location Sterling, Connecticut - 40% of 30 violations are health-based (upper-third health share (> 23%)); groundwater source; 25 served per SDWIS.
- 25
- People served (this PWS)
- 30
- EPA violations (this PWS)
- 12
- Health-based (this PWS)
- Untested
- UCMR5 (this PWS)
Oneco Market standing, mid SDWIS violation third
40% of 30 recorded violations are health-based - upper-third health share (> 23%). Corpus terciles use 29,740 systems serving 500+ (the sitemap cohort). Health-based share 40% is upper-third health share (> 23%).
The verdict
Oneco Market lands in the middle third by violation volume (30), large enough for peer comparisons without matching the fleet's heaviest ledgers. Population served is smaller (25; smaller served population (≤ 999)), so each violation row represents a compact service footprint. Health-based share is 40% - most of this ledger is MCL or treatment-technique exceedance. No UCMR5 PFAS test appears for this system in this extract.
- 30
- Total EPA violations on record
- 40%
- Health-based (MCL / treatment failure)
- 25
- 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
- 1
- County
- Windham
- School/Daycare
- No
- MCL Violations
- 12
- Monitoring Violations
- 18
- Treatment Tech Violations
- 0
Violation History
Contaminant violations recorded by EPA.
| Contaminant | Category | Count | Latest |
|---|---|---|---|
| Coliform (TCR) | MR | 16 | 2015 |
| Coliform (TCR) | MCL | 12 | 2005 |
| Nitrate | MR | 1 | 2003 |
| Nitrite | MR | 1 | 2003 |
Violation Count vs. the National Corpus
Oneco Market has 30 recorded EPA violations, 42% of the 29,740 public water systems serving 500+ people nationwide carry fewer, and 57% carry more. 40% of this system's own violations are health-based (12 of 30), 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)
30 Lower than most fewer violations than 57% 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 Oneco Market
12 health-based rows in the tables above map to MCL or treatment-technique exceedances, verify each contaminant code on the federal SDWIS report for CT1360154.
Sources: EPA SDWIS
Nationwide peers
30 violations · 25 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 Oneco Market
Use this system's EPA-reported record as a starting filter, not a final verdict.
- See how every tracked system in Connecticut compares on the same EPA violation measures. Connecticut 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.