Community Water System · PWS CT0600041
Quonnipaug Hills - Main System
Operator location Branford, Connecticut - smaller served population (≤ 999) at 564 people served; 409 SDWIS violations on record from groundwater sources.
- 564
- People served (this PWS)
- 409
- EPA violations (this PWS)
- 37
- Health-based (this PWS)
- Untested
- UCMR5 (this PWS)
Quonnipaug Hills - Main System standing, high SDWIS violation third
564 people served (SDWIS) - smaller served population (≤ 999). Corpus terciles use 29,740 systems serving 500+ (the sitemap cohort). Health-based share 9% is middle-third health share (≤ 23%). Population rank #27,160 of 29,740 among systems serving 500+.
The verdict
Quonnipaug Hills - Main System sits in the upper third of the sitemap cohort by violation count (409), so the tables below sample a dense compliance trail rather than a near-clean ledger. Population served is smaller (564; smaller served population (≤ 999)), so each violation row represents a compact service footprint. Health-based share is 9% (middle-third health share (≤ 23%)). No UCMR5 PFAS test appears for this system in this extract.
- #27,160 of 29,740
- Population · /systems
- #161 of 184
- Population · CT
- 409
- Total EPA violations on record
- 9%
- Health-based (MCL / treatment failure)
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
- 187
- County
- New Haven
- School/Daycare
- No
- MCL Violations
- 37
- Monitoring Violations
- 349
- Treatment Tech Violations
- 0
Violation History
Contaminant violations recorded by EPA.
| Contaminant | Category | Count | Latest |
|---|---|---|---|
| Coliform (TCR) | MCL | 37 | 2011 |
| E. COLI | MR | 28 | 2025 |
| Chlorine | MR | 8 | 2019 |
| Consumer Confidence Rule | Other | 7 | 2016 |
| Coliform (TCR) | MR | 6 | 2013 |
| 1,2,4-Trichlorobenzene | MR | 6 | 2019 |
| cis-1,2-Dichloroethylene | MR | 6 | 2019 |
| p-Dichlorobenzene | MR | 6 | 2019 |
| Vinyl chloride | MR | 6 | 2019 |
| trans-1,2-Dichloroethylene | MR | 6 | 2019 |
| Carbon tetrachloride | MR | 6 | 2019 |
| 1,2-Dichloropropane | MR | 6 | 2019 |
| Trichloroethylene | MR | 6 | 2019 |
| Tetrachloroethylene | MR | 6 | 2019 |
| CHLOROBENZENE | MR | 6 | 2019 |
| Styrene | MR | 6 | 2019 |
| Benzene | MR | 6 | 2019 |
| Toluene | MR | 6 | 2019 |
| Ethylbenzene | MR | 6 | 2019 |
| DICHLOROMETHANE | MR | 6 | 2019 |
| 1,1,2-Trichloroethane | MR | 6 | 2019 |
| o-Dichlorobenzene | MR | 6 | 2019 |
| 1,1,1-Trichloroethane | MR | 6 | 2019 |
| 1,2-Dichloroethane | MR | 6 | 2019 |
| 1,1-Dichloroethylene | MR | 6 | 2019 |
| Public Notice | Other | 5 | 2011 |
| Revised Total Coliform Rule | RPT | 4 | 2019 |
| Arsenic | MR | 4 | 2017 |
| Barium | MR | 4 | 2017 |
| Cadmium | MR | 4 | 2017 |
Violation Count vs. the National Corpus
Quonnipaug Hills - Main System has 409 recorded EPA violations, 94% of the 29,740 public water systems serving 500+ people nationwide carry fewer, and 6% carry more. 9% of this system's own violations are health-based (37 of 409), and it ranks #27,160 of 29,740 by population served among that same cohort.
EPA violations vs. the national water-system corpus
Public water systems serving 500+ people (EPA SDWIS)
409 Higher than most more violations than 94% 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 Quonnipaug Hills - Main System
EPA SDWIS lists 564 people served and 187 connections for this PWS, confirm the service-area footprint on the federal report before comparing to municipal census totals.
Sources: EPA SDWIS
Nationwide peers
409 violations · 564 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.
Cross-state systems with smaller service footprints
Nearest cross-state systems by EPA SDWIS population_served (same 500+ sitemap gate).
What to do with Quonnipaug Hills - Main System
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.