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COLCHESTER SEWER & WATER COMMISSION

PWS ID: CT0280011 · COLCHESTER, Connecticut 06415

COLCHESTER SEWER & WATER COMMISSION serves 4,020 people in COLCHESTER, Connecticut using Groundwater water sources. It has 159 recorded EPA violations, including 0 health-based violations. PFAS "forever chemicals" were detected in UCMR5 testing (2 compounds found).

Water Quality Snapshot: COLCHESTER SEWER & WATER COMMISSION

COLCHESTER SEWER & WATER COMMISSION is a local-owned community water system that delivers drinking water to 4,020 residents in COLCHESTER, Connecticut (New London County) through 2,100 service connections. Its water is drawn from groundwater sources. EPA's Safe Drinking Water Information System records 159 total violations for this system , of which 0 (0%) are health-based — meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 141 monitoring and reporting violations are on file. The most recent violation on record dates to 2025.

The most frequently cited contaminant at this system is E. COLI, recorded in 22 violations (MR). Under EPA's UCMR5 PFAS monitoring program, 2 PFAS compounds were detected in samples collected from this system, with a maximum reported concentration of 0.009 ppt. PFAS are persistent synthetic chemicals linked to health effects at very low exposure levels.

Across Connecticut, EPA tracks 2,332 public water systems serving 2,886,005 people, with 206,662 cumulative violations and 21,779 health-based violations on record. About 94% of systems in the state carry at least one violation, and state-wide the average per system is 88.6 violations. COLCHESTER SEWER & WATER COMMISSION's 159 violations sit above the Connecticut average. Statewide, 40 of 63 UCMR5-tested systems have reported PFAS detections (63.5%). All figures above are sourced directly from EPA SDWIS and UCMR5 public data releases and are updated as EPA publishes new reporting cycles.

PFAS Detected

2 PFAS "forever chemicals" detected in testing under EPA's UCMR5 monitoring program.

Population Served
4,020
Total Violations
159
Health-Based Violations
0
Water Source
Groundwater

System Details

System Type
Community
Owner Type
Local
Connections
2,100
County
New London
School/Daycare
No
MCL Violations
0
Monitoring Violations
141
Treatment Tech Violations
0

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
E. COLI MR 22 2024
Chlorine MR 20 2022
Public Notice Other 8 2025
Consumer Confidence Rule Other 7 2025
Nitrate MR 6 2005
Arsenic MR 4 1990
Mercury MR 4 1990
Revised Total Coliform Rule MON 4 2018
Chromium MR 4 1990
Cadmium MR 4 1990
Barium MR 4 1990
Lead and Copper Rule MR 4 1993
Coliform (TCR) MR 4 2014
Selenium MR 4 1990
Fluoride MR 4 1990
Asbestos MR 3 2012
TTHM MR 3 2024
Total Haloacetic Acids (HAA5) MR 3 2024
1,2,4-Trichlorobenzene MR 2 2014
cis-1,2-Dichloroethylene MR 2 2014
DICHLOROMETHANE MR 2 2014
o-Dichlorobenzene MR 2 2014
1,1-Dichloroethylene MR 2 2014
1,2-Dichloroethane MR 2 2014
Carbon tetrachloride MR 2 2014
1,2-Dichloropropane MR 2 2014
Trichloroethylene MR 2 2014
1,1,2-Trichloroethane MR 2 2014
Tetrachloroethylene MR 2 2014
CHLOROBENZENE MR 2 2014

PFAS Testing Results (UCMR5)

Results from EPA's Fifth Unregulated Contaminant Monitoring Rule. 8 of 240 samples detected PFAS.

Contaminant Date Result MRL Status
11Cl-PF3OUdS 9/11/2023 <0.005 µg/L 0.005 µg/L Not Detected
PFTrDA 9/11/2023 <0.007 µg/L 0.007 µg/L Not Detected
lithium 9/11/2023 <9 µg/L 9 µg/L Not Detected
NEtFOSAA 9/11/2023 <0.005 µg/L 0.005 µg/L Not Detected
PFOS 9/11/2023 <0.004 µg/L 0.004 µg/L Not Detected
PFOA 9/11/2023 <0.004 µg/L 0.004 µg/L Not Detected
PFDA 9/11/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFDoA 9/11/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFHxS 9/11/2023 0.0033 µg/L 0.003 µg/L Detected
PFTA 9/11/2023 <0.008 µg/L 0.008 µg/L Not Detected
PFUnA 9/11/2023 <0.002 µg/L 0.002 µg/L Not Detected
PFBA 9/11/2023 <0.005 µg/L 0.005 µg/L Not Detected
ADONA 9/11/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFHxA 9/11/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFPeS 9/11/2023 <0.004 µg/L 0.004 µg/L Not Detected
4:2 FTS 9/11/2023 <0.003 µg/L 0.003 µg/L Not Detected
8:2 FTS 9/11/2023 <0.005 µg/L 0.005 µg/L Not Detected
PFMPA 9/11/2023 <0.004 µg/L 0.004 µg/L Not Detected
PFPeA 9/11/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFMBA 9/11/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFHpA 9/11/2023 <0.003 µg/L 0.003 µg/L Not Detected
NFDHA 9/11/2023 <0.02 µg/L 0.02 µg/L Not Detected
PFNA 9/11/2023 <0.004 µg/L 0.004 µg/L Not Detected
6:2 FTS 9/11/2023 <0.005 µg/L 0.005 µg/L Not Detected
9Cl-PF3ONS 9/11/2023 <0.002 µg/L 0.002 µg/L Not Detected
HFPO-DA 9/11/2023 <0.005 µg/L 0.005 µg/L Not Detected
NMeFOSAA 9/11/2023 <0.006 µg/L 0.006 µg/L Not Detected
PFBS 9/11/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFHpS 9/11/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFEESA 9/11/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFHpA 9/11/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFDoA 9/11/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFDA 9/11/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFOA 9/11/2023 <0.004 µg/L 0.004 µg/L Not Detected
PFOS 9/11/2023 0.0088 µg/L 0.004 µg/L Detected
PFHxS 9/11/2023 <0.003 µg/L 0.003 µg/L Not Detected
NFDHA 9/11/2023 <0.02 µg/L 0.02 µg/L Not Detected
PFUnA 9/11/2023 <0.002 µg/L 0.002 µg/L Not Detected
PFBS 9/11/2023 <0.003 µg/L 0.003 µg/L Not Detected
lithium 9/11/2023 <9 µg/L 9 µg/L Not Detected
PFNA 9/11/2023 <0.004 µg/L 0.004 µg/L Not Detected
PFEESA 9/11/2023 <0.003 µg/L 0.003 µg/L Not Detected
11Cl-PF3OUdS 9/11/2023 <0.005 µg/L 0.005 µg/L Not Detected
PFHpS 9/11/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFMBA 9/11/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFHxA 9/11/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFPeA 9/11/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFMPA 9/11/2023 <0.004 µg/L 0.004 µg/L Not Detected
8:2 FTS 9/11/2023 <0.005 µg/L 0.005 µg/L Not Detected
4:2 FTS 9/11/2023 <0.003 µg/L 0.003 µg/L Not Detected

Verify This Water System

The figures above are aggregated from EPA's public databases. To verify the underlying records — or to file a complaint, request a Consumer Confidence Report, or check current monitoring status — go directly to the federal and state regulators that enforce the Safe Drinking Water Act for COLCHESTER SEWER & WATER COMMISSION.

Federal Source of Truth

EPA SDWIS — Federal Reports

EPA's Safe Drinking Water Information System (SDWIS) holds the federal compliance record for every regulated public water system. Open the system-level report by PWS ID:

View PWS ID CT0280011 on SDWIS

Source: EPA SDWIS Federal Reports Search

State Regulator

Connecticut Drinking Water Authority

Connecticut's primacy agency administers the Safe Drinking Water Act locally. Search EPA SDWIS for the current state contact, or use the state's public health or environment department portal.

Find CT regulator via EPA SDWIS

Violation Timeline

Each row links to the EPA SDWIS public record for verification. Cross-reference the contaminant code on EPA's federal report to see violation dates, return-to-compliance status, and enforcement actions.

Year (latest) Contaminant Category Count EPA Record
2025 Public Notice Other 8 SDWIS / CT0280011 / 7500
2025 Consumer Confidence Rule Other 7 SDWIS / CT0280011 / 7000
2024 E. COLI MR 22 SDWIS / CT0280011 / 3014
2024 TTHM MR 3 SDWIS / CT0280011 / 2950
2024 Total Haloacetic Acids (HAA5) MR 3 SDWIS / CT0280011 / 2456
2022 Chlorine MR 20 SDWIS / CT0280011 / 0999
2018 Revised Total Coliform Rule MON 4 SDWIS / CT0280011 / 8000
2014 Coliform (TCR) MR 4 SDWIS / CT0280011 / 3100
2014 1,2,4-Trichlorobenzene MR 2 SDWIS / CT0280011 / 2378
2014 cis-1,2-Dichloroethylene MR 2 SDWIS / CT0280011 / 2380
2014 DICHLOROMETHANE MR 2 SDWIS / CT0280011 / 2964
2014 o-Dichlorobenzene MR 2 SDWIS / CT0280011 / 2968
2014 1,1-Dichloroethylene MR 2 SDWIS / CT0280011 / 2977
2014 1,2-Dichloroethane MR 2 SDWIS / CT0280011 / 2980
2014 Carbon tetrachloride MR 2 SDWIS / CT0280011 / 2982

How COLCHESTER SEWER & WATER COMMISSION Compares

Cross-reference this system's record against state averages and the federal MCL framework for context.

Metric COLCHESTER SEWER & WATER COMMISSION Connecticut avg Federal benchmark
Total violations 159 88.6 SDWA compliance — any non-zero count is a recorded breach
Health-based violations 0 9.3 Indicates a contaminant exceeded a federal MCL
PFAS detection 2 compounds 63.5% EPA final rule (2024): PFOA/PFOS MCL = 4.0 ppt
Population served 4,020 1,238 Sizing context for compliance burden

Sources: EPA SDWIS and EPA National Primary Drinking Water Regulations (40 CFR Part 141). State averages computed across 2,332 regulated public water systems in Connecticut.

Federal MCL reference — Safe Drinking Water Act thresholds ▼
Contaminant Federal MCL / Action Level Note
Lead 0 mg/L (Action Level: 0.015 mg/L) Lead and Copper Rule treatment technique
Arsenic 0.010 mg/L (10 ppb) Health-based MCL since 2006
Total Coliform Treatment technique (RTCR) Indicator organism, monitoring trigger
PFOA / PFOS (PFAS) 4.0 ppt each (final 2024 rule) Compliance deadline 2029
Nitrate (as N) 10 mg/L Acute health risk for infants

Frequently Asked Questions

Is COLCHESTER SEWER & WATER COMMISSION water safe to drink? ▼
COLCHESTER SEWER & WATER COMMISSION (PWS ID: CT0280011) has 159 recorded violations in the EPA SDWIS database. PFAS contamination has been detected in UCMR5 testing, with 2 PFAS compounds found. This system serves 4,020 people using Groundwater sources.
How many people does COLCHESTER SEWER & WATER COMMISSION serve? ▼
COLCHESTER SEWER & WATER COMMISSION serves 4,020 people in COLCHESTER, Connecticut. It is a Local-owned system using Groundwater water sources with 2,100 service connections.
What type of violations does COLCHESTER SEWER & WATER COMMISSION have? ▼
COLCHESTER SEWER & WATER COMMISSION has 159 total violations: 0 health-based violations (MCL exceedances or treatment failures), 141 monitoring/reporting violations, and 0 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in COLCHESTER SEWER & WATER COMMISSION water? ▼
Yes. UCMR5 testing detected 2 PFAS compounds in COLCHESTER SEWER & WATER COMMISSION's water supply: PFHxS, PFOS. PFAS are persistent "forever chemicals" that do not break down in the environment.
What water source does COLCHESTER SEWER & WATER COMMISSION use? ▼
COLCHESTER SEWER & WATER COMMISSION uses Groundwater as its primary water source. It is classified as a Community Water System (CWS), serving residential populations year-round.
Where does this data come from? ▼
All data comes from the EPA Safe Drinking Water Information System (SDWIS) and the UCMR5 PFAS monitoring program. SDWIS tracks compliance for all public water systems regulated under the Safe Drinking Water Act.

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Data Sources: EPA Safe Drinking Water Information System (SDWIS), Q4 2025. PFAS data from EPA UCMR5 monitoring program (2023-2025). This data is provided for informational purposes only.

Read our methodology — how this data is sourced, computed, and verified.

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Data sourced from $official public datasets. See our methodology for details. Retrieved and formatted by PlainWater Editorial