Public water system · CT0280011
ActiveColchester Sewer & Water Commission
At a glance
Colchester Sewer & Water Commission (PWSID CT0280011) is an active community water system in New London County, Connecticut. It reports serving 4,020 people through 2,109 service connections. Its primary water source is groundwater, and EPA lists it as owned by a local government. Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in March 2026.
This page covers its drinking water system only; sewer and wastewater service are not part of EPA's drinking water records.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
4,020
Service connections
2,109
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Colchester Sewer & Water Commission compare with other water systems in New London County?
By EPA's size categories, Colchester Sewer & Water Commission is a medium system (3,301 to 10,000 people). New London County has 394 active public water systems. Its population served is about 7.6 times the county average of 532 people per system, and accounts for 1.9% of the 209,444 people reported by systems filed under the county. Across Connecticut, the 2,363 active systems average 1,247 people each. Nationally, the average active community water system reports serving 6,703 people, so Colchester Sewer & Water Commission is about 40% below that figure.
What does “community water system” mean?
A community water system serves at least 15 connections used by year-round residents, or regularly serves at least 25 year-round residents. Homes, apartments and mobile-home parks are served by these. Connecticut has 481 active community water systems, 20% of the state's 2,363 active systems. Groundwater means the system draws its water from wells or springs fed by underground aquifers. 2,263 Connecticut systems (96%) list groundwater as their primary source.
Who owns and regulates Colchester Sewer & Water Commission?
EPA lists Colchester Sewer & Water Commission as owned by a local government. The CT state drinking water program is its primacy agency, the regulator with primary enforcement responsibility for the system under the Safe Drinking Water Act. 64 of the 394 active systems in New London County (16%) are also owned by a local government.
Does Colchester Sewer & Water Commission have drinking water violations?
Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in March 2026. The violations listed here began between October 2022 and March 2026. By type: 6 monitoring and reporting and 6 public notice, recordkeeping or other. The contaminant or rule involved most often is E. coli (3 of them). EPA lists 11 as resolved and 1 as archived. Resolved means at least one resolving action is on record: the system returned to compliance, the rule no longer applies, or no further action was needed. Archived means the violation was not marked resolved but is more than five years past the end of the noncompliance period, so it no longer counts toward current compliance status.
| Began | Violation | Contaminant or rule | Health-based | Status |
|---|---|---|---|---|
| 2026-03-01 | Monitoring and reportingFailure to Conduct Assessment Monitoring · code 19 | E. colicode 3014 | No | Archived |
| 2025-08-10 | Public notice, recordkeeping or otherConsumer Confidence Report Inadequate Reporting · code 72 | Consumer Confidence Rulecode 7000 | No | Resolved |
| 2025-07-01 | Public notice, recordkeeping or otherConsumer Confidence Report Complete Failure to Report · code 71 | Consumer Confidence Rulecode 7000 | No | Resolved |
| 2025-06-15 | Public notice, recordkeeping or otherPublic Notification Violation for NPDWR Violation · code 75 | Public Noticecode 7500 | No | Resolved |
| 2025-06-15 | Public notice, recordkeeping or otherPublic Notification Violation for NPDWR Violation · code 75 | Public Noticecode 7500 | No | Resolved |
| 2024-05-25 | Public notice, recordkeeping or otherPublic Notification Violation for NPDWR Violation · code 75 | Public Noticecode 7500 | No | Resolved |
| 2024-03-01 | Monitoring and reportingFailure to Conduct Assessment Monitoring · code 19 | E. colicode 3014 | No | Resolved |
| 2024-01-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Haloacetic acids (HAA5)code 2456 | No | Resolved |
| 2024-01-01 | Monitoring and reportingFailure to Conduct Assessment Monitoring · code 19 | E. colicode 3014 | No | Resolved |
| 2024-01-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Total trihalomethanes (TTHM)code 2950 | No | Resolved |
| 2023-07-01 | Public notice, recordkeeping or otherConsumer Confidence Report Complete Failure to Report · code 71 | Consumer Confidence Rulecode 7000 | No | Resolved |
| 2022-10-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Chlorinecode 0999 | No | Resolved |
The 12 most recent violations in EPA's records, newest first.Labels and codes come from EPA's SDWIS reference tables. A monitoring or reporting violation means a required test or report was missed or late; it does not by itself mean a contaminant was found. "Health-based" marks violations of a legal limit or required treatment.
Colchester Sewer & Water Commission: frequently asked questions
Who runs Colchester Sewer & Water Commission?
Colchester Sewer & Water Commission (PWSID CT0280011) is a community water system owned by a local government. It is regulated by the CT state drinking water program.
How many people does Colchester Sewer & Water Commission serve?
Colchester Sewer & Water Commission reports serving 4,020 people through 2,109 service connections in New London County, Connecticut.
Where does Colchester Sewer & Water Commission get its water?
EPA SDWIS lists this system's primary water source as groundwater. Groundwater means the system draws its water from wells or springs fed by underground aquifers.
Does Colchester Sewer & Water Commission have any drinking water violations?
Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in March 2026. A monitoring or reporting violation means a required test or report was missed or late; it does not by itself mean a contaminant was found.
Is Colchester Sewer & Water Commission's water safe to drink?
AquaCensus shows EPA compliance records, not current water test results, so it cannot say whether the water is safe at a given moment. Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in March 2026. For current results, consult the system's annual water quality report, EPA ECHO, or the CT state drinking water program.
Where can I find Colchester Sewer & Water Commission's water quality report?
As a community water system, Colchester Sewer & Water Commission must deliver an annual water quality report, called a Consumer Confidence Report, to its customers by July 1 each year, covering the previous calendar year. The system can provide a copy on request.
Other water systems in New London County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Norwich Public Utilities | New London | 36,163 | Community | Surface water |
| Groton Utilities | New London | 30,200 | Community | Surface water |
| New London Dept. of Public Utilities | New London | 27,620 | Community | Surface water |
| Waterford Wpca | New London | 16,578 | Community | Purchased surface water |
| East Lyme Water & Sewer Commission | New London | 15,245 | Community | Purchased surface water |
| Aquarion-Mystic | New London | 10,788 | Community | Surface water |
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About this data
Source: U.S. EPA Safe Drinking Water Information System (SDWIS) and SDWA violation records, via EPA ECHO, as published October 1, 2026 — AquaCensus refreshes it quarterly. See the methodology for how records are matched, cleaned and scored.
Cite as: AquaCensus, “Colchester Sewer & Water Commission, PWSID CT0280011, Connecticut”, https://aquacensus.com/water-systems/connecticut/colchester-sewer-water-commission-ct0280011 (data as of October 1, 2026).