Public water system · NH0481010
ActiveColebrook Water Works
At a glance
Colebrook Water Works (PWSID NH0481010) is an active community water system in Coos County, New Hampshire. It reports serving 1,300 people through 523 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, one is health-based, and the most recent began in September 2025.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
1,300
Service connections
523
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Colebrook Water Works compare with other water systems in Coos County?
By EPA's size categories, Colebrook Water Works is a small system (501 to 3,300 people). Coos County has 112 active public water systems, and Colebrook Water Works is the 6th-largest of them by population served. Its population served is about 3.5 times the county average of 368 people per system, and accounts for 3.2% of the 41,217 people reported by systems filed under the county. Across New Hampshire, the 2,450 active systems average 508 people each. Nationally, the average active community water system reports serving 6,703 people, so Colebrook Water Works is well 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. New Hampshire has 706 active community water systems, 29% of the state's 2,450 active systems. Groundwater means the system draws its water from wells or springs fed by underground aquifers. 2,374 New Hampshire systems (97%) list groundwater as their primary source.
Who owns and regulates Colebrook Water Works?
EPA lists Colebrook Water Works as owned by a local government. The NH state drinking water program is its primacy agency, the regulator with primary enforcement responsibility for the system under the Safe Drinking Water Act. 18 of the 112 active systems in Coos County (16%) are also owned by a local government.
Does Colebrook Water Works have drinking water violations?
Of the 12 most recent violations in EPA's records, one is health-based, and the most recent began in September 2025. The violations listed here began between July 2015 and September 2025. By type: 6 monitoring and reporting, 3 public notice, recordkeeping or other, 1 reporting, 1 monitoring and 1 contaminant level above the legal limit. The contaminant or rule involved most often is Public Notice (3 of them). EPA lists 10 as resolved and 2 as unaddressed. 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. Unaddressed means the violation is not resolved or archived and is not yet covered by formal enforcement.
| Began | Violation | Contaminant or rule | Health-based | Status |
|---|---|---|---|---|
| 2025-09-11 | ReportingReport Sample Result/Fail Monitor (RTCR) · code 4B | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2025-08-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2022-12-10 | Monitoring and reportingMonitoring, Source Water (GWR) · code 34 | E. colicode 3014 | No | Resolved |
| 2021-07-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Total trihalomethanes (TTHM)code 2950 | No | Resolved |
| 2021-07-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Haloacetic acids (HAA5)code 2456 | No | Resolved |
| 2016-07-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Chlorinecode 0999 | No | Resolved |
| 2016-04-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Single Sample · code 01 | Arseniccode 1005 | Yes | Resolved |
| 2015-12-06 | Public notice, recordkeeping or otherPublic Notification Violation for NPDWR Violation · code 75 | Public Noticecode 7500 | No | Unaddressed |
| 2015-12-06 | Public notice, recordkeeping or otherPublic Notification Violation for NPDWR Violation · code 75 | Public Noticecode 7500 | No | Resolved |
| 2015-12-06 | Public notice, recordkeeping or otherPublic Notification Violation for NPDWR Violation · code 75 | Public Noticecode 7500 | No | Unaddressed |
| 2015-07-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Total trihalomethanes (TTHM)code 2950 | No | Resolved |
| 2015-07-01 | 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.
Colebrook Water Works: frequently asked questions
Who runs Colebrook Water Works?
Colebrook Water Works (PWSID NH0481010) is a community water system owned by a local government. It is regulated by the NH state drinking water program.
How many people does Colebrook Water Works serve?
Colebrook Water Works reports serving 1,300 people through 523 service connections in Coos County, New Hampshire.
Where does Colebrook Water Works 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 Colebrook Water Works have any drinking water violations?
Of the 12 most recent violations in EPA's records, one is health-based, and the most recent began in September 2025. 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 Colebrook Water Works' 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, one is health-based, and the most recent began in September 2025. For current results, consult the system's annual water quality report, EPA ECHO, or the NH state drinking water program.
Where can I find Colebrook Water Works' water quality report?
As a community water system, Colebrook Water Works 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 Coos County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Berlin Water Works | Coos | 9,575 | Community | Surface water |
| Groveton Water Sys | Coos | 2,650 | Community | Groundwater |
| Gorham Water and Sewer Dept | Coos | 2,630 | Community | Surface water |
| Lancaster Water Dept | Coos | 2,500 | Community | Surface water |
| Whitefield Water | Coos | 1,640 | Community | Groundwater |
| Rogers Campground | Coos | 1,250 | Transient non-community | Groundwater |
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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, “Colebrook Water Works, PWSID NH0481010, New Hampshire”, https://aquacensus.com/water-systems/new-hampshire/colebrook-water-works-nh0481010 (data as of October 1, 2026).