Public water system · NH1121010
ActiveCogswell Springs Water Works
At a glance
Cogswell Springs Water Works (PWSID NH1121010) is an active community water system in Merrimack County, New Hampshire. It reports serving 3,000 people through 581 service connections. Its primary water source is groundwater, and EPA lists it as owned by a local government. EPA's records list 11 violations for this system; 5 are health-based, and the most recent began in December 2019.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
3,000
Service connections
581
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Cogswell Springs Water Works compare with other water systems in Merrimack County?
By EPA's size categories, Cogswell Springs Water Works is a small system (501 to 3,300 people). Merrimack County has 244 active public water systems. Its population served is about 5.9 times the county average of 509 people per system, and accounts for 2.4% of the 124,152 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 Cogswell Springs Water Works is about 55% 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 Cogswell Springs Water Works?
EPA lists Cogswell Springs 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. 40 of the 244 active systems in Merrimack County (16%) are also owned by a local government.
Does Cogswell Springs Water Works have drinking water violations?
EPA's records list 11 violations for this system; 5 are health-based, and the most recent began in December 2019. The violations listed here began between March 1991 and December 2019. By type: 5 monitoring and reporting, 5 contaminant level above the legal limit and 1 public notice, recordkeeping or other. The contaminant or rule involved most often is Total coliform bacteria (TCR) (7 of them). EPA lists 10 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 |
|---|---|---|---|---|
| 2019-12-30 | Monitoring and reportingLead Consumer Notice · code 66 | Lead and Copper Rulecode 5000 | No | Resolved |
| 2017-06-08 | Monitoring and reportingMonitoring, Source Water (GWR) · code 34 | E. colicode 3014 | No | Resolved |
| 2010-10-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2010-08-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2010-07-01 | Public notice, recordkeeping or otherConsumer Confidence Report Complete Failure to Report · code 71 | Consumer Confidence Rulecode 7000 | No | Resolved |
| 2010-04-01 | Monitoring and reportingMonitoring, Repeat Major (TCR) · code 25 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2010-04-01 | Monitoring and reportingMonitoring, Source Water (GWR) · code 34 | E. colicode 3014 | No | Resolved |
| 2008-09-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2004-10-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 1994-08-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Archived |
| 1991-03-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
All 11 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.
Cogswell Springs Water Works: frequently asked questions
Who runs Cogswell Springs Water Works?
Cogswell Springs Water Works (PWSID NH1121010) is a community water system owned by a local government. It is regulated by the NH state drinking water program.
How many people does Cogswell Springs Water Works serve?
Cogswell Springs Water Works reports serving 3,000 people through 581 service connections in Merrimack County, New Hampshire.
Where does Cogswell Springs 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 Cogswell Springs Water Works have any drinking water violations?
EPA's records list 11 violations for this system; 5 are health-based, and the most recent began in December 2019. 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 Cogswell Springs 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. EPA's records list 11 violations for this system; 5 are health-based, and the most recent began in December 2019. For current results, consult the system's annual water quality report, EPA ECHO, or the NH state drinking water program.
Where can I find Cogswell Springs Water Works' water quality report?
As a community water system, Cogswell Springs 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 Merrimack County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Concord Water Dept | Merrimack | 44,215 | Community | Surface water |
| Franklin Water Works | Merrimack | 7,200 | Community | Groundwater |
| Pembroke Water Works | Merrimack | 5,200 | Community | Groundwater |
| Central Hooksett Water Pct | Merrimack | 4,650 | Community | Purchased surface water |
| Penacook Boscawen Water Pct | Merrimack | 3,800 | Community | Groundwater |
| New London Springfield Water | Merrimack | 3,250 | 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, “Cogswell Springs Water Works, PWSID NH1121010, New Hampshire”, https://aquacensus.com/water-systems/new-hampshire/cogswell-springs-water-works-nh1121010 (data as of October 1, 2026).