Public water system · NH1391010
ActiveLondonderry
At a glance
Londonderry (PWSID NH1391010) is an active community water system in Rockingham County, New Hampshire. It reports serving 6,255 people through 1,791 service connections. Its primary water source is purchased surface water, and EPA lists it as privately owned. EPA's records list 2 violations for this system; none is health-based, and the most recent began in October 2013.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
6,255
Service connections
1,791
Primary source
SWP
Purchased surface water
System type
CWS
Community water system
System record
How does Londonderry compare with other water systems in Rockingham County?
By EPA's size categories, Londonderry is a medium system (3,301 to 10,000 people). Rockingham County has 554 active public water systems. Its population served is about 13 times the county average of 492 people per system, and accounts for 2.3% of the 272,726 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 Londonderry is roughly in line with 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. Purchased surface water means the system buys surface water from another public water system rather than drawing its own. 27 New Hampshire systems (1.1%) list purchased surface water as their primary source.
Who owns and regulates Londonderry?
EPA lists Londonderry as privately owned. 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. 477 of the 554 active systems in Rockingham County (86%) are also privately owned.
Does Londonderry have drinking water violations?
EPA's records list 2 violations for this system; none is health-based, and the most recent began in October 2013. The violations listed here began between October 2013 and October 2013. By type: 2 monitoring and reporting. The contaminants or rules involved are Total trihalomethanes (TTHM) and Haloacetic acids (HAA5). EPA lists 2 as resolved. 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.
| Began | Violation | Contaminant or rule | Health-based | Status |
|---|---|---|---|---|
| 2013-10-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Total trihalomethanes (TTHM)code 2950 | No | Resolved |
| 2013-10-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Haloacetic acids (HAA5)code 2456 | No | Resolved |
All 2 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.
Londonderry: frequently asked questions
Who runs Londonderry?
Londonderry (PWSID NH1391010) is a community water system privately owned. It is regulated by the NH state drinking water program.
How many people does Londonderry serve?
Londonderry reports serving 6,255 people through 1,791 service connections in Rockingham County, New Hampshire.
Where does Londonderry get its water?
EPA SDWIS lists this system's primary water source as purchased surface water. Purchased surface water means the system buys surface water from another public water system rather than drawing its own.
Does Londonderry have any drinking water violations?
EPA's records list 2 violations for this system; none is health-based, and the most recent began in October 2013. 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 Londonderry'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. EPA's records list 2 violations for this system; none is health-based, and the most recent began in October 2013. For current results, consult the system's annual water quality report, EPA ECHO, or the NH state drinking water program.
Where can I find Londonderry's water quality report?
As a community water system, Londonderry 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 Rockingham County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Aquarion Water/Nh | Rockingham | 34,000 | Community | Groundwater |
| Portsmouth Water Works | Rockingham | 33,000 | Community | Surface water |
| Salem Water Dept | Rockingham | 21,000 | Community | Surface water |
| Derry Water Dept | Rockingham | 17,370 | Community | Purchased surface water |
| Seabrook Water Dept | Rockingham | 14,000 | Community | Groundwater |
| Exeter Water Dept | Rockingham | 12,236 | 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, “Londonderry, PWSID NH1391010, New Hampshire”, https://aquacensus.com/water-systems/new-hampshire/londonderry-nh1391010 (data as of October 1, 2026).