Public water system · NJ1103001
ActiveAqua Nj - Hamilton Square
At a glance
Aqua Nj - Hamilton Square (PWSID NJ1103001) is an active community water system in Mercer County, New Jersey. It reports serving 39,128 people through 12,738 service connections. Its primary water source is purchased surface water, and EPA lists it as privately owned. Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in July 2024.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
39,128
Service connections
12,738
Primary source
SWP
Purchased surface water
System type
CWS
Community water system
System record
How does Aqua Nj - Hamilton Square compare with other water systems in Mercer County?
By EPA's size categories, Aqua Nj - Hamilton Square is a large system (10,001 to 100,000 people). Mercer County has 97 active public water systems, and Aqua Nj - Hamilton Square is the 2nd-largest of them by population served. Its population served is about 12 times the county average of 3,340 people per system, and accounts for 12% of the 323,956 people reported by systems filed under the county. Across New Jersey, the 3,496 active systems average 2,750 people each. Nationally, the average active community water system reports serving 6,703 people, so Aqua Nj - Hamilton Square is about 5.8 times 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 Jersey has 582 active community water systems, 17% of the state's 3,496 active systems. Purchased surface water means the system buys surface water from another public water system rather than drawing its own. 128 New Jersey systems (3.7%) list purchased surface water as their primary source.
Who owns and regulates Aqua Nj - Hamilton Square?
EPA lists Aqua Nj - Hamilton Square as privately owned. The NJ state drinking water program is its primacy agency, the regulator with primary enforcement responsibility for the system under the Safe Drinking Water Act. 74 of the 97 active systems in Mercer County (76%) are also privately owned.
Does Aqua Nj - Hamilton Square have drinking water violations?
Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in July 2024. The violations listed here began between July 2023 and July 2024. By type: 12 monitoring and reporting. The contaminant or rule involved most often is Lead and Copper Rule (3 of them). EPA lists 7 as archived, 3 as resolved and 2 as unaddressed. 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. 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 |
|---|---|---|---|---|
| 2024-07-01 | Monitoring and reportingWater Quality Parameter M/R · code 53 | Lead and Copper Rulecode 5000 | No | Archived |
| 2024-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Radium-226code 4020 | No | Archived |
| 2024-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Radium-228code 4030 | No | Archived |
| 2024-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Gross alpha (excluding radon and uranium)code 4000 | No | Archived |
| 2024-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Combined Uraniumcode 4006 | No | Archived |
| 2024-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Combined Radium (-226 and -228)code 4010 | No | Archived |
| 2023-12-30 | Monitoring and reportingLead Consumer Notice · code 66 | Lead and Copper Rulecode 5000 | No | Unaddressed |
| 2023-10-03 | Monitoring and reportingMonitoring, Source Water (GWR) · code 34 | E. colicode 3014 | No | Unaddressed |
| 2023-07-01 | Monitoring and reportingMonitoring, Regular · code 03 | Radium-226code 4020 | No | Resolved |
| 2023-07-01 | Monitoring and reportingMonitoring, Regular · code 03 | Combined Radium (-226 and -228)code 4010 | No | Resolved |
| 2023-07-01 | Monitoring and reportingWater Quality Parameter M/R · code 53 | Lead and Copper Rulecode 5000 | No | Archived |
| 2023-07-01 | Monitoring and reportingMonitoring, Regular · code 03 | Combined Uraniumcode 4006 | 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.
Aqua Nj - Hamilton Square: frequently asked questions
Who runs Aqua Nj - Hamilton Square?
Aqua Nj - Hamilton Square (PWSID NJ1103001) is a community water system privately owned. It is regulated by the NJ state drinking water program.
How many people does Aqua Nj - Hamilton Square serve?
Aqua Nj - Hamilton Square reports serving 39,128 people through 12,738 service connections in Mercer County, New Jersey.
Where does Aqua Nj - Hamilton Square 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 Aqua Nj - Hamilton Square 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 July 2024. 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 Aqua Nj - Hamilton Square'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 July 2024. For current results, consult the system's annual water quality report, EPA ECHO, or the NJ state drinking water program.
Where can I find Aqua Nj - Hamilton Square's water quality report?
As a community water system, Aqua Nj - Hamilton Square 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 Mercer County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Trenton Water Works | Mercer | 217,000 | Community | Surface water |
| East Windsor Mua | Mercer | 25,000 | Community | Groundwater |
| Aqua Nj - Lawrence | Mercer | 8,655 | Community | Groundwater under influence of surface water |
| Hightstown Water Department | Mercer | 5,400 | Community | Groundwater |
| Pennington Shop-Rite | Mercer | 3,663 | Non-transient non-community | Groundwater |
| Pennington W Dept | Mercer | 2,600 | 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, “Aqua Nj - Hamilton Square, PWSID NJ1103001, New Jersey”, https://aquacensus.com/water-systems/new-jersey/aqua-nj-hamilton-square-nj1103001 (data as of October 1, 2026).