Public water system · NJ1111001

Active

Trenton Water Works

At a glance

Trenton Water Works (PWSID NJ1111001) is an active community water system in Mercer County, New Jersey. It reports serving 217,000 people through 62,403 service connections. Its primary water source is surface water, 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 October 2024.

Dataset updated October 2026 . Source: EPA SDWIS/ECHO public records.

Population served

217,000

Service connections

62,403

Primary source

Surface water

System type

CWS

Community water system

System record

PWSIDNJ1111001

System typeCommunity water system

Activity statusActive

Population served217,000

Service connections62,403

Primary water sourceSurface water

Owner typeLocal government

Primacy agencyNJ state drinking water program

City servedLawrence Twp.-1107

StateNew Jersey

ZIP—

CountyMercer County

How does Trenton Water Works compare with other water systems in Mercer County?

By EPA's size categories, Trenton Water Works is a very large system (more than 100,000 people). Mercer County has 97 active public water systems, and Trenton Water Works is the largest of them by population served. Its population served is about 65 times the county average of 3,340 people per system, and accounts for 67% 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 Trenton Water Works is about 32 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. Surface water means the system draws its water from rivers, lakes, streams or reservoirs. 29 New Jersey systems (0.8%) list surface water as their primary source.

Who owns and regulates Trenton Water Works?

EPA lists Trenton Water Works as owned by a local government. 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. 17 of the 97 active systems in Mercer County (18%) are also owned by a local government.

Does Trenton 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 October 2024. The violations listed here began between September 2023 and October 2024. By type: 9 monitoring and reporting, 2 monitoring and 1 contaminant level above the legal limit. The contaminant or rule involved most often is Total trihalomethanes (TTHM) (2 of them). EPA lists 8 as resolved and 4 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
2024-10-01	Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02	Total trihalomethanes (TTHM)code 2950	Yes	Archived
2024-07-01	Monitoring and reportingWater Quality Parameter M/R · code 53	Lead and Copper Rulecode 5000	No	Resolved
2023-12-28	Monitoring and reportingFailure Submit IDSE/Subpart V Plan Rpt · code 35	Haloacetic acids (HAA5)code 2456	No	Resolved
2023-11-01	MonitoringMonitoring, Routine (RTCR) · code 3A	Revised Total Coliform Rulecode 8000	No	Resolved
2023-11-01	Monitoring and reportingMonitoring of Treatment (SWTR-Filter) · code 36	Surface Water Treatment Rulecode 0200	No	Resolved
2023-10-01	Monitoring and reportingMonitoring and Reporting (DBP) · code 27	Haloacetic acids (HAA5)code 2456	No	Archived
2023-10-01	MonitoringMonitoring, Routine (RTCR) · code 3A	Revised Total Coliform Rulecode 8000	No	Resolved
2023-10-01	Monitoring and reportingMonitoring of Treatment (SWTR-Filter) · code 36	Surface Water Treatment Rulecode 0200	No	Resolved
2023-10-01	Monitoring and reportingMonitoring and Reporting (DBP) · code 27	Chlorinecode 0999	No	Archived
2023-10-01	Monitoring and reportingMonitoring and Reporting (DBP) · code 27	Chlorinecode 0999	No	Resolved
2023-10-01	Monitoring and reportingMonitoring and Reporting (DBP) · code 27	Total trihalomethanes (TTHM)code 2950	No	Archived
2023-09-29	Monitoring and reportingLead Consumer Notice · code 66	Lead and Copper Rulecode 5000	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.

Trenton Water Works: frequently asked questions

Who runs Trenton Water Works?

Trenton Water Works (PWSID NJ1111001) is a community water system owned by a local government. It is regulated by the NJ state drinking water program.

How many people does Trenton Water Works serve?

Trenton Water Works reports serving 217,000 people through 62,403 service connections in Mercer County, New Jersey.

Where does Trenton Water Works get its water?

EPA SDWIS lists this system's primary water source as surface water. Surface water means the system draws its water from rivers, lakes, streams or reservoirs.

Does Trenton 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 October 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 Trenton 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 October 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 Trenton Water Works' water quality report?

As a community water system, Trenton 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 Mercer County

Water system	County	Population served	Type	Source
Aqua Nj - Hamilton Square	Mercer	39,128	Community	Purchased 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, “Trenton Water Works, PWSID NJ1111001, New Jersey”, https://aquacensus.com/water-systems/new-jersey/trenton-water-works-nj1111001 (data as of October 1, 2026).