Public water system · MA4173000
ActiveMattapoisett Water Department
At a glance
Mattapoisett Water Department (PWSID MA4173000) is an active community water system in Plymouth County, Massachusetts. It reports serving 7,685 people through 3,240 service connections. Its primary water source is groundwater, and EPA lists it as owned by a local government. EPA's records list 10 violations for this system; 9 are health-based, and the most recent began in November 2015.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
7,685
Service connections
3,240
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Mattapoisett Water Department compare with other water systems in Plymouth County?
By EPA's size categories, Mattapoisett Water Department is a medium system (3,301 to 10,000 people). Plymouth County has 129 active public water systems. Its population served is about 73% above the county average of 4,447 people per system, and accounts for 1.3% of the 573,676 people reported by systems filed under the county. Across Massachusetts, the 1,636 active systems average 6,275 people each. Nationally, the average active community water system reports serving 6,703 people, so Mattapoisett Water Department is about 15% above 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. Massachusetts has 531 active community water systems, 32% of the state's 1,636 active systems. Groundwater means the system draws its water from wells or springs fed by underground aquifers. 1,354 Massachusetts systems (83%) list groundwater as their primary source.
Who owns and regulates Mattapoisett Water Department?
EPA lists Mattapoisett Water Department as owned by a local government. The MA state drinking water program is its primacy agency, the regulator with primary enforcement responsibility for the system under the Safe Drinking Water Act. 37 of the 129 active systems in Plymouth County (29%) are also owned by a local government.
Does Mattapoisett Water Department have drinking water violations?
EPA's records list 10 violations for this system; 9 are health-based, and the most recent began in November 2015. The violations listed here began between November 1991 and November 2015. By type: 9 contaminant level above the legal limit and 1 monitoring and reporting. The contaminant or rule involved most often is Total coliform bacteria (TCR) (9 of them). EPA lists 7 as resolved and 3 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 |
|---|---|---|---|---|
| 2015-11-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2014-09-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2013-06-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2001-04-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitratecode 1040 | No | Archived |
| 1997-01-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 1995-09-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 1995-08-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 1995-06-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 1992-10-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Acute (TCR) · code 21 | Total coliform bacteria (TCR)code 3100 | Yes | Archived |
| 1991-11-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Archived |
All 10 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.
Mattapoisett Water Department: frequently asked questions
Who runs Mattapoisett Water Department?
Mattapoisett Water Department (PWSID MA4173000) is a community water system owned by a local government. It is regulated by the MA state drinking water program.
How many people does Mattapoisett Water Department serve?
Mattapoisett Water Department reports serving 7,685 people through 3,240 service connections in Plymouth County, Massachusetts.
Where does Mattapoisett Water Department 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 Mattapoisett Water Department have any drinking water violations?
EPA's records list 10 violations for this system; 9 are health-based, and the most recent began in November 2015. 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 Mattapoisett Water Department'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 10 violations for this system; 9 are health-based, and the most recent began in November 2015. For current results, consult the system's annual water quality report, EPA ECHO, or the MA state drinking water program.
Where can I find Mattapoisett Water Department's water quality report?
As a community water system, Mattapoisett Water Department 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 Plymouth County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Brockton Water Department | Plymouth | 105,788 | Community | Surface water |
| Plymouth Water Department | Plymouth | 47,100 | Community | Groundwater |
| Weir River Water System | Plymouth | 45,339 | Community | Surface water |
| Marshfield Water Department | Plymouth | 34,000 | Community | Groundwater |
| Abington/Rockland Joint Wtr. Works | Plymouth | 33,387 | Community | Surface water |
| Mattapoisett River Valley W.D. | Plymouth | 29,600 | Community | Purchased 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, “Mattapoisett Water Department, PWSID MA4173000, Massachusetts”, https://aquacensus.com/water-systems/massachusetts/mattapoisett-water-department-ma4173000 (data as of October 1, 2026).