Public water system · MA4351000
ActiveYarmouth Water Department
At a glance
Yarmouth Water Department (PWSID MA4351000) is an active community water system in Barnstable County, Massachusetts. It reports serving 38,900 people through 16,360 service connections. Its primary water source is groundwater, and EPA lists it as owned by a local government. Of the 12 most recent violations in EPA's records, 3 are health-based, and the most recent began in April 2021.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
38,900
Service connections
16,360
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Yarmouth Water Department compare with other water systems in Barnstable County?
By EPA's size categories, Yarmouth Water Department is a large system (10,001 to 100,000 people). Barnstable County has 125 active public water systems, and Yarmouth Water Department is the 6th-largest of them by population served. Its population served is about 7.8 times the county average of 5,016 people per system, and accounts for 6.2% of the 627,054 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 Yarmouth Water Department 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. 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 Yarmouth Water Department?
EPA lists Yarmouth 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. 31 of the 125 active systems in Barnstable County (25%) are also owned by a local government.
Does Yarmouth Water Department have drinking water violations?
Of the 12 most recent violations in EPA's records, 3 are health-based, and the most recent began in April 2021. The violations listed here began between April 2006 and April 2021. By type: 7 monitoring and reporting, 2 contaminant level above the legal limit, 1 reporting, 1 required treatment not met and 1 public notice, recordkeeping or other. The contaminant or rule involved most often is Total coliform bacteria (TCR) (4 of them). EPA lists 6 as resolved, 5 as archived and 1 as addressed. 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. Addressed means the violation is not resolved or archived and is covered by formal enforcement.
| Began | Violation | Contaminant or rule | Health-based | Status |
|---|---|---|---|---|
| 2021-04-06 | Monitoring and reportingMonitoring, Source Water (GWR) · code 34 | Enterococcicode 3002 | No | Addressed |
| 2021-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitratecode 1040 | No | Archived |
| 2020-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitritecode 1041 | No | Archived |
| 2020-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitratecode 1040 | No | Archived |
| 2018-02-02 | ReportingNotify Level 1/Level 2 Treatment Technique Violation, Correct Action (RTCR) · code 4F | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2018-02-01 | Required treatment not metTreatment Technique, Level 1 Assessment (RTCR) · code 2A | Revised Total Coliform Rulecode 8000 | Yes | Resolved |
| 2013-07-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2011-07-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2011-07-01 | Monitoring and reportingMonitoring, Repeat Major (TCR) · code 25 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2011-07-01 | Public notice, recordkeeping or otherNotification, State · code 05 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2007-10-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitratecode 1040 | No | Archived |
| 2006-04-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nickelcode 1036 | No | Archived |
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.
Yarmouth Water Department: frequently asked questions
Who runs Yarmouth Water Department?
Yarmouth Water Department (PWSID MA4351000) is a community water system owned by a local government. It is regulated by the MA state drinking water program.
How many people does Yarmouth Water Department serve?
Yarmouth Water Department reports serving 38,900 people through 16,360 service connections in Barnstable County, Massachusetts.
Where does Yarmouth 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 Yarmouth Water Department have any drinking water violations?
Of the 12 most recent violations in EPA's records, 3 are health-based, and the most recent began in April 2021. 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 Yarmouth 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. Of the 12 most recent violations in EPA's records, 3 are health-based, and the most recent began in April 2021. For current results, consult the system's annual water quality report, EPA ECHO, or the MA state drinking water program.
Where can I find Yarmouth Water Department's water quality report?
As a community water system, Yarmouth 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 Barnstable County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Falmouth Water Dept | Barnstable | 97,551 | Community | Surface water |
| Dennis Water District | Barnstable | 65,000 | Community | Groundwater |
| Upper Cape Regional Water Cooperative | Barnstable | 56,250 | Community | Groundwater |
| Centerville Osterville Marstons Mills Wd | Barnstable | 50,000 | Community | Groundwater |
| Harwich Water Department | Barnstable | 39,144 | Community | Groundwater |
| Mashpee Water District | Barnstable | 36,922 | 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, “Yarmouth Water Department, PWSID MA4351000, Massachusetts”, https://aquacensus.com/water-systems/massachusetts/yarmouth-water-department-ma4351000 (data as of October 1, 2026).