Public water system · MA4126000
ActiveHarwich Water Department
At a glance
Harwich Water Department (PWSID MA4126000) is an active community water system in Barnstable County, Massachusetts. It reports serving 39,144 people through 10,154 service connections. Its primary water source is groundwater, and EPA lists it as owned by a local government. EPA's records list 4 violations for this system; 3 are health-based, and the most recent began in September 2000.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
39,144
Service connections
10,154
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Harwich Water Department compare with other water systems in Barnstable County?
By EPA's size categories, Harwich Water Department is a large system (10,001 to 100,000 people). Barnstable County has 125 active public water systems, and Harwich Water Department is the 5th-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 Harwich 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 Harwich Water Department?
EPA lists Harwich 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 Harwich Water Department have drinking water violations?
EPA's records list 4 violations for this system; 3 are health-based, and the most recent began in September 2000. The violations listed here began between September 1995 and September 2000. By type: 3 contaminant level above the legal limit and 1 public notice, recordkeeping or other. The contaminant or rule involved most often is Total coliform bacteria (TCR) (4 of them). EPA lists 2 as archived and 2 as resolved. 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.
| Began | Violation | Contaminant or rule | Health-based | Status |
|---|---|---|---|---|
| 2000-09-01 | Public notice, recordkeeping or otherNotification, State · code 05 | Total coliform bacteria (TCR)code 3100 | No | Archived |
| 2000-09-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Archived |
| 1996-10-01 | 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 |
All 4 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.
Harwich Water Department: frequently asked questions
Who runs Harwich Water Department?
Harwich Water Department (PWSID MA4126000) is a community water system owned by a local government. It is regulated by the MA state drinking water program.
How many people does Harwich Water Department serve?
Harwich Water Department reports serving 39,144 people through 10,154 service connections in Barnstable County, Massachusetts.
Where does Harwich 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 Harwich Water Department have any drinking water violations?
EPA's records list 4 violations for this system; 3 are health-based, and the most recent began in September 2000. 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 Harwich 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 4 violations for this system; 3 are health-based, and the most recent began in September 2000. For current results, consult the system's annual water quality report, EPA ECHO, or the MA state drinking water program.
Where can I find Harwich Water Department's water quality report?
As a community water system, Harwich 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 |
| Yarmouth Water Department | Barnstable | 38,900 | 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, “Harwich Water Department, PWSID MA4126000, Massachusetts”, https://aquacensus.com/water-systems/massachusetts/harwich-water-department-ma4126000 (data as of October 1, 2026).