Public water system · MA4261000
ActiveSandwich Water District
At a glance
Sandwich Water District (PWSID MA4261000) is an active community water system in Barnstable County, Massachusetts. It reports serving 23,000 people through 7,335 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, 10 are health-based, and the most recent began in April 2025.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
23,000
Service connections
7,335
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Sandwich Water District compare with other water systems in Barnstable County?
By EPA's size categories, Sandwich Water District is a large system (10,001 to 100,000 people). Barnstable County has 125 active public water systems. Its population served is about 4.6 times the county average of 5,016 people per system, and accounts for 3.7% 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 Sandwich Water District is about 3.4 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 Sandwich Water District?
EPA lists Sandwich Water District 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 Sandwich Water District have drinking water violations?
Of the 12 most recent violations in EPA's records, 10 are health-based, and the most recent began in April 2025. The violations listed here began between August 1996 and April 2025. By type: 10 contaminant level above the legal limit, 1 monitoring and 1 monitoring and reporting. The contaminant or rule involved most often is Total coliform bacteria (TCR) (11 of them). EPA lists 10 as resolved and 2 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 |
|---|---|---|---|---|
| 2025-04-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Archived |
| 2009-08-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2009-07-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2008-10-01 | Monitoring and reportingMonitoring, Routine Minor (TCR) · code 24 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2007-08-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Archived |
| 2006-11-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2006-10-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2006-07-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2005-09-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 1997-08-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 1996-09-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 1996-08-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | 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.
Sandwich Water District: frequently asked questions
Who runs Sandwich Water District?
Sandwich Water District (PWSID MA4261000) is a community water system owned by a local government. It is regulated by the MA state drinking water program.
How many people does Sandwich Water District serve?
Sandwich Water District reports serving 23,000 people through 7,335 service connections in Barnstable County, Massachusetts.
Where does Sandwich Water District 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 Sandwich Water District have any drinking water violations?
Of the 12 most recent violations in EPA's records, 10 are health-based, and the most recent began in April 2025. 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 Sandwich Water District'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, 10 are health-based, and the most recent began in April 2025. For current results, consult the system's annual water quality report, EPA ECHO, or the MA state drinking water program.
Where can I find Sandwich Water District's water quality report?
As a community water system, Sandwich Water District 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 |
| Yarmouth Water Department | Barnstable | 38,900 | 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, “Sandwich Water District, PWSID MA4261000, Massachusetts”, https://aquacensus.com/water-systems/massachusetts/sandwich-water-district-ma4261000 (data as of October 1, 2026).