Public water system · MA2139000
ActiveHopkinton Water Department
At a glance
Hopkinton Water Department (PWSID MA2139000) is an active community water system in Middlesex County, Massachusetts. It reports serving 12,680 people through 4,405 service connections. Its primary water source is groundwater, and EPA lists it as owned by a local government. EPA's records list 9 violations for this system; 5 are health-based, and the most recent began in April 2014.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
12,680
Service connections
4,405
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Hopkinton Water Department compare with other water systems in Middlesex County?
By EPA's size categories, Hopkinton Water Department is a large system (10,001 to 100,000 people). Middlesex County has 204 active public water systems. Its population served is about 59% above the county average of 7,986 people per system, and accounts for 0.8% of the 1,629,099 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 Hopkinton Water Department is about 89% 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 Hopkinton Water Department?
EPA lists Hopkinton 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. 66 of the 204 active systems in Middlesex County (32%) are also owned by a local government.
Does Hopkinton Water Department have drinking water violations?
EPA's records list 9 violations for this system; 5 are health-based, and the most recent began in April 2014. The violations listed here began between July 1998 and April 2014. By type: 5 contaminant level above the legal limit and 4 monitoring and reporting. The contaminant or rule involved most often is Total coliform bacteria (TCR) (6 of them). EPA lists 9 as resolved. 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 |
|---|---|---|---|---|
| 2014-04-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitratecode 1040 | No | Resolved |
| 2008-09-01 | 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 |
| 2005-02-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2004-09-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2004-09-01 | Monitoring and reportingMonitoring, Repeat Minor (TCR) · code 26 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2000-09-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 1999-01-01 | Monitoring and reportingFollow-up Or Routine LCR Tap M/R · code 52 | Lead and Copper Rulecode 5000 | No | Resolved |
| 1998-07-01 | Monitoring and reportingFollow-up Or Routine LCR Tap M/R · code 52 | Lead and Copper Rulecode 5000 | No | Resolved |
All 9 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.
Hopkinton Water Department: frequently asked questions
Who runs Hopkinton Water Department?
Hopkinton Water Department (PWSID MA2139000) is a community water system owned by a local government. It is regulated by the MA state drinking water program.
How many people does Hopkinton Water Department serve?
Hopkinton Water Department reports serving 12,680 people through 4,405 service connections in Middlesex County, Massachusetts.
Where does Hopkinton 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 Hopkinton Water Department have any drinking water violations?
EPA's records list 9 violations for this system; 5 are health-based, and the most recent began in April 2014. 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 Hopkinton 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 9 violations for this system; 5 are health-based, and the most recent began in April 2014. For current results, consult the system's annual water quality report, EPA ECHO, or the MA state drinking water program.
Where can I find Hopkinton Water Department's water quality report?
As a community water system, Hopkinton 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 Middlesex County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Lowell Regional Water Utility | Middlesex | 120,418 | Community | Surface water |
| Cambridge Water Department | Middlesex | 118,214 | Community | Surface water |
| Newton Water Dept. (MWRA) | Middlesex | 88,931 | Community | Purchased surface water |
| Somerville Water Dept. (MWRA) | Middlesex | 81,045 | Community | Purchased surface water |
| Framingham Water Dept. (MWRA) | Middlesex | 72,362 | Community | Purchased surface water |
| Malden Water Division (MWRA) | Middlesex | 66,263 | Community | Purchased surface water |
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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, “Hopkinton Water Department, PWSID MA2139000, Massachusetts”, https://aquacensus.com/water-systems/massachusetts/hopkinton-water-department-ma2139000 (data as of October 1, 2026).