States → Massachusetts

State profile · EPA SDWIS + UCMR5

Massachusetts Drinking Water Quality

1,599 public water systems serve 10,332,845 people across Massachusetts, with every Safe Drinking Water Act violation and UCMR5 PFAS result on record.

Compiled by PlainWater Editorial, Drinking Water Quality Editorial Team · May 15, 2026

1,599
Water systems: 73,886
Total violations: 95.2%
Systems w/ a violation: 56.3%
PFAS detection rate

The verdict

Across Massachusetts, 1,522 of 1,599 water systems (95.2%) carry at least one EPA violation, and 148 of 263 UCMR5-tested systems show PFAS.

73,886
Total EPA violations on record: 10%
Health-based (MCL / treatment): 95.2%
Systems with ≥1 violation: 56.3%
UCMR5 PFAS detection rate

Water Systems

1,599

Total Violations

73,886

Violation Rate

95.2%

PFAS Detection

56.3%

148 of 263 tested

Violation Composition

How Massachusetts's 73,886 violations break down by type, per EPA SDWIS classification.

Health-based (7,389) Monitoring/Reporting (66,497)

Metric	Value	Share
Public water systems	1,599	-
Population served	10,332,845	-
Total violations	73,886	100%
Health-based violations	7,389	10.0%
Systems with violations	1,522	95.2%
PFAS detection rate	148 of 263	56.3%

Health-based violations indicate the contaminant exceeded an EPA Maximum Contaminant Level (MCL) or treatment-technique requirement. Monitoring/reporting violations indicate procedural issues (missed tests, late reports) - not necessarily a contamination event.

Largest Water Systems

Mwra

Chelsea, MA · 2,660,000 served

6 violations

Boston Water and Sewer Commission (Mwra)

Boston, MA · 675,647 served

8 violations

Worcester Dpwp, Water Supply Division

Worcester, MA · 206,518 served

47 violations

Springfield Water and Sewer Commission

Springfield, MA · 167,954 served

41 violations

Cambridge Water Department

Cambridge, MA · 118,214 served

70 violations

Lowell Regional Water Utility

Lowell, MA · 115,000 served

54 violations

Quincy Water Dept. (Mwra)

Quincy, MA · 106,000 served

14 violations

Brockton Water Department

Brockton, MA · 105,643 served

110 violations

Inima USA / Aquaria LLC

North Dighton, MA · 105,643 served

39 violations

Lynn Water and Sewer Comm

Lynn, MA · 101,253 served

39 violations

City of New Bedford Dpi

New Bedford, MA · 101,079 served

12 violations

Falmouth Water Dept

Falmouth, MA · 97,551 served

59 violations

Fall River Water Department

Fall River, MA · 94,000 served

87 violations

Salem and Beverly Water Supply Board

Beverly, MA · 90,330 served

19 violations

Lawrence Water Works

Lawrence, MA · 88,877 served

296 violations

Newton Water Dept. (Mwra)

Newton, MA · 88,415 served

22 violations

Somerville Water Dept. (Mwra)

Somerville, MA · 81,045 served

33 violations

Framingham Water Dept. (Mwra)

Framingham, MA · 72,362 served

12 violations

Malden Water Division (Mwra)

Malden, MA · 66,263 served

45 violations

Waltham Water Department

Waltham, MA · 65,218 served

35 violations

Most Violations

#1 New England Laborers Training Academy Hopkinton

965

#2 Metrowest YMCA Framingham

744

#3 Cool Sandy Beach Community Water System Rutland

642

#4 Broomfield Laboratories Leominster

641

#5 Paragon Communications Bolton

582

#6 Boxborough Executive Office Center Boxborough

549

#7 Centre Village Apartments Harvard

531

#8 Brook Village Condominium Hopkinton

515

#9 Auburn Water District Auburn

503

#10 Growing Footprints Education Center Charlton

497

#11 Pine Hill Condominium Worcester

493

#12 Heritage Association Warren

484

#13 Lancaster County Road LLC Boston

477

#14 Immaculate Heart of Mary School Still River

470

#15 Madden Estates West Brookfield

444

Counties in Massachusetts

Suffolk

8 systems · 3,456,243 served · 111 violations

Middlesex

204 systems · 1,623,176 served · 16,575 violations

Essex

67 systems · 908,499 served · 3,080 violations

Norfolk

57 systems · 842,114 served · 2,645 violations

Worcester

345 systems · 773,172 served · 23,751 violations

Bristol

133 systems · 673,471 served · 3,611 violations

Barnstable

127 systems · 628,756 served · 2,953 violations

Plymouth

129 systems · 574,062 served · 4,809 violations

Hampden

115 systems · 440,281 served · 3,254 violations

Hampshire

93 systems · 146,028 served · 2,908 violations

Berkshire

179 systems · 133,575 served · 4,895 violations

Franklin

112 systems · 58,737 served · 3,736 violations

Dukes

25 systems · 42,168 served · 1,211 violations

Nantucket

5 systems · 32,563 served · 347 violations

View all 1,599 systems in Massachusetts →

Drinking Water Guides

Is Your Tap Water Safe?

How to interpret water quality reports and know when to take action.

PFAS in Drinking Water

What forever chemicals are, EPA testing results, and 2024 standards.

Check Your Water System

Step-by-step guide to finding and understanding your local water data.

Frequently Asked Questions

How many water systems are in Massachusetts? ▼

Massachusetts has 1,599 public water systems serving approximately 10,332,845 people. These include community water systems, non-transient non-community systems, and transient non-community systems regulated under the Safe Drinking Water Act.

How many drinking water violations are in Massachusetts? ▼

Massachusetts has 73,886 total drinking water violations on record, with 7,389 classified as health-based violations. 95.2% of water systems in the state have at least one violation.

Has PFAS been found in Massachusetts drinking water? ▼

Of 263 water systems tested for PFAS in Massachusetts, 148 had PFAS detected, a 56.3% detection rate. PFAS are persistent "forever chemicals" that do not break down in the environment.

What is the violation rate for Massachusetts water systems? ▼

Massachusetts's violation rate is 95.2%. This measures the percentage of public water systems that have at least one recorded violation in the EPA SDWIS database, including both health-based and monitoring/reporting violations.

Where does this Massachusetts water data come from? ▼

All drinking water data comes from the EPA Safe Drinking Water Information System (SDWIS) and the UCMR5 PFAS monitoring program. SDWIS is the federal database that tracks compliance for all public water systems regulated under the Safe Drinking Water Act.

Data Sources & Methodology

Drinking water violation data from the EPA Safe Drinking Water Information System (SDWIS). PFAS testing data from the UCMR5 monitoring program. SDWIS tracks all public water systems regulated under the Safe Drinking Water Act.

Read our methodology - how this data is sourced, computed, and verified.

All states → | Most violations → | Compare counties →

Data sourced from EPA SDWIS and UCMR5 PFAS monitoring data. See our methodology for details. Retrieved and formatted by PlainWater Editorial

Every figure on PlainWater is rendered directly from EPA SDWIS drinking-water data, no number is typed in by an editor. This page draws directly on EPA SDWIS data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.