Middlesex County, Massachusetts — public water systems

203 active public water systems serve Middlesex County, reporting 1.6M people served.

Dataset updated July 2026 . Source: EPA SDWIS/ECHO, refreshed quarterly.

Active systems

203

Population served

1.6M

Community systems

Groundwater share

78.8%

Water systems in Middlesex County

Active public water systems in Middlesex County, Massachusetts
#	Water system	County	Population served	Type	Source
1	Cambridge Water Department	Middlesex	118,214	Community	Surface water
2	Lowell Regional Water Utility	Middlesex	115,000	Community	Surface water
3	Newton Water Dept. (MWRA)	Middlesex	88,415	Community	Purchased surface water
4	Somerville Water Dept. (MWRA)	Middlesex	81,045	Community	Purchased surface water
5	Framingham Water Dept. (MWRA)	Middlesex	72,362	Community	Purchased surface water
6	Malden Water Division (MWRA)	Middlesex	66,263	Community	Purchased surface water
7	Waltham Water Department	Middlesex	65,218	Community	Purchased surface water
8	Medford Water Dept. (MWRA)	Middlesex	61,700	Community	Purchased surface water
9	Everett Water Dept. (MWRA)	Middlesex	49,075	Community	Purchased surface water
10	Arlington Water Dept. (MWRA)	Middlesex	46,308	Community	Purchased surface water
11	Billerica Water Works	Middlesex	42,119	Community	Surface water
12	Marlborough Dpw Water Div. (MWRA)	Middlesex	41,799	Community	Purchased surface water
13	Woburn Water Dept.	Middlesex	40,876	Community	Purchased surface water
14	Natick Water and Sewer Division	Middlesex	37,006	Community	Groundwater
15	Watertown Water Dept. (MWRA)	Middlesex	35,329	Community	Purchased surface water
16	Lexington Water Dept. (MWRA)	Middlesex	34,074	Community	Purchased surface water
17	Tewksbury Water Department	Middlesex	31,342	Community	Surface water
18	Melrose Water Division (MWRA)	Middlesex	29,357	Community	Purchased surface water
19	Chelmsford Water District	Middlesex	28,750	Community	Groundwater
20	Belmont Water Dept. (MWRA)	Middlesex	27,442	Community	Purchased surface water
21	Reading Water Department (MWRA)	Middlesex	27,358	Community	Purchased surface water
22	Wakefield Water Dept	Middlesex	27,090	Community	Surface water
23	Burlington Water Dept	Middlesex	26,680	Community	Surface water
24	Dracut Water Supply District	Middlesex	25,808	Community	Purchased surface water
25	Stoneham Water Dept (MWRA Supply)	Middlesex	23,244	Community	Purchased surface water
26	Winchester Water Dept	Middlesex	22,970	Community	Surface water
27	Wilmington Water Dept	Middlesex	22,481	Community	Purchased surface water
28	Acton Water Supply District	Middlesex	20,780	Community	Groundwater under influence of surface water
29	Hudson Water Supply	Middlesex	20,032	Community	Surface water
30	Ashland Water and Sewer Dept.	Middlesex	18,832	Community	Groundwater
31	Concord Water Dept	Middlesex	18,788	Community	Surface water
32	Westford Water Department	Middlesex	18,680	Community	Groundwater under influence of surface water
33	Sudbury Water District	Middlesex	18,416	Community	Groundwater
34	North Reading Water Dept.	Middlesex	16,379	Community	Purchased surface water
35	Holliston Water Department	Middlesex	15,713	Community	Groundwater
36	Bedford Water Dept.	Middlesex	14,394	Community	Purchased surface water
37	Wayland Water Department	Middlesex	13,196	Community	Groundwater
38	Hopkinton Water Department	Middlesex	12,586	Community	Groundwater
39	Weston Water Dept.	Middlesex	11,941	Community	Purchased surface water
40	Hanscom Afb	Middlesex	11,789	Community	Purchased surface water
41	Maynard Dpw, Water Division	Middlesex	10,401	Community	Groundwater
42	Kenwood Water District	Middlesex	9,620	Community	Purchased surface water
43	Littleton Water Department	Middlesex	9,611	Community	Groundwater
44	Pepperell Dpw Water Division	Middlesex	9,217	Community	Groundwater
45	Ayer Dpw Water Division	Middlesex	8,479	Community	Groundwater
46	North Chelmsford Water Dist	Middlesex	7,498	Community	Groundwater
47	Devens Massdevelopment	Middlesex	6,500	Community	Groundwater
48	Townsend Water Department	Middlesex	6,500	Community	Groundwater
49	Lincoln Water Dept	Middlesex	5,593	Community	Surface water
50	Groton Water Department	Middlesex	5,456	Community	Groundwater