New London County, Connecticut — public water systems

At a glance

394 active public water systems are filed under New London County, Connecticut in EPA's SDWIS records, together reporting 209,444 people served. The largest is Norwich Public Utilities, which reports serving 36,163 people. 88 are community water systems serving people where they live; the other 306 are non-community systems, such as schools, workplaces, campgrounds and gas stations with their own supply.

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

Active systems

394

Population served

209.4K

Community systems

Groundwater share

96.2%

How does New London County compare with other Connecticut counties?

New London County has the most active public water systems among the 22 counties listed for active Connecticut systems in EPA records; among the 9 with 3 or more systems, the median has 277. Its systems report 209,444 people served in total, the 4th-largest county figure in the state and 7.1% of the statewide total. The average system here reports serving 532 people, about 57% below the Connecticut average of 1,247. Population figures are what each system reports; people served by more than one system, such as a wholesaler and the town that buys from it, are counted by each.

Where does New London County's drinking water come from?

By primary water source, New London County's active systems draw on groundwater (379, 96%), purchased surface water (10, 2.5%) and surface water (5, 1.3%). Overall, 96% rely mainly on groundwater (including purchased groundwater) and 3.8% on surface water, compared with 96% and 3.8% across Connecticut. Groundwater means the system draws its water from wells or springs fed by underground aquifers. The county's largest system, Norwich Public Utilities, draws primarily on surface water.

What kinds of water systems operate in New London County?

New London County's active systems break down as 88 community systems (22%), 73 non-transient non-community systems (19%) and 233 transient non-community systems (59%). 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. A non-transient non-community water system regularly serves at least 25 of the same people for more than six months a year, but not where they live. Schools, factories, office buildings and hospitals with their own supply are typical examples. A transient non-community water system serves places where people do not stay long, such as gas stations and campgrounds, and regularly serves at least 25 people a day for at least 60 days a year. EPA lists their owner types as private (81%), local government (16%) and state government (2.5%).

The 50 largest water systems in New London County

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Active public water systems in New London County, Connecticut
#	Water system	County	Population served	Type	Source
1	Norwich Public Utilities	New London	36,163	Community	Surface water
2	Groton Utilities	New London	30,200	Community	Surface water
3	New London Dept. of Public Utilities	New London	27,620	Community	Surface water
4	Waterford Wpca	New London	16,578	Community	Purchased surface water
5	East Lyme Water & Sewer Commission	New London	15,245	Community	Purchased surface water
6	Aquarion-Mystic	New London	10,788	Community	Surface water
7	Jewett City Water Company	New London	6,840	Community	Surface water
8	Colchester Sewer & Water Commission	New London	4,020	Community	Groundwater
9	Ctwc - Shoreline Region-Sound View	New London	3,397	Community	Groundwater
10	Ledyard Wpca - Ledyard Center	New London	3,294	Community	Purchased surface water
11	Scwa, Montville Division (Mtv)	New London	2,570	Community	Groundwater
12	Scwa, Tower-Ferry View Division	New London	2,567	Community	Groundwater
13	Groton Long Point Association	New London	2,400	Community	Purchased surface water
14	Ledyard Wpca, Gales Ferry System	New London	2,369	Community	Purchased surface water
15	Noank Fire District	New London	1,947	Community	Purchased surface water
16	Scwa, North Stonington Division (Nst)	New London	1,860	Community	Groundwater
17	Leonard J.Tyl Middle School&High School	New London	1,466	Non-transient non-community	Groundwater
18	Scwa, Mohegan Division	New London	1,428	Community	Groundwater
19	Montville Water Supply	New London	1,300	Community	Purchased surface water
20	Region 18 Schools - Lyme Street	New London	1,102	Non-transient non-community	Groundwater
21	Ctwc - Shoreline Region-Point O Woods	New London	1,068	Community	Groundwater
22	Sprague Water & Sewer Authority	New London	1,058	Community	Groundwater
23	Strawberry Park	New London	1,047	Non-transient non-community	Groundwater
24	St. Bernard School	New London	950	Non-transient non-community	Groundwater
25	Scwa, Oakdale Heights Division	New London	876	Community	Groundwater
26	Hopeville Pond S.P./Beach-Well #2	New London	800	Transient non-community	Groundwater
27	Indian Field Coop Campground Assn., Inc..	New London	685	Non-transient non-community	Groundwater
28	Salem Elementary School	New London	675	Non-transient non-community	Groundwater
29	Scwa, Ledyard Center Division	New London	652	Community	Groundwater
30	Lisbon Central School	New London	620	Non-transient non-community	Groundwater
31	Preston Plains Water Company	New London	550	Community	Groundwater
32	Lebanon Elementary School	New London	525	Non-transient non-community	Groundwater
33	Scwa, Chesterfield Division	New London	524	Community	Groundwater
34	C E Murphy School	New London	520	Non-transient non-community	Groundwater
35	Preston Veterans Memorial School	New London	500	Non-transient non-community	Groundwater
36	Kitemaug Orchard Association, Inc..	New London	490	Community	Groundwater
37	Scwa, Hillcrest Division (Hlc)	New London	450	Community	Purchased surface water
38	Ctwc - Shoreline Region-Masons Island	New London	445	Community	Purchased surface water
39	Ctwc - Bay Mountain	New London	440	Community	Groundwater
40	Lebanon Middle School	New London	415	Non-transient non-community	Groundwater
41	Lyman Memorial High School	New London	412	Non-transient non-community	Groundwater
42	Aquarion-Arlington Acres	New London	392	Community	Groundwater
43	Scwa, Robin Hill Division (Rbn)	New London	388	Community	Groundwater
44	Scwa, Cedar Ridge Division	New London	370	Community	Groundwater
45	Voluntown Elementary School	New London	365	Non-transient non-community	Groundwater
46	Aquarion-Pleasure Valley	New London	328	Community	Groundwater
47	Jewett City Water Co., S & W System	New London	320	Community	Groundwater
48	Classee Water System - Latimer Point	New London	316	Non-transient non-community	Purchased surface water
49	Pachaug Marina Campground	New London	310	Non-transient non-community	Groundwater
50	Church of Christ the King	New London	305	Transient non-community	Groundwater

All other water systems in New London County (344)

The remaining active systems filed under New London County, largest first, with the population each reports serving.

New London County water systems: frequently asked questions

How many public water systems are in New London County, Connecticut?

EPA's SDWIS records file 394 active public water systems under New London County, Connecticut: 88 community systems (22%), 73 non-transient non-community systems (19%) and 233 transient non-community systems (59%).

Who supplies drinking water in New London County, CT?

The largest community water systems filed under New London County are Norwich Public Utilities (36,163 people served), Groton Utilities (30,200 people served) and New London Dept. of Public Utilities (27,620 people served). Which system serves a particular address depends on its service area, which EPA's SDWIS records do not include; a water bill or the local utility can confirm it.

Does New London County's drinking water come from groundwater or surface water?

Of the 394 active public water systems in New London County, 96% draw mainly on groundwater and 3.8% on surface water, counting purchased supplies. The largest system, Norwich Public Utilities, uses surface water.

Where can I find a water quality report for New London County?

Each community water system must deliver an annual water quality report, called a Consumer Confidence Report, to its customers by July 1, covering the previous calendar year. 88 community systems are filed under New London County, so the report to look for is the one from the system that supplies your address.

How can I check violations for a water system in New London County?

Open the system's profile from the list on this page. Each profile shows the most recent Safe Drinking Water Act violations in EPA's records, with plain-English labels and whether each one is resolved. For current compliance status, EPA ECHO is the primary source.

More Connecticut water systems

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, “Public water systems in New London County, Connecticut”, https://aquacensus.com/water-systems/connecticut/new-london (data as of October 1, 2026).