St. Lawrence County, New York — public water systems

At a glance

229 active public water systems are filed under St. Lawrence County, New York in EPA's SDWIS records, together reporting 81,125 people served. The largest is Massena Village, which reports serving 16,729 people. 40 are community water systems serving people where they live; the other 189 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

229

Population served

81.1K

Community systems

Groundwater share

93.9%

How does St. Lawrence County compare with other New York counties?

St. Lawrence County has the 8th-most active public water systems among the 100 counties listed for active New York systems in EPA records; among the 64 with 3 or more systems, the median has 94. Its systems report 81,125 people served in total, the 31st-largest county figure in the state and 0.4% of the statewide total. The average system here reports serving 354 people, well below the New York average of 2,374. 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 St. Lawrence County's drinking water come from?

By primary water source, St. Lawrence County's active systems draw on groundwater (211, 92%), surface water (11, 4.8%), groundwater under influence of surface water (3, 1.3%) and purchased surface water (3, 1.3%). Overall, 94% rely mainly on groundwater (including purchased groundwater) and 6.1% on surface water, compared with 91% and 8.5% across New York. Groundwater means the system draws its water from wells or springs fed by underground aquifers. The county's largest system, Massena Village, draws primarily on surface water.

What kinds of water systems operate in St. Lawrence County?

St. Lawrence County's active systems break down as 40 community systems (17%), 27 non-transient non-community systems (12%) and 162 transient non-community systems (71%). 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 (80%), local government (15%), state government (4.8%) and federal government (0.4%).

The 50 largest water systems in St. Lawrence County

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Active public water systems in St. Lawrence County, New York
#	Water system	County	Population served	Type	Source
1	Massena Village	St. Lawrence	16,729	Community	Surface water
2	Ogdensburg City	St. Lawrence	10,064	Community	Surface water
3	Potsdam Village	St. Lawrence	8,312	Community	Surface water
4	Canton Village	St. Lawrence	7,055	Community	Groundwater
5	Gouverneur	St. Lawrence	4,263	Community	Surface water
6	East Louisville Water District	St. Lawrence	3,235	Community	Surface water
7	Norfolk Water District	St. Lawrence	2,300	Community	Groundwater
8	Norwood	St. Lawrence	1,685	Community	Groundwater
9	Star Lake Water District	St. Lawrence	1,250	Community	Surface water
10	Waddington Village	St. Lawrence	944	Community	Groundwater
11	Colton Water District	St. Lawrence	850	Community	Groundwater
12	Heuvelton Village	St. Lawrence	830	Community	Groundwater
13	Madrid Water District	St. Lawrence	800	Community	Groundwater
14	Edwards-Knox Central School	St. Lawrence	800	Non-transient non-community	Groundwater
15	Madrid-Waddington Central School	St. Lawrence	700	Non-transient non-community	Groundwater
16	Massawepie Scout Camps	St. Lawrence	600	Transient non-community	Groundwater
17	Jakes on the Water	St. Lawrence	517	Transient non-community	Groundwater
18	Cranberry Lake Campground	St. Lawrence	500	Transient non-community	Groundwater
19	Lisbon Water District	St. Lawrence	499	Community	Groundwater
20	Hermon-Dekalb Central School	St. Lawrence	492	Non-transient non-community	Groundwater
21	Hermon Water District	St. Lawrence	492	Community	Groundwater
22	Dekalb Water District	St. Lawrence	492	Community	Purchased groundwater
23	St. Lawrence Central Jr-Sr High	St. Lawrence	490	Non-transient non-community	Groundwater
24	Coles Creek State Campsite	St. Lawrence	470	Transient non-community	Groundwater
25	Edwards Water District	St. Lawrence	465	Community	Groundwater
26	St. Lawrence Central Elementary	St. Lawrence	460	Non-transient non-community	Groundwater
27	Parishville Water District #1	St. Lawrence	450	Community	Groundwater
28	Robert Moses State Park	St. Lawrence	407	Transient non-community	Groundwater
29	Higley Flow State Park	St. Lawrence	400	Transient non-community	Groundwater
30	Town of Lisbon Campground	St. Lawrence	400	Transient non-community	Groundwater
31	Morristown Water District	St. Lawrence	395	Community	Surface water
32	Hammond Central School	St. Lawrence	380	Non-transient non-community	Groundwater
33	Postwood Park	St. Lawrence	350	Transient non-community	Groundwater
34	Wal-Mart Potsdam	St. Lawrence	350	Non-transient non-community	Groundwater
35	Gran View	St. Lawrence	350	Transient non-community	Groundwater
36	Southwest Tech	St. Lawrence	272	Non-transient non-community	Groundwater
37	Nypa Hawkins Point Visitors Center	St. Lawrence	260	Transient non-community	Groundwater
38	Corning	St. Lawrence	260	Non-transient non-community	Groundwater
39	Schermerhorn Harbor LLC	St. Lawrence	250	Transient non-community	Groundwater
40	Schermerhorn Landing-Duck Cove	St. Lawrence	250	Transient non-community	Groundwater
41	Seaway Area Technology Center	St. Lawrence	250	Non-transient non-community	Groundwater
42	Stables @ Windy Point	St. Lawrence	250	Transient non-community	Groundwater
43	Chars Bar	St. Lawrence	221	Transient non-community	Groundwater
44	Potsdam Water District No. 1	St. Lawrence	220	Community	Groundwater
45	Mclears Cottage Colony Inc.	St. Lawrence	200	Transient non-community	Groundwater
46	Waddington Town Beach	St. Lawrence	200	Transient non-community	Groundwater
47	Wanakena Water Company	St. Lawrence	200	Community	Groundwater under influence of surface water
48	New York Power Authority	St. Lawrence	200	Non-transient non-community	Surface water
49	Gerald Roy Amvets Post #4	St. Lawrence	200	Transient non-community	Groundwater
50	Helena Water District	St. Lawrence	180	Community	Groundwater

All other water systems in St. Lawrence County (179)

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

St. Lawrence County water systems: frequently asked questions

How many public water systems are in St. Lawrence County, New York?

EPA's SDWIS records file 229 active public water systems under St. Lawrence County, New York: 40 community systems (17%), 27 non-transient non-community systems (12%) and 162 transient non-community systems (71%).

Who supplies drinking water in St. Lawrence County, NY?

The largest community water systems filed under St. Lawrence County are Massena Village (16,729 people served), Ogdensburg City (10,064 people served) and Potsdam Village (8,312 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 St. Lawrence County's drinking water come from groundwater or surface water?

Of the 229 active public water systems in St. Lawrence County, 94% draw mainly on groundwater and 6.1% on surface water, counting purchased supplies. The largest system, Massena Village, uses surface water.

Where can I find a water quality report for St. Lawrence 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. 40 community systems are filed under St. Lawrence 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 St. Lawrence 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 New York 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 St. Lawrence County, New York”, https://aquacensus.com/water-systems/new-york/st-lawrence (data as of October 1, 2026).