New York
Nassau County drinking water quality
44 active public water systems serve 1,387,479 people in Nassau County. 36 are compliant, 8 had at least one EPA violation in the past three years, 0 are designated serious violators, and 0 carry a health flag.
Community water systems
40 systems, largest first| System | Serves | Status | Rules violated, 3 yr | Unresolved |
|---|---|---|---|---|
|
Liberty Utilities New York Lynbrook Hempstead (t), Lynbrook (v) |
220,000 | 1 | 0 | |
|
Liberty Utilities New York Merrick Hempstead (t) |
135,000 | 1 | 0 | |
|
WA of Western Nassau Hempstead (t), North Hempstead (t) |
120,000 | 0 | 0 | |
|
Town of Hempstead Water Department Hempstead (t) |
110,000 | 0 | 0 | |
|
Jericho WD Oyster Bay (t) |
58,000 | 1 | 0 | |
|
Hempstead (v) Hempstead (v) |
56,000 | 1 | 0 | |
|
Hicksville WD Oyster Bay (t) |
48,000 | 0 | 0 | |
|
Freeport (v) Freeport (v) |
45,000 | 0 | 0 | |
|
South Farmingdale WD Oyster Bay (t) |
44,700 | 0 | 0 | |
|
Manhasset Lakeville WD North Hempstead (t) |
43,000 | 0 | 0 | |
|
Massapequa WD Massapequa Park (v), Oyster Bay (t) |
43,000 | 0 | 0 | |
|
Long Beach City Long Beach (c) |
35,000 | 0 | 0 | |
|
Plainview WD Oyster Bay (t) |
34,000 | 0 | 0 | |
|
Port Washington WD North Hempstead (t) |
34,000 | 0 | 0 | |
|
Bethpage WD Oyster Bay (t) |
33,000 | 0 | 0 | |
|
West Hempstead WD Hempstead (t) |
32,031 | 1 | 0 | |
|
Glen Cove City Glen Cove (c) |
28,000 | 0 | 0 | |
|
Rockville Centre (v) Rockville Center (v) |
24,700 | 0 | 0 | |
|
Garden City (v) Garden City (v) |
23,272 | 0 | 0 | |
|
Mineola (v) Mineola (v) |
20,600 | 0 | 0 | |
|
Westbury WD North Hempstead (t), Westbury (v) |
20,500 | 0 | 0 | |
|
Franklin Square WD Hempstead (t), Stewart Manor (v) |
20,000 | 0 | 0 | |
|
Garden City Park WD New Hyde Park (v) |
18,000 | 0 | 0 | |
|
Roslyn WD Roslyn (v) |
17,000 | 0 | 0 | |
|
Albertson WD North Hempstead (t) |
13,500 | 1 | 0 | |
|
Liberty Utilities New York Sea Cliff Sea Cliff (v) |
13,400 | 0 | 0 | |
|
Carle Place WD North Hempstead (t) |
9,005 | 0 | 0 | |
|
Farmingdale (v) Farmingdale (v) |
8,744 | 0 | 0 | |
|
Oyster Bay WD Oyster Bay (t) |
8,700 | 0 | 0 | |
|
Locust Valley WD Mill Neck (v), Oyster Bay (t) |
7,500 | 0 | 0 | |
|
Williston Park (v) Williston Park (v) |
7,287 | 0 | 0 | |
|
Bayville (v) Bayville (v) |
6,700 | 1 | 0 | |
|
Old Westbury (v) Old Westbury (v) |
4,700 | 1 | 0 | |
|
Sands Point (v) North Hempstead (t), Sands Point (v) |
2,900 | 0 | 0 | |
|
East Williston (v) East Williston (v) |
2,556 | 0 | 0 | |
|
Lido-Point Lookout WD Hempstead (t) |
2,000 | 0 | 0 | |
|
Plandome (v) Plandome (v) |
1,600 | 0 | 0 | |
|
Cathedral Gardens WD Hempstead (t) |
1,500 | 0 | 0 | |
|
Glenwood WD Oyster Bay (t) |
1,000 | 0 | 0 | |
|
Liberty Utilities New York Mill Neck Mill Neck (v), Oyster Bay (t) |
280 | 0 | 0 |
Non-community systems (4: schools, campgrounds, workplaces, restaurants)
These systems serve places people visit rather than homes.
| System | Serves | Status | Rules violated, 3 yr | Unresolved |
|---|---|---|---|---|
|
Jones Beach State Park Hempstead (t) |
30,799 | 0 | 0 | |
|
Tobay Beach Oyster Bay (t) |
2,410 | 0 | 0 | |
|
Seawanhaka Yacht Club Centre Island (v), Oyster Bay (t) |
60 | 0 | 0 | |
|
Beaver Dam Winter Sports Matinecock (v), Oyster Bay (t) |
35 | 0 | 0 |
Inactive systems (4, no longer operating or reporting)
Kept for the record and excluded from the county totals above. Browse inactive systems.
About this data
Totals cover active systems. Systems serving more than one county are counted in each county. EPA counts the rules a system was in violation of, not the individual violations; one rule can carry several.
Source: the U.S. EPA's Enforcement and Compliance History Online system (ECHO), which publishes the federal Safe Drinking Water Information System. EPA's terms and values are shown as published. The New York records are from EPA's data refresh of Oct 7, 2026; EPA refreshes this data quarterly, and states report to EPA with a lag of three to six months, so the newest violations may not appear yet. Retrieved from ECHO on Oct 11, 2026.