Water quality for ZIP code 11791
ZIP 11791 covers Syosset, Muttontown, Laurel Hollow, Oyster Bay Cove, Hicksville, and Plainview in Nassau County, New York, one of 69 ZIP codes in the county. 44 active public water systems serve the county; 8 had an EPA violation in the past three years.
Most likely your provider
Your location is within the outer bounds of this system's EPA service area.
Other community water systems in Nassau County
39 systems, nearest first| System | Serves | Status | Rules violated, 3 yr | Distance |
|---|---|---|---|---|
| Oyster Bay WD Oyster Bay (t) |
8,700 | 0 | 2.6 mi | |
| Glenwood WD Oyster Bay (t) |
1,000 | 0 | 3.0 mi | |
| Liberty Utilities New York Mill Neck Mill Neck (v), Oyster Bay (t) |
280 | 0 | 4.0 mi | |
| Plainview WD Oyster Bay (t) |
34,000 | 0 | 4.3 mi | |
| Hicksville WD Oyster Bay (t) |
48,000 | 0 | 4.8 mi | |
| Locust Valley WD Mill Neck (v), Oyster Bay (t) |
7,500 | 0 | 5.5 mi | |
| Old Westbury (v) Old Westbury (v) |
4,700 | 1 | 5.6 mi | |
| Bethpage WD Oyster Bay (t) |
33,000 | 0 | 5.8 mi | |
| Westbury WD North Hempstead (t), Westbury (v) |
20,500 | 0 | 5.9 mi | |
| Bayville (v) Bayville (v) |
6,700 | 1 | 6.2 mi | |
| Liberty Utilities New York Sea Cliff Sea Cliff (v) |
13,400 | 0 | 6.5 mi | |
| Glen Cove City Glen Cove (c) |
28,000 | 0 | 7.0 mi | |
| Farmingdale (v) Farmingdale (v) |
8,744 | 0 | 7.3 mi | |
| Roslyn WD Roslyn (v) |
17,000 | 0 | 7.4 mi | |
| Carle Place WD North Hempstead (t) |
9,005 | 0 | 7.6 mi | |
| Town of Hempstead Water Department Hempstead (t) |
110,000 | 0 | 7.9 mi | |
| East Williston (v) East Williston (v) |
2,556 | 0 | 8.1 mi | |
| Albertson WD North Hempstead (t) |
13,500 | 1 | 8.3 mi | |
| South Farmingdale WD Oyster Bay (t) |
44,700 | 0 | 8.5 mi | |
| Williston Park (v) Williston Park (v) |
7,287 | 0 | 8.8 mi | |
| Mineola (v) Mineola (v) |
20,600 | 0 | 9.0 mi | |
| Port Washington WD North Hempstead (t) |
34,000 | 0 | 9.3 mi | |
| Garden City (v) Garden City (v) |
23,272 | 0 | 10.0 mi | |
| Garden City Park WD New Hyde Park (v) |
18,000 | 0 | 10.0 mi | |
| Plandome (v) Plandome (v) |
1,600 | 0 | 10.4 mi |
Non-community systems in Nassau County (4: schools, campgrounds, workplaces, restaurants)
These systems serve places you visit rather than homes.
| System | Serves | Status | Rules violated, 3 yr | Unresolved |
|---|---|---|---|---|
|
Beaver Dam Winter Sports Matinecock (v), Oyster Bay (t) |
35 | 0 | 0 | |
|
Seawanhaka Yacht Club Centre Island (v), Oyster Bay (t) |
60 | 0 | 0 | |
|
Tobay Beach Oyster Bay (t) |
2,410 | 0 | 0 | |
|
Jones Beach State Park Hempstead (t) |
30,799 | 0 | 0 |
About this data
Water systems are matched to Nassau County, the county this ZIP code lies in, nearest to the ZIP code's centre first. Your exact provider depends on your address and connection; the largest community water system in a county is usually the city or town utility. Distances are measured to the centre of the service area EPA publishes for the system or, for systems without one, to the centre of the first town EPA lists the system as serving, from Census Bureau place files.
ZIP code areas and town boundaries come from the U.S. Census Bureau's 2020 ZCTA files.
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.