AQUA New York  – (516) 378-3922 or (877) 987-2982
No local office
Services easterly border areas of Massapequa and Massapequa Park, as well as Nassau Shores area of Massapequa; also services Glen Head, Sea Cliff, major portion of Glenwood Landing and areas of Old Brookville

Bayville Water Department – (516) 628-1439
34 School Street, Bayville 11709
Services Village of Bayville, border area of Centre Island

Bethpage Water District – (516) 931-0093
25 Adams Avenue, Bethpage 11714
Services major portion of Bethpage, border areas of Hicksville, Old Bethpage, Plainview and South Farmingdale

(Village of) Farmingdale Water District – (516) 249-0111
Ketcham Lane, Farmingdale 11735
Services Village of Farmingdale

Hicksville Water District – (516) 931-0184
4 Dean Street, Hicksville 11801
Services Hicksville and border areas of Bethpage, Jericho, Syosset and Westbury

Jericho Water District – (516) 921-8280
125 Convent Road, Syosset 11791
Services Brookville, East Norwich and Muttontown; major portions of Jericho, Old Brookville, Syosset and Woodbury; border areas of Glenwood Landing, Laurel Hollow, Old Westbury, Oyster Bay Cove, Plainview and Upper Brookville

Locust Valley Water District – (516) 671-1783
226 Buckram Road, Locust Valley 11560
Services Lattingtown, Locust Valley, borders areas of Matinecock and Mill Neck

Massapequa Water District – (516) 798-5266
84 Grand Avenue, Massapequa 11758
Services major portions of Massapequa and Massapequa Park

(Village of) Old Westbury Water District – (516) 626-0800
1 Store Hill Road, Old Westbury 11568
Services Old Westbury

Oyster Bay Water District – (516) 922-4848
45 Audrey Avenue, Oyster Bay 11771
Services Oyster Bay hamlet, parts of Cove Neck and Oyster Bay Cove

Plainview Water District – (516) 931-6469
10 Manetto Hill Road, Plainview 11803
Services Plainview, portions of Old Bethpage and Syosset

South Farmingdale Water District – (516) 249-3330
40 Langdon Road, Farmingdale 11735
Services South Farmingdale, North Massapequa and border areas of Bethpage and Seaford