Maine Water Utilities:
- Alfred Water District
- Anson Madison Water District
- Ashland Water & Sewer District
- Auburn Water District
- Baileyville Utilities District
- Bangor Water District
- Bar Harbor Water Department
- Bath Water District
- Berwick Water Department
- Bethel Water District
- Biddeford & Saco Water Company
- Boothbay Region Water District
- Bowdoinham Water District
- Brownville Water Department
- Brunswick & Topsham Water District
- Caribou Utilities District
- City of Brewer Water Department
- City of Lewiston Water Division
- Dexter Utility District
- Dixfield Water Department
- East Millinocket Water Works
- Ellsworth Water Department
- Fort Fairfield Utilities District
- Fort Kent Water Department
- Gray Water District
- Great Salt Bay Sanitary District
- Greater Augusta Utility District
- Guilford/Sangerville Water District
- Hallowell Water District
- Hampden Water District
- Harrison Water District
- Houlton Water Company
- Jackman Utility District
- Kennebec Water District
- Kennebunk/Kennebunkport/Wells Water
- Kittery Water District
- Limestone Water & Sewer District
- Lincoln Water District
- Lisbon Water Department
- Madison Water District
- Maine Water Company (f/k/a Aqua Maine)
- Northport Village Corporation (Water Department)
- Old Town Water District
- Orono-Veazie Water district
- Pittsfield Water Department
- Portland Water District
- Sabattus Sanitary District (Water Department)
- Sanford Water District
- Searsport Water District
- South Berwick Water District
- Wilton Water Department
- Winterport Water District
- Wiscasset Water District
- York Water District