We found 145 public water systems in Clay county (ordered by population size).
| Name | Areas served | Population served | Contaminant count | Violation count |
|---|---|---|---|---|
| Moorhead | Moorhead | 42,005 | 40 | 0 |
| Dilworth | Dilworth | 4,024 | 0 | 5 |
| Barnesville | Barnesville | 2,600 | 0 | 6 |
| Hawley | Hawley | 2,094 | 0 | 5 |
| Glyndon | Glyndon | 1,393 | 0 | 3 |
| Ulen | Ulen | 547 | 0 | 0 |
| Sabin | Sabin | 544 | 0 | 4 |
| Brentwood Acres | County of Clay | 275 | 0 | 0 |
| Galaxie Sports Bar, Supper Club & Lanes | County of Clay | 250 | 0 | 0 |
| Hitterdal | Hitterdal | 201 | 0 | 4 |
| Felton | Felton | 171 | 0 | 8 |
| Spring Prairie Colony | County of Clay | 170 | 0 | 1 |
| Tom Brantner Memorial Camp Bsa | County of Clay | 150 | 0 | 0 |
| Lysne Lutheran Church | County of Clay | 135 | 0 | 6 |
| North Buffalo Lutheran Church | County of Clay | 125 | 0 | 0 |
| Buffalo River State Park | County of Clay | 120 | 0 | 0 |
| Americana Estates I | County of Clay | 112 | 0 | 0 |
| Scandia Lutheran Church | County of Clay | 110 | 0 | 0 |
| Lee Lake Campgrounds | County of Clay | 100 | 0 | 0 |
| Hoff Lutheran Church | County of Clay | 100 | 0 | 0 |
| Rollag Lutheran Church | County of Clay | 100 | 0 | 0 |
| Regional Science Center | County of Clay | 100 | 0 | 0 |
| Mainline Bar And Grill | County of Clay | 100 | 0 | 0 |
| Lee Veterinary Clinic | County of Clay | 100 | 0 | 0 |
| Vintage Gardens | County of Clay | 100 | 0 | 0 |
| Landstad Lutheran Church | County of Clay | 100 | 0 | 0 |
| Comstock | Comstock | 95 | 0 | 0 |
| Georgetown | Georgetown | 90 | 0 | 0 |
| Fargo Moorhead Campground | County of Clay | 85 | 0 | 0 |
| Hegland Lutheran Church | County of Clay | 75 | 0 | 0 |
| Renee's Drive Inn | County of Clay | 75 | 0 | 0 |
| Solem Lutheran Church | County of Clay | 75 | 0 | 0 |
| John Bouton Housing Development | County of Clay | 69 | 0 | 0 |
| Park Lutheran Church | County of Clay | 60 | 0 | 0 |
| Walworth Baptist Church | County of Clay | 60 | 0 | 0 |
| Romantic Moon Event Center | County of Clay | 50 | 0 | 0 |
| Daybreak Investments Llc | County of Clay | 50 | 0 | 0 |
| Ponderosa Golf Club | County of Clay | 50 | 0 | 0 |
| Phil's Midway | County of Clay | 45 | 0 | 0 |
| West Central Ag | County of Clay | 42 | 0 | 0 |
| Concordia Lutheran Church | County of Clay | 40 | 0 | 0 |
| Willow Creek Golf Course | County of Clay | 40 | 0 | 0 |
| County Heritage Housing Dev | County of Clay | 40 | 0 | 0 |
| Gran Lutheran Church | County of Clay | 35 | 0 | 0 |
| Westminster Presbyterian Church | County of Clay | 35 | 0 | 0 |
| Oakmound United Church Of Christ | County of Clay | 35 | 0 | 0 |
| Grong Lutheran Church | County of Clay | 35 | 0 | 0 |
| Titan Machinery | County of Clay | 34 | 0 | 0 |
| Mac's, Inc. | County of Clay | 30 | 0 | 0 |
| Alderon Industries | County of Clay | 30 | 0 | 0 |
| Little Bethany Lutheran Church | County of Clay | 30 | 0 | 0 |
| Wagner Park | County of Clay | 28 | 0 | 0 |
| Koch Nitrogen Company | County of Clay | 28 | 0 | 0 |
| Agassiz Valley Grain Llc | County of Clay | 25 | 0 | 0 |
| Hawley Municipal Airport | County of Clay | 25 | 0 | 0 |
| Kragnes Farmers Elevator Company | County of Clay | 25 | 0 | 0 |
| Kragnes Elevator | County of Clay | 25 | 0 | 0 |
| Buffalo River Speedway | County of Clay | 25 | 0 | 0 |
| Top End Dragway | County of Clay | 25 | 0 | 0 |
| Kragnes Inn | County of Clay | 25 | 0 | 0 |
| Western Minnesota Steam | County of Clay | 25 | 0 | 0 |
| Moorhead Municipal Airport | County of Clay | 25 | 0 | 0 |
| Red River Weigh Station Mndot | County of Clay | 25 | 0 | 0 |
| Casey Jo's Catering | County of Clay | 25 | 0 | 0 |
| Rustic Oaks | County of Clay | 25 | 0 | 0 |
| American Estates | County of Clay | 25 | 0 | 0 |
| Barnesville Boat Works | County of Clay | 25 | 0 | 0 |
| Butches Marine | County of Clay | 25 | 0 | 0 |
| A And W Drive In | County of Clay | 25 | 0 | 0 |
| Anderson Group Home | County of Clay | 25 | 0 | 0 |
| Midway Service | County of Clay | 25 | 0 | 0 |
| Ulen Park | County of Clay | 25 | 0 | 0 |
| Sabin Elem School | County of Clay | 25 | 0 | 0 |
| Amer Crystal Sugar Co | County of Clay | 25 | 0 | 0 |
| Centennial Park | County of Clay | 25 | 0 | 0 |
| Fairmount Creamery | County of Clay | 25 | 0 | 0 |
| Vigesaa Auto Parts | County of Clay | 25 | 0 | 0 |
| Sellin Bros Construction | County of Clay | 25 | 0 | 0 |
| A1a Contractors | County of Clay | 25 | 0 | 0 |
| Fertilizer Plant | County of Clay | 25 | 0 | 0 |
| Georgetown Bar | County of Clay | 25 | 0 | 0 |
| St Johns Church | County of Clay | 25 | 0 | 0 |
| Georgetown Elem School | County of Clay | 25 | 0 | 0 |
| Double D Truck Stop | County of Clay | 25 | 0 | 0 |
| Truckers Inn/tj's | County of Clay | 25 | 0 | 0 |
| C Casslin Implement | County of Clay | 25 | 0 | 0 |
| Farmers Fertilizer Co | County of Clay | 25 | 0 | 0 |
| North Buffalo Church | County of Clay | 25 | 0 | 0 |
| Sabin Trinity Luth Church | County of Clay | 25 | 0 | 0 |
| Hudsons Bay Park | County of Clay | 25 | 0 | 0 |
| Concordia Scandia Parish | County of Clay | 25 | 0 | 0 |
| Pioneer Hi-bred Intntnl | County of Clay | 25 | 0 | 0 |
| Dr Ian B Edwards | County of Clay | 25 | 0 | 0 |
| Buffalo River State Park | County of Clay | 25 | 0 | 0 |
| Elks Ponderosa Golf Crse | County of Clay | 25 | 0 | 0 |
| Midway Service Stations | County of Clay | 25 | 0 | 0 |
| Kost Bros Cement Factory | County of Clay | 25 | 0 | 0 |
| Thompson Greenery | County of Clay | 25 | 0 | 0 |
| Larry Davis Garage | County of Clay | 25 | 0 | 0 |
| Johnson-rogers Implement | County of Clay | 25 | 0 | 0 |
| Kurtz Township Hall | County of Clay | 25 | 0 | 0 |
| Harvick Manufacturing Co | County of Clay | 25 | 0 | 0 |
| F M Animal Hospital | County of Clay | 25 | 0 | 0 |
| Moonlight Theater | County of Clay | 25 | 0 | 0 |
| Town And Country Golf Cse | County of Clay | 25 | 0 | 0 |
| Bethesda Lutheran Church | County of Clay | 25 | 0 | 0 |
| Brookdale Baptist Church | County of Clay | 25 | 0 | 0 |
| Gran Church | County of Clay | 25 | 0 | 0 |
| Highway Rest Area | County of Clay | 25 | 0 | 0 |
| Barnesville Minnesota Dept Of | County of Clay | 25 | 0 | 0 |
| Country Faith Church | County of Clay | 25 | 0 | 0 |
| Viking Oakes | County of Clay | 25 | 0 | 0 |
| Cozy Trailer Court | County of Clay | 25 | 0 | 0 |
| Baker Post Office | County of Clay | 25 | 0 | 0 |
| Harvest States Cooperative | County of Clay | 25 | 0 | 0 |
| Rdo Equipment Co | County of Clay | 25 | 0 | 0 |
| Thysell Brothers Implement | County of Clay | 25 | 0 | 0 |
| Rollag Implement | County of Clay | 25 | 0 | 0 |
| Johnson Feed Service | County of Clay | 25 | 0 | 0 |
| Rollag General Store | County of Clay | 25 | 0 | 0 |
| National Agri-services | County of Clay | 25 | 0 | 0 |
| Kvox, K100 Radio Station | County of Clay | 25 | 0 | 0 |
| Syre Fertilizer Company | County of Clay | 25 | 0 | 0 |
| Terra | County of Clay | 25 | 0 | 0 |
| Bel Air Kennels | County of Clay | 25 | 0 | 0 |
| Betaseed, Inc | County of Clay | 25 | 0 | 0 |
| Krabbenhoft Seed Company | County of Clay | 25 | 0 | 0 |
| Hi-ten Sports | County of Clay | 25 | 0 | 0 |
| Barnesville Gun Club | County of Clay | 25 | 0 | 0 |
| Hawley Truck Station-mndot | County of Clay | 25 | 0 | 0 |
| Barnesville Municipal Airport | County of Clay | 25 | 0 | 0 |
| Ponderosa Golf Course | County of Clay | 25 | 0 | 0 |
| Coneflower Camp | County of Clay | 25 | 0 | 0 |
| Swimming Beach | County of Clay | 25 | 0 | 0 |
| Helmer O Melaas Rest Area | County of Clay | 25 | 0 | 0 |
| Mercantile Processing Company | County of Clay | 25 | 0 | 0 |
| Novartis, Inc | County of Clay | 25 | 0 | 0 |
| Country Acres Mobile Home Park | County of Clay | 25 | 0 | 0 |
| Pj's Drive Inn | County of Clay | 25 | 0 | 0 |
| Starlite Motel | County of Clay | 25 | 0 | 0 |
| Concord Environmental Equipment Company | County of Clay | 25 | 0 | 0 |
| Dilworth Weigh Station Mndot | Moorhead | 25 | 0 | 0 |
| Monsanto Company | County of Clay | 25 | 0 | 0 |
| Country Acres Mobile Home | County of Clay | 20 | 0 | 0 |
| Department Of Agriculture | County of Clay | 4 | 0 | 0 |