We found 51 public water systems that could serve the same population as Frederick (ordered by population size).
| Name | Areas served | Population served | Contaminant count | Violation count |
|---|---|---|---|---|
| Aberdeen | Aberdeen | 26,091 | 41 | 32 |
| Web Water Development Association | Aberdeen, Eureka | 14,000 | 39 | 4 |
| Belcourt-turtle Mtn Rural Water System | Aberdeen | 13,500 | 10 | 24 |
| Brown-day-marshall Rws | Britton, Langford | 5,375 | 0 | 2 |
| Groton | Groton | 1,458 | 0 | 5 |
| Lakeside Estates | Aberdeen, St Louis Park | 625 | 0 | 28 |
| Warner | Warner | 496 | 0 | 10 |
| Country Village Park | Aberdeen, Cando | 340 | 0 | 29 |
| Prairiewood Property Owners | Aberdeen | 288 | 0 | 5 |
| Hecla | Hecla | 227 | 0 | 16 |
| Bath Country Cafe & Truck Stop | Bath | 200 | 0 | 0 |
| Grassland Colony | Aberdeen, Westport | 155 | 0 | 145 |
| Hutterville Colony South Dakota Inc | Beresford, Stratford | 140 | 0 | 154 |
| Claremont | Britton, Claremont | 127 | 0 | 39 |
| Westport Sanitary District | Aberdeen, Westport | 125 | 0 | 9 |
| Barnard Elementary School | County of Brown | 120 | 0 | 0 |
| Pleasant Valley Estates | Aberdeen | 105 | 0 | 0 |
| Dot Rest Area 111 - Orton | County of Brown | 100 | 0 | 0 |
| Bath Country Cafe | County of Brown | 100 | 0 | 0 |
| Dot Rest Area 112 - Lk Albert | County of Brown | 100 | 0 | 0 |
| Dot Rest Area 118 - Clark | County of Brown | 100 | 0 | 0 |
| Dot Rest Area 116 - Damero | County of Brown | 100 | 0 | 0 |
| Long Lake Colony | Aberdeen, Westport | 95 | 0 | 0 |
| The Meadows | Aberdeen | 80 | 0 | 0 |
| Rolling Meadows | Aberdeen | 78 | 0 | 0 |
| The Place At The Lake | Aberdeen | 75 | 0 | 0 |
| Green Acres Association | Bath | 75 | 0 | 0 |
| Jobee Acres | Aberdeen | 75 | 0 | 0 |
| Aberdeen Livestock Cafe | Aberdeen | 75 | 0 | 0 |
| Hub City Livestock Cafe | Aberdeen | 75 | 0 | 0 |
| Stratford | Aberdeen, Stratford | 72 | 0 | 0 |
| Mansfield Water Users Association | Mansfield | 70 | 0 | 0 |
| Richmond Heights Homeowners Associat | Aberdeen | 67 | 0 | 0 |
| Barnard | Barnard | 65 | 0 | 0 |
| Northwood First Subdivision | Aberdeen | 55 | 0 | 0 |
| Bar-n Silo | Aberdeen | 50 | 0 | 0 |
| The Shed | Westport | 50 | 0 | 0 |
| B & E Cafe | County of Brown | 50 | 0 | 0 |
| Gfp 3-c/richmond Recreation Ar | Aberdeen | 50 | 0 | 0 |
| Gfp 3-b/richmond Forest Drive | Aberdeen | 50 | 0 | 0 |
| Nwr-sand Lake Headquarter Area | County of Brown | 50 | 0 | 0 |
| Columbia Elementary School | Columbia | 40 | 0 | 0 |
| Bath Elementary School | Bath | 30 | 0 | 0 |
| Gfp 3-c/richmond Rec Area | Aberdeen | 25 | 0 | 0 |
| Nwr-sand Lake Rec Area | Columbia | 25 | 0 | 0 |
| Gfp 3-b/richmond Forest Dr. | Aberdeen | 25 | 0 | 0 |
| Ginger Bread House Cafe | County of Brown | 25 | 0 | 0 |
| Northern Electric | Bath | 25 | 0 | 0 |
| Elm Lake Resort | County of Brown | 25 | 0 | 0 |
| Mocassin Creek | County of Brown | 25 | 0 | 0 |
| Nwr-sand Lake Rec Area | County of Brown | 2 | 0 | 0 |