We found 16 public water systems in Clark county (ordered by population size).
| Name | Areas served | Population served | Contaminant count | Violation count |
|---|---|---|---|---|
| Sioux Rural Water System | Goodwin, Watertown | 4,000 | 0 | 0 |
| Clark Rural Water System | Clark, Florence | 2,130 | 0 | 34 |
| Clark | Clark | 1,189 | 0 | 7 |
| Clark Rural Water-kampeska | Clark, Florence | 578 | 0 | 42 |
| Willow Lake | Willow Lake | 275 | 0 | 19 |
| Fordham Colony | Aberdeen, Carpenter | 120 | 0 | 0 |
| Clark Colony | County of Clark | 97 | 0 | 0 |
| Collins Colony | Aberdeen, Iroquois | 92 | 0 | 0 |
| Hillcrest Colony | Aberdeen, Garden City | 90 | 0 | 0 |
| Shamrock Colony | Aberdeen, Carpenter | 75 | 0 | 0 |
| Bradley | Bradley, Redfield | 72 | 0 | 0 |
| Raymond | Raymond | 50 | 0 | 0 |
| Garden City | Garden City | 50 | 0 | 0 |
| Carpenter Cafe | Carpenter | 30 | 0 | 0 |
| Highway 212 Wide Spot | County of Clark | 25 | 0 | 0 |
| Sportsman's Bar | County of Clark | 25 | 0 | 0 |