We found 24 public water systems in Plymouth county (ordered by population size).
| Name | Areas served | Population served | Contaminant count | Violation count |
|---|---|---|---|---|
| Lemars Water Department | Le Mars | 9,848 | 0 | 16 |
| Remsen Municipal Utilities | Remsen | 1,673 | 0 | 9 |
| Akron, City Of | Akron | 1,486 | 0 | 12 |
| Kingsley Water Supply | Kingsley | 1,411 | 0 | 10 |
| Hinton Water Supply | Hinton | 928 | 0 | 10 |
| Merrill Municipal Water Supply | Merrill | 756 | 0 | 45 |
| Mikes Saloon | Sioux City | 240 | 0 | 23 |
| Remsen-union Community School Dist | County of Plymouth | 175 | 0 | 0 |
| Brunsville Municipal Water Supply | Brunsville | 151 | 0 | 4 |
| Westfield Water Supply | Westfield | 140 | 0 | 13 |
| Golden Pheasant Lounge | County of Plymouth | 130 | 0 | 0 |
| Oyens Water Supply | Oyens | 103 | 0 | 0 |
| Hidden Acres Country Club | Sioux City | 100 | 0 | 0 |
| Craig Water Works | Craig | 95 | 0 | 0 |
| Hole N The Wall Lodge | Akron | 90 | 0 | 0 |
| Struble Water System | County of Plymouth | 85 | 0 | 0 |
| Northwest Iowa Power Cooperative | Le Mars | 73 | 0 | 0 |
| Camp Joy Hollow | Westfield | 51 | 0 | 0 |
| Smith Co Manufacturing | County of Plymouth | 42 | 0 | 0 |
| Hillview Pk-plymouth Conservation | Hinton | 38 | 0 | 0 |
| Country Drive | Sioux City | 35 | 0 | 0 |
| Lakeside Motel | County of Plymouth | 25 | 0 | 0 |
| Golden Pheasant | County of Plymouth | 25 | 0 | 0 |
| Millnerville Store | County of Plymouth | 25 | 0 | 0 |