We found 35 public water systems in Decatur county (ordered by population size).
| Name | Areas served | Population served | Contaminant count | Violation count |
|---|---|---|---|---|
| Rathbun Regional Water Assn (rathbun) | Centerville | 29,500 | 33 | 29 |
| Sirwa #2 (creston) | Creston | 18,510 | 35 | 9 |
| Sirwa #3 (leon) | Decatur City | 2,395 | 0 | 4 |
| Lamoni Municipal Utilities | Lamoni | 2,324 | 0 | 14 |
| Leon Water Supply | Leon | 1,977 | 0 | 18 |
| Dot-1 (i-35 Ra 034e Decatur) | County of Decatur | 406 | 0 | 0 |
| Garden Grove Water Supply | Garden Grove | 216 | 0 | 6 |
| Davis City Water Supply | Davis City | 204 | 0 | 9 |
| Nine Eagles State Park | County of Decatur | 190 | 0 | 0 |
| Clarke Community School | County of Decatur | 162 | 0 | 0 |
| Morman Trail Community School | County of Decatur | 160 | 0 | 0 |
| Central Decatur Community Sch. | County of Decatur | 142 | 0 | 0 |
| Grand Valley Community School | County of Decatur | 142 | 0 | 0 |
| Presbyterian Church | County of Decatur | 130 | 0 | 0 |
| New Salem Baptist Church | County of Decatur | 110 | 0 | 0 |
| Christian Church | County of Decatur | 100 | 0 | 0 |
| Grand River Methodist Church | County of Decatur | 100 | 0 | 0 |
| 4 Seasons Restaurant And Station | County of Decatur | 100 | 0 | 0 |
| Van Wert Cafe | Van Wert | 90 | 0 | 0 |
| Slip Bluff Pk-decatur Conserva | County of Decatur | 75 | 0 | 0 |
| Procom Corporation | County of Decatur | 60 | 0 | 0 |
| Nine Eagles Cafe | County of Decatur | 60 | 0 | 0 |
| Shewmaker County Park | County of Decatur | 50 | 0 | 0 |
| D&c's Bar | County of Decatur | 50 | 0 | 0 |
| Lion's Club | County of Decatur | 50 | 0 | 0 |
| Tiedje's 66 Station | County of Decatur | 50 | 0 | 0 |
| Barb's Place Tavern | County of Decatur | 50 | 0 | 0 |
| Ellie's Bar And Grill | County of Decatur | 32 | 0 | 0 |
| Decatur Co. Livestock Auction | County of Decatur | 25 | 0 | 0 |
| Shewmaker Pk-decatur Conservat | County of Decatur | 25 | 0 | 0 |
| Smith Oil Co. | County of Decatur | 25 | 0 | 0 |
| Barton General Store | County of Decatur | 25 | 0 | 0 |
| Carol's Cuddles Inn | County of Decatur | 25 | 0 | 0 |
| Decatur Tavern | County of Decatur | 25 | 0 | 0 |
| Wade's Cafe | County of Decatur | 25 | 0 | 0 |