We found 49 public water systems in Jefferson county (ordered by population size).
| Name | Areas served | Population served | Contaminant count | Violation count |
|---|---|---|---|---|
| Mount Vernon | Mount Vernon | 15,750 | 46 | 6 |
| Northeast Mount Vernon Water Company | County of Jefferson | 5,532 | 0 | 8 |
| Woodlawn | Woodlawn | 3,646 | 0 | 6 |
| Belle Rive | Belle Rive | 2,040 | 0 | 9 |
| Waltonville | Waltonville | 1,933 | 0 | 2 |
| Bluford | Bluford | 1,883 | 0 | 14 |
| Dix-kell Water Commssion | County of Jefferson | 1,863 | 0 | 2 |
| Bonnie | Bonnie | 527 | 0 | 3 |
| Field School | County of Jefferson | 255 | 0 | 0 |
| Donald J Kelly, Principal | County of Jefferson | 255 | 0 | 0 |
| Nason | County of Jefferson | 244 | 0 | 3 |
| Moores Prairie Township Water Company | Belle Rive | 175 | 0 | 0 |
| Scheller Playhouse | County of Jefferson | 150 | 0 | 0 |
| Grand Prairie School | County of Jefferson | 105 | 0 | 0 |
| Grand Prairie School | County of Jefferson | 105 | 0 | 0 |
| State Of Illinois Warren G. Mu | State Of Illino | 100 | 0 | 0 |
| Farrington Comm Cons School | County of Jefferson | 84 | 0 | 0 |
| East Salem Miss Baptist Church | County of Jefferson | 75 | 0 | 0 |
| East Salem Miss Baptist Church | County of Jefferson | 75 | 0 | 0 |
| Well's Chapel | County of Jefferson | 60 | 0 | 0 |
| Well's Chapel | County of Jefferson | 60 | 0 | 0 |
| Shiloh United Meth Church | County of Jefferson | 50 | 0 | 0 |
| White Swan Baptist Church | County of Jefferson | 50 | 0 | 0 |
| Church Of Bethesda | County of Jefferson | 50 | 0 | 0 |
| Mt Olive General Baptist Churc | County of Jefferson | 50 | 0 | 0 |
| Marlow General Baptist Church | County of Jefferson | 50 | 0 | 0 |
| Long Prairie Christian Church | County of Jefferson | 50 | 0 | 0 |
| Boyd Christian Church | County of Jefferson | 50 | 0 | 0 |
| Mt Olive General Baptist Churc | County of Jefferson | 50 | 0 | 0 |
| St Barbara Church | County of Jefferson | 50 | 0 | 0 |
| Oak Grove Free Will Baptist Ch | County of Jefferson | 50 | 0 | 0 |
| Boyd Christian Church | County of Jefferson | 50 | 0 | 0 |
| Oak Grove Free Will Baptist Ch | County of Jefferson | 50 | 0 | 0 |
| St Barbara Church | County of Jefferson | 50 | 0 | 0 |
| Long Prairie Christian Church | County of Jefferson | 50 | 0 | 0 |
| New Hope Miss Baptist Church | County of Jefferson | 45 | 0 | 0 |
| New Hope Miss Baptist Church | County of Jefferson | 45 | 0 | 0 |
| Mooney's Store | County of Jefferson | 40 | 0 | 0 |
| Mooney's Store | County of Jefferson | 40 | 0 | 0 |
| Wal-mart Supercenter 0224 | County of Jefferson | 25 | 0 | 0 |
| Icehouse South Mt Vernon | County of Jefferson | 25 | 0 | 0 |
| Country Boutique | County of Jefferson | 25 | 0 | 0 |
| Icehouse Main Mt Vernon | County of Jefferson | 25 | 0 | 0 |
| Kroger L-711 | County of Jefferson | 25 | 0 | 0 |
| Country Boutique | County of Jefferson | 25 | 0 | 0 |
| Midway Farm Market | County of Jefferson | 25 | 0 | 0 |
| County of Jefferson | 25 | 0 | 0 | |
| Grand Prairie Campground | County of Jefferson | 25 | 0 | 0 |
| Borowiaks Iga - Mount Vernon | County of Jefferson | 25 | 0 | 0 |