We found 41 public water systems in Johnson county (ordered by population size).
| Name | Areas served | Population served | Contaminant count | Violation count |
|---|---|---|---|---|
| Water District 1 Of Johnson Co | Kansas City | 331,900 | 92 | 3 |
| Mo American Warrensburg | Warrensburg | 19,687 | 6 | 1 |
| Johnson Co Pwsd 2 | Holden | 13,500 | 5 | 8 |
| Whiteman Air Base | County of Johnson | 7,886 | 0 | 3 |
| Laf/jo/saline Co Cons Pwsd 2 | Counties of Johnson, Lafayette, Saline | 6,365 | 110 | 9 |
| Johnson Co Pwsd 1 | Warrensburg | 4,554 | 0 | 1 |
| Johnson Co Pwsd 3 | Warrensburg | 4,490 | 0 | 2 |
| Knob Noster | Knob Noster | 2,709 | 0 | 25 |
| Holden | Holden | 2,389 | 0 | 9 |
| Pettis/johnson/saline Pwsd 1 | Saline | 1,263 | 122 | 14 |
| Knob Noster State Park Campgrd | Knob Noster | 767 | 0 | 0 |
| Leeton | Leeton | 620 | 0 | 3 |
| Kingsville R-i Schools | Kingsville | 341 | 0 | 0 |
| Chilhowee | Holden | 335 | 0 | 0 |
| Knob Noster State Park Bobwhite | County of Johnson | 300 | 0 | 0 |
| Centerview | Centerview | 267 | 0 | 6 |
| Kingsville | Kingsville | 250 | 0 | 12 |
| Village At Whiteman | Warrensburg | 237 | 0 | 0 |
| Bill Sharps Country | County of Johnson | 200 | 0 | 0 |
| Pembrooke Park | Warrensburg | 170 | 0 | 6 |
| Knob Noster State Park Shawnee | County of Johnson | 160 | 0 | 2 |
| Knob Noster Trailer Park | Knob Noster | 150 | 0 | 0 |
| Lakewood Mhp | Knob Noster | 138 | 0 | 0 |
| Country Acres Subd | Knob Noster | 130 | 0 | 8 |
| Knob Noster State Park Clearfork | County of Johnson | 104 | 0 | 0 |
| Powell Scout Reservation | Powell Scout | 100 | 0 | 0 |
| Johnson R-vii Farmers Elem | Centerview | 100 | 0 | 0 |
| M & M Mobile Home Park | County of Johnson | 100 | 0 | 0 |
| Oak Grove Estates | Knob Noster | 75 | 0 | 0 |
| B J's Steakhouse | County of Johnson | 50 | 0 | 0 |
| Hazel Hill Mhp | County of Johnson | 45 | 0 | 0 |
| Whiteman Mhp | County of Johnson | 32 | 0 | 0 |
| Country Aire Estates | Warrensburg | 30 | 0 | 0 |
| Skyhaven Mhp | Centerview | 30 | 0 | 0 |
| A Little Off Base | Knob Noster | 30 | 0 | 0 |
| Pleasant Bethel Baptist Church | Pleasant Bethel | 25 | 0 | 0 |
| High Point Baptist Church | High Pt Baptist | 25 | 0 | 0 |
| Forrest Trails Estates | Warrensburg | 25 | 0 | 0 |
| Brants Airway Service | Centerview | 25 | 0 | 0 |
| Mt Zion Baptist Church | County of Johnson | 25 | 0 | 0 |
| Kingsville Baptist Church | Baptist Church | 25 | 0 | 0 |