Registered onsite wastewater professionals in Missouri
Missouri’s roster of individually registered onsite wastewater professionals covers 1,827 licensed people across 82 counties. Pick a county to see who is based there.
Counties with the most registered onsite wastewater professionals
- Barry County219
- Christian County140
- Camden County116
- Benton County115
- Audrain County108
- Franklin County105
- Bates County74
- Boone County74
- Crawford County62
- Cass County60
- Lincoln County50
- Bollinger County48
- Andrew County44
- Jefferson County41
- Barton County37
Every county with registered onsite wastewater professionals
- Adair22
- Andrew44
- Atchison2
- Audrain108
- Barry219
- Barton37
- Bates74
- Benton115
- Bollinger48
- Boone74
- Buchanan27
- Butler22
- Caldwell26
- Callaway20
- Camden116
- Cape Girardeau9
- Carroll9
- Carter3
- Cass60
- Cedar33
- Chariton5
- Christian140
- Clark4
- Clay15
- Clinton4
- Cole4
- Cooper6
- Crawford62
- Dade10
- Dallas16
- Daviess6
- DeKalb
- Dent12
- Douglas21
- Dunklin1
- Franklin105
- Gasconade2
- Gentry1
- Greene15
- Grundy
- Harrison
- Henry4
- Hickory
- Holt
- Howard
- Howell2
- Iron19
- Jackson11
- Jasper20
- Jefferson41
- Johnson8
- Knox3
- Laclede5
- Lafayette2
- Lawrence5
- Lewis3
- Lincoln50
- Linn2
- Livingston
- Macon1
- Madison3
- Maries2
- Marion6
- McDonald3
- Mercer
- Miller3
- Mississippi4
- Moniteau
- Monroe
- Montgomery2
- Morgan3
- New Madrid
- Newton3
- Nodaway
- Oregon
- Osage
- Ozark4
- Pemiscot
- Perry
- Pettis
- Phelps1
- Pike1
- Platte3
- Polk1
- Pulaski4
- Putnam
- Ralls
- Randolph
- Ray1
- Reynolds1
- Ripley
- Saline
- Schuyler
- Scotland
- Scott1
- Shannon
- Shelby
- St. Charles13
- St. Clair
- St. Francois5
- St. Louis
- St. Louis (city)
- Ste. Genevieve2
- Stoddard1
- Stone10
- Sullivan
- Taney3
- Texas1
- Vernon1
- Warren2
- Washington1
- Wayne
- Webster2
- Worth
- Wright
Where the roster is filed, and where the work happens
These records are organised by the address on the licence, and that address is not a service area. A Missouri licence is granted by Missouri DHSS and is valid across the state — the county tells you where the person is, not the limit of where they will go.
In practice a rural county showing two registered onsite wastewater professionals is rarely the real choice set. Every county page here lists its neighbours for exactly that reason.
Records as published August 26, 2026.