Septic system requirements in Missouri
What landplan.io applies when it designs a septic system in Missouri: the system types allowed, tank sizes, setbacks and soil loading rates, with what septic products cost there.
Updated
Design a septic system for an address in Missouri
Reviewed landplan.io designs by Missouri's own rules, which our staff reviewed against the state's regulations. Last published 5 October 2026.
Septic systems allowed in Missouri
The system types landplan.io permits in Missouri:
- Conventional Trench System
- Drip Dispersal System
- Low Pressure Distribution
- Surface Discharging System
Septic tank size in Missouri
The daily design flow of a home: 150 gal/day per bedroom, at least 240 gal/day. The septic tank is sized from that flow:
| Daily design flow | Minimum tank |
|---|---|
| up to 240 gal/day | 1,000 gallons |
| 240 to 360 gal/day | 1,500 gallons |
| 360 to 600 gal/day | 2,000 gallons |
| 600 to 720 gal/day | 2,500 gallons |
| 720 to 840 gal/day | 2,750 gallons |
| 840 to 920 gal/day | 3,000 gallons |
| 920 to 1,040 gal/day | 3,250 gallons |
Septic setbacks in Missouri
| From | To | Distance |
|---|---|---|
| Polygon | Existing Septic Component to be Abandoned | 5 ft |
These are the values the landplan.io design engine applies in Missouri. Confirm a design with the Missouri health department or your county's before you build.
Parcel data in Missouri
landplan.io has parcel boundaries for 81 of Missouri's 115 counties, and part of 5 more: the counties where 92.6% of the state's people live. Type an address there and the design starts from the parcel.
Septic companies, designers and jobs in Missouri
- Septic companies and distributors in Missouri (20)
- Septic designers in Missouri
- Septic design jobs in Missouri
Where the rules come from
The regulations and documents landplan.io's Missouri rules are read from:
- Minimum Construction Standards for On-Site Sewage Disposal Systems (19 CSR 20-3.060)
- 19 CSR 20-3.060 (1)(D) Table 1 - Minimum Set-Back Distances (transcribed from the Code of State Regulations image) (19 CSR 20-3.060(1)(D) Table 1)
Septic rules by county in Missouri
- Adair County
- Andrew County
- Atchison County
- Audrain County
- Barry County
- Barton County
- Bates County
- Benton County
- Bollinger County
- Boone County
- Buchanan County
- Butler County
- Caldwell County
- Callaway County
- Camden County
- Cape Girardeau County
- Carroll County
- Carter County
- Cass County
- Cedar County
- Chariton County
- Christian County
- Clark County
- Clay County
- Clinton County
- Cole County
- Cooper County
- Crawford County
- Dade County
- Dallas County
- Daviess County
- Dekalb County
- Dent County
- Douglas County
- Dunklin County
- Franklin County
- Gasconade County
- Gentry County
- Greene County
- Grundy County
- Harrison County
- Henry County
- Hickory County
- Holt County
- Howard County
- Howell County
- Iron County
- Jackson County
- Jasper County
- Jefferson County
- Johnson County
- Knox County
- Laclede County
- Lafayette County
- Lawrence County
- Lewis County
- Lincoln County
- Linn County
- Livingston County
- Macon County
- Madison County
- Maries County
- Marion County
- Mcdonald County
- Mercer County
- Miller County
- Mississippi County
- Moniteau County
- Monroe County
- Montgomery County
- Morgan County
- New madrid County
- Newton County
- Nodaway County
- Oregon County
- Osage County
- Ozark County
- Pemiscot County
- Perry County
- Pettis County
- Phelps County
- Pike County
- Platte County
- Polk County
- Pulaski County
- Putnam County
- Ralls County
- Randolph County
- Ray County
- Reynolds County
- Ripley County
- Saline County
- Schuyler County
- Scotland County
- Scott County
- Shannon County
- Shelby County
- St Charles County
- St Clair County
- St Francois County
- St Louis County
- Ste Genevieve County
- Stoddard County
- Stone County
- Sullivan County
- Taney County
- Texas County
- Vernon County
- Warren County
- Washington County
- Wayne County
- Webster County
- Worth County
- Wright County
Questions
What septic systems are allowed in Missouri?
landplan.io permits these system types in Missouri: Conventional Trench System, Drip Dispersal System, Low Pressure Distribution and Surface Discharging System.
What size septic tank do I need in Missouri?
landplan.io sizes the septic tank in Missouri from the daily design flow: up to 240 gal/day: 1,000 gallons; 240 to 360 gal/day: 1,500 gallons; 360 to 600 gal/day: 2,000 gallons; larger flows need larger tanks. A home's design flow is 150 gal/day per bedroom, at least 240 gal/day.
Does landplan.io have parcel data in Missouri?
Yes, for 81 of Missouri's 115 counties, and part of 5 more.