Septic system requirements in Oklahoma
What landplan.io applies when it designs a septic system in Oklahoma: 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 Oklahoma
Reviewed landplan.io designs by Oklahoma's own rules, which our staff reviewed against the state's regulations. Last published 5 October 2026.
Septic systems allowed in Oklahoma
The system types landplan.io permits in Oklahoma:
- Conventional Subsurface Absorption field
- ET/A Field
- Low Pressure-dosed Absorption field
- Drip Irrigation
- Mound
- Spray Irrigation
Septic tank size in Oklahoma
The daily design flow of a home: 75 gal/day per bedroom, at least 225 gal/day. The septic tank is sized from that flow:
| Daily design flow | Minimum tank |
|---|---|
| up to 250 gal/day | 750 gallons |
| 250 to 350 gal/day | 1,000 gallons |
| 350 to 500 gal/day | 1,250 gallons |
Septic setbacks in Oklahoma
| From | To | Distance |
|---|---|---|
| Polygon | Existing Septic Component to be Abandoned | 5 ft |
These are the values the landplan.io design engine applies in Oklahoma. Confirm a design with the Oklahoma health department or your county's before you build.
Parcel data in Oklahoma
landplan.io has parcel boundaries for 56 of Oklahoma's 77 counties, and part of 4 more: the counties where 89.9% of the state's people live. Type an address there and the design starts from the parcel.
Septic companies, designers and jobs in Oklahoma
- Septic companies and distributors in Oklahoma (1)
- Septic designers in Oklahoma
- Septic design jobs in Oklahoma
Where the rules come from
The regulations and documents landplan.io's Oklahoma rules are read from:
- Chapter 641 - Individual and Small Public On-Site Sewage Treatment Systems (Okla. Admin. Code (OAC) Title 252, Chapter 641)
- OAC 252:641 Appendices A-O - system options and vertical separation, minimum lot size, soil groups, pipe specifications, small public flows, size charts, net evaporation zones and example drawings (transcribed from the published images) (OAC 252:641 Appendices A, B, C, F, H, I, J, K, L, M, O)
- OAC 252:641 Appendix E as codified through the 2012 Legislative session (superseded; source of footnote 11 text) (OAC 252:641 Appendix E (2012 codification), footnote 11)
- OAC 252:641 Appendix E - Horizontal Separation Distance Requirements for On-Site Sewage Treatment Systems (transcribed from the published image)
Septic rules by county in Oklahoma
- Adair County
- Alfalfa County
- Atoka County
- Beaver County
- Beckham County
- Blaine County
- Bryan County
- Caddo County
- Canadian County
- Carter County
- Cherokee County
- Choctaw County
- Cimarron County
- Cleveland County
- Coal County
- Comanche County
- Cotton County
- Craig County
- Creek County
- Custer County
- Delaware County
- Dewey County
- Ellis County
- Garfield County
- Garvin County
- Grady County
- Grant County
- Greer County
- Harmon County
- Harper County
- Haskell County
- Hughes County
- Jackson County
- Jefferson County
- Johnston County
- Kay County
- Kingfisher County
- Kiowa County
- Latimer County
- Le flore County
- Lincoln County
- Logan County
- Love County
- Major County
- Marshall County
- Mayes County
- Mcclain County
- Mccurtain County
- Mcintosh County
- Murray County
- Muskogee County
- Noble County
- Nowata County
- Okfuskee County
- Oklahoma County
- Okmulgee County
- Osage County
- Ottawa County
- Pawnee County
- Payne County
- Pittsburg County
- Pontotoc County
- Pottawatomie County
- Pushmataha County
- Roger mills County
- Rogers County
- Seminole County
- Sequoyah County
- Stephens County
- Texas County
- Tillman County
- Tulsa County
- Wagoner County
- Washington County
- Washita County
- Woods County
- Woodward County
Questions
What septic systems are allowed in Oklahoma?
landplan.io permits these system types in Oklahoma: Conventional Subsurface Absorption field, ET/A Field, Low Pressure-dosed Absorption field, Drip Irrigation, Mound and Spray Irrigation.
What size septic tank do I need in Oklahoma?
landplan.io sizes the septic tank in Oklahoma from the daily design flow: up to 250 gal/day: 750 gallons; 250 to 350 gal/day: 1,000 gallons; 350 to 500 gal/day: 1,250 gallons. A home's design flow is 75 gal/day per bedroom, at least 225 gal/day.
Does landplan.io have parcel data in Oklahoma?
Yes, for 56 of Oklahoma's 77 counties, and part of 4 more.