Who issues a septic permit in each Missouri county

The Authority column is the state's own classification, and it tells you what kind of arrangement your county is under.

• Ordinance means the county has adopted its own onsite wastewater ordinance and may have requirements beyond the state minimum construction standards. Ask that agency what its ordinance adds.
• DHSS means no local government has taken the program on, so the state Department of Health and Senior Services administers the standard there directly.
• Contract means the work is handled under an arrangement with another agency, which is why the agency named may not carry your county's name. Carroll County's permits, for instance, are listed to the Ray County Health Department.
• Incorporated city marks the cities the state lists separately and returns no agency for. They are kept in this table rather than dropped, because a missing row reads as an oversight rather than as the state's actual answer.

Source: Missouri Department of Health and Senior Services, Onsite Wastewater Treatment, read 2026-08-26.

Because the requirements differ. Missouri lets a city or county enforce its own ordinance provided it is at least equal to state regulation and inspection, and lets counties adopt standards more restrictive than the state's. Counties with their own ordinance can and do add minimum lot sizes, stricter setbacks, mandatory maintenance reporting, and in some cases an inspection when a property is sold. None of that appears in the state standard.

So the state rule tells you the floor, and the agency in this table tells you what you actually have to build to.

Two things this table cannot tell you. If you are inside an incorporated city, the city may handle the work rather than the county. And certain large lots are excluded from the state sections altogether under conditions set out in statute, though a county ordinance can still reach them. The permit page covers both.

Source: Section 701.031, Revised Statutes of Missouri, read 2026-08-26.