Septic System Regulations in Missouri

In Missouri, onsite wastewater (septic) systems are regulated by Missouri Department of Health and Senior Services (DHSS), Onsite Wastewater Treatment Program (Bureau of Environmental Health Services), which sets the statewide code, and permits are issued and inspections carried out by county or local health jurisdictions. Installing, replacing or repairing a septic system here means, in sequence: a site and soil evaluation, a design, a permit application, an inspection while the system is open, and a final as-built record once it is approved.

Who regulates septic systems in Missouri

The state-level regulator is Missouri Department of Health and Senior Services (DHSS), Onsite Wastewater Treatment Program (Bureau of Environmental Health Services) (official program page). DHSS sets statewide minimum construction standards for onsite wastewater treatment systems (OWTS), but in most counties the local county or city/county health department issues the actual OWTS construction permit; in counties without that authority, another local entity (sewer district, building department, or planning/zoning department) may issue permits instead.

The statewide onsite-wastewater code is cited as 19 CSR 20-3.060 (Minimum Construction Standards for On-Site Sewage Disposal Systems) and 19 CSR 20-3.080 (Requirements for Percolation Testers, On-Site Soils Evaluators and Registered On-Site Wastewater Treatment System Installers). We link the agency's own page above rather than restating specific numeric requirements from it, since those change by rule revision and by local amendment.

The permit sequence

The order of operations is broadly consistent across the country, even though the specific numbers in each step vary by state and often by county. None of the figures below are specific to Missouri; treat this as the shape of the process, and get the actual numbers from the agency linked above or from the county office.

1. Site and soil evaluation. A qualified evaluator (see licensing below) digs test pits or runs a percolation test, and records the soil profile, depth to seasonal water table, depth to any restrictive layer, and slope. This determines whether the lot can support a conventional system or needs an alternative design.
2. Design. Under most state codes, daily design flow is set from bedroom count, not square footage. That flow drives tank capacity, and the soil evaluation sets the drainfield application rate and therefore its size. The designer also lays out setbacks to wells, property lines, surface water, foundations and a reserve/replacement area.
3. Permit application. Submitted to whichever office issues permits here (state agency or county/district health office, per the delegation model above), along with the design and soil work.
4. Installation and open inspection. The installer builds the system, and it is inspected before backfill while it is still open to view.
5. As-built and approval. A final drawing of what was actually built is filed once the system is approved. That as-built is the document a future owner, pumper or inspector needs, and it is what ends up in the county record.

Who can design and install a septic system

Getting septic records in Missouri

Septic records in Missouri are generally held by the county or local health jurisdiction that issued the permit, not by the state agency, and are released under the state's public records law. We have not logged the specific statute name and response deadline for Missouri yet; check with the county office listed on its records page below, or with Missouri Department of Health and Senior Services (DHSS), Onsite Wastewater Treatment Program (Bureau of Environmental Health Services).

Counties in Missouri we hold records for

We hold 65 septic records across 6 of 114 Missouri counties. Each county page below shows exactly where its records are kept and how many we hold.

Full Missouri county-by-county index · Open the parcel map

Common questions

Who regulates septic systems in Missouri?

Missouri Department of Health and Senior Services (DHSS), Onsite Wastewater Treatment Program (Bureau of Environmental Health Services). DHSS sets statewide minimum construction standards for onsite wastewater treatment systems (OWTS), but in most counties the local county or city/county health department issues the actual OWTS construction permit; in counties without that authority, another local entity (sewer district, building department, or planning/zoning department) may issue permits instead.

What is the septic permit process in Missouri?

The sequence is a site and soil evaluation, a design sized from the evaluation and (under most state codes) bedroom count, a permit application, an inspection before backfill, and a final as-built filed once the system is approved. Exact numeric requirements are set by the agency's own code, not restated here.

Who can install a septic system in Missouri?

DHSS-registered On-Site Wastewater Treatment System Installer (basic or advanced registration level, per 19 CSR 20-3.080); a registered installer must be used per local permit requirements (e.g., Cole County).

How do I get septic records for a property in Missouri?

Septic records are generally held by the county or district health office that issued the permit. See our county-by-county Missouri index for the specific office and portal in each county.

Sources

• https://health.mo.gov/living/environment/onsite/index.php
• https://regulations.justia.com/states/missouri/title-19/division-20/chapter-3/section-19-csr-20-3-080/
• https://www.law.cornell.edu/regulations/missouri/19-CSR-20-3-060

Regulatory information on this page was researched against official state agency sources and last verified 2026-08-31. It is informational only: the agency linked above is authoritative, and requirements can change. We are not lawyers, not a government body, and not affiliated with, licensed or certified by any agency named on this page.