Is Composting Toilets Legal in Missouri? (2026)
Partially — Composting Toilets are legal with restrictions in Missouri as of 2026.
Quick Answer
Composting toilets may be used in Missouri but typically only as a supplemental system alongside a conventional toilet. No significant legislative changes have been made to the state's onsite sewage disposal system laws.
What the Law Says
Allows composting toilets as supplemental systems to conventional toilets with county health department approval; prohibits installation without proper permits and compliance with local plumbing codes.
— Mo. Rev. Stat. § 701.025
| Category | Details |
|---|---|
| State Plumbing Code | May require conventional toilet as primary; composting as supplemental |
| Permit Requirements | Legal to sell |
| Code Violation Penalties | Installation without permits may result in code violations. |
| Pending Legislation | None known |
No significant legislative changes have been made to the state's onsite sewage disposal system laws.
Enforcement Reality
Enforcement is handled by local public health agencies. While state law allows for composting toilets as an alternative system, some counties, like Camden County, have banned them near the Lake of the Ozarks.
A common mistake is not checking for local ordinances, which can be more restrictive than state law. Another is failing to have a proper system for greywater disposal.
Local Exceptions
None identified. State law applies uniformly across Missouri. Local ordinances may still vary — check with your city or county government for any additional rules.
Bottom Line
Composting Toilets are legal with restrictions in Missouri. This activity is permitted, but specific conditions apply. Violating those conditions can result in fines or criminal charges. Read the rules carefully and consult an attorney if unsure.
Missouri vs. the Rest of the US
Across the US, installing a composting toilet is fully legal in 20 states, restricted in 30, and illegal in 0. Missouri falls in the RESTRICTED category.
View the full 50-state map →Neighboring States
Laws change at state lines. Here is how bordering states compare on Composting Toilets:
Frequently Asked Questions
Is installing a composting toilet legal in Missouri?
What are the restrictions on installing a composting toilet in Missouri?
What mistakes do people make with installing a composting toilet in Missouri?
Does the law on installing a composting toilet change at the Missouri border?
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Reviewed by cross-referencing the cited state statute against current legislative databases and regulatory publications.
Sources & Verification
This page was reviewed by Ethan Harper by comparing the legal status against the cited state statute. AllowedHere is an informational resource and does not provide legal advice. Consult a licensed attorney for guidance specific to your situation.
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