Is Composting Toilets Legal in Maryland? (2026)
Partially — Composting Toilets are legal with restrictions in Maryland as of 2026.
Quick Answer
Composting toilets may be used in Maryland but typically only as a supplemental system alongside a conventional toilet. No significant legislative changes have occurred since the General Permit for the Discharge of Composting Toilet Wastewater (18-CT) was issued in 2018.
What the Law Says
Regulates the use and discharge of composting toilet wastewater, requiring a general permit from the Maryland Department of the Environment and maintenance by a state-approved Designated Operator to ensure environmental safety.
— Maryland Department of the Environment, General Discharge Permit No. 18-CT
| 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 occurred since the General Permit for the Discharge of Composting Toilet Wastewater (18-CT) was issued in 2018.
Enforcement Reality
The Maryland Department of the Environment (MDE) issues a general permit for discharging composting toilet wastewater to groundwater. A state-approved 'Designated Operator' is required to maintain the system.
A common mistake is failing to obtain the MDE general permit or not having a Designated Operator for the system. Discharging liquid waste without a permit is a frequent violation.
Local Exceptions
None identified. State law applies uniformly across Maryland. 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 Maryland. 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.
Maryland 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. Maryland 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 Maryland?
What are the restrictions on installing a composting toilet in Maryland?
What mistakes do people make with installing a composting toilet in Maryland?
Does the law on installing a composting toilet change at the Maryland 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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