Since January 1, 2023, Miami-Dade County no longer accepts conventional septic systems for new construction or total replacements. If you’re building, redeveloping, or replacing a failed system anywhere in the county, Ordinance 22-83 changed what your engineer must design — here’s what it means in practice.
What Ordinance 22-83 Did
On July 7, 2022, the Miami-Dade Board of County Commissioners adopted Ordinance 22-83, creating more rigorous standards for onsite sewage treatment and disposal systems (OSTDS — the formal name for septic systems). The ordinance added Section 24-42.7 to the County Code, and effective January 1, 2023, the Water and Wastewater Division of DERM reviews every new and total-replacement septic system in the county.
The Four System Types
The ordinance classifies septic systems into four tiers:
- Type 1 — conventional septic systems. No longer allowed for new development or total replacements anywhere in Miami-Dade.
- Types 2, 3, and 4 — performance-based systems with enhanced levels of pollutant reduction, with Type 4 being the most advanced.
This applies to residential, commercial, and industrial developments served by an OSTDS.
What This Means for Your Project
Performance-based systems are engineered systems — they must be designed, calculated, and sealed for your specific property, soils, and use. That makes choosing your designer the first real step of any septic project in Miami-Dade today. An experienced Professional Engineer will select the right system type, produce the design DERM expects to see, and handle the permit submission.
Official resources: the county’s OSTDS program page and the OSTDS Guidance Manual. Forms are on our Resources page.
This article is general information, not engineering or legal advice for a specific property. Requirements change — always confirm current rules with Miami-Dade RER/DERM or consult a licensed Professional Engineer about your project.