Marion County Septic Permit Guide (OSTDS)

Who administers septic permits in Marion County

In Florida, an onsite sewage treatment and disposal system, or OSTDS, is what most people call a septic system. For years these systems were permitted by the Florida Department of Health through county health departments. That changed. Under the 2020 Clean Waterways Act, the OSTDS program is moving to the Florida Department of Environmental Protection (FDEP) in phases, and Marion County transitioned to FDEP on July 1, 2025.

In practice, that means new permits, site evaluations, and inspections for Marion County are now handled by FDEP, largely through its online OSTDS portal. The governing statute is Section 381.0065, Florida Statutes, and the technical standards live in Chapter 62-6 of the Florida Administrative Code, the rule chapter that replaced the former Chapter 64E-6 used under the health department.

The permit process, step by step

A new system and a full drainfield replacement follow the same general path. A licensed contractor usually manages it for you, though the property owner is the legal permit holder.

1. Application. The contractor submits the construction permit application and fee, typically through the FDEP OSTDS portal.
2. Site evaluation. An evaluator examines the soil and site conditions, including soil borings to read the soil profile and estimate the seasonal high water table.
3. Soil and loading assessment. The soil texture and water table determine the soil loading rate and which system types the lot can support.
4. System design. The system is designed for the home size and the site conditions, including the drainfield size and any advanced treatment the location requires.
5. Construction permit. FDEP reviews the application against the site evaluation and, if it approves, issues the construction permit.
6. Construction. The contractor installs the permitted system.
7. Final inspection and approval. An inspection confirms the tank, drainfield, setbacks, and grading before the system is approved for use.

For a standard home, expect roughly four to twelve weeks from application to approval, depending on the site, the system, and scheduling.

Site evaluation and soil testing

The site evaluation is the part homeowners most often underestimate, and it is where Marion County geology matters. The evaluator reads the soil profile to find the soil texture and the estimated seasonal high water table. Florida rules require unsaturated soil between the bottom of the drainfield and that water table, so a high seasonal water table can push a site toward a mound or other engineered system. Sandy, well-drained soils, which are common on the Ocala karst uplands, are generally easier and cheaper to work with than wet or restrictive soils.

Drainfield sizing basics

Drainfield sizing in Florida is governed by Rule 62-6.008, Florida Administrative Code. A few principles drive it:

• System size is based on estimated sewage flow, with a minimum baseline used for small homes.
• Estimated flow increases with each additional bedroom or each additional increment of building area.
• There is a minimum drainfield area, with additional area added for each bedroom beyond two.
• The soil loading rate, set by the soil texture, converts that flow into the required drainfield area.
• Where the soil profile changes, sizing is based on the most restrictive soil found within a set depth below the drainfield.
• New systems also require a minimum septic tank capacity that grows with the number of bedrooms.

The exact per-bedroom flow figures and loading-rate tables are in Rule 62-6.008. Your contractor applies them to your specific soil results, which is why two lots on the same street can need different drainfields.

Setbacks

Rule 62-6.005, Florida Administrative Code, sets minimum separation distances. These shape where a system can go, especially on smaller or waterfront lots:

• 75 feet from a private potable well.
• 100 feet from a public potable well serving up to 2,000 gallons per day, and 200 feet from larger public wells.
• 75 feet from surface water, such as a lake, river, or wetland.
• 5 feet from property lines.
• 5 feet from building foundations.
• 10 feet from potable water lines (with exceptions for sleeved or stronger pipe).
• 15 feet from certain drainage swales and dry retention areas.

On riverfront lots near Rainbow Springs in Dunnellon or lakefront lots on Lake Weir in Ocklawaha, the surface-water setback can be the single biggest constraint on where a drainfield fits.

Permit fees

Florida law sets fee ranges in Section 381.0066, Florida Statutes. The statute provides for roughly:

• $25 to $125 for application review, permit issuance, or a system inspection.
• $40 to $115 for a site evaluation.
• $150 to $300 for an annual operating permit on an engineer-designed performance-based system.

When advanced treatment is required

Much of Marion County sits in spring-protection zones. Inside a Priority Focus Area of the Silver Springs or Rainbow Springs Basin Management Action Plan (BMAP), new and many replacement systems must be enhanced nutrient-reducing (ENR) systems that cut total nitrogen by at least 65 percent. This is the single biggest factor that can change the cost and design of a system here. Our springs and BMAP guide explains where these rules apply and what they mean.

How this connects to your project

Whether you are planning a new septic system, a drainfield replacement, or septic for new construction, the permit and the site evaluation come first. Marion County Septic is a free matching service. Tell us about your property and we connect you with a licensed local contractor who handles the FDEP permit, the soil evaluation, and the installation, then provides a free quote.