Recap: Septic System 101 – Understanding Septic Systems and Common Homeowner Practices - UF/IFAS Mid-Florida Research and Education Center

Last Updated on September 29, 2026 by Yilin Zhuang

Thank you to everyone who joined us for the Septic System 101 webinar, hosted by the UF/IFAS Extension Florida Well Owner Network (FWON). This was the second webinar in our Private Well and Septic System Webinar Series, and we appreciated everyone’s participation and thoughtful questions throughout the session!

What We Covered

This webinar provided an overview of how septic systems work, why they are important to Florida’s water resources, current regulations, and practices homeowners can use to properly maintain their systems. Topics included:

Why septic systems matter in Florida. Approximately 2.6 million septic systems are estimated to be in use across Florida, making them an important part of the state’s wastewater infrastructure and a significant source of nitrogen entering some water bodies.
How conventional septic systems work. We discussed the two main components of a conventional system—the septic tank and drainfield—and how wastewater moves through each part of the system.
Septic system components and separation distances. The webinar covered septic tank construction, drainfield design, minimum separation distances, and the importance of appropriate soil and groundwater conditions for proper treatment.
Nutrient removal and water quality. Conventional septic systems were designed primarily to protect public health by removing pathogens, rather than nutrients such as nitrogen and phosphorus. We discussed how nitrogen and phosphorus can move from septic systems into groundwater and surface waters.
Signs of septic system failure. Warning signs can include odors, sewage or wastewater surfacing over the drainfield, sewage backing up into the home, and elevated nitrate or coliform bacteria levels in well water.
Florida septic system regulations. We discussed the development of Basin Management Action Plans (BMAPs), septic system remediation requirements, and regulations requiring enhanced nutrient-reducing systems in certain areas.
Advanced nitrogen-reducing systems. The webinar introduced three types of approved enhanced nutrient-reducing systems: aerobic treatment units (ATUs), performance-based treatment systems (PBTSs), and in-ground nitrogen-reducing biofilters (INRBs).
Septic system maintenance. Homeowners can extend the life of their systems by properly disposing of waste, protecting the drainfield, using water efficiently, and inspecting and pumping the septic tank when needed.

Audience Q&A Highlights

How far can a septic tank be from the house?

Florida regulations establish minimum setback distances rather than a general maximum distance between a house and its septic system. The system generally is at least 5 feet from a building foundation. Longer distances may be possible, but the sewer line must be properly designed with adequate slope and cleanout access. Site conditions and local requirements can also affect placement, so the system location should be determined during the permitting and site evaluation process.

If an older septic system does not meet current setback requirements, does it have to be moved when it is repaired?

Not necessarily. Florida’s rules include provisions for repairing existing systems that cannot meet all current setback requirements. In general, an existing setback cannot be reduced further, and the system should be brought closer to current requirements where practical. Requirements depend on the type and extent of the repair and site conditions. A complete system replacement may be treated differently, so homeowners should check with their local septic permitting authority before making repairs.

I have been told that putting raw vegetable material down the drain is good for my septic system. Is that correct?

No. There is no need to add raw vegetables or other food waste to a septic system. The microorganisms needed for septic treatment are already naturally present in household wastewater. Food scraps add solids to the septic tank and can increase sludge accumulation and the frequency of pumping. Compost vegetable scraps or dispose of them with household waste instead.

How far should trees be planted from a septic system?

Keep trees and large woody plants away from the septic system and especially the drainfield. There is not one distance that works for every tree because root systems vary considerably. A useful guideline is to consider the tree’s mature size and root spread. Tree roots can extend two to three times beyond the canopy and may damage drainfield pipes or interfere with system operation. Shallow-rooted grasses and herbaceous plants are better choices over and around the drainfield. More info: Landscaping on or near Septic Drain Fields

If I am buying a home with an existing septic system, what should I check before purchasing?

Before purchasing a home with a septic system, consider having the system professionally inspected. An inspection can help identify the condition of the tank and drainfield and any potential problems before you purchase the property.

Ask the seller for available records, such as the septic system permit, system location or site plan, repair or modification records, and pumping and maintenance history. You can also contact the local septic permitting authority to ask what records are available for the property.

It is also helpful to know what type of system is installed and whether it has special maintenance requirements. Some advanced systems, such as aerobic treatment units and performance-based treatment systems, have ongoing maintenance requirements.

Can an RV on a residential property be connected to a septic system?

Possibly. RV wastewater must be properly collected and disposed of through an approved sewage system. Florida regulations specifically provide for RV sewer connections in permitted RV parks, including connections to approved onsite sewage treatment and disposal systems.

For an RV on a residential property, however, do not assume that it can simply be connected to the home’s existing septic system. The existing system may not have been designed or permitted for the additional wastewater, and adding a connection may require review or modification of the septic system. Contact the local septic permitting authority before making a connection.

For additional information about Florida requirements for mobile home and recreational vehicle parks, visit the Florida Department of Health Mobile Home and Recreational Vehicle Parks program.

Are there septic system additives we could add to the septic tank to help it function better?

According to the U.S. EPA commercial bacterial or chemical additives designed to improve septic system performance are not recommended for home wastewater treatment. This is because septic systems naturally contain bacteria, enzymes, and fungi needed to break down waste. These come from human and domestic waste that goes down your household drains and into the septic tank. Commercial products added to the system can be ineffective or can even damage the system’s operation and the environment. The EPA additives fact sheet provides good, detailed information regarding additives.

The Florida Department of Environmental Protection (FDEP) reviews biological and chemical additives to ensure they do not violate state water quality standards or harm septic system operation. A product complying with the law and appearing on the FDEP approved products list is not an endorsement or recommendation for use. It simply means these products meet state standards.

Instead of using additives, homeowners can extend the life of their systems by properly disposing of waste, protecting the drainfield, using water efficiently, and inspecting and pumping the septic tank when needed.

Who do I contact with questions or concerns about septic systems, including permitting, inspections, or potential problems in my area?

For environmental health concerns or suspected septic system problems anywhere in Florida, first contact your county Florida Department of Health (FDOH). They can help address your concern or refer you to the appropriate agency. Find your local health department through the FDOH County Health Department Directory.

For septic system permitting, responsibilities depend on where you live:

Marion County and 16 Northwest Florida counties: As of 2025, the Florida Department of Environmental Protection (FDEP) manages septic or onsite sewage treatment and disposal system (OSTDS) permitting in Marion, Bay, Calhoun, Escambia, Franklin, Gadsden, Gulf, Holmes, Jackson, Jefferson, Leon, Liberty, Okaloosa, Santa Rosa, Wakulla, Walton, and Washington counties. For more information about permitting, see the DEP Onsite Sewage FAQ – Permitting.

All other Florida counties: The local county health department handles septic system permitting.

Visit the FDEP Onsite Sewage Program and the FDOH Onsite Sewage and Septic site for more information.

Does clay soil require significantly different septic system and drainfield management?

Homeowners should use maintenance practices recommended for septic systems in all soil types: avoid excessive water use, only flush human waste and toilet paper, pump the system as recommended and protect the drainfield from soil compaction.

However, clay soils do drain much more slowly than sandy soils and depending on the amount of clay in your soil, this can affect septic system design and performance. System design is based on a site and soil evaluation (including a water percolation test) which takes into account soil characteristics, drainage, and the vertical distance to the seasonal high-water table. Clay soils may require a larger drainfield to handle the wastewater effluent (the liquid waste) and ensure it is properly treated. If clay layers limit wastewater movement, a mounded or elevated system may be needed to provide the required 24 inches of well-drained soil below the drainfield to ensure that wastewater is filtered and treated before reaching the groundwater table.

Why are nitrogen and phosphorus important when talking about septic systems?

Conventional septic systems are designed from a public health perspective to remove pathogens from wastewater effluent. Properly sited and well-maintained systems do a good job of this. However, they are not designed to remove nitrogen or phosphorus. Conventional systems only remove about 30% of nitrogen and about 80% of phosphorus in wastewater.

Nitrogen is a concern because in a septic system, it is converted to nitrate, which is highly mobile and can move through Florida’s sandy soils into groundwater and eventually surface waters. FDEP lists 24 of Florida’s 30 Outstanding Florida Springs as impaired by excess nitrogen. Enhanced nutrient-reducing septic systems can reduce nitrogen reaching groundwater. See FDEP’s Enhanced Nutrient-Reducing Systems FAQ for more information.

Phosphorus generally moves much more slowly because it binds to soil minerals like iron, aluminum, and calcium and is often retained near the drainfield. However, phosphorus can become a concern when soils become saturated with phosphorus or conditions allow it to reach surface waters.

Is a septic system required when wells are installed for agricultural purposes?

No. In Florida, installing an agricultural well does not automatically require you to install a septic system. Septic systems (or OSTDS) are required for buildings that produce domestic wastewater such as from bathrooms, sinks, dishwashers, and laundry machines. If the well is only used for agricultural uses, like irrigating crops or watering livestock, no septic system is required. However, if a septic system is present or added to the property Florida Statutes require that the system be located at least 50 feet away from a non-potable or agricultural well, and at least 75 feet away from a potable (drinking water) well.

My septic system is 25 years old. Is it in danger of failing?

The lifespan of a septic system depends on its materials, design, installation, use, and maintenance. According to the US EPA, a concrete or plastic septic tank may last 40-50 years or more, while pumps and controls usually need replacement every 10–20 years. The drainfield typically has a lifespan of about 25–30 years or more, depending on site conditions and maintenance.

As drainfields age, excessive biomat buildup can slow wastewater movement into the soil and contribute to ponding, surfacing wastewater, or backups. A biomat is a natural layer of microorganisms and organic material that forms where wastewater enters the soil. A healthy biomat is vital to pathogen removal, but excessive buildup can cause drainfield failure. Other causes of failure include soil compaction or poor drainage, excessive water use, poor tank maintenance, root intrusion, and changes in groundwater or site conditions. Advanced treatment systems and other specialized components may have different maintenance and replacement schedules, so check the manufacturer’s recommendations.

Signs of a failing system can include slow drains, plumbing backups, sewage odors, unusually wet or lush areas over the drainfield, or wastewater surfacing in the yard.

If your system is 25 years old and you are concerned about its condition, consider having it evaluated by a licensed septic system contractor/operator, particularly if you notice any signs of problems.

Watch the Recording

Septic System 101 — Understanding Septic Systems and Common Homeowner Practices

Water Testing Kit Drawing

As part of this webinar series, participants who completed all four quiz questions were entered into a drawing for a $200 home water testing kit. The drawing was held after the webinar series and livestreamed on the UF/IFAS Extension Central Florida Water Resources Facebook page.

Additional Resources

For more information about septic systems, private wells, and water quality, explore the resources listed above or visit the Florida Well Owner Network website.

Prepared by: Sofia Cordoba, Andrea Albertin, and Yilin Zhuang.