Aerobic Treatment Unit Homeowner Education

For Owners/Users of Aerobic Treatment Systems:

Did you know that your household waste is processed directly onsite by a special kind of septic system called an aerobic treatment unit (ATU)? ATUs are not only more versatile than a conventional system but, also more efficient at processing waste. This highly versatile and efficient system has many advantages including the ability to be installed in a place where a conventional systems could not go (due to soil quality or site conditions), as well as providing the ability to build a larger house on a smaller lot (ATUs require a smaller drainfield size than conventional systems). Additionally, ATUs reduce the amount of biological material that enters your drainfield. This not only extends the lifespan of your drainfield, but also makes your ATU more environmentally friendly than a conventional system. ATUs can even be added to existing systems to help fix malfunctioning systems. So, go ahead—feel proud to be the owner of an ATU!

Just like the city sewer system, there are fees associated with using an ATU. These fees are a direct result of the need to maintain a current operating permit and a maintenance contract for the life of the system. With these in place, you can rest assured that your ATU is receiving the maintenance it requires to function at its peak levels.

The information contained within this packet should answer most of the questions you have about your ATU. The first section will define an ATU and explain how it works. The second section introduces you to the state’s requirements concerning ATUs, as well as the people who will be helping you to uphold those requirements. The next section is a quick reference section containing bulleted lists with crucial information (i.e. state requirements, homeowner do’s and don’ts, common compliance issues, suggested items for homeowner records, etc.). The final section includes information that you will want to keep for your records: a copy of the original construction permit, a copy of the operating permit, a copy of the maintenance agreement, a site plan showing the location of the ATU on your property, information on your specific ATU, and a maintenance record. It is highly recommended that you take the time to review this information.

ATU Program Coordinator:
Richard Tompkins, Environmental Specialist II
2295 Victoria Ave #206
Fort Myers, FL. 33901
(239) 690-2100

• How Aerobic Treatment Units Work

• Maintaining your ATU

• Quick References

• Homeowner Do’s and Don’ts (avoid problems)

• Suggested Maintenance Record

• List of Approved Maintenance Entities with Brands of units they service

How Aerobic Treatment Units Work

ATUs force compressed air through the liquid effluent in the tank to create a highly oxygenated (aerobic) environment for bacteria. “Bacteria that thrive in oxygen-rich environments work to break down and digest the wastewater inside the aerobic treatment unit [1]”. Aerobic units come in a variety of sizes and shapes such as rectangular, conical, and oval. They can be made of concrete, fiberglass or polyurethane. They are designed to collect and treat all the water from your home, including water from toilets, showers, bathtubs, sinks, and laundry. There are as many as three stages that your ATU takes wastewater through before the sewage is dispersed into the drainfield.

*Pretreatment*

Some ATUs have a step before the actual aeration begins. This is pretreatment and it helps to reduce the amount of solids and other materials that the bacteria cannot degrade that go into the system. These solids include grease, oil, toilet paper, and other substances that get put down the drain or flushed into the system. This stage may take place in a separate tank or in a compartment of the ATU itself. Typically pretreatment is optional but it can greatly improve the ATUs performance.

*Aerobic Treatment Unit*

The aeration chamber is where the bacteria decompose the pollutants in the wastewater. The ATU consists of a pump, pipes, and diffusers. The pump compresses the air that flows into the chamber. The pipes carry the air from the aerator to the diffusers. The diffuser forces air into the water in the form of bubbles which introduces oxygen into the sewage. There are two main types of ATUs: suspended growth units and attached growth units. Suspended units are the most common type of ATU and work by mixing air with the sewage to feed the free floating bacteria without the use of any type of medium. In attached growth units the bacteria is attached to some type of medium located inside the ATU itself.

*Settling Chamber*

The settling chamber is a calm area which allows settling to occur with the use of gravity. This is the area where the clear, treated water is separated from the bacteria that have been treating the sewage and other solids before they leave the system and travel to the drainfield.

*Drainfields*

After all the treatment is complete what started as sewage is now effluent which is discharged into the ground and allowed to filter through the soil and continue further treatment. The effluent from aerobic treatment units can be discharged into a variety of different drainfield systems. There are gravel systems, chamber systems, pipe systems, and Dripline systems. All these different materials have different requirements, sizes and capacities. There are gravity feed systems and pump systems. The type of drainfield material you have present depends on what you, the builder or the engineer wanted installed. The health department is not involved in that decision.

Maintaining a Healthy ATU (it’s a Team Effort!)

The Department of Health (DOH) has outlined a list of requirements in chapter 64E-6 of the state’s administrative code that, when properly followed, will ensure the preservation of the integrity of each ATU installed in Florida. Upholding these requirements is truly a team endeavor, as it depends upon a concerted effort on behalf of the maintenance entity, the DOH ATU coordinator, and YOU—the homeowner.

What are the requirements?

The homeowner is required to maintain a current maintenance agreement for the life of the system. The maintenance agreement must initially be good for two years. Subsequent contracts must be good for at least a one year period. The cost of a maintenance agreement varies depending on the type of system you have and the maintenance entity you select or, whether the operating permit fee is included or billed separately. The maintenance entity you select is required to inspect/ service your system at least two times per year and submit service reports to the health department. The maintenance entity is responsible for obtaining an operating permit from the health department for the system. The operating permit must be renewed with the health department every two years at a cost of $150. In addition, an environmental specialist employed by the health department is required to inspect your ATU at least once per year to verify that it is functioning properly.

Who are the Team Members?

The maintenance entity is an important team member as they have earned certification to service your specific type of ATU directly from the manufacturer. Therefore, the maintenance entity is not only equipped to handle all technical aspects of maintaining your ATU, but also is a valuable source of information. Florida administrative code places the following responsibilities on the maintenance entity: submission of semi-annual inspection reports to the health department, obtaining the operating permit and service related issues. (NOTE: Not all malfunctions are covered under the warranty/maintenance agreement. See copy of maintenance agreement in this packet.)

The DOH ATU coordinator is responsible for ensuring that the ATU remains compliant with Florida administrative code and does not become a public nuisance. To accomplish this, your DOH ATU coordinator reviews the inspection reports submitted to the health department by the maintenance entity for completeness, keeps detailed records of issues relevant to your ATU, and performs annual DOH ATU inspections.

The homeowner is the most essential team member as their lifestyle has a direct effect on the performance of the ATU. The homeowner can do their part to maintain peak performance of their ATU by keeping accurate records (i.e. site plan showing location of system and copies of maintenance contracts, operating permits, service reports, and correspondence) and being mindful of how they dispose of their waste (please refer to list of Do’s and Don’ts contained within the quick reference section of this packet).

Quick References

Code Requirements:

• The maintenance entity must maintain a current operating permit for the life of the system. The operating permit must be renewed every two years. Payment of $150.00 to the Lee County Health Department will be due.
• The homeowner must maintain a current maintenance contract with an approved maintenance entity for the life of the system. The maintenance contract should initially be good for two years. Subsequent renewals must be good for at least a one-year term for the life of the system. Prices vary depending on maintenance entity selected and type of system.
• Maintenance entity is required to inspect/service the ATU at least two times per year. Inspection reports must be submitted to the Lee County Health Department.
• The health department must inspect the maintenance, and performance, of the ATU at least once per year.

• No current maintenance contract on file
• No current operating permit on file
• Evidence of overflow
• Alarm not functioning properly
• Blower/aerator not functioning properly
• Hole/crack in lid and /or lid not secured
• Unit not readily accessible
• Bypass on system

• Alarms or lights going off
• Changes in the system’s normal operating sound
• Plumbing backups
• Sewage odors in the house or yard
• Sewage on the ground

• Copy of site plan showing location of ATU
• Copy of all operating permits issued
• Copy of all maintenance contracts
• Copy of service reports
• Copy of any correspondence between maintenance entity and/or DOH ATU program coordinator
• Copy of original permit

Do’s

• Keep the system accessible for inspection and pumping yet protected from unauthorized entrance
• Keep electricity going to the ATU at all times
• Call a service professional whenever you experience problems with your system, whenever the alarm is activated, or whenever there are any signs of system failure.
• Conserve water to avoid over loading the system. Be sure to repair any leaky faucets or toilets
• Space out loads of laundry over the week—too much water at once can hinder system performance
• Divert other sources of water, like roof drains, house footing drains, and sump pumps away from the system
• Slowly add water back into system when arriving home from vacation. Too much water entering system after an extended leave can wash the bacteria in the system out.
• Limit the amount of fat, grease, and food that enters the system—overloading system with organic material can cause premature failure. Garbage disposals are NOT recommended for houses on septic systems.
• Become familiar with how you own particular system operates, and the way it looks, sounds and smells when it is working correctly
• Keep detailed records on your system (suggestions below)

• Don’t drive or park a vehicle over any part of your system
• Don’t use your toilet as a trash can
• Don’t poison your treatment system and the ground water by pouring harmful chemicals down the drain
• Don’t make or allow unauthorized repairs to the system. A permit for repair must be obtained from the county health department.
• Don’t attempt to clean or perform maintenance on any sealed aerobic unit components
• Don’t plant trees on or within 4’ of the drainfield.

Maintenance Record