An aerobic treatment unit (ATU) works similarly to a municipal sewage plant but on a smaller scale. When properly designed, operated, and maintained, it can effectively treat sewage at a high level. ATUs come in various shapes and sizes and play a crucial role in safeguarding human health and the environment.

The system offers several advantages. It can be used in homes with smaller lots, inadequate soil conditions, high water tables, or in areas close to surface water bodies sensitive to nutrient contamination from effluent wastewater. However, regular lifetime maintenance should be expected for ATUs.

The ATU utilizes oxygen to accelerate the breakdown of organic matter. It consists of separate chambers within a single tank for trash removal, aeration, clarification, and sludge return. The system includes a pump, pipes, and diffusers to introduce air into the aeration chamber, where sewage is broken down by bacteria.

 The process involves serval steps:

• Pre-Treatment: The septic tank is placed in front of the ATU to separate solids from the sewer water.
• Aeration Chamber: A blower or air compressor forces air to mix with the wastewater, promoting the growth of aerobic bacteria to digest effluent solids.
• Disinfection: Extra treatment for the wastewater leaving the ATU involves using UV light, bleach, chlorine, or other disinfection processes to further treat the wastewater before it goes into the pump tank.
• Final Treatment Disposal: The treated wastewater is discharged into the drainage area, such as an evapotranspiration bed, an absorption area, or a sand filter.

Watch this video to learn how to maintain a sewer system: