• Larry Thompson

Aerobic Pre-Treatment Units

Updated: Feb 4, 2018

Aerobic treatment units (ATUs) rely on air injection systems to create an oxygenated (aerated) environment, which is able to support bacterial populations that break down organic material. This aeration process produces an effluent that is lower in total suspended solids (TSS) and biochemical oxygen demand (BOD) than that of conventional systems.


The injection of air into the ATU agitates the wastewater, so solids are readily mixed with the bacteria, facilitating digestion of the organic matter by bacteria. There is a step in the process where any settled solids and bacteria are returned back to the aerobic portion of the tank for mixing and additional treatment. A clarification step is also a part of the treatment, allowing for solids and bacteria to settle out of the wastewater prior to distribution to the drainfield, helping to ensure that effluent leaving the ATU contains as few solids and organic matter particulates as possible. Tertiary treatment through ultra-violet disinfection is also available.


An ATU is an excellent option for use on challenging lots where reduced vertical separation distances to unsuitable soil features are required or reduced setbacks to a water feature are desired. Contact Thompson Environmental Consulting for a free consultation! #AerobicTreatmentUnit #SepticSolutions #ThompsonEnvironmental