Aerobic Treatment Units:  ***Pictures Below***

Aerobic treatment units (ATU's) are similar to standard septic systems in that they use natural processes to treat wastewater.  But unlike conventional septic systems, ATU's also use oxygen to break down organic matter, much the same as municipal wastewater treatment plants, but on a much smaller scaled-down version.  Usually, a trash tank (or septic) tank is used in-line prior to the ATU.

Because ATU's decompose organic solids quickly, the wastewater leaving the system is cleaner.  ATU's are very useful when environmentally sensitive areas are less suitable for conventional or gravity flow septic systems or when a water table is too high.

The most common residential ATU process is called "suspended growth".  Most styles of these ATU's have a main compartment which air is forced and mixed with the wastewater.  This creates an environment where bacteria are free-floating in the liquid and grow as they digest the solids (suspended growth).

Many of the ATU's will have a second chamber where solids that bacteria are unable to digest, settle.  The two chambers are connected so these undigested solids can be returned to the aeration chamber either by gravity or a pump.  This process of return & mixing is important for effective operation of the aerobic treatment unit.  Some ATU manufacturers have designed a three compartment aerobic treatment unit.

ATU's due to their complexity, require proper maintenance usually at 6 month intervals.  Each manufacturer requires testing/servicing certain components of the ATU.  These service intervals are very important to ensure the health and longevity of the ATU.

Below are some pictures of just a sample of various types of aerobic treatment units.  All the ATU's listed/shown below are registered trademark names from their respective companies.






                         Copyright- Septic Plus, Inc. - all rights reserved