Published April 2007

Biomat Basics

By Roger E. Machmeier

I have written about the biomat and its function before, but perhaps this is a good time for a refresher course. Septic tank effluent flowing into a trench is already deficient in oxygen. The effluent from an aerobic sewage treatment tank contains oxygen, but in the environment of the trench, the conditions soon turn anaerobic, or oxygen deficient. So we must understand that the environment of the soil treatment trench and the liquid in the trench is naturally very low or deficient in oxygen.