Why do septic tanks smell?
Food product waste from homes as well as human digestive system waste contains microbes. The biological digestion of these wastes begins in the wastewater collection system; the septic tank. Of the many kinds of microbes introduced into the septic tank one of the more prevalent are SRBs (sulfate reducing bacteria). SRBs are anaerobes (non-oxygen metabolizing bacteria) which means they function in an environment without oxygen. These SRBs use the oxygen from sulfates naturally occurring in wastewater as part of the process of breaking down waste constituents. Sulfides are one of the by-products of the SRB digestion process that combines with other elements to form a gas called hydrogen sulfide and other sulfide compounds. It is the hydrogen sulfide gas, often referred to as rotten egg odor that you can smell from your septic tank.
