Final answer:
A septic tank system prevents sewer gases from emanating from the drainage system by using a sewer line, septic tank, and drain field. Sludge settles in the tank, where microorganisms decompose the organic solids anaerobically, and clarified water is purified in the drain field.
Step-by-step explanation:
A septic tank system prevents sewer gases from emanating from the drainage system. It is an individual sewage treatment system for homes in typically rural settings. The basic components of a septic tank system include a sewer line from the house, a septic tank, and the drain field. The septic tank acts as a large container where sludge settles to the bottom and microorganisms decompose the organic solids anaerobically, preventing sewer gases from escaping. The clarified water seeps into the soil through a network of perforated pipes in the drain field and is further purified by bacteria.