|1. A reservoir, or tank, which receives crude sewage, and by bacterial action and sedimentation effects a process of clarification and decomposition of solids.
2. A tank in which the solid matter of continuously flowing sewage is deposited and retained until it has been disintegrated by anaerobic bacteria.
3. A water tight receptacle which receives the discharge of a building sanitary drainage system, or part, and is designed and constructed so as to separate solids from the liquid, digest organic matter through a period of detention, and allow the liquids to discharge into the soil outside of the tank through a system of open joints