Infiltration means water other than wastewater that enters a sewer system (including sewer system and foundation drains) from the ground through such means as defective pipes, pipe joints, connections, or manholes. Infiltration does not include, and is distinguished from, inflow.
Filtration means a process for removing particulate matter from water by passage through porous media.
Direct filtration means a series of processes including coagulation and filtration but excluding sedimentation resulting in substantial particulate removal.
Diatomaceous earth filtration means a process resulting in substantial particulate removal in which a precoat cake of diatomaceous earth filter media is deposited on a support membrane (septum), and while the water is filtered by passing through the cake on the septum, additional filter media known as body feed is continuously added to the feed water to maintain the permeability of the filter cake.
Mold means mold, fungus, microbial contamination or pathogenic organisms.