Grease from industrial and residential areas is prohibited from entering wastewater treatment facilities because it promotes the growth of the Nocardia, a filamentous type bacteria which is a major constituent of foam in activated sludge plants. Infiltration is any unwanted contamination source entering into water or sewer service lines or holding areas. Influent is any water or wastewater entering a plant for treatment. Wastewater collection is necessary to the health of a society. This process transports wastewater from where it is generated to where it is treated.
Manholes are collection points for sewage and storm water and are gravity operated.
PVC, ABS, cast iron, galvanized metal, and concrete are some of the materials used for pipes and manholes. Each material has an advantage. Cast iron is strong mechanically. PVC and ABS resist acids and bases. ABS is much more resistant than PVC for solvents.