According to Al Kelm, director of both our Water Plant & Wastewater Treatment Plant, the grease build-up at the Haynes Ave. lift station is a primary cause of backed-up sewers in the neighborhoods it serves.
A "lift station" is a pump designed to augment the gravity flow of sewage downstream to the wastewater treatment plant. There are several lift stations installed as part of our sewer system.
Restaurants are required to dispose of waste oil & grease in tallow barrels rather than dumping it down the drain. When that grease is dropped into the sewer system, either directly or indirectly (through the use of high-temperature dishwashers), it mixes with colder affluent and coagulates. The grease then clogs the system at the lift station and backs up the sewer system.
The city must then dispatch a crew to manually remove the grease from the lift station at unnecessary expense to the city and, often, great inconvenience to homeowners upstream.