Patent ID: 6997201

Claim:
A method of reducing entry of sanitary waste from a building drain wastewater source into a sewer main in response to a high flow in the sewer main, the method comprising: providing a sewer service line having an upstream end connected to the building drain and a downstream end connected to the sewer main, the sewer service line conducting wastewater from the building drain to the sewer main; detecting a first flow in the sewer main resulting from a high flow in the sewer main; blocking the sewer service line in response to detecting the first flow; accumulating the wastewater in the sewer service line to prevent its flow into the sewer main, thereby reducing entry of sanitary waste from the building drain into the sewer main; detecting a second flow in the sewer main after the high flow; and unblocking the sewer service line in response to detecting the second flow to release wastewater accumulated in the sewer service line into the sewer main.