Delayed by recent winter weather, Edgerton Utilities Department will soon be performing smoke testing on sanitary sewer lines in the city to identify locations where stormwater is penetrating the city’s sanitary sewer system.
There are two ways that stormwater can enter into the city’s sanitary sewer system negatively impacting its ability to transport water to be treated by the city’s wastewater treatment facilities.
The intrusion of ground water into the sanitary system is known as Infiltration. Unfortunately, some of Edgerton’s sanitary sewer infrastructure is aging, and as it gets older cracks and loose joints can form in the underground pipes, particularly older pipes made of clay tile. As such, stormwater enters into the system through these cracks or loose joints impacting the capacity of the pipe to transport water to be treated at the wastewater treatment facilities and unnecessarily treating stormwater.
The other way of intrusion is called Inflow. Inflow is allowing stormwater to enter the sanitary sewer system by sump pumps and drains, etc. Most of these connections are considered illegal connections.
Together these impact on the sanitary sewer system as “I & I” (Inflow and Infiltration).
Smoke testing can aid in identifying sources of inflow and locations of infiltration in Edgerton’s s sanitary sewer lines. Smoke testing is performed by blowing smoke mixed with large volumes of air into the sanitary sewer line through nearby manholes. This smoke will rise through the ground near cracks or breaks in public main lines and private lateral lines.
This testing can also find illegal connections to the system by smoke coming out drain lines and vents. The smoke is non-toxic, does not leave stains or residues and is of low odor. Residents should be advised that during the testing smoke can enter their home through their sewer line, but it is not dangerous and will dissipate. Staff has identified targeted areas of concern and anticipate testing will begin in March, weather permitting. Advance notification will be provided to affected residents through door hangers and NotifyJoCo.
— City of Edgerton newsletter