Sewer backups on a rainy day don’t originate in the sewers. On a dry day in the heat of the summer, the public system works perfectly, no matter how many residents and students at Northern flush their toilets or take showers. The number of people who take showers and flush doesn’t get any greater when it rains.
Deficits of an Old Collection System
The 130 miles of sanitary sewer we took over in November of 1987 and now maintain came to us in very bad condition. The average age of all sanitary main in town is fifty years. Some of it is in surprisingly good shape. Much of it is not.
Water that should not be in the sanitary system enters it through cracks in the mains, improperly connected house service laterals, and something called “infiltration,” in which water travels from where there’s more of it (the ground during wet weather) to where there’s less of it (the sanitary sewer) through osmosis.
Identifying Problem Areas
As part of ongoing sanitary sewer improvement planning, DeKalb Sanitary District do testing to evaluate the condition of the sanitary sewers.
These kinds of tests are used:
Restoring Collection System Integrity
DeKalb Sanitary District has aggressively been attacking intrusions of storm and groundwater into the sanitary collection system by