Sewer backups in the basements of many Wheaton homes during heavy rainstorms are caused primarily by stormwater entering and overloading the sanitary sewer system. There are many ways in which rainwater enters the sanitary sewer system, including: directly - by connections from sump pumps, downspouts, and area drains (inflow) - and indirectly - by cracks and failures of the sewer pipes (infiltration).
To help identify the sources of rainwater inflow and infiltration, the City sometimes uses an investigation program using smoke testing of the sanitary sewer system.
About Smoke Testing
Smoke testing is a simple means of locating openings in the sewer system that allow surface rainwater runoff to enter the sanitary sewers. Air combined with nontoxic smoke is forced into the sewer lines to disclose the location of connections and leaks. Smoke will appear where there are defects in the main sewer line or laterals (connection between the main line and a building) or where there are other connections to the sewer system such as roof drains, patio drains and footing drains.
Smoke should not enter buildings unless there is defective plumbing or dried-up drain traps. To help prevent smoke from entering your home, please pour water into unused sinks and floor drains. The smoke is nontoxic, creates no fire hazard, leaves no residue, dissipates quickly and is harmless.
Testing in Your Area
If a contractor of the City will be performing smoke testing in your area, you will receive door hanger cards notifying you of the testing, and signs will be posted when the crews are testing in your area.