The city's Department of Environmental Services will smoke test portions of the wastewater collection system in Palolo and Sand Island areas Sept. 25 through Oct. 1.
The daytime testing, which may last up to a week, is part of the department's preventative maintenance program to prevent rainwater from entering the sewer system.
Crews pump smoke into sewer pipes, examine whether smoke escapes and record its location. The smoke used is non-toxic, harmless and minimal odor. The smoke is neither a fire hazard nor health hazard to humans and pets.
Tests locate broken pipes, illegal connections, open cleanouts and other paths for runoff to enter the sewer system. Runoff from heavy rain can overwhelm and surcharge the sewer system and treatment plants, causing sanitary sewer overflows.
Residents and affected businesses were notified by mail and door notices. In addition, the city will contact Fire and Police communications centers at the beginning of each testing day.
Click here for maps of where the smoke testing will take place.