SSO Smoke and Dye Testing

The Smoke and Dye Testing by the contractor AECOM will begin at the end of June in the areas surrounding downtown. If you are in the area being tested, you will receive a letter and a door hanger with information. Here is additional information about the program:

Smoke Testing


Smoke testing is a common test method used to identify sections of the sanitary sewer collection system that have defects such as cracks, leaks, or illicit connections that allow rainwater to enter the sanitary sewer system.

During the test, workers will blow a dense, white, non-hazardous smoke into the sanitary sewer system. 

The smoke will escape through openings such as holes in manhole covers and plumbing vent pipes located on or near rooftops. Smoke will also escape through defects such as cracks or breaks, open or broken cleanout covers, damaged or defective manhole frame seals, illegally connected roof or area drains, and any other opening(s).


Dye Testing

The locations where smoke is escaping the systems, the workers place a non-staining water soluble dye in the drain or downspout and flush it with water.

If dye is visible in the sanitary sewer only, this is an indication that there is an illicit connection. If dye is visible in both the sanitary and storm sewer, a broken or leaky pipe(s) are suspected. 

Picture4Smoke Dye1