People along 22nd Street W may notice a white smoke coming from catch basins and on property Friday. The City’s sewer maintenance staff is using a non-toxic liquid smoke to identify weak points in the storm water sewer system. Westbound lanes will merge to the median lane on 22nd Street from Avenue I N to Avenue L N until 3:00 Friday afternoon.

The oil-based smoke mimics the properties of invisible sewer gases. It will be poured into the storm water manholes in the street and tracked as it follows the pipes to identify weak points or small openings where contaminants could enter.

While the test is being carried out thick, white smoke will be visible exiting from the vent stacks and rooftop drains on houses, catch basins, yard drains tied to the sewer system, and from any holes or cracks in the contained area. It is possible for the smoke to enter a home through rarely used drain traps. To prevent this, residents and businesses in the testing area were advised to run water into all drains for one minute.
The smoke itself is an odourless, oil-based product that appears thick and white when activated. The city says that it is non-toxic.