Smoke Testing

The Public Works Department smoke tests neighborhood sewer lines to verify connections and determine if there are areas where storm water or groundwater are entering the system.

It is important to prevent storm water and groundwater from entering the sewer system because those water sources do not require treatment at a wastewater treatment plant, which is very costly. Storm water and groundwater also impact the overall capacity of the sewer pipes, which are engineered to accommodate estimated wastewater flow from surrounding homes and businesses. Ensuring storm water and groundwater do not enter the sewer reduces the need to increase the capacity of the existing pipes and helps prevent sewer spills during rain storms.

The Process

Smoke testing is conducted by circulating colored smoke through manholes into sewer lines to locate broken pipes and other defects. White smoke then exits from vent pipes on home roofs. The smoke is non-toxic, leaves no residue, creates no fire hazard, and has no effect on plants/animals.

Smoke will not enter the house unless there is defective plumbing or the drain traps are dry. Visibility and odor last only a few minutes where there is adequate ventilation. Although this smoke is non-toxic, it is recommended that anyone with respiratory difficulties not remain indoors during the testing.

Preparing Your Home

To prepare your home, flush all toilets and run a gallon of water into sinks, drains, tubs, and showers to ensure a water seal to keep smoke out. Since interior appliances and plumbing fixtures may be connected to the sewer system, smoke may enter your house if plumbing fixtures are dry because of non-use (like sinks or tubs) or improper installation; or if vent connections, pipes, or seals are defective or improperly installed. Repair work on private property is the property owner's responsibility.