ST. CHARLES – The city is testing its sanitary sewer system to identify potential faulty lines and connections where seasonal water runoff may enter the system or where sewer gases may escape, according to a news release from the city.

The testing is required by the Illinois Environmental Protection Agency and will take place on the city’s west side, through June 30. See map for areas to be tested.

The smoke testing is designed to identify sewer line faults in order to reduce backups, eliminate unnecessary wastewater treatment, and identify the location of gas leaks that need to be repaired, according to the release.

Affected residences and businesses will be notified prior to testing and signs will be posted in neighborhoods being tested.

The smoke testing is being performed by RJN Engineering Group of Downers Grove, contracted by the city of St. Charles.

Smoke testing pushes air mixed with liquid smoke into the sewer lines to identify the location of leaks and faulty connections in the sanitary sewer system.

The smoke is odorless, non-toxic, and safe for humans and pets, similar to that used in concerts and haunted houses. During the test, smoke may be seen escaping from vent stacks on the roof and out of the ground, according to the release.

Smoke will not enter homes or buildings unless the plumbing is defective or the drain traps are dry. Pouring water into any floor drains and into any unused sinks prior to the test will seal the drain traps so smoke will not enter through the drains.

The smoke is non-staining, does not create a fire hazard, and will dissipate in a few minutes, according to the release.

For more information about the smoke testing, contact the St. Charles public works department at 630.377.4405 or visit the sanitary Sewer project webpage.