Smoke Testing

The Summerville Commissioners of Public Works occasionally conducts inspections on the sanitary sewer system utilizing the “Smoke Testing” method. As part of the inspection process, one or two blocks of sewer main is isolated from the remaining system. A non-toxic smoke is blown into the system under very low pressure until all defects are photographed, documented and marked. Identification of defect locations is easy, simply watch for smoke to exit the ground or exposed piping.  

The purpose of the inspections is to identify locations where rainwater and groundwater enter into the system via unauthorized connections, broken pipes and cross connections with public storm drain systems. Unauthorized connections include, but are not limited to, such things as roof gutters and downspouts, yard drain systems, foundation drains, sump pumps and customers not being billed for services provided. Identifying, repairing and/or abandoning defects and unauthorized connections will minimize the costs required for SCPW to provide service to its customers and free capacity in the system currently consumed by extraneous storm and groundwater flows.

The EPA approved smoke is manufactured for this purpose and creates no fire hazard. It will leave no residue or stains, and it has no effects on plant and animal life. Although the smoke is relatively harmless, customers are encouraged to avoid unnecessary exposure to the smoke as a precaution, especially individuals and their animals with respiratory problems. During the testing, it is not necessary for customers to be present. 

With proper plumbing system ventilation, the chance of smoke entering homes/businesses is reduced. However, if the plumbing vents are defective, traps under sinks/tubs/toilets are dry from non-use, and/or pipes and seals are defective, smoke could enter homes/businesses. The appearance of smoke inside a home/business indicates that the possibility of unpleasant and potentially hazardous wastewater gases entering the structure does exist and the owner should contact a licensed plumber to assess the problem immediately.    

It is recommended that customers run water into all facilities prior to the testing if they are infrequently used, and if smoke does emerge, open several doors and windows to allow the smoke to dissipate. Under normal conditions, all traces of the smoke will be gone within a few minutes.

Smoke exiting the ground outside the structure will indicate defects in the service pipe, such as missing cleanout caps, faulty joints, broken pipe, etc., which allow unwanted water to enter the sewer system and consume costly capacity. After the testing is complete, SCPW will notify customers of identified defects and unauthorized connections. Customers will be allowed 60 calendar days to make required repairs. Failure to comply with the request for repairs within the allotted time may result in minimum $24 per month charge being assessed to the current water and/or sewer bill, unless justified time extensions have be granted.

SCPW will assist customers with locating and identifying defects external to homes/businesses. However, the inspection team is not permitted to enter private buildings for any reason, without exception to identify internal defects. In these cases, and for making all necessary repairs, a licensed plumbing company should be consulted.