SMOKE TESTING
The intent of smoke testing sewers is to detect sources of inflow . . . area drains, abandoned building sewers, storm sewer cross connections, roof downspouts, and illegal connections.
Smoke testing is not intended to detect sources of infiltration such as leaking joints and faulty building sewers. Smoke testing is performed by blowing a high volume of very low-pressure smoke into the sewer at one or more manholes. Observation of the emergence of smoke enables the crew to deduce sources of inflow.
Since the sewer is connected to roof vents at every building, the smoke has very low pressure regardless of the pressure capability of the smoke blower. Smoke will not escape through pipe defects (infiltration sources) which are below the groundwater table. Smoke may escape through pipe defects which are above the groundwater table, but the smoke must find a path to the surface in order to be observed.
Smoke emerging from the ground or from cracks in the street surface indicates pipe defects above the groundwater table, but does not indicate the type or exact location of the defects.
Smoke Testing in Caribou, Maine
August 2009 with CES Engineering
Dye Testing is often done along with a smoke test to confirm leaks or cross connections. Our dyes are safe and can be either green or red in color. All smoke or dye tests are followed up with a report that includes digital pictures of all observations.
(Line break location in 12" gravity sewer main )
