TQI Catch Basin DYE TESTING
Sewer (storm or sanitary) connectivity of various sewer system drainage features (catch basins, downspouts, drains, laterals etc) can make a difference in flood reduction strategy.
Sanitary sewer smoke testing is an economic and efficient way to find suspected sources of unwanted inflow & infiltration of rain water into sanitary sewer systems. The more smoke that is seen the more certain a direct connection exists between the source and the sewer system being tested.
Dye Testing is an efficient methodology to test and confirm the connectivity of suspect catch basins (as flagged during smoke testing).
This Toronto City-Wide Project, is concerned with confirming the connectivity of storm sewer catch basins that were found and documented as connected (a source of I/I) to the sanitary sewer system through smoke testing. These identified storm system catch basins are being dye tested to further confirm the unwanted connection of the catch basin to the sanitary sewer.
Once the suspected connection (through smoke testing) is confirmed through dye testing, rehabilitation work will be designed and completed in order to disconnect the catch basin from the sanitary sewer and properly connect it to the storm sewer system.
Post rehabilitation smoke testing (more economic) or dye testing if carried out, would then confirm that the rehabilitation work (connection of the catch basin to the storm sewer and disconnection from the sanitary sewer) was successful.
TQI developed an apparatus that allows us to rapidly introduce dyed water directly into a catch basin lead to test its connectivity. Dyed water is injected and flushed down the catch basin lead with water. Observers stationed at downstream sanitary and storm manholes, observe where the injected dye appears. Photos are taken and the connection is documented. When suspect inlets are close together, we utilize different colours of dye and proceed upstream along a sewer line when testing.
The dye being used is environmentally friendly and not harmful to people or the waterways.