During smoke testing, RJN identified areas where stormwater is leaking into the sanitary sewers. Dye flooding is a technique that is used to pinpoint those locations so they can be repaired. Dyed water testing is performed by flooding an area with non-toxic fluorescent dye to identify the location and magnitude of a defect. Inflow sources are identified by dye water flooding storm sewer sections, stream sections, ditch sections, and ponding areas that may be contributing to inflow. Plugs are used to conserve water and to isolate the specific storm sewer segment being tested. Flow measurements are taken in the downstream sanitary sewer manhole before flooding and then again at peak flood conditions to quantify the extraneous flows coming from the cross-connections. At peak flooding conditions, CCTV cameras are inserted into the sanitary sewer and are used to televise the locations where dyed water is observed flowing into the sanitary sewers. Manholes adjacent to the flooded storm sewer are also inspected for defects, such as leaky frame seals and wall joints. Residents may see green dye in the storm sewers and ditches; this will dissipate quickly and does not stain the ground.
