Dual CCTV Cameras Assist with Residential Dye Testing – A New Way to Investigate Leaks on Private Property, City of Westlake, Ohio

The City of Westlake, Ohio has a program to remove Inflow and Infiltration (I/I) from both their public and private property segments of the sewer system. Specifically, the private property program uses residential dye testing to identify houses that have downspouts that contributes water into the sanitary sewer system. Historically, houses that test positive are scheduled for rehabilitation using a lateral liner from the mainline sewer to the house. A liner is inserted into the sanitary lateral which prohibits any stormwater or groundwater from entering the lateral. During the installation of the liners, it was found that a more detailed testing of the house would have shown that the deficiencies could have been corrected with cheaper, spot repairs or other methods of rehabilitation may have been more effective. The more detailed testing included dye testing as many downspouts as possible on the home being tested, and using two Closed Circuit Television Camera for the inspection The sanitary pipe layout is also identified to provide a more detailed knowledge of how the sanitary and storm pipes cross over each other. The CCTV cameras were installed in both the storm and sanitary sewer and advanced to the lateral of the test house. Subsequent testing followed by using a push camera in the lateral and recreating the test, further isolating the deficiency on the property. From this information the City was able to isolate which downspouts could be spot repaired, eliminating lateral lining rehabilitation resulting in a cost savings to the City. The detailed testing methods of both Phase I and II eliminated 70% of the lateral linings. Estimated cost per house for lining was $8000.00. In an area with 100 homes, in which 40% were positive, reducing 70% of the lateral lining is significant in terms of cost and additionally, accurately solving the problem. At the conclusion of the program, the City accurately identified private properties with inflow, removed stormwater from the sanitary sewer, minimized lateral rehabilitation and construction disruption, and provided overall project cost savings. Source: WEFTEC 2009 Proceedings