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Case Study may lie on private property as well as public property, and all 50 houses in the area were dye tested by adding dye to each downspout. Wherever dye transferred from the downspout of a house to the sanitary sewer, rehabilitation was performed. The city was faced with the issue of who should pay for the new repairs, which included work on private property. The city council agreed that residents should pay for structur- al repairs outside the right-of-way (ROW), and the city would pay for all work in the ROW and lateral grouting outside the ROW. The result was that only $5,000 of the total of $338,000 for rehabilitation costs fell under the homeowner's responsi- bility (approximately 1.5 percent of the contract). Lessons Learned Lessons learned from the King James Subdivision showed that both public and private sides need to be addressed when completing sewer system rehabilitation. The city also decided that all of the future rehabilitation work for these types of projects shall be 100 percent funded by the city. Salem-Radcliffe Subdivision The next area to be investigated was the Salem-Radcliffe Subdivision. The sewer investigation for this area was also conducted by a contractor, and data was provided to the city as data with no engineering recommendations. For this area, CIP sanitary lateral lining was utilized from the main- line sewer to the house. The CIP method used consisted of a felt liner with a polyester resin and steam curing. A pit was used to expose both storm and sanitary laterals for cleaning and televising, sanitary lateral lining, and installation of new cleanouts. Manhole sealing was conducted using a spray- applied polyurethane liner. Lessons Learned Lessons learned from the Salem-Radcliffe Subdivision showed that the liner was installed short of the mainline with the work not addressing the mainline sewer/ lateral interface. This allowed groundwater to migrate down the lateral to the path of least resistance at the mainline/lateral con- nection. In manholes that had the spray liner applied, the grade ring area was not sealed with a flexible product. This allowed groundwater to enter and led to the prod- uct cracking at the grade interface. Berkeley Estates Berkeley Estates was the first area to be tested by a consultant. Both mainline and residential dye testing was completed in this area showing that both public and private property sewers were contributing to I/I in the system. The same type of lateral lining CIP process from the mainline sewer to the house was used for this area. The CIP method used consisted of a felt liner with a polyester resin and ambient curing instead of hot water. A pressure launch- ing vessel was used for the inversion and the lateral/main interface was grouted with a lateral packer. Manhole sealing was conducted using a cementitious product with a flexible urethane product at the grade ring. This was an improvement from the last project, which did not use a flexible material. Prefabricated rubber membranes with expansive straps were also used in several manholes. Lessons Learned Lessons learned from the Berkeley Estates project showed that liner failures, possibly due to ambient curing or the resin introduction process, impacted the ability to grout the main- line/lateral connection. This area was previously serviced with septic systems, and records were not available on how they were tied into the mainline when they were converted. This resulted in the contractor sometimes needing to excavate two pits to expose both the storm and sanitary laterals, which was not in the bid document. Storm laterals were difficult to locate due to the lack of data from not televising the storm sewer prior to the repair work. The city found that testing requirements need to be estab- lished to verify that the liner met the performance strength requirements that were specified in the contract documents. Vacuum testing for manhole products also needs to be implemented on future projects. This project also showed that more research needs to be conducted during the design stage of the project, espe- cially in identifying the pipe layout in septic tank conversions. Canterbury Area The Canterbury Area was the most recent area investigated with a rehabilitation of the mainline sewers and laterals based on the recommendations of the investigation. Like Berkeley Estates, a consultant conducted the exact type of testing and provided an engineering report. Again, sanitary lateral lining utilized a CIP process from the mainline to the house. The original CIP installation utilized a felt liner with a polyester resin and ambient cur- 38 wateronline.com ■ Water Online The Magazine Prior to any sewer rehabilitation or repairs, a sewer investigation must be conducted to identify the types and locations of defects in the sewer system. Storm lateral root blockage