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OF'�fC <br /> ' � y� <br /> - _ c <br /> v �o <br /> �L1:►! <br /> '/[lINO\Y <br /> September 23, 1999 <br /> PUBLIC WORKS MEMORANDUM <br /> NO. 99-59 <br /> MEMORANDUM TO: Honorable Mayor and City Council <br /> G <br /> FROM: Rolanda A. Johnson, Acting City Manager <br /> Bruce A. McNabb, P. E., Director of Public Work�� <br /> Stephen P. Swanson, P. E., City Engineer� <br /> SUBJECT: Water Main Extension Program <br /> City Project 9801 <br /> The field representative for the Phillips Pipe Line Company (PPL) has advised the <br /> City's Engineering Division that there is a conflict with the City's proposed pipeline in <br /> Wyckles Road and the PPL's anode field protecting its gas transmission line. The <br /> anode field serves as a cathodic protection system for the gas transmission line from <br /> stray underground electrical currents. These currents cause corrosion problems to <br /> metal pipelines leading to pipeline breaks. PPL representatives advised staff that the <br /> water main would either have to be shifted to another location, constructed of plastic <br /> pipe material, or the City would have to install a similar protection field for its ductile iron <br /> pipe (DIP) water main. <br /> In the designing process, the Division's underground utility research noted the <br /> presence of the gas transmission line and standard design provisions were made to <br /> avoid conflicts with the transmission line. The anode field was not noted in the field <br /> review or expected to exist in a location that would conflict with the City's water main. <br /> This anode field is a unique installation because of its offset from the pipeline and is not <br /> typically encountered. The design of the water main extension specified the use of DIP <br /> which is the standard pipe line material used by the City. <br /> Staff discussed this matter with the Ductile Iron Pipe Association's field engineer in <br /> Indiana and confirmed the three basic options recommended by PPL. The shifting of <br /> the pipe location was not considered to be a viable option considering other potential <br /> utility conflicts along with the need to acquire new easements and permits. The option <br /> of installing a cathodic protection system for the City's DIP water main represented a <br /> perpetual ongoing operations and maintenance for the City's crews. This was not <br /> considered to be a desirable option because of the initial and long term costs <br /> associated with the operation and maintenance of the system. It was decided that the <br /> installation of a polyvinyl chloride (PVC) pipe material was the best option. This option <br />