AWWA DSS60313

The Northwest Suburban Municipal Joint Action Water Agency (NSMJAWA) owns and operates approximately 58 miles of water main supplying water from Lake Michigan to 7 suburbs northwest of the city of Chicago. The distribution system piping ranges in size from 12" to 90" and consists of prestressed concrete cylinder (PCCP) and ductile iron pipe. Construction of the system was completed in 1986. Within ten years of installation, corrosion related leaks began to appear in the system. The exact cause of these leaks is not known, but contributing factors are believed to include stray current interference, naturally occurring galvanic corrosion cells and damaged pipe which studies indicated occurred during installation in some areas of the system. As a result of the accelerated leak activity and studies done on the water distribution system, cathodic protection was installed on portions of the system in the mid-1990s. Additionally, a routine monitoring schedule was implemented to monitor the integrity of the cathodic protection system and monitor the level of cathodic protection on the pipeline. Includes 4 references, table, figures.