Dynamic Stray Current Interference Testing and Mitigation Design for a 90" Water Main

Due to the large number of pipelines in the Chicagoland area, pipeline operators are faced with operational and maintenance challenges including the mitigation of static and dynamic stray current interference from current sources including foreign pipelines and DC electric rail systems.  In the Chicago Area, the Chicago Transit Authority (CTA) railway system is a source of dynamic DC stray current that affects many pipeline operators. 
After testing on a local 90-inch water transmission pipeline indicated the presence of dynamic stray current interference, the Company hired an engineering firm to perform confirmatory testing and design services related to DC stray current mitigation.
Field testing and analysis, calculations and the final mitigation design are presented in this paper.