The Michigan Public Service Commission wants a plan to find and remove what it estimated to be hundreds of miles of out-of-service power lines in Detroit following the accidental electrocution of a 12-year-old girl in September 2016.
Michigan regulators on Dec. 7 told DTE Electric Co. to coordinate with commission staff and the city of Detroit's Public Lighting Department, or PLD, to identify the scope of the problem of unused arc lines. The lines, also known as arc wires, were used to supply electricity to arc-type street lamps. Those lamps are no longer used, but arc wires are still attached to utility poles.
Last September, a child playing near PLD arc wires that had fallen from a utility pole came into contact with one of them and was electrocuted, the commission said. DTE's investigation found that the city's abandoned arc wire became energized when it came in contact with DTE Electric facilities.
In its review of the incident, officially closed on Dec. 7, (Case No. U-18172), the commission said DTE and the PLD have improved communication and response times regarding downed wires in the city, and have worked together on two successful pilot programs that removed more than 140,000 feet of abandoned electric lines.
But the commission said to fully resolve the issue, out-of-service arc wire must be removed or isolated, something the commission called "a daunting task because the complex street lighting system spans the entire city of Detroit and some outlying areas."
One hurdle is that it is hard to determine where all of the pertinent arc wire is located, as it is no longer in use and there varying estimates as to how much is still around. The PLD has estimated there are at least 600 to 900 miles of out-of-service arc wires in its service area that includes all of Detroit and some outlying areas, the commission said.
Further, there is arc wire in areas where there are no DTE Electric facilities, the commission said.
"In addition, for a variety of reasons, the system was poorly maintained and documented when it was in service," the commission said.
The commission called for an assessment about how much arc wire remains, who owns the lines and the poles to which they are attached and areas where the arc wire is easily and more difficult to access.
A report on progress of the project is due from DTE, a DTE Energy Co. subsidiary, by March 30, 2018. In 2013, the PSC approved a plan under which DTE Electric would take over the PLD due to Detroit's financial condition at that time. (Michigan PSC Case No. U-18484).