The new facility will provide multiple supply routes to get power to substations. ComEd says this should reduce the chances for significant power outages downtown and in some neighborhoods.
As hot summer days approach, officials have a message for customers.
"We are absolutely ready for summer is the key message. We prepare for it, we drill to it, we build to it. We work many jobs to prepare and we are absolutely ready," said Terry Donnelly, ComEd senior V.P.
ComEd officials say this is the largest and most complex project of its kind ever done by the company.
