A section of North Boulevard closed since last fall was reopened in June, following the partial completion of work on a high-voltage ComEd substation near the street, according to David Powers, village government spokesman.
Powers said in a telephone interview that firefighters at the Oak Park Fire Department at North Boulevard and Euclid Avenue noticed cracks in a masonry wall at the substation, and the building department determined the leaning wall was a structural issue.
"They felt that it was kind of a public safety issue with the wall on the street and the fact that there was high volt equipment on the reverse side, and that was the reason for the decision to close the road as opposed to closing off one lane," Powers said.
A pedestrian walkway and chain link fence were installed along the south side of North Boulevard while installation of the wall is being completed.
ComEd spokeswoman Liz Keating said the company is replacing a brick wall and putting a façade up. "The street was partially opened (last month) but it will be a month or so before the project is complete," she said.
Keating said the substation takes "an enormous degree of energy and downgrades it and distributes it."
She said in an email that electricity travels to Oak Park through large transmission lines at 340,000 volts. The transmission network reaches the village and the voltage has to be reduced.
A step-down transformer reduces the voltage to a distribution level of 4,000 to 34,000 volts.
"For typical residential and small commercial customers, power from the substations is transmitted along overhead poles and underground cables," according to a ComEd memo.
According to a village memo, ComEd has completed installation of precast wall panels to the west of the substation entry gate. A mansard roof will be added to the top of the wall.