Rust caused a steel catch basin and drainage pipe to fall from the Tarentum Bridge on Labor Day, but the bridge is safe, PennDOT said.
"One U-bolt on one of two catch basins failed. The bridge is structurally sound," said PennDOT district spokesman Jim Struzzi.
Nevertheless, sometime today PennDOT will remove the only other catch basin on the bridge "just to make sure," Struzzi said.
"The engineers will find some other way to direct the drainage," he added.
Struzzi said catch basins are sometimes incorrectly called "scuppers." The basins direct rainwater from the bridge to the pipes that handle run-off from the bridge that spans the Allegheny River between Allegheny and Westmoreland counties.
One of the green steel catch basin and section of pipe — weighing about 200 pounds — fell onto the Fish Commission access driveway at about 2 a.m. Monday. "We're happy no one was injured," Struzzi said.
Carolyn Peters, of 101 First Ave., who lives about 100 feet away, heard the steel hitting the driveway.
"It was a big, big bang. I woke up. I thought someone hit a car," she said.
"I saw this thing," she said, pointing at the catch basin.
Peters called Tarentum Borough Manager Bill Rossey. He arrived at about 8 a.m. Monday to roll the steel out of the driveway. PennDOT picked up the pipe later.
"It hit here and bounced," Rossey said Tuesday, pointing to a half-inch gouge in the blacktop. "And there's the mark where it landed" about 15 feet away.
While Rossey and a borough maintenance worker looked at the catch basin, PennDOT inspectors climbed a ladder to investigate.
Peters thinks bridge vibration and bridge deterioration caused the catch basin and pipe to fall about 50 feet from the Allegheny River.
Peters said she and her family have lived in the house for 40 years. "We never had vibrations like this until about seven months ago," Peters said.
Replied Struzzi, "All bridges vibrate. I don't know of any special problems like that on this bridge. This happened because of a rusty U-bolt."
Struzzi said some concrete deterioration can be seen on the bridge piers and superstructure but the span is safe, he said.
He agreed that steel reinforcing rods can be seen poking out of deteriorating concrete on a pier near where the catch basin had been installed.
Nevertheless, the deck and essential parts have been inspected and the bridge isn't on PennDOT's list of structurally unsafe bridges, Struzzi said.
There are about 167 structurally deficient spans in the state, including some in the Alle-Kiski Valley.
