PennDOT plans emergency repairs for Route 30 sinkhole at Greensburg-Hempfield border

PennDOT on Wednesday halted work on a sinkhole along Route 30 at the border of Greensburg and Hempfield as it prepares to make emergency repairs on an inlet connecting two underground storm water pipes — including one that runs beneath the heavily traveled roadway.

The inlet connects pipes that run between 40 and 50 feet underneath Route 30 and Greensburg Commerce Park, which is located well beyond the side of the highway.

“We just put everything on hold for now,” PennDOT District 12 executive Joe Szczur said.

Since Saturday, crews working for the commerce park property owner made progress filling in the gigantic hole along the highway next to Towne Square and the park, which houses Gander Outdoors and Dino’s Sports Lounge. John D. Wagner is listed as general partner of property owner Greensburg Commerce Park, according to county records.

A barrier was placed Tuesday afternoon separating traffic from the work.

The storm water line failed after record-setting rains last week inundated the region and caused at least two other major sinkholes — one in North Huntingdon and another in Ross. More rain was expected Wednesday with the remnants of Hurricane Barry moving into the area.

Szczur said the emergency project will be conducted at a “rapid pace” with a lot of help from engineers.

“It’s going to be complicated,” he said.

It’s just one more layer of complexity in issues the state agency and local municipalities have been dealing with in light of continued heavy precipitation. The July 11 storm brought the region’s official precipitation total for 2019 to 30.02 inches, ahead of last year’s record-breaking 29.35 inches in the same time frame, according to the National Weather Service.

Aging infrastructure plus wet weather are among the key ingredients to sinkholes in Western Pennsylvania, according to experts. Rushing storm water can force apart already deteriorated underground pipes and eat away at the surrounding dirt, causing the land to drop — unexpectedly and quickly.

“With the extremely high flows we’ve been having, high flow puts stress on the pipe,” said Jim Pillsbury, hydraulic engineer with the Westmoreland Conservation District. “Water is heavy and moving water has a great deal of force behind it.”

Numerous factors can cause a sinkhole, said Benjamin Stufft, a professional geologist with CME Engineering, which has an office in Hempfield. Precipitation, old underground mines, land previously used as a landfill and poor underground infrastructure are all potential causes for a sinkhole, he said. Stufft is not involved in any of the Westmoreland County projects.

“We’re exceeding record-level precipitation events on almost a monthly basis here,” Stufft said. “The result of that causes super saturated soils and sub soils” that can’t handle any more water.

Part of the pipe that collapsed along Route 30 has been sealed off, said Chris Droste, senior erosion control specialist with the Westmoreland Conservation District.

“It’s all these legacy pipes, they’re old,” he said.

It’s the same situation in North Huntingdon, where a drainage pipe collapsed during the storms, causing the earth to open up behind North Huntingdon KinderCare and forcing its evacuation. It remained blocked off by a fence Wednesday.

Excela Health owns the property and is handling the repairs, said spokeswoman Robin Jennings.

“We are now working with others to arrive at a safe resolution for the property and patients and visitors,” Jennings said.

A sinkhole in Rostraver has been growing over the last eight years — even more rapidly over the last year or so with the record-setting wet weather — since a storm water pipe collapsed in 2011. The crater, along Route 51 near the Interstate 70 interchange, has remained because of a dispute between neighboring property owners.

Ross officials issued an emergency declaration Friday that allowed the township to repair a large sinkhole at the entrance to Waldorf Park apartments. Officials said the sinkhole was created when water flowing through an underground storm water line blew out a manhole cover, causing the pavement to collapse.

That has been the only sinkhole Allegheny County officials are aware of, said public works director Stephen Shanley. Sinkholes there in the past have been the result of mine subsidence, but rain can eat away at land surrounding a structure and cause failures, Shanley said.

To prevent that, the county has regular inspections of bridges and their supports, he said.

Inspections of old pipes can be one way to ward off problems and geotechnical investigation can be helpful. But those problems can be hard to detect.

“A lot of our infrastructure is old,” Pillsbury said. “Someone inherits it and doesn’t know” which can result in costly repairs.