PHILADELPHIA (KYW Newsradio) — Drivers could be in for some long-term inconvenience as PennDOT tackles a sinkhole problem on two suburban roadways.
For years, sinkholes have been a recurring issue on DeKalb Pike in Upper Merion and along Route 29 in East Whiteland. That's because each has underground stretches of limestone and carbonate rock where erosion can create voids, causing the ground to collapse under the roadway.
On Monday, PennDOT will begin a $22 million project to prevent more sinkholes from forming. Crews will drill holes in a grid pattern along the roads, injecting grout to fill those voids and stabilize the ground.
"It's a pressurized grout that they inject into the drilled holes that they create. And then that's what goes into the voids beneath the roadway,” said PennDOT's Robyn Briggs.
The work will mean lane closures to start. But Briggs says by mid-February, there will be a complete northbound closure for three to four months on Route 202 between Saulin Boulevard and Ivy Lane — about a quarter-mile stretch. Traffic will be detoured to Henderson Road. A complete southbound closure will follow.
For the Route 29 work, only lane closures and traffic shifts are expected. The entire project should be finished by late summer.
PennDOT used this process, known as "mobility grouting," in 2021 on Chemical Road in Plymouth Meeting.