July 11, 2023
Crews are working to repair a large sinkhole that opened Monday night on Route 202 in Upper Merion, shutting down a busy stretch of Dekalb Pike near the King of Prussia Mall.
The road was closed in both directions around 8 p.m. Monday between Henderson Road and Saulin Boulevard, where the sinkhole was discovered during an investigation into a reported water outage. Motorists are now being directed to use Henderson Road and Saulin Boulevard to detour around the worksite. Upper Merion police will assist and traffic signals have been adjusted to ease congestion, PennDOT said.
Pennsylvania American Water, the utility provider in Montgomery County, inspected the sinkhole overnight and determined that a water main had broken. A secondary leak was also found under the roadway. Those repairs were made early Tuesday and crews later began preparing the road for repaving.
⚠️ Road update! ⚠️— Senator Amanda Cappelletti (@SenCappelletti) July 11, 2023
Avoid the section of East Dekalb Pike between Henderson Road and Saulin Blvd in Upper Merion Township which will be closed in both directions so crews can repair a broken water main that has caused a sinkhole. https://t.co/jKPVvx7ymd
The work will hopefully be completed Wednesday or Thursday, PennDOT spokesperson Brad Rudolph said.
To speed up the reopening, the road initially will be repaired using a layer of asphalt on top of other backfill materials instead of concrete. Once the road is reopened, lane restrictions will be put in place to remove the asphalt and repave each lane with concrete, which is more durable.
"This area is prone to these kinds of geological incidents due to the bedrock underneath the roadway surface," Rudolph said.
Groundwater circulating beneath the road gradually dissolves the foundation over time, creating crevices that can grow to the size of the sinkhole seen on Route 202.
Rudolph said it's unclear whether this sinkhole was caused by heavy rain on Sunday or the broken water main.
"It's hard to say. This could be hundreds of years of buildup. Water gets in there and it gives when it gives," Rudolph said. "Maybe it was the storms. Maybe it was the water main. That will be investigated."