Construction & Materials
Collaborative Conservation: Protecting Endangered Species During Bridge Rehabilitation Project
Hundreds of digger bees, also known as eastern chimney bees, had been nesting beneath the Interstate 78 bridge over the Schuylkill River in northern Berks County, PennDOT Engineering District 5. Coal silt beneath the bridge in Tilden Township is an ideal location for the bees to dig their tunnels. Digger bees do not sting, but they do pollinate plants and flowers.
The Pennsylvania Department of Conservation and Natural Resources notified PennDOT about the bees under the bridge when work to rehabilitate and widen the bridge began on a construction project in spring 2020. The digger bees are listed as a state endangered species because there are so few of them, but they have no regulatory protection, which means PennDOT could have done nothing to avoid or mitigate any impacts.
Instead, District 5 decided to work with local environmental officials to develop a plan to mitigate the impacts to these bees.
Plastic foam nesting boxes were installed under the bridge, and the bees migrated to the boxes where they stayed until they were relocated.
Mike Slater, a local entomologist, devised a plan to bring the bees to his Brecknock Township, Berks County home in 18 plastic foam nesting boxes to rest. Slater researched the process, contacting bee researchers worldwide. He also met with District 5 engineers and others to discuss his plan.
“We are elated to play a small part in keeping the local ecosystem intact,” District Executive Chris Kufro, P.E., said. “Now these bees will continue doing what they are here to do, which is pollinate plants and prey on harmful insects.”
During the early stages of construction, District 5 had the contractor fence the area off to keep the digger bee nesting site from being impacted. They also had them install plastic foam nesting boxes under the bridge, and the bees migrated to the boxes where they stayed until they were moved to Slater’s garage. PennDOT made the nesting area off limits to the contractor for the first three months of construction, which allowed the bees to use the nesting boxes until they were relocated.
After the bees spent a short period in his garage, Slater moved them to a pavilion in Robeson Township, Berks County, where they have a larger area to dig. The local entomologists intend to return the bees under the I-78 bridge at some point in the future.
The $134.2 million project includes the reconfiguration/reconstruction of the Interstate 78/PA 61 interchange ramps, replacement of the I-78 mainline approach structures, widening and rehabilitation of the I-78 mainline arch bridge over the Schuylkill River, widening of the I-78 Bridge over Port Clinton Avenue, replacement of the PA 61 Bridge over I-78, construction of retaining walls, sound barriers, frame and cantilever monotube sign structures, highway lighting, ITS devices, drainage system improvements, guide rail, safety barriers, signing, pavement marking, delineators, and other miscellaneous construction. This project was completed in late 2025.
Advancing e-Construction: Inside PennDOT’s Project Delivery Collaboration Center
Advancing e-Construction: Inside PennDOT’s Project Delivery Collaboration Center
Coordinator Position Keeps Utility Work on Track and Projects Moving Forward
Coordinator Position Keeps Utility Work on Track and Projects Moving Forward