SHAMOKIN DAM — The state Department of Environmental Protection concurs with PennDOT's assessment of acid bearing rock in the path of the southern section of the $865 million Central Susquehanna Valley Thruway project.
Pennsylvania Department of Transportation assistant plans engineer Matt Beck discussed the application for the National Pollutant Discharge Elimination System permit from DEP at the Greater Susquehanna Valley Chamber of Commerce Transportation Committee on Friday. The southern section of the project will start construction in 2022.
"We met with DEP and the County Conservation District to review the investigations we performed related to the acid bearing rocks as well as the preliminary plans for dealing with the materials as we excavate it," said Beck. "DEP did concur that we did the appropriate soil borings and lab testing. We are fairly confident in where we will encounter that material, and they also concurred we have appropriate measures planned to deal with that material and prevent issues with acid runoff in construction."
One mitigation effort for acid bearing rock is using spraying the area with a compound to prevent air and water from reacting with the rock. Another mitigation effort is covering the exposed acid rock areas with soil as part of a longterm solution, Beck said.
Erosion control and stormwater management are required for part of this permit application, he said.
"We feel we are on the right track to eventually get the NPDES permit that we need, but we also need to consider the wetland and waterway permit that's required for the project," Beck said. "We have a meeting scheduled with DEP, Conservation District, Army Corp of Engineers, Fish and Boat Commissioner, fish and wildlife service, and other agencies, next month, to review updated wetland and waterway impact to make sure we're not missing any major concerns."
Both permits were needed for the northern section, but the acid rock issues are more prominent in the southern section, Beck said.
Both permits are expected to be awarded by the end of the year, he said.
The final design for the southern section is ongoing, including designs for drainage, bridge, traffic signal and highway lighting; right of way acquisition plans; and utility relocation plans, Beck said.
In the northern section, Ted Deptula, assistant construction engineer for PennDOT District 3-0, said the deck of the bridge is about 30 percent completed. The bridge is expected to be open to traffic in 2022.
"The bridge will be completed by the end of the construction season," Deptula said. "If we had a roadway going up to the bridge, we'd be able to use it. Construction equipment may use it until it's open for traffic."
A wind study will be conducted on the bridge in March to determine how truck traffic can pass across the bridge, Deptula said.
The initial locations for the wind data will be temporary, but it will eventually be permanent. Wind warnings won't mean trucks have to find an alternative route, it just means that trucks may have to use a specific lane, said Beck.