Faced with a landfill nearing capacity, the Delaware Solid Waste Authority awarded a contract to Sevenson Environmental Services, Inc. of Niagara Falls to construct a mechanically stabilized earth berm that is being recognized for its innovative design.
Sevenson was the prime contractor on the Cherry Island Landfill Vertical Expansion Project in Wilmington, Del., one of five finalists for the American Society of Civil Engineers’ 2012 award for Outstanding Civil Engineering Achievement.
“ This was one of the most demanding projects of its kind ever undertaken,” said Dave Santarosa, Sevenson’s project manager . “Installing more than 81,000 prefabricated drains, implementing advanced monitoring systems and moving more than two million cubic yards of engineered fill was a demanding, 48 month undertaking. We couldn’t have done it without an incredible project team, which demonstrated its commitment, dedication and know-how to this challenging project.”
Installation of a wick drain system and berm construction increased the foundation strength of the landfill from 200 pounds per square foot to 3,200 pounds per square foot. “That engineering solution saved more than $159 million based on the original design, increased landfill capacity by 20.7 million cubic yards and extended the life of the landfill by about 20 years ,” said the president and CEO of Sevenson Environmental, Michael E. Elia
Sevenson’s team installed a storm water management system to accommodate settlement that took place during construction of the berm, including reinforced concrete pipes, manholes and pump stations. Temporary electrical, mechanical and communication systems were installed to operate the existing temporary leachate transmission system. Sevenson safely worked over 350,000 man hours on the project.
The ASCE praised the project, saying, “ Completion of this project represents a significant engineering achievement in view of the size of the mechanically stabilized earth berm, the depth of the layer of very soft soils over which the berm was constructed, and the unconventional design methodology.”
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Press Release, November 27, 2012