Early Construction of MSE Wall

Lanchester Landfill Area D Expansion Chester County, PA Landfill Expansion Permitting, Design & Construction Phase Engineering Client: Chester County Solid Waste Authority

ARM is providing comprehensive waste management engineering services to Chester County Solid Waste Authority (CCSWA) for the Area D Expansion at CCSWA's Lanchester Landfill. Because CCSWA had little available space to expand its landfill laterally, ARM developed a solution that provided the needed capacity through vertical expansion. This design combines: 1) piggybacking of new disposal space over the existing landfill; and 2) construction of a Mechanically Stabilized Earth (MSE) wall along the northern permit boundary. Through the construction of the 40-foot high MSE wall, waste thickness can be significantly increased along 3,000 feet of the northern boundary, which would not have been achieved using conventional landfill grading.

The 3,000-foot long MSE wall is designed with a 63.5-degree sloped front face. The front face is stepped with welded wire mesh forms and geogrid reinforcing elements are utilized for primary stabilization of the wall.

This expansion provides CCSWA with an additional net waste disposal capacity of approximately two million tons.

Conceptual drawing showing piggybacking. The green represents part of the existing landfill and blue represents the expansion.

ARM also designed other critical components of the landfill, including an active landfill gas collection system and a leachate recirculation system. Leachate recirculation will be used to enhance biodegradation and waste settlement resulting in increased air space and decreased post-closure settlement.

As part of the permitting process for this expansion, ARM prepared a comprehensive harms/benefits analysis for the Project, including a line-of-sight study, using a method developed by ARM and approved by PADEP.

ARM provided final design and construction-phase engineering services during Stage 1 construction, which was completed in 2005, and for Stages 2 and 3 construction, which were completed in 2006.

If you would like additional information about this project or any of ARM's projects or services please send an e-mail to info@armgroup.net.

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