Construction Considerations When Incorporating an MSE Berm Wall on a CCR Landfill
As federal and state regulations are forcing electric utilities to remove Coal Combustion Residuals (CCR) from historic disposal units, construction of on-site CCR landfills is emerging as a lower “short term” cost alternative for most sites. Although cost-effective, siting a CCR landfill at an active utility site can be challenging. Space may be limited by existing site infrastructure, topography, jurisdictional boundaries, and regulatory requirements for landfill siting and will reduce available real estate. Yet anticipated disposal volumes are fixed by the material present in the historic disposal units.
One viable option for utilities dealing with space constraints is incorporating a Mechanically Stabilized Earth (MSE) Wall into the landfill design. Use of an MSE Wall can help maintain a smaller overall landfill footprint while gaining valuable vertical airspace. Having recently completed a 1,583 foot long by ~75 foot high MSE wall, we’ll explore the overall construction process for a CCR landfill that incorporates an MSE Wall. Consideration will be given to the limited working space, additional safety aspects of working at heights and confined areas, the labor intensity of the MSE Wall construction, and the impacts on adjacent landfill construction.
The Waste Management (WM) presentation will discuss the means and methods employed to address the unique conditions for the specific project. An unconventional approach to MSE wall construction was taken to meet the challenges of limited working space, accounting for the safety concerns of the construction, and minimizing the ripple effect that delays to the MSE wall construction would have on the overall landfill construction. The design of the wall lent itself to considering an unconventional approach, which WM identified and successfully implemented. The effort took a tight coordination between the the subcontractor and WM personnel, allowing both entities to maintain the necessary production schedule.