Vertical Increase of Impoundment/Landfill No. 6


MAX Environmental Technologies, Inc.


Pittsburgh, PA

CEC Services

  • Landfill Design & Permitting
  • Geotechnical Engineering
  • Erosion & Sediment Control Design and Inspection
  • Operations Support
  • Landfill Closure

Owner Objective

MAX Environmental Technologies, Inc. (MAX) is a residual and hazardous waste management company that provides waste treatment and disposal services to various industries. MAX has two facilities located in southwestern Pennsylvania.

MAX was seeking to add additional disposal capacity to the last operating disposal unit at its Yukon Facility by increasing the final grades of the existing disposal impoundment from a 15 percent configuration to a steepened three horizontal to one vertical (3H:1V) slope. The disposal impoundment had previously received large volumes of industrial sludge, so the steepened 3H:1V grades would be founded on the sludge material. Additionally, the disposal facility was originally permitted as a residual waste disposal impoundment, and as a result of this permitting effort (i.e., conversion of an impoundment to a landfill), many of the existing environmental control systems would require conversion/retrofitting.

CEC Approach

CEC developed a vertical increase design to convert the existing disposal impoundment to a landfill. CEC performed extensive subsurface geotechnical investigations and slope stability analyses to evaluate the proposed steepened final grades. Additionally, CEC prepared designs to address changes in the leachate management system, erosion and sedimentation control system, and operations plan.

As part of the associated major permit modification application, CEC prepared an environmental assessment that included a harms benefit analysis, noise evaluations (see picture below), and visual impact evaluations. The vertical increase design included a revision to the permitted capping system that would see a 40-mil linear low-density polyethylene (LLDPE) geomembrane liner, a geocomposite drainage layer, and two feet of final cover soil. The permit modification was approved in late 2016. The increased disposal capacity allows MAX to continue disposal services for five additional years.