Wet/Soft Waste Evaluations




Various Locations

CEC Services

  • CCR and Industrial Waste Management
  • Landfill Design and Permitting
  • Waste Characterization

Owner Objective

Confidential projects were completed for several national waste management companies, whose primary business focuses are the collecting and disposing of waste. These projects addressed and evaluated the disposal of industrial wastes that are often wet and soft, and can present challenges to landfill operations and slope stability.

The owners are seeking to understand the physical, chemical, thermal, and geotechnical characteristics of these wastes to allow their disposal in a manner that will maintain the environmental compliance and stability of their landfills. These types of wastes represent a growing segment of the waste industry and are seeing increased disposal due to a changing marketplace (e.g. exploration and production wastes from the oil and gas industry) and a regulatory environment where these materials may not have required disposal in a landfill previously (e.g. paper mill sludges).

The types of wastes evaluated can present challenges to both short- and long-term landfill operations. Therefore, landfill owners want to dispose of these wastes in manner that provides stability of the working face and overall waste mass, which eliminates or minimizes the potential for heat and hydrogen sulfide generation and accumulation, and that minimizes leachate production.

CEC Approach

CEC has developed and performed numerous field sampling events at landfills to obtain representative samples, and observed landfill operations to understand how these wet/soft wastes are currently disposed. CEC directed various laboratory test programs to determine properties for these wastes, including shear strength, thermal generation and kinetics, hydrogen sulfide generation, and water/leachate release and generation.

CEC performed a variety of engineering analyses using the laboratory test results. The analyses, coupled with field observations, enabled CEC to recommend acceptable tonnages of these wastes that could be disposed while minimizing negative impacts on slope stability, hydrogen sulfide generation, and heat accumulation. CEC also provided recommendations for waste slope angles and methods of waste placement to enhance short- and long-term landfill stability. The end result of CEC’s field observations, field sampling and testing, laboratory testing, and various engineering analyses has enabled the owners to continue to collect and dispose of these wet/soft wastes in a manner that maintains environmental integrity and compliance.