For all those interested in the design of waste disposal facilities, the volume on the design of a mixed waste disposal facility at the Idaho National Engineering and Environmental Laboratories (INEEL) is a must-read. While this volume does not deal with mining wastes, its technical approach is worthy of emulation by those striving to reclaim mine waste disposal facilities for the long term.

I refer to a 2002 document entitled Liner and Cover Long-term Performance Evaluation and Final Cover Life Cycle Expectation. Here is the abstract:

“This study presents the engineering analysis for the design of the INEEL CERCLA disposal facility liner and cover systems. For each design analysis, the associated applicable or relevant and appropriate requirements and performance design criteria are defined, and appropriate calculations completed. This study also includes and explanation of how the design analyses demonstrate compliance with the required liner and cover service life. In addition, and explanation is provided to demonstrate quantitatively that the ICDF landfill will meet the required design life of a 1,000 years.”

The disposal facility incorporates a double composite liner and leachate collection and leak detection and recovery system. After placement of the wastes a cover will be placed to control infiltration for 1,000 years and beyond. I was intrigued by the cover design:

  • Water Storage System. The upper nine feet of the cover is engineered earth fill that will act as an evapotranspirative cover.
  • Capillary Break and Biointrusion. The middle layer of the cover includes filters and a 2.5-ft thick biointrusion barrier of cobbles and gravel.
  • RCRA Subtitle C Barrier and Lateral Drainage. The lower four feet of the cover includes filters, a geomembrane, and compacted clay placed over earth fill.

While you may never need all these layers in your mine’s liner or cover systems, the volume is valuable for the clarity with which it explains the function of each layer and the insight into the long-term performance of each component in the liner and cover.