Invited Session: Closing Dumpsites

Management of Water in the Final Cover of Dumpsites (0.5 CEU)

Tuesday, September 26, 2017
17:00 – 17:30
Room 323

Moderator: Christophe Cord’Homme, Development Director, CNIM of France

The intent of this presentation is to address:

  1. An important component of final cover systems used for closure of dumpsites
  2. The design of an effective management system for one of several types of liquids at a landfill facility

The presentation discusses the issue of collecting water from landfills final cover drainage layer. Due to significant advances in manufacturing of geosynthetics and effectiveness of geocomposites as a drainage medium, most landfill final covers have geocomposite drainage layers directly above the geomembrane barrier layer that collect and convey water in the final cover. Rain water that percolates into the final cover upper soil layer reaches the geocomposite drainage layer and flows down the slope to the toe of the slope. A collection system is needed to collect and remove the water from the drainage layer. An effective collection and management system that has been perfected over the past 18 years and implemented at numerous final cover projects is the subject of the presentation. The system is namely referred to as the Rainwater Toe Drain System (RTDS). The presentation begins with describing the system with simple sketches and continues with photos of construction events showing step-by-step construction of a RTDS.

Following the presentation, participants will be able to develop and design an effective collection and management system for water in the drainage layer of dumpsites final covers to maintain final cover stable and to prevent pore pressure build up in the final cover. Without an effective and properly design collection system, there will always be the possibility of failure or slippage by veneer instability of the final cover.


Ali Khatami, Vice President, SCS Engineers, Virginia

Ali Khatami

Ali Khatami is a vice president with SCS Engineers and also serves as the national expert for landfill design and construction quality assurance. Dr. Khatami has degrees in mechanical engineering, structural engineering, and civil engineering. Dr. Khatami has more than 28 years of experience in the areas of solid and hazardous waste landfills. Also, Dr. Khatami has extensive experience in the design of final covers for low level radioactive facilities, surface water management systems, liquid waste impoundments and floating covers, landfill gas collection and disposal systems, and various types of solid waste facilities for transfer and recycling of solid waste. Dr. Khatami has many technical publications, including two books.