Ali Khatami, Ph.D., P.E., of SCS Engineers, provides sage advice for solid waste professionals using average leachate generation values in long-term care cost estimates for landfills with low to medium rise and those that are taller or deeper landfills with active leachate recirculation prior to the closing.
Dr. Khatami provides insight based on his decades of experience that can be of value to solid waste professionals responsible for closed Subtitle D landfills as very few Subtitle D landfills have been entirely closed with final covers that include a geomembrane barrier layer. He advises that leachate can continue to be generated after closure, consisting of excess liquids already in the waste mass that migrates to the leachate collection system and moisture released during the waste degradation process.
