Field Evaluation of Permeable Blanket for Leachate Recirculation

Abstract

Enhanced leachate recirculation (ELR) landfills are designed and operated for rapid waste stabilization, waste decomposition and increased rate of gas generation. The fundamental process improvement involved in the operation of landfills as ELR landfills is the addition of water and/or the recirculation of leachate into the landfill's waste mass. The study of moisture movement within Municipal Solid Waste (MSW) due to leachate recirculation plays an important role in developing the design and optimizing the operation of a leachate recirculation system. The utilization of high permeability material (crushed glass or shredded tire chips) as recirculation blanket inside the landfill cell is expected to improve the moisture distribution inside the landfill cell. The main objective of this paper is to evaluate the performance of permeable blanket consisting of shredded tire chips for leachate recirculation at an ELR landfill located in Denton, Texas. The City of Denton landfill, the first ELR landfill in Texas, utilizes 0.15 m (6 in) diameter perforated HDPE recirculation pipes to inject leachate. The leachate recirculation performance, conducted through the perforated recirculation pipe placed on top of a 90 m x 30 m x 1 m (300 ft x 100 ft x 3 ft) shredded tire bed, will be investigated in this study. The moisture distribution and the extent of recirculation have been monitored using Resistivity Imaging (RI). Based on the preliminary field investigation results using RI technique, permeable blanket is performing well in distributing moisture through the waste mass over a wide area.