Production and Drainage of Leachate and Landfill Gas

Based on the degradation‒consolidation model, this chapter introduces a modified calculation formula accounting for leachate production from waste is introduced. Remarkably, this formula demonstrates better predictive accuracy than the traditional leaching coefficient method. Next, a new calculation approach for LFG production is proposed, considering the distinct degradation properties of rapidly and slowly degrading MSW components. Based on this method, the LFG production behaviors of HFWC and LFWC MSWs are compared. Furthermore, the chapter explores three-dimensional collection and drainage technologies for leachate and LFG, presenting detailed discussions on horizontal well dewatering and vertical well vacuum pressure pumping tests. Additionally, strategies for optimizing LFG collection efficiency are explored, along with an examination of the relationship between collection rates and leachate levels. This analysis is complemented by a case study on the Xiaping Landfill in Shenzhen, demonstrating that the implementation of a three-dimensional collection and drainage system and enhanced temporary cover structure increased LFG collection efficiency from 23% to 90%.