The July 10 2000 Payatas Landfill Slope Failure

Jafari, Stark & Merry present a detailed forensic investigation of the catastrophic Payatas MSW slope failure in the Philippines. Using site observations, HELP modelling, leachate analysis, gas generation effects, geometry reconstruction, and stability back-analysis, they identify key causes: elevated leachate levels from typhoons, landfill gas pressure, weak and uncompacted waste, absence of cover soil, steep slopes, and a near-surface translational failure surface. The paper provides guidance for analysing MSW stability in tropical climates.