Geosynthetic Fundamentals in Landfill Design

Abstract

Contemporary design of lined landfills in the United States began in the early 1980&s with Federal regulations focused on hazardous waste disposal. This regulatory framework was expanded to include municipal solid waste in the early 1990&s. With nearly 30-years experience in the design of lined landfills, simple design practices have evolved to ensure the successful performance of lined landfills. Geosynthetic components play a critical role in the two main components of these landfills: (1) liners to limit the vertical migration of liquids, and (2) drainage field that collect the liquids and limit the potential for leaks to develop. Geomembrane liners provide a very stable barrier to the spread of liquids but must be built to very high standards, be protected from damage during construction and their service life, and come with the potential for stability problems generated by their slick surfaces. Geosynthetic drainage composites provide a means of draining the collected liquid from large areas of the liner surface. Properly designed, such geosynthetic drainage layers will add to the stability of the landfill by limiting hydrostatic forces due to the collected liquids. Past failures of lined landfills provide an effective means of demonstrating the inevitable consequences of not meeting fundamental design requirements for these components.