Landfills are necessary to safely dispose of the large amounts of waste generated by humans. Without proper waste management, trash piles up in communities and creates health problems. The document discusses how Americans generate a lot of trash each day that needs to be disposed of properly. It then describes the Rolling Hills Landfill, including what types of waste it accepts, its size, and agricultural land on the property. It also provides details about the layers of a landfill, specifically the bottom liner system which separates waste from groundwater using a clay liner, geomembrane, leachate collection system, and layer of sand.