Daily cover
Daily cover is the name given to the layer of compressed soil
Soil is a natural body consisting of layers of mineral constituents of variable thicknesses, which differ from the parent materials in their morphological, physical, chemical, and mineralogical characteristics...

 or earth which is laid on top of a day's deposition of waste
Waste is unwanted or useless materials. In biology, waste is any of the many unwanted substances or toxins that are expelled from living organisms, metabolic waste; such as urea, sweat or feces. Litter is waste which has been disposed of improperly...

 on an operational landfill
A landfill site , is a site for the disposal of waste materials by burial and is the oldest form of waste treatment...

 site. The cover helps prevent the interaction between the waste and the air, reducing odors and enabling a firm base upon which for vehicles to operate. Work at the Fresno Sanitary Landfill was instrumental in establishing the need and utility of daily cover.

While soils are the traditional materials employed in daily cover, alternative options such as mixtures of paper sludge and tire derived aggregate (TDA) have displayed mechanical characteristics desirable for daily cover. When compared to traditional soil layers, the paper sludge paste was 2-3 times lighter, at least two orders of magnitude more impermeable, and comparable in shear strength.
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