To protect the ground from contamination, they
employ thick plastic and various levels of intervening materials then pile on top of the trash. That is, they pack down the garbage and lay 7 feet worth of different materials above the waste, finally topping the layers off with dirt. We can see this action up close as our school bus climbs up the steep hills (made entirely of garbage).
The process of layering dirt upon the garbage is not only better for retaining natural gases produced by the trash while keeping the ground clean, it also assists in reducing the smell. Combined with the dust abatement program of the misting system and the hiding of the trash under dirt and layers of plastic, our guide assures us that these new, sanitary methods are the ultimate in landfill technology.