A new garbage treatment system, developed by Ronaldo Izzo, a researcher at the Federal University of Rio de Janeiro, could reduce the area covered by dumps by 75 percent. The technique consists of treating the waste and using it to make the soil of the landfill impermeable. Urban solid waste goes through composting and serves in the construction of a “capillary barrier,” which retains rainwater until it evaporates or is drained, preventing its from diluting the waste.

“Currently, up to 25 percent of the volume of landfills is the barriers made by soil,” he said, noting that replacing it with solid waste vastly increases the storage capacity. Controlling the water in the landfill prevents leaching of putrefaction from organic materials, which can pollute rivers and groundwater.