As waste decomposes gas is generated within the landfill. A gas collection system allows WM to remove the gas from the landfill thereby preventing the gas from escaping the facility. The gas collection system consists of wells that are installed into the waste mass. Each of the wells is connected with piping to form a network. Blowers are used to create a vacuum on the network of wells and the gas is used as fuel to run engines within the gas-to-energy plant. The engines power turbines that generate electricity.
Landfill gas has become a new source of renewable energy in recent years. WM in conjunction with Energy Developments, Inc. and CPS Energy held a ribbon cutting ceremony on January 27, 2006 to celebrate the addition of the Covel Gardens Gas-To-Energy Plant going into service. This new plant generates approximately 9 megawatts of power which is enough to light 6,000 homes in San Antonio. Using landfill gas in this manner re-defines trash in the landfill as "buried treasure" since it is the source of this new fuel.