A gas collection grid for use at landfills having a gas-producing waste pile, including a lower geocomposite positioned over the gas-producing waste pile, a protective layer of soil is positioned over the lower geocomposite. An upper geocomposite is positioned over the protective layer of soil such that the protective layer of soil is positioned between the lower and upper geocomposites. An impermeable geomembrane is positioned over the upper geocomposite. A cruciform gas collector conduit grid is positioned within or atop the protective layer of soil and has a plurality of collection orifices formed adjacent the vertical openings formed in the protective layer of soil. The impermeable geomembrane is non-perforated adjacent the collection orifices and the cruciform gas collector conduit grid is adapted for delivering collected gas laterally from beneath the geomembrane rather than vertically through the geomembrane.