Abstract: A system for a method of treating effluent from refuse in a landfill which includes a water-impermeable refuse basin, a catch basin, and a lagooning system. Leachate is conveyed from the refuse basin to the catch basin and then to the lagooning system. The leachate is treated in the lagooning system in at least two stages; the first stage consists primarily of oxidation by aeration and the second stage consists primarily of oxidation by biological means.