The Solar Composting Advanced Toilet is designed to recycle human excrement and urine into a relatively dry and deodorized compost which can be safely and easily applied to the immediately surrounding landscape. The S.C.A.T. is a self-contained freestanding structure using inexpensive convenient organic materials such as peat moss or sawdust to promote effective composting. Earthworms provide mixing and aeration, eliminating the need for a rotating drum. A durable watertight plastic bin in the solar chamber has enough capacity for 4-6 persons in daily use. Easy access to the compost bin simplifies emptying at 6-12 month intervals, depending on loading. Portability: Built on a 4'X8' platform and weighing 300 pounds, the completed S.C.A.T. can be transported by pickup truck, trailer, or barge. Alternatively, the use of screw fasteners allows prefabrication of panels for simple onsite assembly. No electric hook-up: Translucent roofing material over the stall provides ample light during the day. Passive solar heat enhances evaporation to dewater the compost pile. Ventilation is provided by convection currents through a storm-proof ventilator. No foul odors: Composting is an aerobic process in which microorganisms convert organic material into soil. By-products are heat, water vapor and carbon dioxide. Screened vents exclude insects. Environmentally safe: There is no leachate to contaminate nearby ground or surface waters. Pathogens are removed by heat and aging. Handicap accessible: Construction plans for the optional handicap model include a self-closing 36" wide door, extra-large stall for a wheelchair, and sturdy grab bars to assist users with physical limitations. Low maintenance: Construction materials are durable and easily cleaned. Modular design simplifies damage repair. Y2K Compliant.