Results of computer simulation of methane migration around sanitary landfills are presented. Five computer codes, designed to treat a variety of landfill configurations and migration control schemes are described. Typical results for the migration codes are given in the form of printouts of methane mole fraction as a function of position and time. These results are used to generate design charts which allow planners to assess whether there is a potential methane migration hazard at a given site. If such potential exists, the appropriate codes can be run using additional site specific data. Migration control configurations treated include pumped and unpumped trenches and pipes as well as barriers. Also treated are hybrid systems involving pumped or unpumped trenches with barriers installed on the outside of the trench. A case history is presented wherein several migration design alternatives are compared for a particular site. The best configuration is then studied in more detail to optimize the design. Finally, the effects of system shut down are evaluated to determine the probable rate of readvance of methane.