A heuristic was devised for shifting contaminant detection wells near landfills. The heuristic establishes an initial configuration of monitoring wells and then shifts the wells iteratively until it reaches a specified release detection efficiency. Computer simulations of contaminant transport gauge the performance of the monitoring configurations. In configurations derived by the heuristic, all wells are located the same distance from a landfill, measured parallel to groundwater flow. This facilitates a uniform lag time for release detection. However, the distance between wells, measured perpendicular to groundwater flow, can vary to enhance overall detection efficiency. In practice, the heuristic can be used to identify effective monitoring configurations for detecting potential releases from landfills.