The Department of Defense (DOD), is faced with the monumental task of assessing the extent to which its past activities have effected the environmental quality of the properties it owns. Also, because of limited budgets, DOD needs to establish the capability to prioritize the waste sites based on various criteria including, but not limited to, the types, levels, and location of contaminants and site scoring generated through the use of a variant of EPA's hazard ranking system (HRS) model. In support of these efforts a geographic information system (GIS), is being used to store, analyze, summarize, and report on the prodigious amounts of data collected by field crews. Particular areas to be discussed include the design of the system (that is, the user interfaces, the database schemas, and the software), types of data accepted by the system, the analyses performed, the standard information (that is, reports) provided, ad hoc reporting capabilities, and the use of the GIS to produce highly complementary, single or multithematic base maps. The overall project (which these tools/systems are supporting), currently in the site precharacterization phase, is being undertaken by both DOD and several WESTON technical groups.