The United States Coast Guard Civil Engineering Unit has been developing ArcView GIS and MS Access-based environmental data maintenance, visualization, and reporting tools. The first system, the Materials Management System, or MMS, is used to maintain and analyze information on toxic material usage, report on toxic air emissions, and provide a mapping and visualization tool for toxic material usage. The second system, the Monitoring Well Visualization System, or MWVS, is used to maintain and report results from monitoring activities to support remediation and environmental compliance. The MWVS includes extensive three-dimensional data visualization tools within ArcView GIS. The presentation will discuss the development of a comprehensive GIS database to support applications, development of GIS applications, migration of existing non-GIS data into those applications, and how the use of the MMS and MWVS has enhanced USCG productivity and empowered USCG staff with better understanding of environmental trends on USCG base facilities.