[en] A Geographic Information System (GIS) provides the ability to manage and analyze all types of geographic and environmental information. It performs these functions by providing the tools necessary to capture, access, analyze, and display spatially referenced information in graphic and tabular form. Typical data elements that can be visualized in a map might include roads, buildings, topography, streams, waste areas, monitoring wells, groundwater measurements, soil sample results, landcover, and demography. The intent of this document is to provide data management and quality assurance (QA) guidelines that will aid implementors and users of GIS technology and data bases. These guidelines should be useful in all, phases of GIS activities, including the following: (1) project planning, (2) data collection and generation, (3) data maintenance and management, (4) QA and standards, (5) project implementation, (6) spatial analysis and data interpretation, (7) data transformation and exchange, and (8) output and reporting. The daily use of desktop GIS technologies within Martin Marietta Energy Systems, Inc. (Energy Systems), is a relatively new phenomenon, but usage is increasing rapidly. Large volumes of GIS-related data are now being collected and analyzed for the U.S. Department of Energy (DOE) Oak Ridge Reservation (ORR) and its facilities. It is very important to establish and follow good data management practices for GIS. In the absence of such practices, data-related problems will overwhelm users for many years. In comparison with traditional data processing and software life-cycle management, there is limited information on GIS QA techniques, data standards and structures, configuration control, and documentation practices. This lack of information partially results from the newness of the technology and the complexity of spatial information and geographic analysis techniques as compared to typical tabular data management