GIS plays a valuable role in Environmental Site Assessment and mapping out environmental impacts to soil, air, and water. Firms who assist property owners with site surveys, environmental assessments, and site cleanup use GIS to accurately determine the extent of contaminations and plan how best to approach site cleanup. Often large amounts of site data are collected through long-term monitoring efforts and GIS provides an intuitive way to view this information in an easy-to-read map. Map-based comparisons between data from different time periods can be used to readily visualize how contamination levels have changed over time. GIS services for clients in this industry include traditional hard-copy map generation for use in reports, documents, meetings, etc. as well as a variety of data management tasks.