USE OF GEOGRAPHIC INFORMATION SYSTEMS FOR SITE CHARACTERIZATION AT THE CHEMICALS, METALS, AND PESTICIDES PITS, SAVANNAH RIVER SITE, SOUTH CAROLINA

The Chemicals, Metals, and Pesticides (CMP) Pits Operable Unit is located in the central portion of the Savannah River Site. The CMP Pits consists of seven unlined pits placed in two rows. Between 1971 and 1979 the pits received non-radioactive waste including chemicals, metals, pesticides, and lighting ballasts which contained PCBs. In 1984 the pits were excavated to remove drums and other contaminated media. Vadose zone and groundwater contamination exists at the site. The CMP Pits are undergoing re-characterization because Silvex was detected in soil previously thought to be clean and because the water table is about ten feet below previous estimates; both discoveries impact the selection of a final remedial action.

Prior to 1999, all data collected at the CMP Pits was published in data reports which took approximately six to eight months to develop. In 1999 the CMP Pits project began using ArcView to manage data. The use of GIS streamlines the characterization process by making data immediately accessible, by providing a single source for data location, and by speeding the process of map construction. The use of GIS eliminates delays in data viewing; the data is loaded into ArcView and available for viewing immediately after it is received. Data that was once stored in multiple reports which were maintained by several different people is now located in one project that the entire team can view and update. Because information on water levels and contaminant concentrations is continuously updated, potentiometric surface maps and plume maps are more accurate and current. Additionally, several generations of plume interpretations can be overlain, enhancing our understanding of contaminant transport in the area. The ability to layer several themes has also made it easier to identify data gaps, hastening the characterization process.