Hydrogeologic Setting of A/M Area: Framework for Groundwater Transport. Book 1

摘要

This document includes a brief summary of the regional geology within a 200--mile radius of the A/M Area, a summary of stratigraphy and hydrostratigraphic nomenclature as it applies to the A/M Area, and a summary of stratigraphy and hydrostratigraphy specific to the A/M Area. Five different stratigraphic cross sections show site-specific geology of the Tertiary section of the Upper Atlantic Coastal Plain geologic province within the A/M Area. The Cretaceous section lacks detail because the deepest wells penetrate only the uppermost part of the Upper Cretaceous sediments. Most of the wells are confined to the Tertiary section. The A/M Area is located in the northwestern corner of the Savannah River Site (SRS). The area serves as a main administrative hub for the site. Between 1958 and 1985, approximately 2,000,000 pounds of volatile organic solvents (metal degreasers, primarily trichloroethylene and tetrachloroethylene) were routed to the M Area Settling Basin. Between 1954 and 1958, effluent also was discharged to Tim's Branch via the A014 Outfall. In the main M Area Solvent Handling/Storage Area, a significant amount of leakage occurred from drums stored during this time period. Extensive quantities of solvents were transported, via the Process Sewer Line, to the M Area Settling Basin, and leaks occurred along this line as well. A smaller source area has been identified and is centered around the Savannah River Laboratory (SRL) (now called the Savannah River Technology Center (SRTC)) Complex. All of these source areas are represented by solvent contamination in the groundwater system. (Abstract Truncated)