The integration of core, geophysical log, seismic and hydrologic data, made possible the detailed delineation of the stratigraphy and structure of the sedimentary sequence underlying the proposed site of a new sanitary landfill at the Savannah River Site, and the hydrologic response of the attendant hydrogeologic units. Lateral and vertical facies changes are characteristic of the sequence.
This study considered the characteristics of the sediments in the upper 105m (Tertiary) part of the section. The Floridan Aquifer underlying the area is composed mostly of clastic sediments and minor calcareous sediments and includes two aquifers, the Upper Three Runs aquifer and the underlying Gordon aquifer, separated by the Gordon confining unit.
Two faults (faults M and L) were delineated that significantly impacts the hydrologic characteristics of the aquifers beneath the site. Fault L, is a major northwest-southeast striking, northeast-dipping normal fault. Fault M is a down to the southwest normal fault that flanks fault L on the northeast and provides the northeastern limb of the down-dropped graben block located at the northwest end of the site. Fault L coalesces with fault M towards the center of the site, and Fault L continues to the southeast with reduced throw. All the aquifer and aquifer zones in the Tertiary portion of the section are breached along all or part of faults M and L. The result is hydraulic communication between the aquifers, eliminating the site for consideration as a landfill.