A hydrogeologic characterization was performed to evaluate the nature of groundwater flow in an alluvial and underlying fractured bedrock aquifer in the area between an unlined, inactive landfill and a river in southern California. The hydrogeologic characterization was used to enhance the site conceptual model for the site, and to design a bioaugmentation pilot test to evaluate the use of enha...

We present experimental observations and a conceptual model for understanding the compression swelling characteristics of Old Alluvium (OA) from San Juan, Puerto Rico. Prior studies have classified OA as transported, in situ weathered tropical soil whose intact macrostructure comprises cemented, pseudo-silt with mixture quartz grains aggregated clay particles. The aggregates include mixtures ka...

Selective Sequential Extractions (SSE) were used to study the retention mechanisms of heavy metals on three estuarine alluvium soil columns obtained from leaching experiment for up to 5 pore volumes (PV). Leaching results indicate that almost 99 % of heavy metals (Pb, Cu, and Zn) were retained in the soils with the Ce/Co values in the order of 10 -3 to 10. This is in accord with the results obt...

Optical and radiocarbon dating indicates that alluvium underlying dunes near Abilene was deposited at or before 45 ka, and that the overlying dunes were active at 1.1–0.5 ka. Geochemical data indicate that the Abilene dune sand is immature and was derived from the underlying Pleistocene alluvium, and not from Holocene age Smoky Hill River deposits. These findings suggest that dune activation wa...