Institution: U of Memphis, Memphis, Memphis, Millsap College
Sponsor: USGS, Shelby County, Tenn. Dept of Environment, Cargill
Start_Date: 4/1/2006, 7/1/2006
End_Date: 4/30/2006, 7/31/2006
Lat: 35.125
Long: -89.85
Multichannel: 4
Descr: The project is designed to image the confining clay unit that protects the Memphis aquifer, a high quality ground water reservoir, from the unconfined, surficial aquifer that is hydraulically connected to the surface water bodies and therefore is prone to contamination from anthropogenic sources. Recent studies in the area reveal the presence of breaches in the confining unit, called “windows”, where the clay thins or becomes absent. Pumping from the Memphis aquifer over the past 100 years has depressed the water table of as much as ~40 m, resulting in higher water levels in the surficial aquifer relative to the Memphis aquifer. A consequence of the difference in water levels is that water can leak downward from the surficial system to the Memphis aquifer through the breaches, with the potential for contamination and degradation of the high-quality drinking water in the Memphis aquifer. The goal of this project is to map the subsurface structure of the aquitard to validate the existence of breaches in the protective layer and to determine its orientation as well as possibly ascertain the parent process that resulted in the formation of the breaches.
