Thesis Defense Announcement

The Herff College of Engineering announces the Final Thesis of

Rodrigo Villalpando Vizcaino

for the Degree of Master of Science

on October 8, 2018 at 9:00 AM in Engineering Administration Building, Room 101

Advisor: Brian Waldron

Development of a numerical groundwater model to simulate multi-layered aquifer exchange in Shelby County, Tennessee, USA

ABSTRACT: Aquifer exchange between the shallow and Memphis aquifers in Shelby County, Tennessee, pose a contamination threat due to the downward vertical transference of younger, lesser quality groundwater, into deeper, more pristine aquifers. Discontinuities in the protective Upper Claiborne aquitard allow for leakage into the Memphis aquifer, a sand-dominated formation that provides about 95 percent of the water used in the Memphis area. A multi-layered groundwater model for Shelby County was created using the U.S. Geological Survey's MODFLOW-NWT to evaluate water exchange with a simulation period from January 2005 to December of 2016. Results indicated an overall inflow to the Memphis aquifer of five percent (i.e., 61 m3/min) in Shelby County, with localized areas experiencing as much as 16 percent exchange. That accounts for 54 percent of the total inflow if only assessing the upper 60 m of the Memphis aquifer. We considered this approach more realistic due to the prevalence of horizontal flow. More localized studies need to be conducted to understand the characteristics and orientation of aquitard breaches and their interaction between the aquifers