Electronic Theses and Dissertations
Date
2022
Document Type
Dissertation
Degree Name
Doctor of Philosophy
Department
Civil Engineering
Committee Chair
Brian Waldron
Committee Member
Daniel Larsen
Committee Member
Farhad Jazaei
Committee Member
Scott Schoefernacker
Abstract
The Memphis Light, Gas, and Water (MLGW) operates ten pumping wellfields in the Memphis, Tennessee area for municipal and industrial water supply. The shallow, Memphis, and Fort Pillow aquifers are the three major water-bearing strata beneath Memphis, where the Memphis aquifer serves as the primary groundwater source. The Upper-Claiborne confining unit (UCCU) separates shallow and Memphis aquifers across much of Shelby County, acting as an upper protective layer for the Memphis aquifer. However, hydrogeologic breaches within the UCCU create a hydraulic connection and provide an avenue for contaminant migration from the shallow aquifer to the Memphis aquifer. This research aims to minimize the contaminant migration, find suitable locations for future well construction, mitigate risks, and extend the life of wells that may face water contamination issues. Several strategies were developed addressing well depth, seasonal well operation, and mapping no-drilling or red zones to provide practical solutions to the MLGW’s wellfield management problem. A numerical groundwater modeling technique was developed for each strategy that included stochastic simulation-optimization and customized simulation models depending on the strategy. The models resulted in many thousands of numerical simulations for each scenario to identify recurring patterns of contaminant movement to and through the Memphis aquifer. The simulation model integrated MODFLOW and MODPATH to simulate 3D groundwater flow and advective contaminant trasnport, respectively, and transferred via FloPy to couple with the optimization model or to simulate recurrence model runs that were custom scripted in Python. The results indicate that optimum well positions (spatially and vertically) and modification to pumping can increase the life expectancy of MLGW wellfields, offer sustainable management of the Memphis aquifer, and reduce contaminant migration through 2050.
Library Comment
Dissertation or thesis originally submitted to ProQuest.
Notes
Open access
Recommended Citation
Paul, Sondipon, "GROUNDWATER WELL OPTIMIZATION TO MINIMIZE CONTAMINANT MOVEMENT FROM A SURFICIAL SHALLOW AQUIFER TO A LOWER WATER SUPPLY AQUIFER USING STOCHASTIC SIMULATION-OPTIMIZATION MODELING TECHNIQUES" (2022). Electronic Theses and Dissertations. 3393.
https://digitalcommons.memphis.edu/etd/3393
Comments
Data is provided by the student.