Wednesday, April 2, 2008 : 1:20 p.m.

Water Budget Results from Selected Models of the Mississippi Embayment Aquifer System

David E. Langseth, Gradient Corp. and Eric J. Wannamaker, Gradient Corporation

            Aquifers within the Mississippi Embayment Aquifer System (MEAS), including the Memphis Sand and Sparta Aquifers, are important regional sources of public water supply and other water uses.  Accordingly, these aquifers have been the subject of studies by several entities including the United States Geological Survey, state geological surveys, academic institutions, and water users.  As components of these studies, several numerical models have been developed to gain an understanding of the flow behavior in these complex aquifer systems.  This study synthesizes and compares the results of MEAS modeling efforts, based on the published reports, with a particular focus on water balance calculations for the Middle Claiborne aquifer, which encompasses both the Memphis Sand and Sparta aquifers.  We first review and compare available models, including aspects such as geographic coverage, grid resolution, and outcrop recharge and inter-aquifer leakage modeling techniques.  We then analyze water budgets from selected models, illustrating how regional and smaller scale water budgets have evolved over time as aquifers have been subject to increasing amounts of withdrawals.  Water budgets are evaluated in terms of both major aquifer units and, to the extent supported by information in the published model reports, political boundaries.  Finally, based on our review, we suggest areas for further modeling, analysis, and data collection that would support future understanding and management of the MEAS.

David E. Langseth, Gradient Corp. Dr. Langseth is a registered professional engineer with over 20 years domestic and international experience in consulting and academic settings. He is currently a Principal at Gradient Corporation. He has worked on a variety of water resources management issues, including ground water flow and contaminant transport, integrated watershed modeling, watershed specific water quality criteria evaluation, TMDL evaluation, point source discharge evaluation, storm water management and modeling, ground water/surface water interactions, and discharge permitting. Dr. Langseth also has experience dealing with environmental remediation, environmental impact assessment, and environmental program management.

Eric J. Wannamaker, Gradient Corporation Mr. Wannamaker is an environmental engineer specializing in the fate and transport of contaminants in ground water and surface water, with expertise in vapor intrusion, design and operation of ground water treatment systems, contaminant transport and hydrological modeling, statistical and geostatistical data analyses, and database management. Mr. Wannamaker was a National Science Foundation Graduate Research Fellow at the Massachusetts Institute of Technology.


2008 Ground Water Summit