Dept of Earth & Environmental Sciences
Centre for Environmental and Information Technology (EIT)
200 University Ave. W
Waterloo, Ontario, Canada N2L 3G1
Phone: (519) 888-4567
Stephen E. Silliman, Department of Civil Engineering and Geological Sciences. University of Notre Dame.
Characterization of a Complex, Sole-Source Aquifer System
In Benin, West Africa
The Godomey wellfield is the sole source of freshwater for Cotonou, Benin. The Cotonou/Calavi area is the largest population center in Benin, with an estimated population between 1.5 and 2 million people. Located directly on the Atlantic coast, this population center is also bordered by the southern and western shores of a large, shallow lake. Groundwater wells serving this population are located about 6 km north of the Atlantic coast and as close as 1 km to the western shore of the lake. With most production wells located within partially confined portions of this complex aquifer system, this water resource is threatened by contamination from saltwater intrusion (both from the lake and the ocean) and anthropogenic activities.
Collaboration among scientists and students from the United States and Benin has allowed development of increasing insight into the hydrogeology of this important coastal aquifer system. Research efforts discussed in this presentation include numerical modeling, hydraulic testing, water quality characterization, and electrical resistivity surveys. Discussion of a number of technical and social/cultural issues encountered during this research effort illustrates the value of close cooperation with in-country collaborators, including those from both the technical and social science disciplines.
The 2011 Henry Darcy Distinguished Lecturer Stephen “Steve” E. Silliman, Ph.D., joined the University of Notre Dame in January 1986 and is currently a professor of civil engineering and geological sciences, with an emphasis in groundwater hydrology. He received his bachelor’s degree in civil engineering from Princeton University, and both a master’s degree and Ph.D. from the Department of Hydrology and Water Resources at the University of Arizona. At Notre Dame, he has been responsible for developing a research program in theoretical and applied aspects of groundwater hydrology. He has also enjoyed teaching a diverse set of courses at the undergraduate and graduate levels, has served as associate dean for undergraduate programs in the College of Engineering, and currently serves as associate chair in his home department. He is also the principal investigator of the Notre Dame Benin Research Program.
Silliman’s research focus is divided between his theoretical/laboratory studies on groundwater flow/transport processes and water resource development/management in developing countries. His work on groundwater flow/transport has historically been focused on studies of the impact of heterogeneity in the saturated zone (flow, chemical transport, particle transport). Recently, this work has become more focused on the vadose zone as well as wellhead management strategies under uncertainty.
His work in developing countries initially took place in Haiti, but has been focused in Benin, West Africa, for more than a decade. In these efforts, he has worked with his students (undergraduate and graduate) and Benin colleagues to train local populations to monitor water quality. These activities include modeling and field characterization of coastal hydraulics with a focus on the potential for saltwater intrusion of the wellfield serving Cotonou, the largest city in Benin, while assisting in the drilling/equipping of a number of manual-pump groundwater wells.
His research has been supported by a number of agencies, ranging from the Department of Energy and the National Science Foundation to private foundations.
200 University Ave West
Waterloo, ON N2L 3G1