I received degrees from Augustana College in Illinois (Geology, BA) and the University of Wisconsin-Madison (MS Geology; MS Water Resources Management; PhD Geology). Prior to ISU, I worked at the University of Texas, Bureau of Economic Geology researching the hydrogeology of a potential high-level radioactive waste repository in the Texas Panhandle. I am currently a Professor in the Department of Geological and Atmospheric Sciences at ISU and teach courses there as well as in the Environmental Science undergraduate and graduate and Environmental Studies interdepartmental programs.
My research interests in hydrogeology focus on groundwater flow and geochemical reactions in unlithified (non-rock) sediment, particularly glacial aquitards. Within that frame- work, I examine physical and chemical interactions of groundwater with lakes and streams, use isotopes to investigate groundwater source and age, and apply ground- water computer models to assess aquifer sustainability. I am currently investigating the transport of human enteric viruses and pharmaceuticals/hormones in groundwater, the hydrologic impacts of agricultural drainage, the stable isotope record of water in central Iowa, and the hydro- geology of the Ames aquifer.
My work has broad application for developing and main- taining municipal water supplies in Iowa. Understanding geochemical processes in aquifers and aquitards has helped explain the presence and absence of nitrate and phosphorus in groundwater near lakes, under agricultural fields, and within riparian buffers. I served as an Associate Editor of the journal Ground Water from 1995 to 2006 and I am currently the campus representative for the Consortium of Universities for the Advancement of Hydrologic Sciences, Inc. (CUAHSI).
Simpkins, W.W. and Anderson, M.K. in review. Consumptive and non-consumptive groundwater use in corn ethanol production in Iowa: 2004-2010. Environmental Science and Technology
Simpkins, W.W. 2006. A multi-scale investigation of ground water flow at Clear Lake, Iowa. Ground Water 44(1):35-46
Helmke, M.F., W.W. Simpkins, and R. Horton. 2005. Simulating conservative tracers in fractured till under realistic timescales. Ground Water 43(6):877-889
Helmke, M.F., W.W. Simpkins, and R. Horton. 2005. Fracture-controlled transport of nitrate and atrazine in four Iowa till units. Jour. of Environ. Qual. 34:227-236