Dr. Steefel has over 27 years of experience in developing models for multicomponent reactive transport in porous media and applying them to topics in reactive contaminant transport and water-rock interaction. He developed the first routine for multicomponent nucleation and crystal growth in the Earth Sciences (Steefel and Van Cappellen, 1990) and the first multicomponent, multi-dimensional code for simulating water-rock interaction in non-isothermal environments (Steefel and Lasaga, 1994). He has also worked extensively in applying reactive transport modeling to natural systems, including hydrothermal, contaminant, and chemical weathering environments. Recently, he has been involved in experimental studies of cation exchange (Steefel et al., 2003) and mineral dissolution and precipitation (Yang and Steefel, 2008), as well as modeling studies of field systems focused on contaminant transport, microbially-mediated biogeochemical reactions, chemical weathering (Giambalvo et al., 2002; Steefel, 2004; Maher et al., 2009; Li et al., 2009), and isotope systematics (Druhan et al., 2012; Steefel et al., 2014). More recent work has focused on pore scale studies, including those using high performance computing (Li et al, 2008; Molins et al., 2012, 2014; Steefel et al., 2015). He is the principal developer of the reactive transport software CrunchFlow (Steefel et al, 2015).