1) the hydrogeology and geochemistry of till and related glacial sediments; 2) the groundwater quality of restored, multi-species riparian buffers in agricultural watersheds; 3) processes controlling nutrient transport via groundwater to lakes and streams in Iowa; 4) application of groundwater modeling to predict the hydrologic effects of conservation practices in agricultural watersheds; 5) assessing the sustainability of alluvial aquifers in central Iowa under changing climate and biofuels development.