Watersheds are the primary receiving areas for trace element pollution. Sources include ground water, storm flow, agricultural run off, aerial deposition, animal waster etc. All over the globe, watersheds are receiving potentially toxic trace elements far in excess of their pre-civilization loads.

Much of the work carried out by the Trace Element Lab has been dedicated to examining the processes by which trace elements enter and are transported by watersheds into estuaries. Much of our current efforts are focused on the flux of trace elements into and out of watershed impacted by human development. The Patuxent River watershed has been a site of particular interest, with a diverse geography, and an unevenly distributed, and rapidly growing population. We are also studying the Rhode River watershed, a convenient and interesting model watershed. Recently, in collaboration scientist and the D.C government, we have studied the fluxes of trace elements and organic contaminants in the Potomac and Anacostia Rivers in Washington, D.C., with particular focus on the inputs of contaminants as a result of storm water flows, and the historic accumulation of contaminants in sediments.