Recently it has come to the attention of the scientific community and to the public that pharmaceutical compounds are being found in many natural waters, for example, streams, rivers, lakes and sometimes groundwater. The U.S. Centers for Disease Control and Prevention, the World Health Organization, and numerous other global and national agencies have recognized that one potential implication of these findings is that bacterial normally found in natural water may develop resistance to the antibiotics. This may be one of the most critical challenges of this century. Studies have shown that antibiotic resistant bacteria can be selected, maintained, and transported within various environmental compartments, by environmental compartments we mean streams and rivers. This project seeks to explore the impact of the recent flooding in Colorado on what is referred to as mobilization of pharmaceuticals (the partitioning of pharmaceutical compounds from sediments to the flowing water) and to investigate whether or not there is an increase in antibiotic resistance in these organisms associated with these waters. With a database of 10 years in the South Platte River the research team is well positioned to conduct additional sampling. This project will be supporting graduate and undergraduate students from three participating universities and will be used for the students as part of undergraduate independent research or graduate student thesis and dissertations.