Dr. Marirosa Molina is a Research Microbiologist with the Office of Research and Development, Center for Environmental Measurement and Modeling. Dr. Molina has a BS in Biology (Microbiology) from the University of Puerto Rico-Mayagüez, a MS in Microbiology and a PhD in Ecology from the University of Georgia. She is currently serving as ORD’s Hispanic Special Emphasis Program Manager. Dr. Molina’s research efforts include development of tools to assess microbial concentrations (pathogens and indicators of fecal contamination) at the watershed scale, application of microbial source tracking markers, and assessment of the diversity of waterborne pathogens in surface waters through the application of metagenomic approaches.  Her efforts have provided the U.S. EPA with tools for the development of site-specific criteria for fecal indicator microorganisms and the development of models to predict the sources and transport of microbial contaminants in recreational waters.