This project will address an emerging issue along the coast of Lake Michigan in Northwest Indiana: microbiological pollution of beach sands due to failing septic systems. We will sample beaches in areas of known septic system failures and the sand for E. coli, human fecal bacterial DNA markers, and common pathogens. Successful execution of this project will result in data that can be used for a quantitative microbial risk assessment (QMRA) for beachgoers in the area and an experimental framework that can be expanded to examine beach sands in other Indiana coastal communities with high densities of shoreline septic systems.