Examining Septic Tank Pollution in Eastern Shore Waterways through Evaluation of Optical Brighteners

Abstract

We collected water samples along Chesapeake Bay tributary rivers in order to examine septic tank pollution. In order to accomplish this, we tested for optical brighteners, fluorescent chemical compounds found in standard washing detergents. In the Wicomico, Pocomoke, and Nanticoke rivers, we found decreasing optical brightener readings (indicating less septic tank pollution) in more developed areas, with greater optical brightener readings (indicating more septic tank pollution) in less developed areas. This may be because more homes in developed areas are likely to be connected to municipal sewage, while homes in more rural areas are reliant upon septic tanks for wastewater treatment. Furthermore, we investigated the photo-decaying properties of optical brighteners in order to better understand how optical brighteners can accurately be used as a tracing mechanism for septic tank pollution in future studies. We discuss key findings, both of optical brightener properties and concentrations, as well as recommend further study in these areas, in order to increase awareness and knowledge of septic tank pollution problems across the Chesapeake Bay system.