Source Tracking at Beaches

Sources of fecal contamination to beaches include stormwater runoff, combined- and sanitary-sewer overflows; treated wastewater effluents; effluents from private sewage-treatment systems, including septic tanks; and fecal pollution from birds, swimmers, dogs, or boaters.  Identifying and mitigating the source of fecal contamination to a particular beach is often complicated by the spatial and temporal variability of bacterial-indicator concentrations and the dynamic lake currents, weather patterns, and natural processes that affect these concentrations.  In addition, many of the sources are of nonpoint origin and not easily identified. 

Applying several source tracking tools is practical at many beaches.  These include identifying spatial and temporal patterns of bacterial indicator concentrations, determining weather patterns that cause elevated concentrations, understanding coastal hydrologic processes that affect transport and survival of bacterial indicators, and applying microbial source tracking techniques to specific sites. Examples of two source tracking studies at Ohio beaches are listed below.

A Spatial, Multivariable Approach for Identifying Proximate Sources of Escherichia coli to Maumee Bay, Lake Erie, Ohio.

Use of Spatial Sampling and Microbial Source-Tracking Tools for Understanding Fecal Contamination at Two Lake Erie Beaches.