Sources of Enterococci and Their Relation with Environmental Factors at an Inland Beach

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Nonpoint sources of pollution have been reported as an alternative source of high entero-cocci levels in beaches. In this study, persistent high levels of enterococci were investigated at an inland beach in Georgia that has been under permanent advisory since 2005. On a monthly basis for 1 year, data were collected on Enterococci (using method 1600 for water, Enterolert for sediment, and method 1611 for water and sediment), source tracking markers (HF183 and GFD), temperature, salinity, pH, dissolved oxygen, and turbidity. Microbial source tracking analyses showed high HF183 concentrations around the beach at the beginning of the study (405 calibrator cell equivalents/100 milliliters [ml]) and further investigations proved an illicit sewage leak close to the beach. Culturable enterococci in water significantly decreased below 70 CFU/100 ml criteria value and HF183 was below detection limits after controlling the sewage intrusion to the beach. In addition, wildlife particularly avian species) was a major source of enterococci in this area. GFD marker ranged from 152–1077 gene copies/100 ml in HF183 negative water samples. Sediment also harbored culturable enterococci and concentrations ranged from 29–24196 MPN/100 ml throughout the study, showing significant relation to temperature (p < 0.001). Tidal movements and precipitation were the major factors (p < 0.001) for elevated concentrations of enterococci after controlling the point source. Further studies are needed to investigate the relation between culturable enterococci and pathogens such as enteric viruses to assess health risks upon exposure to contaminated sediments on inland beaches.


United States Environmental Protection Acency Recreational Waters Conference (US-EPA)


New Orleans, LA