Factors Affecting 'Escherichia coli' Concentrations at Lake Erie Public Bathing Beaches

摘要

This report describes field studies done throughout the recreational season of 1997 (May through September) at three public bathing beaches in the Cleveland, Ohio, metropolitan area. Concentrations of E. coli were determined in water and lake-bottom sediments collected during a variety of environmental conditions--during dry, calm weather; before, during and after rainfall; for various increased wave heights; and before and after heavy recreational use. The concentrations of E. coli in water and lake-bottom sediments were plotted as a function of time along with wave heights, occurrence of wastewater-treatment plant overflows, and rainfall amounts. These plots were examined qualitatively to determine if these factors affected E. coli concentrations in water and sediment. This report provides water-resource managers with information on the water-quality and environmental factors that affect fecal-indicator concentrations at three Lake Erie beaches. It also provides evidence that predictive models may be developed to help water-resource managers more quickly and accurately assess the degradation of recreational water quality to protect the public health.