Potential Human Health Effects Associated with Urban Wet Weather Flows

High concentrations of likely pathogens and indicator organisms found in urban receiving waters is a common cause of concern. Large amounts of resources are spent attempting to identify and correct their source, while many question the actual public health concerns associated with exposure to these organisms. This paper contains a summary of the historical development of the U.S. water quality standards for pathogens and recent work describing the potential human health effects of stormwater, as contained in a recent EPA report prepared by Lalor and Pitt (1998). This information will enable the reader to more logically appreciate the actual local risks that may be encountered. Future phases of this EPA research will develop and test methods for communities to assess local risk to humans and the environment associated with exposure to stormwater and sewage-contaminated receiving waters.