Case Studies of Urban and Suburban Watersheds

Abstract

Water quality in urban and suburban watersheds is impacted by many sources, ranging from the mixtures contained in stormwater runoff, to human sewage from failed wastewater handling systems, to domestic animals and urban wild animals such as birds (e.g., gulls, geese), opossums, raccoons, and deer. Many urban and suburban water bodies are chronically contaminated with fecal indicator bacteria, and municipalities frequently make choices about the level of resources devoted to determining microbial sources in their various “impaired” (sub-standard) watersheds based on financial constraints. This chapter discusses such considerations and focuses on work done in Florida, although the issues and solutions can be applied to any US or international water body. We outline a weight-of-evidence approach for investigating the sources of microbial contamination in surface waters that emphasizes stakeholder cooperation and engagement, and is economical and relatively easy to implement. The approach includes a strategy for ranking water bodies according to probable pollution sources and human use that is modified from the World Health Organization’s (WHO) Annapolis Protocol. The protocol facilitates decision-making about which areas will be investigated by the more expensive microbial source tracking (MST) methods such as PCR for host-associated microbes, and which will receive more limited attention and resources. Case studies are presented, and the important role of stakeholder cooperation in the process is discussed.