This investigation reviewed and evaluated methodologies used for microbial risk assessment with respect to their applicability for reclaimed water applications. The investigation was comprised of five primary components: a comprehensive database of articles, reports and books describing microbial risk assessment methodologies was established and reviewed. Risk assessment techniques and models were identified for estimating the public health risk from exposure to microorganisms via reclaimed water applications. Two models were identified for further evaluation: a static (individual based) and...

Recent research has shown that the concentrations of microbial indicator organisms (e.g., fecal coliforms) in stormwater may be quite high. However, studies have not clearly established relationships between the concentrations of indicator organisms and microbial pathogens in stormwater, or between stormwater indicator organism concentrations and illness. Thus, it is difficult to interpret indicator data collected by local public agencies in the context of potential risk to human health.
The primary objective of this investigation was to generate guidance to enable more accurate and...