State of the Science in Microbial Source Tracking:

What Environmental Managers and Public Health Practitioners Should Know



Speakers:                   Valerie J. Harwood, PhD

Professor, Department of Biology

University of South Florida, Tampa, FL



Level of Knowledge: Multi-Level


The determination of source(s) of fecal pollution to surface and ground waters is essential for effective protection of public health, for remediation of contaminated waters, and for regulatory tasks such as total maximum daily load (TMDL) assessment. Regulatory standards for microbial water quality are based on indicator bacteria concentrations, yet these organisms are shed in the feces of a wide variety of animals, including humans, therefore they offer no information about contamination source. Various methodologies, collectively termed microbial source tracking (MST), have been applied to the problem of fecal source determination. These methods can be broadly divided into library-based or library-independent methods. Each method has advantages and disadvantages, and managers should be aware of the necessity for method validation on fecal samples and on water samples. Case studies conducted in various geographic areas of the U.S. will be presented. Future directions for MST, including microarray technology, will be discussed.


Learning Objectives:

  1. Understand the purpose of MST and its importance to water quality management and public health
  2. Understand the advantages and disadvantages of various MST methods, and know the minimum validation steps necessary for gauging the usefulness of a methods
  3. Know some of the future possibilities for MST studies and applications