Traditionally, water quality regulation and protection of public health has relied on culture based methods that quantify faecal indicators such as the coliforms. Since Escherichia coli represents over 97% of the thermotolerant coliforms, it ihas been used extensively as a key indicator of faecal contamination in water testing industry. However the presence of E. coli or other coliforms (and recently suggested enterococci) does not provide any information about the source of contamination and therefore is not always an effective indicator of actual risk to humans. While any faecal material in water that is humans come into contact with or consume can pose a health risk, that risk may be managed more efficiently and effectively if the source was know. Microbial source tracking is a developing approach that, while needs to be further refined to produce reliable data, is becoming send by water managers as a tool that will improve management of public health.