Indicator Organisms in Wastewater Treatment Wetlands

1. Indicator Organisms in Wastewater Treatment Wetlands Jepson Sutton SWES 574 10-31-02

2. Indicator Organisms • The detection of pathogenic organisms is a time-consuming, labor-intensive task, requiring highly trained technicians • For this reason, scientist have identified certain organisms that, when detected, are a definitive indication of fecal contamination.

3. Indicator Organisms • Indicator organisms are considered normal flora (always present) in the digestive system of all warm-blooded animals, including humans. • The detection of indicator organisms suggests that enteric pathogenic microorganisms may also be present due to the fecal contamination.

4. Characteristics of an effective Indicator • It is normal flora of warm-blooded animals • It is present when pathogens are present, and undetected in uncontaminated samples • The indicator should be found in greater concentrations than pathogens. • It should have a similar resistance to environmental stress and water treatment processes as the pathogen.

5. Characteristics of an effective Indicator • It must require a host for replication. (eliminates replication in the environment) • Rapid, easy, and inexpensive detection methods • Nonpathogenic

6. Types of indicator organisms • Total coliforms • First group of indicators developed • Problematic because of the ability of some species to replicate in the environment • Fecal coliforms • Subgroup of Total coliforms • Restricted to fecal origins • Fecal Streptococci • Primarily an indication of animal fecal pollution • FC/FS ratio

7. Types of indicator organisms • Anaerobic bacteria • Clostridium: spore forming bacteria / environmental resistance • Bacteroides: limited environmental resistance • Bacteriophage • Viruses that require certain bacterial hosts for replication • Indication of both bacterial and viral contamination.