Indicator Organisms in Wastewater Treatment Wetlands

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Indicator Organisms in Wastewater Treatment
Wetlands

• Jepson Sutton
• SWES 574
• 10-31-02

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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.

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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.

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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.

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Characteristics of an effective Indicator

• It must require a host for replication.
  (eliminates replication in the environment)
• Rapid, easy, and inexpensive detection methods
• Nonpathogenic

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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

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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.