The indicator agents to determine fecal pollution of drinking water is:
Ans (d) E. coliRef: Park 23eJ P 720-21* Ideally, drinking water shouldn't contain any organism known to be pathogenic.* The primary bacterial indicator recommended as a bacteriological indicator is the coliform group of organisms as a whole. These include both fecal and non-fecal organisms.* Typical example of the fecal group is E. coli (single best indicator) and of the non-faecal group, Klebsiella aerogens.Reasons why foliform organisms are chosen as indicators of fecal pollution rater than the water borne pathogens directly* Constant presence of coliform organisms in great abundance in human intestine. These organisms are foreign to potable water. Therefore their presence is looked upon as evidence of fecal contamination.* They are easily detected by culture methods* Longer survival as compared to other water borne pathogens* They have greater resistance to the forces of natural purification, as compared to water borne pathogensOther Indicators Include* Faecal streptococci: Faecal streptococci regularly occur in faeces, but in much smaller numbers than E. coll. Their presence is regarded as important confirmatory evidence of recent faecal pollution of water.* Cl. perfringens: They also occur regularly in faeces and their spores are capable of surviving in water for a longer time than organisms of the coliform group. So, the presence of spores in the absence of the coliform group, suggests that faecal contamination occurred at some remote time.
Proteus species
Coagulase-negative staphylococcus
Klebsieila species
E. coli
Water