Which of the following is used as an indicator for recent fecal contamination of water?
High-Yield Explanation
ANSWER: (D) StreptococciREF: Park 20th edition page 630BIOLOGICAL INDICATORS OF FECAL CONTAMINATION OF WATER:Coliforms: E.coli (fecal group), Klebsiella aerogens (non fecal group)Fecal streptococci - they indicate recent contamination of waterCLperferingens - they resist chlorination in doses normally used.Note: No E. coli or thermotolerant bacteria should be identified in any 100 ml of sample of water intended for drinking, or treated water entering distribution system.