Which of the following is not true about water quality estimation -
Spores of Clostridium are capable of surviving in water for a longer time than the coliform group of organisms. The presence of Clostridium spores in the absence of coliform group suggest faecal contamination occurred at some remote time. Park's Textbook of Preventive and Social Medicine, 25th edition, Page No. 781
Chlostridium spores indicate recent contamination
Not more than 5% samples should have coliforms
Sodium thiosulfate added to neutralize chlorine
Coliforms must not be detected in 100 ml sample
Environment and health