Social & Preventive Medicine All of the following statements about purification of water are true except: A Presence of Clostridial spores indicate recent contamination of water B Coliforms must not be detectable in any 100 ml sample of drinking water C Sodium thiosulphate is used to neutralize chlorine D Coliforms may be detected by multiple tube method & indole production 💡 Explanation All of the following statements about purification of water are true except: ✓ Correct Answer: A. Presence of Clostridial spores indicate recent contamination of water