You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information.
What is All of the following statements about purification of water are true except - and explain in detail?
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