False statement regarding chlorination of water:

(Refer: K. Park’s Textbook of Preventive and Social medicine, 24th edition, pg no: 765, 766) Recommended minimum contact period is 1 hour for chlorination Principles of chlorination Water should be clear, turbid free Chlorine demand should be estimated, which is the amount of chlorine needed to destroy bacteria, oxidize all organic matter, neutralise all ammoniacal substances in water Breakpoint chlorination – The point a which chlorine demand of the water is met Free chlorine begins to appear in water, if further chlorine is added beyond breakpoint Recommended minimum  contact period is 1 hour for chlorination Recommended Residual chlorine for drinking water is 0.5 mg / litre For water bodies, post disaster – 0.7 mg / litre For swimming pool sanitation, it is 1.0 mg/ litre