Primary prevention includes immunization against diseases and public health education about diseases. Primary prevention reduces the rate of chronic diseases. "No life without water" is a common saying depending upon the fact that water is one of the naturally occurring upon the fact that water is one of the naturally occurring essential requirements. Domestic, industrial wastes and sewage discharged contaminate the quality of water and make it unsafe for human consumption. Primary prevention prevents ill health related to water. Chlorination and filtration of public water supply is essential. Public health nutrition about good nutrition comes under primary prevention.