The most important thing under the water supply schemes isthe selection of source of water, which should be reliable and have minimum impurities. After the selection of source of water, the next step isto construct intake works to collect it and carry up to treatment plants. At thetreatment plants the water will be treated. Types of treatment processesdirectly depend on the impurities in water at the source and the quality ofwater required by the consumers. Government of India has passed independentlegislation on water pollution and air pollution. It has become compulsory forthe industries to take clearance from their area Pollution Control Boardsbefore setting new industries. It is the duty of industrialists totreat all types of effluents - gases, solid and semi-solid in water. Variousacts for the prevention and control of pollutionhave been implemented by the state as well central Govt. Attempt have been madeto add most of these acts in WaterSupply And Sanitary Engineering. On the demand of students, a whole new part,Lab Manual on Public Health Engineering, has been added. The book will serve the purpose ofa comprehensiveand complete standard text book on the subject meeting the needs of students,professors, engineers in the field.