The standard was formulated for the purpose of implementing the Environmental Protection Law of the People's Republic of China, Law of the People's Republic of China on Prevention and Control of Water Pollution and Marine Environmental Protection Law of the People's Republic of China, controlling water pollution, protecting good water quality of surface water like rivers, lakes, canals, reservoirs and ocean as well as groundwater. It also serves the purpose of maintaining human health and eco balance and promoting national economic development and urban and rural development. The standard provides the upper limit for 69 pollutant concentrations and the total allowed water discharge for some industries in different period according to the flow direction of wastewater. It applies to existing water treatment facilities for discharge management, environmental impact assessment, design, check upon completion of related construction projects and their management after being put into operation.
