The standard was formulated for the purpose of implementing the Environmental Protection Law of the People's Republic of China and the Law of the People's Republic of China on Prevention and Control of Water Pollution, preventing water pollution, protecting surface water quality and human health as well as maintaining sound eco system. According to different environmental functions of surface water and targets for its protection, the standards provide indexes need to be controlled and the limits for water environment quality, analysis methods for water quality assessment and projects, enforcement and supervision of the standards. The standards apply to all useable surface waters within the territory of P.R. China including rivers, lakes, canals, channels and water reservoirs. Waters with specific functions shall apply special water quality standards accordingly.

Environmental quality standard for surface water  (GB 3838-2002)