October 1, 2015. Approved by the Tianjin Municipal Government, the Municipal Environmental Protection Bureau, the Municipal Market Supervision Commission on the 28th jointly issued a mandatory local standard "Tianjin urban wastewater treatment plant pollutant discharge standards", and formally implemented on October 1, 2015, the "standard" will be divided into the Tianjin municipal wastewater treatment plant pollutant control project limits of the A, B, C three levels of standards, of which: the main indicators of the A standard to reach the level of surface water class IV; B standard main indicators to reach the level of surface water class V; C standard is consistent with the national standard of Class I A. Tianjin municipal sewage treatment plant on October 1, 2015 began to implement the local standards. The implementation of the "Pollutant Discharge Standards for Tianjin Urban Sewage Treatment Plants" will realize the close connection between the effluent standards of urban sewage treatment plants and the environmental quality standards for surface water, the functional requirements of the water environment of the receiving water bodies, and the relevant standards for sewage reclamation and reuse.