The primary standard is divided into A standard and B standard, urban sewage treatment plant effluent discharged into the key watersheds identified by the state and the province and lakes, reservoirs and other closed or semi-enclosed waters, the implementation of the first level of the standard in the A standard;
Discharge into GB3838 surface water Ⅲ functional waters to implement the B standard of the primary standards.
The secondary standards for water discharged into GB3838 Class VI, V waters;
Tertiary standards for non-focused control of watersheds and non-water protection areas of the town of the establishment of the sewage treatment plant, according to the local economic conditions and water pollution control requirements, the use of a level of enhanced treatment of the industry when the implementation. However, the location of secondary treatment facilities must be reserved to achieve secondary standards in stages. You can refer to it.