This Order establishes calculation method of quantity and quality of effluent waste water discharged by the residents to urban sewerage system. The scope of the Methodical Instruction shall be to ensure: (a) trouble-free operation of urban sewerage system and to protect against negative impact of pollutants contained in effluent waste water; (b) safe operation of urban sewerage system; (c) reduction of discharge of effluent waste water to urban sewerage system; and (d) rational management and pr