The main objective of. this research is to exhibit the possibility of designing an expert system, whose primary task is to assist the agencies that are responsible for environment protection in applying a control on pollution caused by discharging different industrial wastes into water sources, by ither giving permission to discharge the industrial wastes directly into a available water source , or requesting treatment of: the wastes before discharging them. To reach this objective,several factors are taken into account. These includes; the characteristics of waste, the regulations of environmental protection, the information about the point of discharge, and information about the factory that produces the wastes. The expert system is called WRES, an acronym for: Water pollution Regulation Expert System, Through interaction between WRES and the user,the system will collect all the required information about the above factors, by asking the user a series of questions. Having done that, WRES will check the concentration of the different pollutants ,that occur in the discharged waste, against the permitted values of pollutants discharge into water source