In this research, the river water quality management is implemented to minimize the costs of environmental protection and to meet the environmental water quality criteria. In order to consider wastewater dischargers role in decision-making and increase the applicability of the proposed waste load allocation programs, different approaches of decision making are used. Firstly, different wastewater treatment scenarios for each discharger are identified and treatment alternatives combined of treatment scenarios are defined. Then for each treatment alternative, penalties due to violations of river water quality standards are calculated using qualitative simulation model (QUAL2KW) and each discharger prioritizes the t reatment alternatives based on their costs of refining and violations fines of the water quality standard. Then, using different social choice, fallback bargaining and multi-criteria decision making methods, the most preferred treatment alternatives are chosen. The results show that the Condorcet Practical and fallback bargaining with impasse (FBI) methods are less costly to enforce dischargers while the environmental water quality criteria are met. Finally, In order to reduce costs and encourage dischargers for participating in the river water quality protection, the most preferred treatment alternatives as initial discharge permits are exchanged among dischargers using the extended trading-ratio system (ETRS). The results of applying the proposed model on a case study, Zarjub River located in north part of Iran, show the model efficiency in development of waste load allocation strategies of rivers. Water pollution trading approach based on results of social choice and fallback bargaining methods reduces costs 1196 and 2039 million Rial, respectively, which contains a relative consensus among dischargers. Also, pollution trading approach based on multi-criteria decision making approach, however, reduces costs to the amount of 7892 million Rial, but it is less acceptable for dischargers. keywords: Waste Load Allocation, Social Choice, Fallback Bargaining, Multi-Criteria Decision Making (MCDM), Extended Trading Ratio System (ETRS)