Waste Load Allocation in Sefidrud Using Water Quality Trading

Water quality trading (WQT) is a novel framework for surface water quality management. This research studies the optimal waste load allocation (WLA) in regard based on BOD parameter in downstream of Sefidrud River. For this purpose, the river is simulated by Qual2kw software and the total maximum daily loads (TMDLs) required are determined. The impact factors of pollutes are also specified using sensitivity analysis and normalized. The optimal WLA is defined through total abatement cost functions and impact factors in which the minimization of total cost is an objective. The analytical results show that WLA based on TMDLs may save 10 percents economically in comparison with the conventional command and control policy in which water quality index (WQI) may increase 20 units in regard. Moreover, WQT also develops cost savings to about 26 percents in which 418 credits may be traded. Here, the industrial and domestic sources that have high impact factors or low marginal costs are assigned as permit sellers. The primary permit price is also estimated within the recommended market. In addition, in long term, the efficiency of market is confirmed in which 466 credits may be traded and save 10 percent in overall.