A seasonal waste load allocation policy in an integrated discharge permit and reclaimed water market

Abstract

This paper intends to assess the seasonal demand for nitrogen discharge permits and its influence on waste load allocation (WLA) strategies. For this purpose, the Sefidrud catchment is analyzed, where the agricultural demands for discharge permits and reclaimed water (RW) are significant and also intermittent. The paper discusses using variable total maximum daily loads and a transferable discharge permit (TDP) with respect to the farming and non-farming seasons to achieve annual economic benefits. However, an integrated TDP and RW market can considerably increase these revenues. Moreover, the latter may provide the flexibility required for practical dynamic WLA and makes it compatible with seasonal demands. The optimal WLA also determines the required wastewater treatment processes. Here, some should be designed and equipped with flexible operational processes. As a result, the novel integrated management approach saves 25% and 13% in comparison with the conventional TDP market in the short and long term, respectively. This framework also recommends the pricing for permits in a year to enhance stakeholders' motivation for active participation. It is concluded that the integrated TDP and RW market, using the recommended treatment processes and dynamic pricing, is an economically attractive and practical policy for seasonal WLA.