Problems and perspectives concerning reclaimed water reuse in urban and agricultural areas

Abstract

Reclaimed water reuse is at present encouraged throughout the world with regulations and international agency guidelines. This reuse allows the saving of water resources, a reduction in the use of high value resources for nonpotable purposes and a lower impact of discharged water on rivers. The technological perspectives for water reuse involves the evaluation of the quality standards that are required for different uses, the treatment, transport and distribution costs, and the benefits that can be obtained from the reduction of supply costs for the users. Four significant experiences in refining treatments, performed on reclaimed municipal and industrial wastewaters in the Piedmont area (Northwest Italy), are proposed in this work: a plant in a big town area (SMAT, Castiglione Torinese, Turin), a plant in an industrial area (SMAT, Collegno, Turin), and two plants in a mixed agriculturalindustrial context (AMIAS, Novi Ligure and Cassano Spinola, Alessandria). The four plants have developed different refining technologies, and therefore obtained different effluent qualities, with different treatment costs. The potential users of the refined water from the four plants were carefully evaluated, with particular reference to industrial activities and also considering agricultural reuse, and an economic analysis was performed. The reuse of reclaimed water for nonpotable purposes is a valid solution in case of resource shortages and it is an alternative to the aqueduct supply that has undeniable environmental benefits.