Developing roadmaps for the sustainable management of the urban water cycle: the case of ww reuse in Athens

Abstract

In the context of water scarcity the interest in the reuse of treated wastewater as an alternative resource for non-potable uses has increased. Recent changes in the regulatory framework (JMD 145116/2011) and the introduction of guidelines and standards for reuse in Greece make a study of the implementation of wastewater reuse in Athens timely. The paper uses state-of-art metabolism modelling tools and approaches to develop and quantify a set of ¿roadmaps¿ towards wastewater reuse for the water company of Athens with the intention to support its sustainability agenda. The paper presents the candidate areas for wastewater reuse in Athens and describes the criteria for their designation, including assessment of suitable uses (such as industrial use, reforestation, crop irrigation, ground water recharge and urban and peri-urban uses) and estimation of their proximity to major Wastewater Treatment Plants (WWTPs). Different roadmaps are developed to assess the feasibility and quantify the effect of a progressive replacement of potable water with reclaimed water for the targeted uses and users. Each step of these roadmaps is simulated using the Urban Water Optioneering Tool (UWOT) which simulates and optimizes the entire urban water cycle, from source to tap. The paper concludes with a comparative assessment of the roadmaps based on the results of the simulations, taking into account the reduction of total water abstractions and the energy consumption for pumping and treatment of potable and reclaimed water. The results indicate that wastewater reuse can improve (a) the quantity and quality of surface and underground water; (b) the ecosystem services; (c) the efficiency of water use; and (d) the reliability of the existing water supply system of Athens.