Recycling and Reuse of Treated Wastewater: Challenges and Perspectives – The Example of the Júcar River Basin District and the Albufera Lake

Abstract

The reuse of reclaimed water is a non-conventional hydrological resource that together with desalination constitutes an important pillar for the integrated water resources management in the Mediterranean, where climate change aggravates the stress on this already very vulnerable region.

The here presented work provides information about two recent documents elaborated in Spain to enforce an increasing use of reused water: the Royal Decree 1620/2007 and the draft National Water Reuse Plan. The first text gives the basic conditions, from a legal and a sanitary water quality point of view, to ensure a proper reuse, while the second presents a series of actions to be financed by the state that permit the incorporation of up to 249 hm³ of additional water with an investment of 344 million euro in 2009–2015.

This document also describes the main reuse actions in the territory of the Júcar River Basin District with interesting characteristics and the corresponding strategies included in the Programme of Measures of the Júcar River Basin Management Plan. This Programme of Measures aims to satisfy water demands and at the same time to achieve the good status of water bodies, especially with regard to the good quantitative status of the groundwater bodies, which are jeopardized by an intensive use of resources. Therefore, reuse actions have been included in the Horizon 2010–2021 of the Programme of Measures that will contribute with an increase of 160 hm³ of the reused water volume and a related investment of 431 million euro.

Those reuse actions, which are located in the vicinity of the Albufera wetland, are outstanding in this set of reuse actions. This wetland is characterized by an important availability of properly treated water resources, and a large irrigated area and was declared Ramsar wetland of international importance, but suffers from eutrophication problems. This set of features leads the Júcar River Basin Authority to propose an investment of 92 million euro in reuse actions that allow a volume increase for agricultural and environmental uses of 40 and 35 hm³, respectively. The purpose of these activities is to improve the quality of certain direct effluents to the wetland and to ensure a contribution that is adequate and stable in time regarding quantity and quality, and that also includes an additional treatment with green filters. These actions are complemented with an intense quality and quantity modelling that ensures the environmental improvement of the wetland.