Water reuse planning and management: the point of view of a contractor-operator

This paper aims at presenting a point of view that, in the author’s opinion, is not considered sufficiently in discussion forums regarding water treatment. This point of view is the one provided in Spain by the so called contractor-operator companies, which are the ones with most practical experience in Spain. From this business point of view, it is reasoned that the water reuse market can be important in the medium and long term because of its volume and the fact that there exists no social-political refusal. So that this market could develop rapidly and without great obstacles, a series of conditions required for it are indicated: a legal framework, quality guidelines, and a basic definition of treatments according to technical considerations and not ideological ones. Finally, it is stressed that treatments should be robust and reliable, and in addition should permit a standardization in the areas they are to be applied.

In the whole development of the market of construction and operation of any type of water treatment plant in Spain, the companies called contractors-operators have been a leading actor in their own achievements and are in a good condition to continue being so at present, generally speaking, and particularly in the case of reuse. The market of plant construction, retrofitting and operation aiming at reuse is important in Spain when considering it at medium and long terms. The socio-political context and public opinion seem to be favorable to reuse, although there should be more information addressed fundamentally to public opinion. To consolidate reuse and its introduction and company activity in this field more rapidly the following is required: a) A state legal framework b) Consequently, clear quality guidelines, with a not very wide range, so that a quality could be applied to several reuse types, elaborated with the participation of companies. c) Definition of correct treatments, again with the participation of companies. Without reaching excessive precisions about the process to use in each stage of the treatment. With regard to the treatments to use, the following starting points should be considered in Spain: • Normally, there are already plants with secondary treatment with outlet qualities different for each case. • If the plant has nutrients removal or if it is being retrofitted with that objective, this situation is a very important advantage and not a disadvantage. • The selection of the most correct solution must take into account the existing secondary treatment plant, population size, weather and other local conditions. • The processes have to be robust and reliable. One should not aim at solutions that do not fulfill this condition for extra-technical reasons. To engage in obliging solutions theoretically “little aggressive” in many cases in Spain has ended up too often discrediting the same treatments intended to promote. The fundamental thing is to achieve the quality required, and the rest of considerations, which many times are put before, should be considered but subordinated to the target quality. • To optimize technically and economically the reuse systems that cover several plants in the same area, it is convenient to homogenize the treatments, as much as possible, and not to carry out the testing of different processes in each area or group of plants, without having solid reasons for it, because in this case people’s health is more at risk than when the treated water is dumped in a river.