Juan G. R. For a better use of wastewater in Spain.
Agua y Riego. Nº 1: 3-4, 2009, Alicante, España
The problem of the use of wastewater is an increasingly widespread worldwide, taking into consideration that the world population growth is already around the 6700 million people and generates billions of m3 of wastewater. This coupled with the lack of water in highly populated regions with large agricultural and industrial development is a major challenge for a better use of purified water available.
Water is a fragile resource and most of European water resources are threatened by pollution and over-large to undergo, the European Union in its water policy provides protection from all water bodies its territory, to guarantee the quality of its water resources, which are not as abundant, but limited by what is strategic to keep the required quality. Untreated sewage that are discharged into seas, rivers, wetlands and degraded areas, represent a great risk and have an effect of pollution of the environment around us so the proper cleaning of wastewater plays an important role in preserving a sustainable environment and development of mankind.
At present there are 343 small town in Spain that discharge wastewater without adequate treatment in sensitive areas or in part, sensitive and there are 59 municipalities with over 15,000 people needing treatment systems of waste water so that the Ministry of Environment, Rural and Marine has developed a national plan of action for a solution to sanitation and water purification before 2015 year. However, some difficulties with the treatment of sewage in some regions of the country, there are communities such as Valencia, which is situated in a coastal area, with a large population and a large water deficit that has given importance required for treatment of wastewater, which currently has 460 water treatment plants, refine around 128 litres / person / day, which puts the Valencia community as more purified water per capita in Spain.
With the treatment properly of waste water assure the protection of the environment, returning the water to the required quality, this also purified wastewater can be exploited in various roles in which it must be gave priority to those activities that present less risk to human and animal health, such as cooling for industry, recreation, street cleaning, irrigation of trees, gardening and irrigation of agricultural crops in which the irrigation water is not in direct contact with part of the harvest that eat directly the humans. It must be ensured the health of the people and the ecosystem. Must determine the involvement of the wastewater in the incidence of infectious gastrointestinal diseases and pests, in areas where they used them.
The consumption of vegetables irrigated with wastewater presents a potential risk to public health, especially when foods are consumed raw, since the waste water from urban areas contain high levels of bacteria, viruses, protozoa, nematodes and fungi. It is necessary a very strict control of the quality of wastewater when they are used in vegetable production.
To support the reuse of treated water, the Environment Department of Valencia together with the Ministry driving projects to bring water purified to the irrigation areas, for that it is incorporated tertiary systems into the treatment plants and improve infrastructure connection with the irrigation networks.
Must assess the current status of wastewater reuse in each community and make a systematic plan to implement measures and investments to ensure the objectives proposed. The different works to build requires economic detailed technical studies to facilitate proper selection of them and that allow the costs of operation of the treated wastewater are acceptable to the user. More research should be conducted on the rational use of wastewater in the different activities that use them.