Juan G. R. Wastewater purification and its use in Spain. Water and Irrigation, Vol: 4, No. 1:5-6, March, 2013, Spain.
Under the conditions of Spain’s autonomous communities there are a group that purify 100% of its wastewater, another group cleans more than 85% of its wastewater and a third group of communities that purify their wastewater from 52 to 80%. The treated wastewater is used primarily to irrigate gardens and landscaping, irrigation of crops for the the production of biofuel, irrigation of pastures, woody crop irrigation, irrigation of golf courses, in clearing roads and sidewalks, in cooling towers, other industrial uses, groundwater recharge, rivers discharge, sending into the sea.
Communities of Madrid, Navarra, La Rioja, Murcia and the autonomous cities of Ceuta and Melilla 100% purified wastewater. The communities of Andalusia, Extremadura, Castilla La Mancha, Galicia and the Vasco Country occupying a total area of 245,504 km2 purged 60 to 80% of its wastewater in accordance with European legislation, the Community of the Canary Islands with an area of 7447 km2 has the lowest rate of clearance with a value of about 52%. The rest of the regions such as Aragon, Cantabria, Catalonia, Castilla Leon, Valencia, Balearic Islands and Asturias purged more than 85% of its wastewater.
The National Plan of Treatment and Purification and the National Water Quality: Treatment and Purification 2007-2015, has been a strong boost in the construction and improvement of sewage treatment plants and has shown interest in the reuse of reclaimed water, they constitute an important solution to the shortage of water resources are of great importance especially in the Mediterranean area. The replacement for certain uses of reclaimed water for prepotable water can increase the net availability of water resources. The degree of use of treated wastewater in Spain is still very low and further uptake corresponds to the Mediterranean, which has a large water deficit.
In the Valencia region with an area of 23,255 km2 and a population of 5,123,511 inhabitants, is located in an area of the Mediterranean basin and treats about 370 million cubic meters per year, of which about 120 million are purged in Pinedo treatment plant, which places it in the first volume of treated water of Valencia and the third of Spain, behind cities such as Madrid and Barcelona, about 50% of treated water is used by Pinedo 1650 farmers free, the rest of the treated water is discharged into the sea and the lagoon. The use of reclaimed water in some areas aimed at orchards and rice fields saves on fertilizers for farmers, since the treated water is composed of various nutrients very beneficial for the development and growth of plants, such as nitrogen, phosphorus, sodium and potassium, among other compounds. Farmers irrigate with treated water to reduce the dose of traditional paid annually, which means savings in fertilizer costs.
It prohibits the direct use of wastewater treated for human consumption, except in emergency or disaster situations, in which checks and guarantees by fixing the health authorities, may be permitted as a transitional use. The treated wastewater is used primarily to irrigate gardens and landscaping, irrigation of crops for biodiesel production, irrigation of pastures, woody crop irrigation, irrigation of golf courses, groundwater recharge, rivers discharge, sending into sea, in clearing roads and sidewalks, in cooling towers and evaporative condensers, other industrial uses. For use in irrigation in certain crops treated wastewater must meet requirements: the content of salts and elements phytotoxic levels, the organic compounds, the content of pathogenic microorganisms, the content of heavy metals, other specifications .
The Plan of Water Quality is a great opportunity to reuse treated water, forcing treating waste water from a large number of municipalities discharged without prior treatment and to renew or extend deficient purification treatments, dramatically improving the ability of treated water for further regeneration and reuse. The degree of contamination of the residual water is crucial to designing the treatment process will be more complex and more expensive when more contaminants be removed. It has done a great job in Spain on wastewater treatment and use, but there is still a great effort to implement, in achieving the objectives.