How do you water your fields when the rains are getting scarcer? In Spain, the region of Murcia has been relying for years on wastewater, which is almost 100% reused. A model that appeals to many countries.
“Here, the water is still dirty… But in the end it will be clear, without bacteria”, assures, near a rectangular basin, Carlos Lardin, operations manager of Esamur, a public body responsible for managing the wastewater from this territory in the southeast of the Iberian Peninsula.
At his feet, khaki-colored water is bubbling in a degreasing tank, brewed by a powerful blower. A first step before sieving, filtration, biological treatment and settling, necessary to give “a second life” to wastewater, according to this 45-year-old engineer.
Murcia, which claims to be the leading fruit and vegetable producing region in the European Union despite an extremely arid climate, launched a vast challenge 23 years ago to compensate for its chronic deficit of water resources: reuse its wastewater to irrigate its orchards and market gardens.
For this, a network of 100 wastewater treatment plants was built. Stations which, as elsewhere in Europe, recover and sanitize water from the sewers, but with an additional disinfection stage which allows it to be reinjected into the fields.
This treatment, via sand filters and ultraviolet rays, makes it possible to guarantee that the water “is not contaminated” and will not transmit bacteria to fruits and vegetables, “like E.coli” for example, details the head of Esamur.
As a result of this strategy, 98% of the region’s wastewater is now reused, compared to an average of 9% in Spain, 5% in the EU… and 1% in France, according to figures from the Spanish government. A key contribution, as Madrid recently reduced water transfers from the Tagus River, threatened with drying up, to the region of Murcia.
A total of 15 percent of the region’s farmland irrigation comes from wastewater, according to Esamur. “It’s not enough” to cover the needs but “it’s still important”, Judge Feliciano Guillen, head of the association responsible for distributing water among farmers in the region.
An opinion shared by José Peñalver, owner of 10 hectares on the heights of the village of Campos del Rio. “Any resource (in water) is good” to take, “whatever its origin”, slices this 52-year-old apricot producer.
In his field, an automated drip system makes it possible to limit irrigation to what is strictly necessary, at the rate of two hours of watering per day. Without water from recycling, “everything here would be dry”, insists this fifty-year-old, for whom “every drop counts”.
Aware of this challenge and wishing to protect its agriculture threatened by global warming, the Spanish government undertook in mid-May to boost the rate of reuse of wastewater on a national scale, by releasing 1.4 billion euros to build infrastructures similar to those of Murcia.
“Water is a precious resource which can also be recycled… The game is worth the candle”, insisted at the beginning of June the Minister for Ecological Transition Teresa Ribera, judging it necessary to support “small towns”, “which have most difficult to undertake these investments”.
According to the Spanish Association for Desalination and Wastewater Recycling (Aedyr), 27% of the 2,000 Spanish wastewater treatment plants are now able to offer treatments that make water reuse possible. A number that could quickly increase.
Less expensive than the desalination of seawater, the recycling of wastewater is also arousing the interest of other countries – such as France, where President Emmanuel Macron announced at the end of March that he wanted to increase the reuse of water, on the model of Spain.
Enough to increase interest in the example of Murcia. In recent months, “many foreign delegations have come to visit our facilities”, in particular “from Lebanon”, “from Argentina”, “from Germany” and “from France”, confides Carlos Lardin, happy with this enthusiasm.
The opportunity to highlight the advantages of this water resource, called according to him to become essential: “it does not depend on the climate and guarantees a stable quantity for irrigation”.
02/07/2023 07:13:54 – Murcia (Spain) (AFP) – © 2023 AFP
