The phenomenon is a problem exacerbated by drought: groundwater supplies half of urban consumption
According to data from the Catalan Water Agency (ACA) that EL PERIÓDICO has accessed, six of the 15 bodies of water subterranean shorelines are found in disrepair by saline intrusion. And three more are under threat. The rest are kept in an optimal situation. These data reinforce the idea that there is still a lot of work to be done to improve the flimsy groundwater map of Catalonia.
Why does this phenomenon occur? “The big culprit is overexploitation of this resource. If you extract more water than is naturally recharged, the sea easily penetrates the aquifer and damages it,” he explains. Santiago M. Barajas, member of Ecologists in Action. If the aquifer is completely full, seawater hits a freshwater barrier. On the other hand, when reserves fall, the sea is free to interfere.
decks mark one difference important, and worrisome, relationship between coastal and inland groundwater: “Inland aquifers that have been overexploited can be recovered if the extractions are stopped. The case of contamination is another story. On the other hand, in coastal groundwater, when the salt has already entered, no matter how much more water is not extracted, the salt concentration 35 grams per liter it will still be there“.
“If you extract more water than is recharged naturally, the sea easily penetrates the aquifer and damages it”
Santiago M. Barajas, Ecologists in Action
The six Catalan aquifers that suffer saline intrusion are in the Cap de Creusin the lower Costa Bravain it low campin the final stretch of the Baix terin it Llobregat delta and in the Alcanar flat. It is not a problem of a specific area. It is common along the entire coastline.
In reality, all aquifers of Spain close to the sea are severely threatened by this salinization process. According to ACA data, these six bodies of water on alert are still they are not 100% contaminated.
Fragile Llobregat
Therefore, there is still hope, since, in many cases, it is a matter of specific effects. In other words, the aquifers conserve fresh water intact in some areas, which is why they continue to be exploited for supply or for industrial or agricultural uses. In times of drought, these aquifers tend to be a strategic resource.
In fact, many of the wells used in the Barcelona area are located on the Llobregat delta aquifer, one of those stalked by the saline intrusion. This, in addition to complicating urban supply, does not help to solve the precarious state of the principal Barcelona wetland. In 2027 the term to improve the situation of the lagoons is over, which at the moment do not meet the environmental quality requirements established.
The problems for the aquifer of the Llobregat delta began during the works of the port of Barcelona
The problems, for this metropolitan groundwater body, began during the works of the port of Barcelonain the decade of the 90s, when the mouth of the river Llobregat. At that time, the aquifer was exploited more than it should. So, the little fresh water that remained could not do the necessary pressure for prevent the entry of seawater and the fragile balance was broken.
What happens in reach, to give another example, is different. And the causes are not always the same. However, the phenomenon is the same: a even fight between fresh water and salt water. Often those who rig this fightin favor of salt water, are humans.
According to deckseach aquifer is a world: “They cannot be compared to each other. Each one has its shape, its corners. After all, an aquifer is a piece of ground, underground, in which water is stored. But it’s not the same calcareous soil than a silicon substrate”.
“Don’t intervene”
And how can the problem be solved? The Generalitat proposes a moderate use of this resource and proposes recharge aquifers with reclaimed water. In other words, wastewater that not only goes through a treatment plant but also undergoes tertiary treatment.
In addition, freshwater barriers have also been created to stop saline intrusion. However, decks You do not agree with this method. He considers that the extractions must stop completely.
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“I don’t know of any case of an aquifer being replenished with reclaimed water. I’m sure next year there will be a bit more salt. A aquifer is not like a bottlethat you can fill it as you want,” he warns. Instead of what he describes as a “patch,” he defends saving the aquifer from excess salt in another way: “If we stop extracting waterat least the areas where the fresh water is still in good condition will be able to be preserved.”
He is of the opinion that the reclaimed water could be used to purify and consume. “In this way, extractions would be avoided, which would not be necessary, and we would conserve groundwater, a increasingly scarce and valuable asset“, ditch.