• To tackle the drought emergency, up to 100 million euros have been approved for three desalination plants in Gela, Trapani and Porto Empedocle.
• To make seawater drinkable: what once seemed utopian is already a reality in many parts of the world.
• Yet challenges remain, from energy costs to the disposal of pollutants.

Up to 100 million euros for the urgent restoration of three desalination plants, in Gela, Trapani and Porto Empedocle: this is the government's response, contained in the emergency decree and PNRR implementation just converted into law by Parliament, to the water crisis that has been affecting around 2 million people in Sicily for months, with cities such as Palermo, Caltanissetta and Enna subject to water rationing since 7 October of last year. Although it is commonly said — including in many politicians' statements — that new desalination plants are being built, the three facilities in question actually already existed, but had been decommissioned years ago due to excessive operating costs, and are currently not functioning. It would appear, however, that they are now needed once again: a discouraging sign on the climate change front. The funds will be managed by the extraordinary commissioner for Drought appointed by the government. His name is Nicola Dell'Acqua — somewhat ironically.

What is a desalination plant: from utopia to reality

But what exactly is a desalination plant? It is a facility that removes salt and impurities from seawater, making it drinkable and suitable for human, agricultural and industrial use. The most common process is reverse osmosis, in which water is forced through semi-permeable membranes that separate the salt and other harmful substances. Thermal techniques also exist, which evaporate and condense water to separate it from salt, but these are generally more energy-intensive.

While in many parts of the world debate continues over their economic (as seen, the three Sicilian desalination plants cost too much) and environmental sustainability, there are countries where desalination plants have long ceased to be an option and have become a daily necessity. Israel, for example, is a world leader in this sector: the country covers around 70 per cent of its domestic water needs through advanced desalination facilities, such as the Sorek plant, one of the largest in the world. A few months before the outbreak of the Middle East conflict, the Italian government had received Israeli Prime Minister Benjamin Netanyahu in Rome, and there had been explicit discussion of an "Israel model" for water management, with Tel Aviv expressing readiness to help Italy solve the problem of water scarcity.

In the United Arab Emirates, too, where natural water resources are scarce, more than 90 per cent of drinking water comes from desalination. Similarly, in Saudi Arabia and parts of California, desalination plants have become an indispensable solution for ensuring access to water.

But even within Europe there are countries where desalination plants are widely used: Spain is one of those with the highest number of facilities, with around 765 active installations as of 2021, including those in Barcelona, which supply drinking water to millions of residents and tourists. Some countries, such as the Bahamas, the Maldives and Malta, meet almost all of their water needs through desalination. In Italy, a plant was recently installed in Veneto to combat the saltwater intrusion phenomenon threatening the aquifers of the Po Delta.

Is this really the solution?

In our country, 4 per cent of drinking water already comes from desalination plants, particularly on small islands and in coastal regions where saltwater intrusion is rendering many aquifers unusable. But are desalination plants truly the definitive solution? While on one hand they guarantee drinking water, on the other they raise significant environmental concerns: high energy consumption, often derived from fossil fuels, and the disposal of brine, a highly saline by-product which, if released into the sea without adequate treatment, can damage marine ecosystems. Moreover, the production of fresh water through desalination generates approximately 1.5 litres of liquid contaminated with chlorine and copper for every litre of drinking water obtained, making adequate disposal measures necessary. Environmental associations, concerned about the protection of the marine environment and bathing water quality, have also raised specific questions that are still awaiting answers: where will the water to be desalinated be drawn from? And where will the post-treatment effluents be discharged?

These are the reasons why relying entirely on this technology cannot be considered a sustainable long-term solution: investment is needed in efficient infrastructure (today, Sicily's water mains lose more than half the drinking water they carry, 51.6 per cent), waste in agriculture and livestock farming must be reduced through precision techniques and the reuse of wastewater, and more rational water resource management policies must be adopted. But above all, if we have reached the point of having to turn the sea into drinking water to survive, perhaps the time has come to ask ourselves what we can do to prevent this from becoming the only possible alternative.