To our knowledge, this is a unique case in France. Nestled a few kilometers from the famous Pointe du Raz, the island of Sein seems to be the only one to drink sea water in France. On this pebble in southern Finistère, there are between 120 and 150 inhabitants in winter. A figure that rises to a thousand during the summer season when a few tourists take the boat to breathe in the spray from the Atlantic. Here, as in the whole country, there are concerns about the consequences of the low rainfall at the start of the year. According to Météo-France, the country has not experienced any real rain for thirty-two days, the longest meteorological drought ever recorded. Data that raise fears of a break in the supply of drinking water in certain regions. But not in Sein, where the available reservoir is immense. The problem is that it is as salty as the bill of the taxpayers who buy it. Welcome to the land of sea water.
The island cannot pump during storms
Before reaching the Sénans tap, the water from the Atlantic must obviously be treated. For this, the island has two osmosis units, which arrived about twenty years ago. Before that, a boiler was used. Developed by the company SLCE, reverse osmosis units are normally fitted to French Navy ships in order to desalinate the sea water on board. “We have two. The largest can treat up to 140 m³ of water per day, the smallest comes as an extra and can treat 30 m³,” explains Mayor Didier Fouquet. More than enough to meet the needs of the inhabitants, even in summer, but we must not forget to fill the reserves. Regularly confronted with storms, the island cannot pump in all weathers and must sometimes cut the valves. “But we have never been deprived of water”, assures the mayor. In January, a blackout had disrupted the supply and the municipality had distributed bottled water.
On the island, “everyone is aware of the scarcity of water” comments the owner of a restaurant. Here, almost all the houses are equipped with rainwater collectors and waste has no place. A strange case of a saboteur who “would have fun” wasting drinking water has been agitating the island for several months. The municipality filed a complaint, hoping to put an end to this regular waste. Because in Sein, water is a precious good. And above all a very expensive good. “People always think seawater is free and it doesn’t cost us much. But it’s just the opposite! “, assures the mayor. Despite the financial efforts of the municipality, the cubic meter of drinking water is billed at 7.55 euros, four times more than on the continent, where it costs an average of 2 euros for 1,000 liters. “The products we use to treat water are very expensive for us, such as replacing equipment that wears out over time.”
This huge cost also explains why the island of Sein is one of the rare territories not to be integrated into a community of municipalities. “Nobody wants us,” laughs the mayor. Impossible either to pipe the bottom of the ocean for 26 kilometers. The attempt made in the past with telephone cables had not withstood the onslaught of the swell.
What does unsalted water taste like?
And this desalinated water, what does it taste like? “The same as on the continent”, assures the mayor. Reached by telephone, a couple from the island are more reserved. “The salt, we do not feel it. But sometimes, it has a rust color, it has a little different taste, ”explain this man and this woman who prefer to remain anonymous. They even noticed a strange phenomenon. In Sein, a hot water tank would last only two or three years, where it can live up to fifteen years on the continent. “In Sein, everything that is metallic does not last very long”, tempers the mayor Didier Fouquet, who had never heard of this inconvenience. The ocean is generous but does not give gifts.