Buoys, balloons, armbands around the arms … Faced with the heat in the sky of Yvelines, between 300 and 500 people, families for the most part, were able to cool off in the water of the ponds of Holland Saturday after -midday. Can they do it next week? The question arises after the proliferation of “cyanobacteria”, nicknamed “blue algae”, these last years. Swimming had even been prohibited between July 13 and 22 after the measures of the regional health agency which revealed a level of toxicity potentially dangerous to health. On the other hand, water activities and access to the beach had been maintained.
In case of too high toxicity, “humans may experience redness, burning“, specifies Jacques Formenty, mayor of Les Bréviaires in charge of the police of the site, “and you have to be careful with small animals especially, dogs that want to drink water can have very violent diarrhea“.
The spread of toxins has also been monitored by the Regional Health Agency for 14 years: “until 2020, it was a check on cyanobacteria, as soon as there were any, the beaches were closed. Since this year, _the ARS carries out weekly toxicity checks_. As soon as there is a danger, we close“, continues the mayor.
A loss of 20,000 euros in 2021
The development of these bacteria is particularly linked to global warming and the situation of the pond basin. “It is not fed by a natural river, the water inflows simply come from precipitation“, explains Thomas Gourlan, president of the Rambouillet Territoires agglomeration, “we know that with global warming, the precipitation is a little less intense and the heat more important and therefore the cyanobacterium grows faster“.
The last ARS check took place on Friday, officials are waiting for Monday or Tuesday to find out if swimming can be authorized next week. Last year she was banned for a month and a half. With entry prices of €5.20 for adults and €3.60 for children, the loss was estimated at €20,000.