Tense atmosphere this Wednesday October 16 in Biganos. At the entrance to the wastewater treatment plant of this small town in Gironde, a few dozen oyster farmers, supervised by municipal gendarmes and police officers, had come “put pressure” on the mayors leading Siba, the intercommunal union of the Arcachon basin.
They held a highly anticipated press conference there: this organization, in charge of the collection and sanitation of the 12 municipalities and their 140,000 inhabitants, came out of its silence for the first time since the pollution of the basin at the end of 2023 by wastewater discharges.
“We await his statements with some anxiety,” confided Thierry Lafon, shellfish farmer and leader of Adeba (association for the defense of the basin’s waters). “We cannot accept that the quality of the natural environment, our working tool, becomes a dumping ground because of dysfunctions and development choices in this territory, which is a wetland. »
Ban on the sale of shellfish
In November and December 2023, following heavy rains which caused the saturation of the sanitation networks, deliberate discharges of dirty water into the environment led to norovirus contamination of the basin’s oysters and numerous cases of poisoning. food.
Just before the holidays, the Gironde prefecture banned the sale of shellfish. A disaster for oyster farmers who make the majority of their turnover during this period. They fear that the situation will happen again this year.
Investigation for “ecocide”
In January, the Bordeaux public prosecutor’s office opened an investigation into “ecocide” after complaints filed by several environmental defense and oyster farmers associations, which pointed to dysfunctions on the Siba side. And in April, at the end of an extremely rare environmental criminal summary procedure initiated by Sepanso, one of these associations, the Bordeaux liberties judge ordered the union to carry out emergency work within six months on two of its safety pools which had overflowed.
Since then, no information has leaked, with the exception of one “bring to notice” of Siba, a document by which he requested, while waiting for the works, authorization to return the overflows from these basins to natural environments in the event of “unusual rain”. This would be contrary to the principle of “zero discharge” into the environment, in force in the basin since the creation of a circular wastewater collector in 1974.
Outcry from environmental activists and oyster farmers: they demonstrated on October 10 in Arcachon against these “permit to pollute”the investigation of which is in progress by the State services.
On Wednesday, Yves Foulon, president of Siba, therefore wanted to express in the preamble “the anger and indignation of the mayors in the face of the unfair accusations made against the union by two elected officials, Vital Baude and Sophie Panonacle (regional environmentalist advisor and Macronist MP for Arcachon, Editor’s note) and three professional associations and corporations that offer nothing.”
The mayor of Arcachon sought to put the situation of the basin into perspective: if last year it experienced “unprecedented rain intensities” – 1.20 m of rain in six months, compared to 0.5 m on average, causing “inevitable overflows” – it “did not suffer the same difficulties recently experienced in Marseille – whose streets were twice under 60 cm of water –, in the tortured Nord Pas-de-Calais or the valley of ‘Devastated Asp’ by floods.
Accelerate the plan
He also affirmed that Siba “is completely legal, and was so before the complaints”. The creation of storm overflows on safety basins “to concentrate and therefore limit overflows” in nature, and to prevent homes from being flooded, was in fact imposed by the courts in its order, we read in its press kit.
And to continue: “Siba, a fervent defender of zero emissions in the environment, has maintained its course, but it is clear that the acceleration of climate change (l’) requires us to adapt and take measures similar to those adopted elsewhere in France; time to carry out the ambitious program of works on rainwater. »
The basin’s elected officials want to accelerate this plan, with 11 million euros of investments committed within five years, instead of the ten years initially planned. Co-financed by the State and the Water Agency, this plan includes expanding existing rainwater pipes and creating natural expansion basins upstream of urban areas, in order to slow down the flow of water.
In addition to this envelope, a multi-year plan of 36 million euros was approved, plus 30 million euros to create a new wastewater treatment plant in the north of the basin, between Cap Ferret and Arès. The treated water will be released into the environment, by infiltration, and not returned to the sea.
