Outcry in the Arcachon Basin over a possible "pollution permit"

The request was made by Siba, the inter-municipal union managing the Basin's sanitation network, to the Departmental Directorate of Territories and the Sea (DDTM).

The aim? To amend the regulations "to include unusual climatic situations, during which the collection of raw wastewater is no longer able to guarantee its transport to the treatment plants without mobilizing the facilities beyond their capacity".

Concretely: beyond 70 mm of rain (70 litres per square metre) accumulated over seven consecutive days, overflows caused by saturation of the system, due to this intense precipitation, would be tolerated by the administrative authority.

The file is "under investigation", according to the Gironde prefecture. But a green light from the DDTM would be similar to a "pollution permit", environmental associations are already protesting.

Among them, Adeba notes that the rainfall threshold used is not unusual: it has been recorded "two to four times per year" since 2012 in years with little rain, "six to eight times" in the wettest - or "around forty episodes in ten years".

Epidemic

"We cannot imagine that such discharges of untreated wastewater into the natural environment occur several times a year," says the Regional Committee of Oyster Farmers, who were dearly affected by last winter's pollution.

Between Christmas and New Year, the sale of local oysters was banned for a month following an outbreak of gastroenteritis among their consumers, a major blow for the industry, which makes half of its sales during the holidays.

The Macronist MP for the Bassin, Sophie Panonacle, challenged the prefect, describing the Siba request as "a serious attack on the future of oyster farming and fishing, on public health and on the image" of the territory.

Asked by AFP on several occasions, the intercommunal union did not make any comments. Its president Yves Foulon, also LR mayor of Arcachon, is hiding behind a court injunction, according to comments reported by the newspaper Sud Ouest.

On April 2, the observation of wastewater discharges into nature led the courts, in the context of an environmental criminal referral, to order emergency measures to put an end to them.

"There can be no question of authorising overflows," stated a Bordeaux magistrate at the time. She gave Siba four months to ask the DDTM for authorisation to build a "storm overflow" on each of the safety basins of the sanitation network.

"Concreting"

Solution proposed "by Siba itself" during the procedure, underlines Jacques Storelli, president of the coordination of environmental associations of the Basin (Ceba), denouncing a "sham". For him, the judge was "deceived" because the spillways "will in no way prevent" pollution.

On the contrary: the planned developments aim to evacuate the overflow from the safety basins, in a controlled manner of course - in order to carry out analyses and measurements, explains Siba in a document sent to the DDTM - but always into nature.

At the beginning of March, the union announced, jointly with the State, an "acceleration" of investments dedicated to the sanitation network, to the tune of 11 million euros.

"What have they done since then?" asks Ceba, which is calling for a "war device" in the face of the emergency: large pumps and appropriate storage means to empty the safety basins when they overflow.

During the autumn and then last winter, heavy rainfall saturated the network, with rainwater flowing into the manholes of the sanitation system... unable to infiltrate or flow elsewhere, deplores Adeba.

Its president Thierry Lafon criticizes the "concreting" that waterproofs the soil and fills in the ditches, in an environment already prone to flooding due to the topography and the outcropping of the water tables. And of building permits issued "in violation of the rules", he accuses.

While the Arcachon Basin development plan provides for thousands of additional homes by 2040, the associations are calling for a "fundamental rethink" of local urban planning practices.