On March 17, Prefect Chavanne signed a formal notice targeting the departmental union Eau47. The latter must implement “the actions and studies necessary to restore water quality in accordance with regulatory limits” for approximately 10,000 inhabitants of Néracais and Mézinais. This part of the population of Albret uses water from the Baïse after treatment in the Nazareth plant located between Moncrabeau and Nérac.
No risk
Useful clarification provided by Gérard Pénidon the director of this departmental union, “it is a regulatory danger, not a health danger.” In other words, the quality of the drinking water taken and treated by the station is not called into question for human consumption. The Regional Health Agency (ARS) and the prefecture also say it in the decree signed by the prefect, “the presence of metolachlor (in the water distributed by the Nazareth plant, Editor’s note) has a” content greater than the quality limit but lower than the maximum health values […] It does not pose a health risk for the population, but the distribution of water that does not comply with the quality limits must be reduced as much as possible. “
The health authorities had alerted in 2013 of the presence of this herbicide authorized in the treatment of crops (read below). However, the Nazareth factory does not have the capacity to transform the samples in Baïse into water and even less into wine. “Even if it is modern, as the Pinel-Hauterive wastewater treatment plant can be, the plant is not designed for this treatment in particular.” Eau 47 recovered the baby with the bath water in 2020, when the delegatee Veolia left the premises, without having really convinced of his ability to eradicate metolachlor from drinking tap water. “We must therefore adapt the plant’s treatment process to this molecule.”
Delivery in 2022
The envisaged deadlines suggest that Nazareth will touch the Holy Grail in 2022, after an expertise, a series of administrative steps and the work itself. for a period of six to twelve months, after the consultation procedure with specialized companies. The sum is tidy “but the investment will not have an impact on the price of water” affirms Gérard Pénidon “even if the sum cannot be invested elsewhere.”
Maximum thresholds sometimes exceeded
at the Nazareth factory
What is the ARS about? The metolachlor referred to in the prefectural decree is a chemical product, a weedkiller. It has been banned in France since 2003, that is to say five years before the commissioning of the Nazareth treatment plant, but it has been replaced by a first cousin, S-metolachlor.
Several factors
“In fact,” continues Gérard Pénidon, “it is the same molecule. We did not know that it existed before the beginning of the 2010s.” It is used in products available to farmers. In raw water before treatment, the limit value is 2 micrograms. In drinking water, it must be less than 0.1. These thresholds were sometimes exceeded in the analyzes of raw water and water made drinkable after treatment by the Nazareth station.
As often, it is necessary to seek the causes of the evil upstream. The collection point on the Baïse is at the entrance to Lot-et-Garonne, the river arrives in a straight line and in the order of appearance on the screen of the Hautes-Pyrénées and the Gers, departments where the major crops predominate, where industry is not predominant, where population density is not urban.
According to Eau 47, there are a series of factors that can explain the presence at a high rate but in accordance with sanitary standards of this product. The land “is often tilled downhill, and this same land is often left bare during the winter.” Without becoming public prosecutor against the use of these chemicals, Gérard Pénidon has been measuring the impact of their use for twenty years. And the director of Eau 47 asked himself aloud: “Is it the fault of the farmers, or should we rather focus on the distributors, on those who make these products available to them?”
Three pages
Commissioned in 2008, the Nazareth water treatment plant was designed to overcome other known molecules such as atrazine, the active substance of a pesticide, simazine molecule of a phytosanitary product from the pesticide family. “In addition to the usual treatments, this represents a regular additional cost for the Nazareth station. And the same Gérard Pénidon brandishing an official three-page document containing a list of phytosanitary products used in agriculture and requiring the raw water to pass through the filters of the treatment stations before becoming drinkable on the family table.
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