More than a quarter of groundwater monitoring stations in France, the country’s primary source of drinking water, have measured water contamination above environmental standards for at least one substance since 2016, according to a survey by the newspaper Le Monde published Wednesday. Out of nearly 24,700 stations, 6,900, or 28%, recorded at least one exceedance of the environmental quality threshold values between 2016 and 2023 for one or more contaminants, analyzes the survey, the French part of a European project on water pollution. underground waters.
Le Monde focused on a list of around 300 contaminants, including pesticides, nitrates, solvents, bisphenol A, certain PFAS (so-called “eternal pollutants”) and even medicines. By combining data from the 2016-2021 period sent by the French authorities to Brussels with those from the National Bank for Access to Groundwater Data (Ades), which extends until 2023, the daily draws up a map “ molecule by molecule” of groundwater pollution in France, which provides two thirds of drinking water.
This work was carried out as part of the “Under the surface” project, carried out with six European media, at the initiative of the Spanish online media Datadista. Pesticides, the primary source of groundwater contamination, were detected in 97% of stations and exceeded standards in nearly 20% of them, located mainly in the large cereal-producing plains of northern France (Beauce, Picardy, Champagne), where phytosanitary treatments are more frequent.
Pollutants of industrial origin exceed maximum concentrations in 460 stations, mainly in industrial basins in Hauts-de-France, Center or Lyonnais. Trichlorethylene and tetrachlorethylene, classified as probable carcinogens, are among the most measured substances.
The journal also identifies exceedances for major polycyclic aromatic hydrocarbons (PAHs), pollutants generated primarily during the incomplete combustion of coal, oil or gas. This mapping has “however limits”, notes the daily, since not all molecules are searched for everywhere on a regular basis. Furthermore, for many industrial pollutants, such as bisphenol A, certain PFAS or even medicines, the authorities have not set threshold values.
However, these measures demonstrate “the scale of a problem that has long been ignored – and which will only get worse,” the newspaper warns. This groundwater feeds rivers and springs, where pollution “resurfaces”, declares Florence Habets, research director at the CNRS, in the article. “We humans can treat our water to a certain extent, but biodiversity will continue to be affected,” worries the scientist.