The picturesque Lake Gerardmer, located 660 meters above sea level in the Vosges region of northeastern France, has long been a popular summer bathing spot and a source of drinking water for the local town.
However, growing concerns about water safety have emerged after high levels of TNT and metals were detected in samples taken from the lake.
The environmental group Odysseus 3.1 revealed in May that its research had uncovered high concentrations of TNT explosives, along with metals such as iron, titanium, and lead, in the lake’s water.
The group’s founder, Lionel Rard, stated that artillery shells from past wars had been found buried in the mud at the lake’s bottom, some of which were damaged, allowing their toxic contents to seep into the water.
The samples, analyzed by a German laboratory, showed some of the highest TNT levels ever recorded, raising alarms among local officials.
Munitions from Past Conflicts
Gerardmer’s mayor, Stessy Speissmann-Mozas, has called for a more detailed government-funded investigation into the potential risks posed by the unexploded ordnance dumped in the lake.
The munitions are believed to have been discarded by retreating armies during World War I and World War II to prevent them from falling into enemy hands.
France, as a country marked by several historic conflicts, is especially affected by unexploded bombs and ordnance, some of which date as far back as the Franco-Prussian War of 1870.
Between 1977 and 1994, extensive efforts were made to remove explosives from Gerardmer. A total of 120 tonnes of munitions, comprising nearly 100,000 individual pieces, were recovered from the lake.
Former local fire chief and diver Pierre Imbert, who took part in the disposal operations, recalled that each explosive was carefully brought to the surface, and the detonators were removed before they were detonated in controlled explosions at the lake’s edge.
Despite the significant cleanup efforts, around 70 tonnes of munitions remain submerged in the mud at depths of up to 30 meters, according to local estimates.
Imbert noted that the exact amount still present in the lake is unknown, as some of the munitions have shifted due to water currents over the decades.
Diverging Opinions on Risk Levels
Despite the findings of Odysseus 3.1, the regional health agency (ARS) and national health and safety agency (Anses) have yet to take any formal action.
Local authorities stated that state agencies conducted their own sampling in February, which was analyzed by French and German laboratories.
According to the regional authority, “no concerning levels were detected,” and the water is deemed safe for drinking and swimming.
However, some environmental groups, including the Vosges region’s AKM eco-tourism association, are urging the government to act.
Aurelie Mathieu, the association’s leader, has called for the state to “decontaminate everything around the edge” of the lake, expressing skepticism about the current safety assessments.
A proposal to map the remaining ordnance at the lake’s bottom has been submitted by a private company, with an estimated cost of €300,000.
Mayor Speissmann-Mozas is considering the offer but insists that the national government should cover the expenses, given that the munitions were dumped there by the French army.
As the debate continues, Gerardmer’s residents and visitors remain caught between conflicting reports about the safety of one of the region’s most treasured natural resources.
