Serenity above, explosions below: Switzerland's lake conundrum explained

The bulk of the explosives, dumped between 1918 and 1964, lie at depths ranging from 500 to 720 feet in three major lakes

Switzerland’s serene lakes, known for mirroring its towering mountains and embracing its cities, conceal a troubling secret beneath their tranquil surfaces. While the crystal-clear waters may appear unblemished, they harbour a potentially explosive problem: decades-old military munitions lie deep below, posing a long-term threat to the lakes' delicate ecosystems, reported The New York Times.

In response to this hidden danger, Switzerland has launched an innovative crowdsourcing initiative, offering a total prize of 50,000 Swiss francs (approximately $58,000) for the top three proposals on how to safely and environmentally extract the submerged munitions if they begin contaminating the water.

No immediate danger, but precautions underway

The Swiss government has said that there is no immediate cause for concern. Regular monitoring of the lake waters and sediments has so far revealed no adverse effects from the submerged explosives.

“A leak of pollutants from the munitions would be against all expectations,” said Samanta Leiser, spokesperson for the Swiss Federal Office for Defence Procurement. The current objective is to prepare for a worst-case scenario, following a 20-year-old assessment that warned of the high risks associated with attempting to remove the munitions, including potential damage to the sensitive lake ecosystems.

Despite these precautions, some experts argue that attempting to remove the munitions, even if they begin leaking toxins, could be more hazardous than leaving them in place. Mike Sainsbury, Managing Director of Zetica, a British company specialising in unexploded ordnance, suggested that if the munitions pose no immediate danger or are unlikely to degrade harmfully, “we’d probably advocate leaving them alone.”

A European challenge: Munitions from past conflicts

Switzerland is not alone in facing this challenge. Across Europe, companies are actively involved in detecting, investigating, and safely disposing of munitions left over from past conflicts. These remnants, often from the World Wars, continue to disrupt daily life, particularly in countries like Germany and the United Kingdom, where old bombs are occasionally unearthed, leading to evacuations and disruptions.

The Swiss munitions, however, present a unique challenge. The bulk of these explosives, dumped between 1918 and 1964, lie at depths ranging from 500 to 720 feet in three major lakes: Lake Thun, Lake Brienz, and Lake Lucerne. This disposal practise predated the environmental movement of the 1960s, at a time when it was believed that deep water could safely contain any potential blasts.

Environmental & safety risks of munitions removal

While the munitions are not currently a blast risk due to their depth, moving them could trigger dangerous outcomes. According to Sainsbury, removing the munitions would require a meticulous, forensic approach, as even old explosives can still be lethal.

The environmental risks of leaving the munitions submerged are also a matter of debate. Over time, the metals may degrade, and chemicals could leach into the water, posing a toxic threat to both wildlife and humans. However, attempting to bring these munitions to the surface could disperse these toxins more widely and rapidly, potentially causing greater harm than if they were left undisturbed.