Switzerland offers prize money for recovering ammunition from lakes

Tourists who enjoy the postcard views of Lake Lucerne, Lake Thun or Lake Neuchâtel may be surprised by what lies beneath these pristine Alpine waters.

For years, the Swiss military used the lakes as a dumping ground for old ammunition, assuming that it could be safely disposed of there.

An estimated 3,300 tons of ammunition are stored in Lake Lucerne alone, and 4,500 tons are stored in the waters off Neuchâtel, which the Swiss Air Force used for bombing exercises until 2021.

Some munitions deposits are located at a depth of 150 to 220 metres, while others in Lake Neuchâtel are only six to seven metres below the surface.

Now the Swiss Ministry of Defense offers 50,000 francs (£45,000) prize money for the best idea to spread the word.

The three best ideas for a safe and environmentally friendly solution to recover the ammunition will share the prize pot – but the recovery operation is likely to cost billions.

The fact that so many shells were dumped in Swiss lakes, including Lake Brienz, has been known for decades, but more recently questions have been raised about safety.

Retired Swiss geologist Marcos Buser, who advised the government on this issue, wrote a research paper ten years ago warning of the dangers of landfills.

The munitions pose two risks, he said. First, despite the fact that they are underwater, there is still a risk of explosion because in many cases “the army did not remove the detonators before sinking the munitions.”

Added to this is the contamination of water and soil. There is a real chance that the highly toxic TNT will contaminate the sea water and sediments.

The Swiss government admits that factors such as poor visibility, magnetic iron and the weight of individual ammunition “pose major challenges for environmentally friendly ammunition recovery”.

An assessment of possible recovery techniques in 2005 showed that all proposed munitions recovery solutions posed significant risks to the lakes' sensitive ecosystems.

This is not the first time that the Swiss military has been somewhat negligent in its handling of its ammunition.

The mountain village Mitholz suffered a severe explosion in 1947, when 3,000 tons of ammunition stored by the army in the mountain above the village exploded.

Nine people died and the village was destroyed. The explosion could even be heard in Zurich, 160 kilometers away.

Three years ago, the military announced that the 3,500 tons of unexploded munitions still buried in the mountain were no longer safe and announced they would be removed.

For the residents of Mitholz, this meant that they had to leave their homes for up to ten years while the clean-up work took place.

There were also scandals over neutral Switzerland's Cold War defence strategy of mining its bridges and tunnels against invasion. Some bridges had to be evacuated quickly as modern heavy-duty vehicles could pose an explosion hazard.

In 2001, eleven people died in the Gotthard Tunnel, one of Europe's most important north-south transport routes, when a fire broke out after two trucks collided.

Large quantities of explosives – not involved in the explosion – were still stored in a depot near the tunnel entrance. After the fire brigade successfully extinguished the fire, the army arrived with bomb disposal equipment.

And this week, the army announced that reports of civilians finding unexploded ordnance in the Swiss countryside increased by 12% last year (compared to 2022).

Even on glaciers that are retreating due to climate change, the melting ice is still revealing remnants of live ammunition left over from training in the high mountains decades ago.

This is a legacy of the Swiss defence strategy of “armed neutrality”: the maintenance of a large militia army (all Swiss men are obliged to do military service) which trains its troops almost exclusively in the interior of this densely populated country.

The removal of ammunition from Swiss lakes is likely to be a lengthy and complicated process. But first someone needs to come up with a practical plan on exactly how the ammunition can be removed.

While some complain that the army should have considered this when disposing of the waste, geologists have been recommending to the military for decades that this approach is safe.

The search for solutions has begun. Following the call from the Swiss Defense Department, the public can submit their ideas until February next year. They will then be assessed anonymously by a jury of experts.

The three winners will be announced next April.

The government said: “There are no plans to implement the submitted proposals immediately, but they could serve as a basis for further clarifications or for initiating research projects.”

Mr Buser suggests turning to the UK, Norway or Denmark for advice their experience in dealing with wartime wreckage containing unexploded weapons.

So will he offer any ideas? “No, I'm too old now… but if you need advice, I'm happy to give it.”