Do you know a way of getting rid of unexploded ammunition hidden in the depths of lakes in Switzerland? The Swiss government would like to hear from you - and a pay packet of up to 50.000 francs may be headed your way!

Over 12.000 tons of munitions beneath Swiss lakes

They may be pretty to look at, but according to the government, an explosive secret lies at the bottom of some Swiss lakes. The Federal Office for Armaments (Armasuisse) recently revealed that 3.300 tons of ammunition can be found beneath Lake Lucerne, while 4.500 tons are in Lake Neuchâtel. The government estimated that in total, over 12.000 tons of unexploded bombs and ammunition can be found in Swiss waters.

Between 1918 and 1964, the Swiss Army dumped unexploded bombs and ammunition in Lakes Thun, Lucerne and Brienz, and until 2021 the Swiss Air Force used Lake Neuchâtel for bombing practice. While most munitions are at depths between 150 and 220 metres, some ammunition can be found just seven metres below the surface.

The risk associated with these munitions is twofold. First, the ammunition still has the potential to explode as, according to local geologist Marcos Buser, “The army did not remove the fuses before dumping the munition". Second, while a Department of Defence report from 2020 found that the ammunition presented “no negative impacts on water quality” if left alone, they could present a major environmental risk in future, or if they are not excavated properly.

Swiss government launches ideas competition over unexploded munitions

Therefore, Armasuisse has launched an “ideas competition”. Anyone can submit suggestions between now and February as to how the ammunition can be removed in an “environmentally friendly and safe manner.” In February, a panel of experts will determine the three best ideas, with the winners sharing a prize pool of 50.000 francs.

Speaking to Swissinfo, a spokesperson for Armasuisse said that while they are “not planning a recovery operation”, the competition is designed so that officials have options on the table should the ammunition ever begin polluting the water. Current methods being discussed include “mining magnets, mechanical grippers and underwater vacuums”, and underwater bomb disposing robots, but the low visibility and depth of some Swiss lakes mean no conventional ideas are foolproof.

Though everyone is able to make suggestions, the government hopes to attract ideas from industry, universities and other research organisations - some suggestions from the public so far include draining the lakes and filling them up again once the ammo is removed, blowing the munitions all up in the water and employing scuba divers to painstakingly remove the munitions one by one. For more information about the competition, check out the official website.