The barrels were found southwest of Åstön and are part of some 21,000 estimated to have been dumped in the area during the 1950s and 1960s.
The barrels contain used catalytic waste from the area’s pulp processing plants that dominated the area earlier in the century. The substance was mixed with cement and poured in 80-litre barrels. In total, about nine tons of pure mercury was involved. The containers are now rusting, exposing the toxic contents.
Geological Survey of Sweden, a government group mapping the coastal sea floor made the discovery.
“We found an area where they dumped these barrels, and after making several passes with the ship, we located 30 barrels of cement and mercury dumped in the water from the pulp processing plants 50 years ago,” said Ingemar Cato, a professor at the Swedish Geological Survey and head of the mapping project.
“It has been down there for so long already, so we have time to find a good solution to the problem.”
He said the mercury over time will convert to methyl mercury which is devastating to the environment. He said his group received funding to continue searching the area this week for additional barrels.
The information about the toxic material was turned over to the county council in Västernorrland. The Swedish Environmental Protection Agency was also notified. Both have provided funding for an expanded search by Cato.
The Geological Survey is studying the geology and sediment content of the Baltic and plans to present its information within two years. The information on toxins and organic material in the water will be used to improve the health of the troubled sea water east of Sweden.
Birgitta Westerling, spokeswoman for Västernorrland County, said that immediate steps must be taken to find the other barrels and see whether mercury has leaked out.
“The first step is to get SGU (Geological Survey of Sweden) to continue searching the area to see if it can find other barrels,” she told The Local on Tuesday.
“We will also give them information on another area where we think more barrels might be found. Then we have to use our legal experts to help us decide who was responsible for the waste.”