For the first time, a major investment is now being made to map how polluted Vättern is.
Right now, around a hundred bottom samples are being collected to find out where the environmental toxins are.
– It provides drinking water to 300,000 people, so this is important, says Olof Larsson, the project manager at SGU.
With special measuring instruments, Sweden’s Geological Survey, SGU, collects bottom samples from Lake Vättern and its connected watercourses. The sediments, which are punched out in long pipes, must be analyzed for dioxins, PAHs, PFASs and PCBs, among other things, in order to map how much toxins are buried in our second largest lake and where they are found.
– We know that there is pollution at the bottom. If they are located on the surface, there is a risk that they can spread when exposed to waves and wind, says Olof Larsson at SGU.
Environmental toxins from the paper industry
Over the years, individual samples have established that Lake Vättern is affected by environmental toxins, not least because of a long history of industries such as paper mills. But for the first time, a comprehensive investigation is now being carried out to find out how extensive the pollution is. The four county administrations around the lake are behind the project, which will eventually end up in a risk analysis for possible measures.
– There are different methods, dig it out, cover it or monitor the natural sedimentation. If we see that there is still some supply, we can also take action on land, says Love Bojén, environmental protection officer at the county administration in Västra Götaland.
The sampling will continue until September at 21 different locations down to a depth of 115 meters. Only next spring will the results be presented.