Environmental impact of alum shale mining and oil and uranium production in Kvarntorp, Sweden, based on historical archives and environmental monitoring data.

Oil production (1942-1966) and uranium extraction (1953-1961) from the Alum Shale Formation in Kvarntorp, Sweden has had a great environmental impact on the area. Other industrial activities have also contributed to pollution. This study combines archive research with monitoring data and new sampling in order to assess the extent of the impact. During the production period, process water containing oil, phenols, sulfur compounds and high concentrations of iron reached the stream resulting in low water quality downstream. Also the landscape was reshaped, resulting in water filled pit lakes and a 100-meter-high shale waste deposit. Today, past alum shale activities still have an impact on the environment. Sulfate concentrations in the pit lakes are significantly higher than background values and downstream water also shows higher concentrations of elements such as nickel and uranium. The waste deposit still has a hot interior and an important question is the cooling rate and possible future leaching scenarios. Remaining hydrocarbons show today only a local impact while trace elements are transported downstream and affect a larger area. [ABSTRACT FROM AUTHOR]