Mobilization, transportation and sedimentation of weathering products from the abandoned brown-coal pits. (Iron pollution of the river Skjernå and Ringkøbing fjord, Western Jutland)

Preliminary results concerning the effect of chemical weathering products from the abandoned brown-coal pits on the river system are presented. Two of these pits are especially contaminating. They include the Haunstrup pit with an outlet to Rimmerhusbæk-Vorgodå, and the Søby pit from where canals discharge into the river system Søbyå-Rindå. Concerning the soluble matter it must be concluded that the contamination from these two pits on the watercourses is intense, but subsides relatively quickly. The river transport of suspended iron is at present not known in detail due to lack of data . - Therefore it cannot be excluded that suspended iron can contribute to the pollution of the river Skjernå, and especially Ringkøbing fjord.