Metal Mine Remediation

Descriptions

Nine percent of Welsh rivers fail to meet the European Water Framework Directive objectives because of polluted discharges from the known 1311 abandoned metal mines across Wales. The polluted waters drain from mines, from the runoff from spoil heaps or from reworking of sediments.Passive mine water treatment technologies that have been applied with great success at coal mine drainage, principally for the removal of iron, will not work so well for the metals in non-coal mine drainage, notably zinc and cadmium. These metals are more soluble and so it is more difficult to remove them from the polluted water.Existing methods rely on active chemical treatment or large land areas for passive treatment (e.g. Reed beds), both of which are impractical at many of the remote metal mines which impact Welsh rivers. The old mine workings, processing areas, tailings dams, spoil tips and washed off sediments contain varying mineralogy’s and concentrations that under continuing wet and dry cycles provide varied metal loading to the river environment. This can be dependent on the availability or formation of metal carbonates at the sites, so understanding the geochemistry will be key to success.NOTE: To register your interest in this notice and obtain any additional information please visit the Sell2Wales Web Site at http://www.sell2wales.gov.uk/Search/Search_Switch.aspx?ID=20073.