Abstract: The recent increases in environmental legislation, especially in the USA'have meant that there is a need on behalf of the mining companies for more judicious operational planning and more thorough restoration techniques in order to reduce costs and prevent violation of the smctly enforced regulations. Water pollution is probably the greatest problem and many less enlightened operators, especially for example, in surface coal milling in Pennsylvania, have been forced into liquidation after having been unable to meet the severe restrictions on Acid Mine Drainage (AMD). The problems of AMD are also inherent in most forms of metalliferous and coal mining and also in some types of aggregate quarrying. As excavations go deeper in search of ever diminishing reserves then they are more likely to encounter groundwater which can become polluted if insufficient care is not taken. It is to be expected that the laws will also become more severe than they are at present in Europe and methods of treatment of AMD will need to be developed that are more efficient than the costly chemical methods currently used. Research by the author and others into the source of AMD pollution and its treatment with engineered wetlands and other operational methods are discussed in the paper. The methods have- the distinct benefit that they are cheap to install, are cost effective over a long period with the minimum of supervision and are environmentally acceptable to the planning and regulatory authorities.

Abstract: Much work has been undertaken on the design of treatment systems to remove iron from ochreous mine water discharges. Unlike iron, manganese removal is far more difficult and generally requires active chemical dosing rather than passive treatment. The need for manganese removal can therefore significantly change the economics, management attention and sustainability of a site. Understanding natural attenuation of manganese in river systems is therefore key to deciding whether (active) manganese treatment is needed to protect downstream receptors. Nuttall (2002, this volume) describes the effectiveness of the passive treatment system at Whittle in reducing both iron and manganese concentrations in ochreous mine waters. This paper discusses the results of in-river monitoring and provides evidence for manganese removal downstream of the discharge point. In addition to dilution, attenuation appears to be in the order of 20 to 50%, depending on relative rates of mine water discharge and river flows. Such attenuation means that active treatment may not be needed for the long-term operation of the Whittle scheme. Operation of the scheme commenced in July 2002, with monitoring to further examine evidence for manganese attenuation and any impact on the ecology of the recipient watercourses.