Abstract: When mining is completed the sites may be completely restored to the originalecosystem, rehabilitated for some desirable environmental characteristics, desirable alternative ecosystemscreated or just neglected. The strategy adopted will depend on the intended uses of the parts of theenvironment (including water) affected by the mining. An example of rehabilitation of a metal mine nearthe Australian Federal Capital is used to illustrate the problems that may be encountered. These include:lack of controls while mining is underway; catastrophic events, such as the collapse of a settling dam,lack of site specific understanding of pyrite oxidation processes, particularly those that are biologicallyenhanced; the need for adequate biological information on which to base decisions to meet biologicalinformation on which to base decisions to meet biological objectives. Experience has shown that biologicalcollections such studies should be stored in museums where they will be valuable for comparisons of changesover long periods.