The best practice considerations identified in the table below can be applied to terrestrial minerals exploration and mining. Please note: the table below currently contains best practice considerations relating to impacts on freshwater only, further material applying to other impacts will be added in the future.
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Potential mitigation measure
- Mining should only be undertaken in areas where acid mine drainage can be effectively contained in the long term or treated. Where mining is undertaken, a site specific management plan and rehabilitation plan should be prepared by a qualified expert.
- Acid Mine Drainage can be addressed by: measures to prevent the formation of contaminated drainage (measures to limit one of the three components necessary for oxidation (water, oxygen and sulphide) or measures to ensure that waste material is effectively treated before it is discharged into a water body. Active treatment involves the use of chemicals and requires regular operation and maintenance. Passive treatment systems rely on natural physical, geochemical and biological processes to reduce the acidity in acid mine drainage. It depends on each site and the status of the mine as to what will be the most acceptable method of treatment.
- A site specific management plan should also minimise the potential for the generation of sediment laden runoff and ensure that any structures will not cause erosion.
- Resource consents should include a condition requiring a bond and other financial assurance to be provided to ensure that rehabilitation of a mining site and ongoing maintenance is provided for.
- Extraction of river gravel can alter the natural character of the river and damage invertebrate communities by altering the composition of the riverbed both at the extraction site and further downstream. Gravel extraction should therefore be avoided in freshwater bodies with high biodiversity and natural character values.
- Avoid areas of significant biodiversity or threatened or endangered species.
- Assessing impacts to enable minimisation, mitigation, offsetting and rehabilitation.
- Ensure adequate baseline monitoring during and after the closure of the mining. Monitoring should be against baseline data at a number of key receptors points.
- Ensure proper closure as to avoid legacy issues with toxic sites.
Last updated at 11:49AM on January 10, 2018