Prepared by National Working Party on Acid Sulfate Soils for
Agricultural and Resource Management Council of Australia and New Zealand, Australian and New Zealand Conservation Council, Ministerial Council Forestry, Fisheries and Aquaculture
ISBN 0 7310 9842 0
Acid sulfate soils (ASS) occur throughout Australia. The focus of this paper is coastal and estuarine ASS. Coastal ASS have formed through natural processes and are generally overlain by other soils. However, when coastal ASS are exposed to air by drainage or excavation and then rewetted, acid drainage water is produced. Past government policies, the high demand for living on the coast and the extensive agriculture along the coastal strip have led to disturbance and increased exposure of ASS. These have resulted in large-scale acid generation and runoff.
Acid runoff causes a range of adverse impacts to the environment, coastal development, fishing and agricultural industries, where it is inadequately neutralised by the receiving environment. Costs to local and regional communities may be measured in terms of:
- Poor water quality with attendant loss of amenity, damage to estuarine environments and reduction of wetland biodiversity.
- The need for rehabilitation of disturbed areas to improve water quality and minimise impacts.
- Loss of fisheries and agricultural production.
- Additional maintenance of community infrastructure affected by acid corrosion.
The National Strategy for the Management of Coastal Acid Sulfate Soils proposes a holistic and comprehensive approach to define the problem, prevent it from increasing and encourage remedial actions to reduce existing acid water runoff. In the absence of the National Strategy a piecemeal, cost ineffective response to this problem is likely. Future remedial actions can be expected to be much more expensive.
The benefits of the National Strategy are expected to be:
- Improving understanding of the problem.
- Preventing the problem increasing.
- Improving water quality and environmental outcomes over time.
- Avoiding/reducing future remedial costs by implementing preventive measures as soon as possible.
The National Strategy is critical to resolving ASS issues affecting industrial, environmental, agricultural and residential developments. The challenge now is for government, industry and the community to implement the National Strategy to improve the prospects for sustainable coastal development and primary industries by ensuring proper management of ASS.