Human Settlements Theme Report

Australia State of the Environment Report 2001 (Theme Report)
Lead Author: Professor Peter W. Newton, CSIRO Building, Construction and Engineering, Authors
Published by CSIRO on behalf of the Department of the Environment and Heritage, 2001
ISBN 0 643 06747 7

Waste, recycling and reuse (continued)

Solid, liquid and hazardous wastes (continued)

Contamination of land

Industrial, mining and municipal wastes have been the major sources of urban land contamination. Within the rural sector, contaminants result largely from the use of agrochemicals. In metropolitan regions contamination can arise also from underground storage tanks and industrial sites. For mining settlements, contamination arises from such activities as poorly engineered tailings dams. Various older industrial practices leading to land contamination may also put at risk urban redevelopment initiatives. Land degradation is caused by stockpiling and landfill disposal of waste without adequate precautions against leaching of substances such as oils and tars, heavy metals, organic compounds and soluble salts, and mining materials. Unless remediation is carried out, pollutants find pathways to urban groundwater, causing significant harm to the natural environment and human health.

Current statutory guidance for the proper assessment and management of contaminated lands is provided under the framework of the Australian and New Zealand Guidelines for the Assessment and Management of Contaminated Sites (ANZECC/NHMRC 1992). State legislation for identifying contaminated sites has been proposed. These instruments may cover remediation and prevention measures for achieving best-practice remediation and land management.

Comprehensive data on contaminated sites across Australia is not available. However, provisional data (Table 71) indicates that there are more than 30 000 contaminated sites in the two most populous states, New South Wales and Victoria; of which at least 7000 sites in New South Wales alone require remediation at a projected cost of $2 billion (Barzi et al. 1996).

Table 71: Estimates of the number of contaminated sites in Australia. [HS Indicator 10.9]
Region Number of sites
Australia 80 000
New South Wales 30 000
Queensland 30 000
Victoria 10 000
South Australia 4 000
Western Australia 4 000
Northern Territory 1 000
Tasmania 500
Australian Capital Territory 500

Source: Summarised from National Environment Protection Council (1999a).

Uncertainties about trends in regulatory requirements for remediation, and about liability for such work, have been major contributory factors in land remaining derelict, by reducing investment confidence and deterring development.

Implications

Continued high levels of waste generation without significant levels of waste recovery and recycling implies a high level of resource wastage. Further, high levels of waste generation that are not accompanied by sufficiently high levels of recycling would impose increasing demands for disposal. Since the dominant form of solid waste disposal in Australia is landfill, there is pressure on land usage, land prices, disposal costs and other spill-over effects related to transportation of waste and siting of landfills.

While the rate of recycling and recovery is generally increasing across all states and territories, the level of waste recovery has, in some states, not been sufficiently high to meet nominal waste minimisation targets already set for 2000. Therefore, these targets need reviewing in conjunction with the development of new initiatives to improve recycling rates. The development of mechanisms to create a realistic market for recycled products would also be a logical step forward.