Wastewater and Stormwater Management
A National Framework for Improved Wastewater Reuse and Stormwater Management in Australia
Task Force on COAG Water Reform
Sustainable Land and Water Resource Management Committee
Commonwealth of Australia, 1997
ISBN 0 642 27116 X
About the paper
The attached policy paper has been prepared by the Standing Committee on Agriculture and Resource Management (SCARM) Task Force on COAG Water Reform (Task Force) in response to a requirement under the 1994 COAG Water Reform Framework that ARMCANZ, ANZECC and the Ministerial Council for Planning, Housing and Local Government examine the management and ramifications of making greater use of wastewater in urban areas and strategies for handling stormwater, including its use, and report to the Council of Australian Governments.
On the basis of a CSIRO study commissioned by ARMCANZ to address this brief, the Task Force prepared the attached policy paper. In the context of the original COAL direction, the Task Force considers the paper, and the policy proposals arising therefrom, a reasonable response. However, it is now more generally accepted that the management of wastewater and stormwater needs to be considered firstly within the context of the overall urban water life cycle rather than as specific resources in isolation. When set properly within this primary context it is recognised that reuse of wastewater and utilisation of stormwater, the measures on which the 1994 brief focussed, will often remain important initiatives in making more efficient use of water resources.
It is the Task Force view that improving the overall efficiency oil' use of water resources, while maintaining (or regaining) appropriate environmental values. Should be the fundamental guiding objectives in the resource management sense. The impact of large diversions of water from the freshwater environment and the effects of stormwater runoff and return of treated effluent to urban waterways, estuaries and coastal waters should be minimised.
In respect to wastewater, the Task Force considers that efficient use of water, is equally as important as reuse following inefficient use and is the first point of consideration in waste minimisation. Efficient use can often be a more cost effective and economic measure.
The Task Force notes that, despite the increasing commercial focus of the water industry Trising fi-om the COAL reforms, water is still underpriced. While urban water pricing now generally covers running costs and for most major metropolitan suppliers provides a return on assets few charges take into account the environmental costs of water (except in the case of wastewater treatment costs). The environmental costs are difficult to quantify and work to identify them is only just commencing.
In regard to the management of stormwater as a resource, the Task Force notes that large quantities of urban stormwater are generated at times when demands for second class water are minimal and that the storage of stormwater in significant quantities in existing urban areas for later use is generally expensive (except in the case of cities which are able to utilise their natural groundwater aquifers as a storage). However, possibilities for incorporating storages at the planning stage for new urban subdivisions should be given consideration (Canberra shows the benefits of this approach).
The Task Force is of the view that the first priority for stormwater management must be focussed upon impacts on receiving waters. A significant proportion of water quality problems in and around urban areas are due to stormwater impacts. Nevertheless, in managing the impact of poor stormwater quality, opportunities to utilise it as a resource will arise, and these should be maximised.
The Task Force notes that the recommendations in the attached paper provide broad policy positions as guidance for wastewater reuse and harvesting of stormwater. More work however, is required to put them in the context of an holistic approach to water resources management which would include evaluation of all options to achieve the water resource and environmental objectives.
There is a range of complementary measures and issues linked to wastewater and stormwater in the urban cycle which need to be addressed to improve the efficiency of resource use and protect environmental values in a cost effective way within the whole life cycle of water. These should include:
- making more efficient use of diverted resources through reform of water pricing and promotion of more efficient water using appliances and garden irrigation practices;
- quantifying the market for recycled water for varying uses over a range of water qualities;
- recycling of treated wastewater of secondary or potable quality (the subject of this policy paper).
Recycling should range from local to large scale whole city schemes;
- improving understanding of the environmental effects of returning treated effluent and associated biosolids to the environment (either to land or water);
- using existing environmental allocations in a more ecologically sensitive manner;
- measures to improve the quality of urban stormwater runoff to protect the receiving waters;
- measures for harvesting stormwater for consumptive use from its source, as well as from the drains, as a means of reducing total pollutant load;
- adoption of water sensitive design criteria in conceptualising, aligning, shaping and sizing stormwater provisions in new urban developments; and
- analysing the economics to enable the most cost effective solutions to the environmental issues to be identified from the full range of potential options.
The Task Force believes that moves to increase the proportion of reuse should be undertaken within the above context. The most significant factor in promoting the efficient use and recycling of wastewater will be pricing water at its true full cost.
The Task Force therefore proposes that ARMCANZ, ANZECC and the urban water industry (through WSAA) evaluate the economics of the urban water life cycle to identify opportunities for improving the sustainable management of water resources and the health of inland and coastal waters in cost effective ways while maintaining customer service and public health