Alternative Overseas Water Treatment and Supply Practices
This report was produced for the Urban Water Research Association of Australia, a now discontinued research program.
Report No UWRAA 112
This report was commissioned by the Urban Water Research Association with the objective of identifying water treatment and supply practices which could offer significant reductions in cost to the major urban water authorities.
The Australian water industry is technologically advanced, and overseas operating and engineering companies are well represented in Australia. In general, overseas technologies and practices are recognised, and are adopted in Australia where they can offer savings. This is engendered by the climate of competition, corporatisation and privatisation which is currently occurring in Australia, and the ongoing program of cost reduction and new technology which is embodies in any major project undertaken by the major urban authorities. This is the “base case” against which the opportunities for further significant saving must be compared against.
To assist in comparing the various options, a summary listing and a graphical presentation of the findings has been prepared indicating the relative savings to the water authority, the consumer, and the net saving overall.
For the purposes of assessing the various options, savings which exceed $30 per property per annum are rated as “high”. For an urban population of (say) 1million, this could correspond to an annual saving of some $10 million.
The options have been divided into 4 main groups those relating to reduction in water usage (Option 1); reduction in peak demand (Option 2), reducing the cost of treatment (Option 3), and improved asset management (Option 4).
The findings of the analysis are as follows:
SAVINGS THROUGH REDUCTIONS IN WATER USAGE
Reductions in water demand offer savings through a reduced extent and sizing of the supply and treatment system. In the short to medium term there can be significant savings through deferring capital works.
Of the options which involve saving through reducing water demand, urban consolidation has the greatest potential for significant cost saving to both the water authority and the consumer. Water restrictions and zoned pressure systems can offer costs savings rated as low.
Other options may offer saving to the water authority; however, they are unlikely to provide an overall cost saving when the costs to the consumer are considered.
SAVINGS BY REDUCING PEAK DEMAND
Reducing peak demand is similar to reducing water demand, and offers savings through a reduced supply system, and deferring capital expenditure in the short to medium term.
Of the options which involve saving through reducing peak water demand, extending water restrictions on peak demand days has the greatest potential for significant cost savings to both the water authority and the consumer.
SAVINGS BY REDUCING THE COST OF TREATMENT
Of the options which seek to reduce the cost of water treatment, avoiding unnecessary treatment of water has the greatest potential for significant cost saving to the water authority.
This may be achieved by maintaining catchment protection, confirming that water from protected catchments is safe and acceptable without treatment, and carefully assessing the benefits of higher levels of water quality and treatment when these are proposed and avoiding treatment when this is not necessary.
IMPROVED ASSET MANAGEMENT
Water authorities are actively considering and introducing improved asset management practices, such as extending the life of the distribution system (Option 4B).The further cost savings available from the introduction of new practices or technology which will extend the life of a major asset such as the distribution system by, say 25%, is rated as low. If a very substantial increase in asset life can be realised (eg asset life is doubled), then the potential savings can be high.
There are opportunities for significant savings to the major urban water authorities through town planning (urban consolidation), restricting the use of water on peak demand days, and avoiding unnecessary treatment of water.
There is also potential for significant savings through the implementation of a range of individual measures, each of which in themselves have only a modest saving.
In general, because the major urban water authorities incorporate assessment and implementation of new technology in their normal course of business, the opportunities for identifying further new technologies and practices which will offer significant savings are limited.
The assessment has sought to identify areas of significant cost saving. Assessing the merit of options will also require consideration as to whether they are consistent with the environmental, social and financial policies and objectives of the water authority.
The assessment has been restricted to water supply; if the total water cycle is considered, then strategies which reduce water consumption and the disposal of wastewater are favoured. Extending this study to consider the total water cycle is recommended.