AlternativeOverseas Water Treatment and Supply Practices
ReportNo WSAA 112
Thisreport was commissioned by the Urban Water Research Association with theobjective of identifying water treatment and supply practices which could offersignificant reductions in cost to the major urban water authorities.
TheAustralian water industry is technologically advanced, and overseas operatingand engineering companies are well represented in Australia. In general,overseas technologies and practices are recognised, and are adopted inAustralia where they can offer savings. This is engendered by the climate ofcompetition, corporatisation and privatisation which is currently occurring inAustralia, and the ongoing program of cost reduction and new technology whichis embodies in any major project undertaken by the major urban authorities.This is the “base case” against which the opportunities for further significantsaving must be compared against.
Toassist in comparing the various options, a summary listing and a graphicalpresentation of the findings has been prepared indicating the relative savingsto the water authority, the consumer, and the net saving overall.
Forthe purposes of assessing the various options, savings which exceed $30 perproperty per annum are rated as “high”. For an urban population of (say) 1million, this could correspond to an annual saving of some $10 million.
Theoptions have been divided into 4 main groups those relating to reduction inwater usage (Option 1); reduction in peak demand (Option 2), reducing the costof treatment (Option 3), and improved asset management (Option 4).
Thefindings of the analysis are as follows:
SAVINGSTHROUGH REDUCTIONS IN WATER USAGE
Reductionsin water demand offer savings through a reduced extent and sizing of the supplyand treatment system. In the short to medium term there can be significantsavings through deferring capital works.
Ofthe options which involve saving through reducing water demand, urban consolidationhas the greatest potential for significant cost saving to both the waterauthority and the consumer. Water restrictions and zoned pressure systems canoffer costs savings rated as low.
Otheroptions may offer saving to the water authority; however, they are unlikely toprovide an overall cost saving when the costs to the consumer are considered.
SAVINGSBY REDUCING PEAK DEMAND
Reducingpeak demand is similar to reducing water demand, and offers savings through areduced supply system, and deferring capital expenditure in the short to mediumterm.
Ofthe options which involve saving through reducing peak water demand, extendingwater restrictions on peak demand days has the greatest potential forsignificant cost savings to both the water authority and the consumer.
SAVINGSBY REDUCING THE COST OF TREATMENT
Ofthe options which seek to reduce the cost of water treatment, avoidingunnecessary treatment of water has the greatest potential for significant costsaving to the water authority.
Thismay be achieved by maintaining catchment protection, confirming that water fromprotected catchments is safe and acceptable without treatment, and carefullyassessing the benefits of higher levels of water quality and treatment whenthese are proposed and avoiding treatment when this is not necessary.
Waterauthorities are actively considering and introducing improved asset managementpractices, such as extending the life of the distribution system (Option 4B).The further cost savings available from the introduction of new practices ortechnology which will extend the life of a major asset such as the distributionsystem by, say 25%, is rated as low. If a very substantial increase in assetlife can be realised (eg asset life is doubled), then the potential savings canbe high.
Thereare opportunities for significant savings to the major urban water authoritiesthrough town planning (urban consolidation), restricting the use of water onpeak demand days, and avoiding unnecessary treatment of water.
Thereis also potential for significant savings through the implementation of a rangeof individual measures, each of which in themselves have only a modest saving.
Ingeneral, because the major urban water authorities incorporate assessment andimplementation of new technology in their normal course of business, theopportunities for identifying further new technologies and practices which willoffer significant savings are limited.
Theassessment has sought to identify areas of significant cost saving. Assessingthe merit of options will also require consideration as to whether they areconsistent with the environmental, social and financial policies and objectivesof the water authority.
Theassessment has been restricted to water supply; if the total water cycle isconsidered, then strategies which reduce water consumption and the disposal ofwastewater are favoured. Extending this study to consider the total water cycleis recommended.
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