Chris Devitt doesn't think he will live to see Dubbo residents drinking effluent.
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Nevertheless, Dubbo Regional Council's water for the future coordinator is helping put in place the stepping stones to potentially making it happen one day.
The council is set to call for tenders for the construction of a 15-kilometre pipeline costing about $10 million and running from the Dubbo Sewage Treatment Plant in the north to the John Gilbert Water Treatment Plant in the south.
Dubbo produces about 3 gigalitres (GL) of effluent a year which Mr Devitt reports is currently being used to irrigate the council's Greengrove property and supplied to others including Fletcher's International Exports for use in growing crops.
"Putting it on crops is okay but if we could effectively turn it into potable water it has a lot higher value to us," he said.
But making effluent drinkable is not on Dubbo Regional Council's agenda during the worst drought in the state's history and about seven months before the forecast end to releases from Burrendong Dam.
Mr Devitt, a civil engineer and consultant, said the pipeline would carry effluent into the city to irrigate recreational areas and free up about 0.5 gigalitres (GL) of bore water for treatment and then use as town water.
He is also keen to see it traded for groundwater belonging to irrigators between Dubbo and Geurie, and stored in the "underground dam", the Upper Macquarie alluvial aquifer, for use at a later date.
"Given the whole groundwater thing is very tight and people hang onto their entitlements, if we can introduce additional water to help the trade, everyone wins because no one gives up water," he said.
Mr Devitt, the council's former director of infrastructure and operations, said the pipeline could be extended to take effluent to pivots.
"There needs to be a lot of science and management done of the quality of the effluent given to the irrigator and how he uses that to make sure that it is taken up by plants.. and excess doesn't seep into the relatively-shallow aquifer," he said.
The consultant said the council currently had "long-term supply agreements" for effluent.
"The idea is get a 1000 megalitres (1 gigalitre) out of that in the first instance once the pipeline is in place and over time it becomes a scalable project as the city grows," he said.
Mr Devitt said if effluent was used to recharge the acquifer it would "almost" be at a drinking standard so as not to contaminate it.
The water for the future coordinator reports that the effluent is currently "crystal clear but there are other things in it".
He said its future uses may require an investment of at least $5 million into the sewage treatment plant for new treatment units which can "virtually come on a truck and be bolted onto the system".
"The type of treatment is microfiltration which has a very high standard for getting the microscopic particles out of the water," he said.
"Potentially, we would also use reverse osmosis which is what the desalination plant in Sydney does to take the salt out of the water."
