The plant will be used to remove salt from water released during coal seam gas extraction in the Gloucester valley.

AGL has conditional approval to establish 110 coal seam gas wells in the valley as part of stage one of its Gloucester Gas Project.

The company said, as part of its extracted water management strategy which is currently in development, the desalination plant would use reverse osmosis and would be the primary water treatment technology for produced water from the project.

While the company has not divulged the likely cost of the plant, the draft plan allows for up to 730 megalitres of water to be treated per annum at an average of two megalitres each day.

The plant will be located at AGL’s Central Processing Facility in the Stratford Industrial Park.

AGL’s manager of hydrogeology John Ross said the desalinated water - which will have low levels of salt similar to drinking water - could be primarily used for irrigation purposes with the residual salt crystallised and disposed at a licensed facility.

“There are so many beneficial uses for the freshwater once it has been desalinated. Gloucester Shire Council also found this to be the case in their recent produced water report,” he said.

“Our draft strategy proposes that the freshwater can be used for irrigation, however, we are looking at ways to make the water available to third parties in the local area. 

“This could include some of the preferred options in the council’s report, such as new industries, aquaculture, irrigating green areas in Gloucester and forestry.”

AGL said the plant would create several jobs during construction.

The company is still exploring options for salt disposal. 

“AGL has made the decision to invest in a desalination plant and we are currently working on salt disposal options which will be included in the draft strategy to be issued for agency and community consultation,” a spokeswoman said.

“There will be jobs created during construction and long term across the project area including the field well sites and central processing facility (including the desal plant).

"Final employment numbers are yet to be confirmed, but our Gloucester Gas Project Environmental Assessment estimated up to 465 temporary construction jobs and about 40 full-time jobs in the long term (excluding local contractors and businesses who may supply services from time to time).”

The desalination plant will operate 24 hours a day, seven days a week.

“Before desalination, the produced water will be stored in a receiving water pond and after desalination, in a discharge water pond. Both will be located at the central processing facility,” the spokeswoman said. 

The company’s draft extracted water management strategy will soon be circulated to regulatory agencies in accordance with AGL’s approval conditions.

Consultation workshops are planned to be held in Gloucester in the coming weeks.

AGL will also make the draft strategy available to the community both online and in information sessions. The exhibition period will be four weeks and anyone is welcome to give feedback.