Newcrest reduces water draw to help Orange through the drought

By October 25, 2019 News, Water

Newcrest’s Cadia mine will reduce the amount of water it uses from Orange to help the community respond to the drought.

In a long-standing arrangement, an average of eight megalitres a day of treated effluent is pumped from Orange’s Sewerage Water Plant to the Cadia mine. The mine also draws on groundwater and other sources to meet its operational needs.

Once this change is implemented, Newcrest will reduce the amount drawn from Orange by two megalitres a day. Orange City Council will use this extra two megalitres to meet its obligation for environmental flow into Summer Hill Creek.

Newcrest Cadia Valley Operations General Manager Peter Sharpe is pleased to be working with the Orange community.

“Newcrest is working with the City of Orange to help meet license requirements concerning environmental flows in the region and has agreed to return 2ML/day of effluent,” Peter Sharpe said.

“This will satisfy the Council’s environmental flow obligations and replace the release of surface water from the Suma Park Dam.”

“This arrangement will be in place for the next few months until this requirement is no longer required.

“Currently average net daily draw of water into the Cadia operations is 30ML/day. This return of water will not impact production in the current year.”

Orange mayor Reg Kidd has welcomed the Newcrest decision.

“Orange City Council and Newcrest have a long history of working together to benefit the local community and this is another example of that collaboration,” Cr Reg Kidd said.

“The use of treated effluent for environmental flows will create a significant buffer during this drought and will mean more water in Suma Park Dam can be retained for domestic use.
“Orange residents have done a great job in reducing consumption and Cadia is doing the same, which will help Orange get through this drought. “

BACKGROUND INFORMATION & EXPLAINER :

Under NSW Government regulations covering the use of Suma Park dam, the dam has a licence requirement to release water into creeks downstream of the dam for the environmental and ecological benefit of Blackman’s Swamp Creek and Summer Hill Creek.

Enough water must be released to produce the required amount of environmental flow-rate (1.75 megalitres a day, assessed on a 3-day average) at a gauge at the 3rd crossing of Summer Hill Creek.

Orange City Council currently releases water from Suma Park Dam or the stormwater harvesting holding pond to meet this requirement.

Under the new arrangement, two megalitres of treated effluent will contribute to this requirement for environmental flow.

Treated effluent is water which has had a high level of treatment to remove bacteria, solids and other contaminants. Orange City Council is licensed by state authorities to release treated effluent into Blackmans Swamp Creek.

This change will leave an extra two megalitres a day in Orange’s water storage reserves to be able to used for community consumption.
Cadia water efficiency :

According to a recent Newcrest market statement (dated 15 October) :

Cadia has continued to implement water saving efficiency measures which has resulted in net water recycling rates increasing from approximately 65-70% to approximately 85%. This higher rate of water recycling has been driven by improving the level of water recycle from the tailings thickeners in the process plant and by exceptionally high water recycle rates being delivered from the Cadia Hill open pit tailings storage facility.

Net external water consumption has reduced by approximately 30% over the last 18 months on a per tonne of ore milled basis. Cadia continues to pursue further water saving initiatives in the plant and optimisation of onsite bores.

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