GlencoreXstrata’s Mangoola coal mine in the Hunter Valley is applying for approval to discharge salt water into the Hunter River.
The application is part of the mine’s bid to increase extraction from 10.5 million to 13.5 million tonnes of coal a year.
The company has applied to discharge 50 megalitres a day over set periods under the Hunter River Salinity Trading Scheme.
Originally called Anvil Hill, Mangoola was approved by the NSW state government in 2008 under the proviso it did “not discharge any saline water from the site’’.
The company said the request is primarily a “contingency” plan and discharging the saline water into the river would not be an everyday event.
Instead, it would only occur ‘‘in extreme or prolonged high rainfall periods’’ and would ‘‘provide assurance’’ against ‘‘unplanned discharges or overtopping’’ of water from voids or dams.
According to the company’s environmental assessment, the mine wants the option to discharge water during long wet periods and to mitigate the risk of uncontrolled spills of saline water.
A GlencoreXstrata spokesperson told Australian Mining that Mangoola has never had to discharge water and that it's a remote possibility that the mine would ever have to.
In the case that water was to be released into the river the spokesperson said it would be "totally supervised and managed".
On public display until the end of next month, the assessment outlines the affect of water discharges on downstream river water, saying it will depend on contaminate concentrations.
But the assessment says controlled discharges will be significantly diluted by natural river flows, predicting the increase of average Hunter River salt load to be less than 0.4per cent at nearby Denman.
Australian Mining reports that ramping up production by almost 30 per cent will create an estimated 150 new jobs, but will also see an increase in blasting from five to six blasts a week and increased localised traffic.
A company spokesperson told Australian Mining that the positions, which are primarily operation roles, would be filled with locals, and that in addition another 90 contractors would be needed.
The spokesperson added that the mine was also open to hiring "cleanskins", or those without mine site experience, saying Mangoola is committed to providing extensive employee training programs.
If granted the discharges will use Mangoola’s existing two-way pipeline and pumping system, which to date has only been used to take water from the river, the Newcastle Herald reports.
Environmentalists in the region are concerned coal mine expansions upstream will “kill” the estuary.
Damaging the water source will debilitate the region’s strong farming sector and hamper further growth of the local tourism industry.