The Hon. JEREMY BUCKINGHAM: My question without notice is directed to the Minister for Finance and Services, representing the Minister for the Environment. The Minister would be aware that antimony is a highly toxic metal. Last week the Office of Environment and Heritage found traces of arsenic, copper and zinc had leaked from the old Hillgrove antimony and gold mine into the Macleay River near Armidale. The Minister also would be aware that past operations at the Hillgrove mine have seriously contaminated 100 kilometres of the Macleay River. Given the recent announcement of Ancoa's intention to purchase the Hillgrove mine and reopen it, what will the Government do to ensure no further leaks or contamination into the Macleay River?

The Hon. GREG PEARCE: I have to make an admission: the Government helped the Hon. Jeremy Buckingham with his question. That is why it is comprehensible and I am able to answer it. The Office of Environment and Heritage was notified that stormwater was overflowing from a dam at the Hillgrove mine, east of Armidale, at 11.45 a.m. on Monday 29 August 2011. The mine is currently not operating but is in care-and-maintenance mode. The spill occurred after continued wet weather produced excess stormwater which exceeded the amount of water that could be stored in the dam. When the mine is operating the stormwater normally would have been used for mineral processing.

As a result, staff of the Office of Environment and Heritage in Armidale notified NSW Health, the Premier's regional coordinator and, subsequently, Kempsey Shire Council and appropriate district emergency officers, and began an investigation into the incident. Run-off from goldmines can contain heavy metals. Therefore, both the company Straits (Hillgrove) Gold Pty Ltd and NSW Health undertook water quality monitoring to provide information to inform the appropriate response. I am advised that historic mining from more than 100 years ago and erosion of highly mineralised soils have deposited a plume of material containing heavy metals in the river system from the Hillgrove area to the Pacific Ocean, an area of approximately 200 kilometres. That is quite a plume. I am further advised that the plume will continue to release elevated levels of heavy metals through physical, biological and chemical processes for millennia.

I am advised that the monitoring data from the company and NSW Health indicate that water quality immediately downstream in Bakers Creek and at the overflow of the Bellbrook water treatment plant, which is 117 kilometres downstream, remained within the usual background range for heavy metals. I am advised that on 1 September 2011 NSW Health notified by phone approximately 20 downstream landowners of the incident. The Office of Environment and Heritage is continuing its investigation and has required Straits (Hillgrove) Gold to implement measures to reduce the likelihood and volume of overflows from continuing wet weather.

Regulatory agencies, including the Office of Environment and Heritage, are requiring current operators to implement world's best practice environmental management to minimise the likelihood of further discharges and continue to support research into technology to minimise any adverse effects from plume already in the river system. The Office of Environment and Heritage takes any environment incidents very seriously. It will continue to monitor the spill and require Straits (Hillgrove) Gold to examine every option to prevent further spills. The Government welcomes The Greens giving us information of any spills or concerns they have. If they do so in the way that Mr David Shoebridge does—that is, by saying please—we will always try to help them.