Friday, 8 July 2011

Mining plans in the Clarence River catchment

On 8 July 2011 The Daily Examiner again addressed the subject of mining exploration in the Clarence River catchment in journalist Terry Deefholt's article Gold mine plan causes concern:

PLANS to build open-cut gold mines in the steep terrain and high rainfall areas of the Orara Valley and near the Little Nymboida River have raised the concerns of well-known Clarence Valley campaigner Judith Melville.

Some of the old gold mine areas targeted are near world heritage-listed rainforest, some is farmland and some is state forest.

Ms Melville, the blog administrator of the community website North Coast Voices, pointed to the prospectus documents of three mining companies, Centius Gold, Anchor Resources and Altius Mining, which have exploration licences for large areas of bushland south and south-west of Grafton (map on page 8).

“The mining boom has led to an increase in exploration pressures in the Clarence catchment and I have serious concerns over the potential impacts on catchment water and the level of water required to successfully run these mines,” she said.

“A lot of these old mines are based in high elevation with pronounced slopes. How are they going to be stabilised?”

Ms Melville described the State Government's regulations on tailings dams as woefully inadequate, referring to a Dam Safety Committee document which outlines how mine owners had to self-assess the risk to public safety from their tailings dams.

She said even a minor spill of mercury or arsenic into the water system could have a major impact.

“It's about perception ... can you imagine how quick Sydney restaurants would stop buying Clarence seafood if there was a perception of contamination?”

She also expressed concern about water usage.

“A thumbnail guide is that processing a tonne of ore requires a tonne of water,” Ms Melville said.

“What happens in a low-flow regime? Are we going to have less water coming in to support a healthy estuary because these companies want to operate all year round.”

Centius Gold's managing director John Slade said the company would conduct aerial magnetic surveys of the Bobo area (south-west of Grafton) in the next couple of weeks with plans to commence drilling shortly after, if the surveys stood up.

Mr Slade said it could take five years of planning, environmental impact statements and decision making before drilling led to a mine.

He said the company would not need to negotiate with any landholders in the next five years because there was enough prospect of gold in state forest areas.

As to concerns about mine tailings, including arsenic, reaching river systems, Mr Slade said the company's gold mining operations “don't touch the water table” unlike coal seam gas.

He said water used to extract gold was pumped into tailings dams unconnected to river systems and the water evaporated over time.

He said the high rainfall of the area would need to be taken into account when planning the size of tailings dams.

An independent geologist's report contained in an Anchor Resources prospectus rates the processing risk of a Bielsdown mine (about 15km north of Dorrigo) as “moderate to high”.

“The mineralisation at Bielsdown contains some mercury, which may be difficult to eliminate from antimony concentrates. If the mercury level in concentrates is too high it could render them unsaleable,” the report said.

A prospectus from Altius mining states the Karangi exploration licence covers at least 150 old gold mines, most of which closed early last century.

“The high grades mined would indicate that there is a strong possibility of developing a number of open-cut mining projects,” the prospectus says.

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