A Hunter-based mining consultant has raised concerns about the potential of acid mine runoff from a proposed silver mine to pollute the surrounding catchment.
The Department of Planning and Environment has recommended approval for Bowdens Silver Project, 30 kilometres east of Mudgee.
The Independent Planning Commission has called for public submissions for the project, which would extract and process around 30 million tonnes of ore to produce a silver/lead concentrate and a zinc concentrate over 23 years.
The Bowdens silver deposit is the largest undeveloped silver deposit in Australia and one of the largest globally.
However, a report prepared by Hunter-based mining consultant Michael White found that the project's claimed economic benefits were not justified by the risks it creates for the environment and the community. In particular he highlights the risk of acid mine drainage escaping to the surrounding environment after mine closure.
"Of the waste rock excavated during the mine life, 57 per cent is classified as potentially acid forming (PAF). The 30 million tonnes of tailings produced over the life of the mine is also classified as PAF and will contain most of the 43,700 tonnes of chemicals added during ore processing. Some of these chemicals are highly toxic. The tailings will also contain 17-20 per cent of the lead, zinc and silver mined due to losses during ore processing. Other metals present in the tailings will include arsenic, antimony, fluorine and manganese," the report prepared for the Lue Action Group, which is opposed to the project's social and environmental impacts, said.
Mr White's report found the mine closure and rehabilitation cost allocation of $39.4 million would not be sufficient to cover leaking acid mine drainage.
In recommending approval, the Department of Planning said the project had been designed in a way that would achieve a practicable balance between maximising resource recovery and minimising associated impacts on the surrounding landholders and the environment through best practice and mitigation measures.
A Bowdens Silver spokesman said the issues raised in Mr White's 2020 report were addressed and responded to in the submissions report.
"Both Mr White's review and the submissions report were considered by the Department of Planning and Environment during its assessment of the project."
"The DPE has ultimately recommended approval of the project."
WHAT DO YOU THINK? We've made it a whole lot easier for you to have your say. Our new comment platform requires only one log-in to access articles and to join the discussion on the Newcastle Herald website. Find out how to register so you can enjoy civil, friendly and engaging discussions. Sign up for a subscription here.
