Mine Name: Benambra (now Stockman Mine)
State: Victoria
Status: Historic, proposed new mining
Mineral: Copper, Zinc
Brief description of impact/history:
The Benambra mine/Stockman Mine operated for just four years in the 1990’s. Benambra is in State Forest in East Gippsland. In 1996 the company went into receivership and the mine was abandoned. Responsibility then fell on the Victorian Government – Department of Primary Industries (DPI), who commissioned work to stabilise the dam walls and to remove the chemicals, alkaline and heavy metals in the tailings and to clean up the processing plant. DPI contracted Abigroup at a cost to the state of $5.4 million, though some funds were recovered through the sale of abandoned machinery.
While the company did not do any of the remediation works at Benambra, there was a report commissioned for them in 1997 on the closure and rehabilitation strategy of the tailings.
There was the potential for Acid Mine Drainage (AMD) at this site, a the orebody contained large volumes of sulphide. The report identified the potential for AMD and recommended that tailings remain wet – to prevent the oxidisation of acids in the tailings.
Also in Benambra region, North of the Benambra mine, there are the following historic gold mines Wildboar Battery, Saltpetre Creek Workings, Sassafras Creek Workings, Lady Lock Mine, Golden Treasure Mine, Agememnon Claim, Cribbate Creek Workings. These mines operated on and off from the 1880’s to 1940’s. They are all listed on the Heritage inventory and are unlikely to ever be rehabilitated but instead make up a historical relic of mining. There is no information available on the environmental status of these sites.
Stockman Mine, Benambra, photo via GEG
References
Sustainability Matters: Restoration of Benambra Mine http://www.sustainabilitymatters.net.au/case_studies/640-Restoration-of-Benambra-Mine
Plans to reopen the mine http://www.abc.net.au/local/stories/2012/11/23/3639436.htm
Independent Group: Project overview http://www.igo.com.au/irm/content/pdf/factsheet.pdf
Department of Natural Resources and Environment 1999, Historic Gold Mining in the North East Region of Victoria: http://www.dpcd.vic.gov.au/__data/assets/pdf_file/0003/44526/ntheastregion1.pdf
Closure and Rehabilitation options for the Benambra Mine Tailings Dam http://er-info.dpi.vic.gov.au/mineral/Reports_by_reference/G-31000/G31884_199708_Special/ML1865_G31884_199708_rehab_tailingsdam.pdf
Abigroup project overview: http://www.abigroup.com.au/ProjectDetail.aspx?PageID=79&ProjectID=85
Abigroup Photo’s of the rehabilitation works: http://www.abigroup.com.au/PhotoGallery.aspx?PageID=39&ItemID=90&type=project