The Australian miner first began mining at Touquoy in 2017, reaching commercial production a year after. The processing plant at Touquoy is a conventional carbon-in-leach (CIL) circuit with a nominal capacity of 2 million tonnes per year.
In 2020, St Barbara began the provincial permitting process to convert the Touquoy open pit into a tailings management facility (TMF) upon completion of open pit mining. This longer-term strategy for tailing deposition was implemented to extend the life of the Touquoy mine, following similar paths to Beaver Dam and Fifteen Mile Stream.
However, late in the process, the Nova Scotia Department of Environment and Climate Change (NSECC) sought further clarification on aspects of the in-pit tailings deposition application, which impacted the timeframes for the company’s in-pit tailings solution. At the current rate, construction work on the in-pit tailings infrastructure will not be completed by the time the current TMF capacity is exhausted.
The company therefore elected to make an application to raise the existing tailings dam as an interim solution while the in-pit deposition matter is settled. The capital cost for the tailings lift is approximately $4.2 million and will extend the life of the Touquoy operation until the end of fiscal 2023.
A permit application to lift the dam was then submitted, but the timeframe for a decision was set at early August 2022. Should approval of the permit not arrive by then, there would be insufficient time to allow for the construction of the raise, leading to the Touquoy operation being placed into care and maintenance.
The potential tailings dam raise has alarmed environmentalists, according to reports by CBC, as the industrial permit is considered separate from the normal environmental assessment process. “Raising a tailings dam puts it more at risk of breaking and this decision is going to be made behind closed doors and you’ve really got to question it,” said Karen McKendry, wilderness outreach co-ordinator for the Halifax-based Ecology Action Centre, in a CBC interview.
At of this moment, the Nova Scotia environmental department is still reviewing St Barbara’s proposed interim tailings solution.
