By Bruce Lantz
Environmentalists are up in arms over a provincial government decision that could allow a Nova Scotia gold mine to raise the height of the wall of its existing tailings waste pond.
The Halifax-based Ecology Action Centre said the approval granted to Australian-based company St Barbara Ltd. (ASX:SBM), which owns the open pit Touquoy gold mine in Moose River, N.S., about 90 minutes’ drive from Halifax, allows the company to change its industrial permit and is separate from the normal environmental assessment process. Also, no public consultation is required. The company had said it would have to suspend operations if the application wasn’t approved.
Karen McKendry, wilderness outreach coordinator for the group, said the higher wall is a greater risk of breaking. “Raising a tailings dam puts it at more risk of breaking,” she said, taking exception to the fact that the decision was made “behind closed doors” and stressing that the provincial government should have sought an independent engineering study and conducted computer modelling on the consequences of a dam breach.
Tailings ponds consist of watered-down waste from the mining process and contain heavy metal byproducts. This could allow Touquoy to store more mining waste and increase the likelihood of an accident, McKendry said. She referenced British Columbia’s Mount Polley disaster in 2014, when about 25 billion litres of mining waste spilled into nearby water sources from the copper and gold mine.
“The request and its respective review process raise major concerns with regards to safety and lack of transparency,” said McKendry.
“There are many examples of tailings dams failing. These breaches lead to toxic mining waste spilling out across nearby areas, resulting in the obliteration and contamination of watercourses, groundwater and wildlife, while jeopardizing the health and safety of people.”
The Eastern Shore Forest Watch Association also protested the height increase and urged that a reasonable amount of time be taken to make a decision that was not “unduly influenced”.
“This is what we’re worried about,” said association spokesperson Patricia Egli. “It’s a behind-the-scenes process where you don’t know what’s going on.”
The Touquoy mine, the size of several football fields and the only operating gold mine in Nova Scotia, has been in operation since 2017, and was acquired by St Barbara in 2019 as part of the purchase of Atlantic Gold Corporation. To date, more than 400,000 ounces of gold have been produced since production started.
Nova Scotia Environment Minister Tim Halman in May had given St Barbara’s Canadian subsidiary, Atlantic Mining Nova Scotia Inc., a year to submit more information on the environmental impacts of storing Touquoy’s tailings in a separate open pit once mining operations are completed. But St Barbara said that was too late, as the mine is nearing its end. The company said raising the wall height of the existing pond would extend operations until the end of the 2023 fiscal year. Without an August approval there would have been insufficient time for construction of the raise before the capacity of the current tailings pond was reached, expected in early September. Then the whole operation would have to be suspended and placed “in care and maintenance,” the company said.
“Increasing the height of the TMF (tailings management facility) provides St Barbara with the ability to process ore from the Touquoy pit as well as stockpiled materials until June 2023,” St Barbara communications consultant Sarah Brannen told Resource World Magazine. “The approval provides continuity of operations while St Barbara seeks approval of an environmental assessment for the long-term future of the Touquoy mine while also seeking approval of three additional projects in the area.”
The TMF includes a tailings pond, polishing pond, a constructed wetland, and associated facilities. The tailings pond manages the tailings discharge slurry, water retained in the tailings’ voids, historical tailings cells and runoff from the contributing TMF catchment. Mine contact water from the mill site, open pit, and waste rock storage facility is also directed to the TMF. Collection ditches along the east, west, and north of the tailings pond are designed to collect shallow seepage from the tailings pond and pump it back into the tailings pond.
Effluent from the tailings pond is treated at the effluent treatment plant (ETP) followed by filtration through geobags to reduce metals and solids prior to release into the polishing pond, which allows additional retention time. Discharge of treated effluent from the polishing pond is controlled via the final discharge point (FDP) control structure. Effluent flows through the FDP to a constructed wetland downstream which provides a final polishing step prior to release to the natural environment.
St Barbara has said it is committed to being a sustainable gold producer and employer, but always with a commitment to safety and respecting the environment. “Our company will continue to work with all parties to ensure we are living up to these commitments in the communities where we operate, now and into the future,” the company said in a statement.
The Nova Scotia Department of the Environment has said all applications are thoroughly reviewed to ensure proposed activities are in compliance with applicable legislation, regulations, policies and standards. In a statement, they said the dam height increase was designed by the company’s engineer of record who is “professionally responsible for ensuring the dam design is sustainable and meets the requirements of the Canadian Dam Safety Guidelines”. Also, a dam breach and inundation study was submitted as part of the company’s application.
But in the opinion of the Ecology Action Centre, the situation involves trust, as Atlantic Mining Nova Scotia Inc. was fined $250,000 in February for violating federal and provincial laws after an investigation found the company had deposited damaging substances into water near the gold mine and failed to test the quality of runoff water at Touquoy and to report those findings to authorities. Initially, 32 environmental infractions were filed against the company, but that number was reduced.
Brannen said the company plans the expansion of three additional projects in nearby Beaver Dam, Fifteen Mile Stream and Cochrane Hill, all in different stages of harmonized permitting process with both the federal and provincial governments. Its original plan has always been to make Touquoy into a storage site for tailings from the other planned nearby operations.
“If our application was not approved, St Barbara would have been required to move to care and maintenance at the Touquoy mine, which would have had a significant affect on the 350 Nova Scotians that are part of St Barbara’s Atlantic operations, as well as hundreds of Nova Scotian contractors and suppliers that support our business,” Brannen said.