Water group warns of arsenic buildup in water pit after Quebec lithium mine closes

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Despite a late January greenlight from the federal government’s recent assessment, controversy is still following the James Bay Lithium Mine Project in Quebec over feared watershed contamination and the loss of wetlands.

Galaxy Lithium Inc.’s open pit mine would have an estimated mine life of 15 to 20 years, and produce on average 5,480 tonnes of ore per day, said federal officials. But nearby First Nations and environmental protection groups have ongoing concerns about its impact on the watershed, particularly in terms of arsenic.

Critical Elements Corp. and Nemaska Lithium are also among the new crop of companies looking to extract lithium in the James Bay region, raising even louder environmental concerns from neighboring First Nations as Northern Quebec quickly becomes a lithium hub.

In Galaxy’s 2021 environmental impact assessment for its lithium project, the company states that arsenic concentrations are generally expected to be in line with 0.2 mg/L federal guidelines; however, they could exceed that value as precipitation decreases during the summer months around year eight of the project, when arsenic treatment “may be required.” Additionally, arsenic levels could spike during backfilling in the post-rehabilitation phase.

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“The quality of the pit lake water could deteriorate since part of the water from precipitations will be exposed to the rock walls,” states Galaxy’s assessment by WSP.

A Quebec-based non-profit water protection organization, Eau Secours, says it has concerns about Galaxy’s rehabilitation plan, which it claims fails when it comes to concrete measures to restore the water quality to its original level. Eau Secours says Galaxy “relies on water balance assumptions and dilution factors that are not demonstrated in any thorough modeling.”

“Three-hundred and five hectares of destroyed natural environments and a pit that will fill with arsenic-contaminated water over 120 years and then flow into nearby rivers, these are examples of the price to pay for a so-called green transition,” Eau Secours announced in a statement translated from French.

Eau Secour also asserts that federal conditions placed on the lithium project should have taken into consideration the “legislative shortcomings” of federal mining effluent regulations, particularly in terms of arsenic and its potential for contamination well beyond the closure of the mine.

“Remember that the pit will fill with water over 120-160 years, and that it will reappear in the neighboring waterways about 50 years after the mine closes,” Eau Secours announced in a statement translated from French.

Canada recently announced that lithium is considered one of six critical minerals in a strategy tied to the clean technology sector, due to its use in electric vehicles and many phone and computer batteries.

Mining experts say the James Bay region may have one of the world’s largest deposits of spodumene, a fairly rare pyroxene composed of lithium, aluminum and silica.

The lithium project will be accompanied by a water treatment plant, pond, and tailings storage areas, according to the minister’s decision statement.

Under the project’s conditions, monitoring must be in place for suspended particulate matter, and concentrations of lithium, fluoride, silver, arsenic, cadmium, chromium, lead, nickel, iron, zinc, mercury and copper.

The impact assessment states that some 305 hectares of wetlands would likely be lost due to the lithium project. The proponent proposes additional measures, such as requiring the creation of new wetlands for an area equivalent to at least 75% of the wetland area losses.

A provincial assessment for the project is still ongoing.

This article appears in ES&E Magazine’s April 2023 issue:

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