Snapshot: The KSM mine, proposed by Seabridge Gold’s subsidiary KSM Mining ULC in northwest British Columbia, Canada, would be one of the world’s largest gold-copper mines, involving open pits and underground mines and massive tailings storage. Environmental groups have raised concerns over threats to the Nass and Unuk rivers, arguing that the project poses significant risks to water quality, fish habitats, and downstream communities. Originally granted an environmental permit in 2014, the project faced multiple delays, including setbacks caused by the COVID-19 pandemic, pushing the deadline for "substantial start" status to 2026. Under the British Columbia’s Environmental Assessment Act, projects must be "substantially started" within a set period or their environmental certificates expire, ensuring adherence to contemporary environmental standards. In July 2024, the British Columbia Environmental Assessment Office (EAO) ruled that the project was "substantially started," allowing it to proceed without a new environmental assessment. In response, Ecojustice, on behalf of SkeenaWild Conservation Trust and the Southeast Alaska Indigenous Transboundary Commission, filed a petition against the Minister of Environment and Climate Change Strategy of British Columbia and Seabridge’s subsidiary, KSM Mining ULC. The lawsuit argues that the ruling was based on outdated environmental data and improperly prioritised Seabridge Gold’s financial interests over ecological concerns.

In January 2024, Seabridge Gold, via its subsidiary KSM Mining, submitted an application to the British Columbia Environmental Assessment Office (BC EAO) for a "substantially started" determination to extend its Environmental Assessment Certificate (EAC) beyond the July 2026 deadline. This status is critical, as without it, the project’s approvals would lapse, requiring Seabridge to restart the permitting process. To qualify, the company must prove significant permanent physical development at the site.

On 25 July 2024, the British Columbia Environmental Assessment Office ruled that the KSM project has been "substantially started," allowing it to proceed without a new environmental assessment.

In November 2024, Ecojustice, representing SkeenaWild Conservation Trust and Southeast Alaska Indigenous Transboundary Commission, filed with the British Columbia Supreme Court, a petition against the Minister of Environment and Climate Change Strategy of British Columbia and against Seabridge's subsidiary, KSM Mining ULC, challenging the EAO’s determination, arguing that the ruling was based on outdated information and improperly considered Seabridge Gold’s financial interests rather than environmental impacts.