It's a critical mineral for the oil industry, but Alberta's plan to vastly expand silica exploration and mining has environmentalists worried.

A ministerial directive issued by Minister of Forestry and Parks Todd Loewen in August creates new categories of “enhanced” silica exploration and mining leases. Alberta’s existing sand and gravel allocation policy allows a maximum size for surface material exploration (SME) approvals of 320 acres. Companies that meet financial and technical criteria in the ministerial directive can now be authorized to hold up to two enhanced SMEs for an area up to 5,700 acres each.