MANKATO — A silica sand mining project had cleared its last local hurdle in Mankato.

The Planning Commission has approved a conditional use permit for Jordan Sands, an affiliate of Coughlan Companies, which is planning to mine 70 acres and use another 40 acres just north of the city for processing the sand.

Commissioner Mark Luepke abstained from the vote on the mine Wednesday night. Luepke says approving the project would be like “swallowing a poison pill” because any new jobs wouldn’t justify environmental concerns. The commission’s approval was needed under an annexation agreement with Lime Township where the mining site is located.

The project still needs state approval. The sand is sought by businesses that use a process called “fracking” to release natural gas and oil from the ground.