BOISE, Idaho — Monsanto employees, farm-state governors and an ex-U.S. Interior secretary urged speedy approval of an Idaho mine to supply an ingredient for Monsanto Co.’s Roundup weedkiller, while the Environmental Protection Agency wants additional pollution safeguards.

Through November, the Bureau of Land Management got 6,834 comments on Monsanto’s Blackfoot Bridge phosphate mine near the Idaho-Wyoming border.

The agency will review them, to see if a proposed mining plan merits changes. A decision could come by next summer. Cecil Andrus, the former Idaho governor and Interior secretary whose public relations firm is under contract with Monsanto, wrote, “This is the type of project Idaho needs.”

The EPA raised concerns about possible failure of a proposed $25 million liner meant to stop naturally occurring but poisonous selenium before it reaches the Blackfoot River.