(Reuters) - Canada’s Northern Dynasty Minerals Ltd said on Thursday its 100%-owned Pebble Limited Partnership would challenge the U.S. Army Corps of Engineers’ (USACE) decision to deny Pebble Mine in Alaska a key water permit. Last month, USACE denied the Clean Water Act permit because the plan submitted by the Pebble Partnership detailing how it would handle the project’s waste in the ecologically sensitive area did not comply with the guidelines. The mine, one of the world’s largest copper and gold deposits, has been through a roller coaster of regulation over the past 13 years. The miner on Thursday said U.S.-based Pebble Partnership is preparing a “request for appeal” (RFA), saying the federal agency’s mitigation requirements for Pebble are contrary to policy and precedent in Alaska. The company said the RFA will be submitted in January.