Pinto Creek and its tributary Haunted Canyon have long been known for their unique riparian values

Since the early 1990’s the Sierra Club has worked to prevent a mine from being built in the middle of the Pinto Creek. The news as of February 2009 is certainly mixed.

Last month, Carlota owners announced that construction of the mine was complete and production of copper had begun. The site is visible on the north side of Highway 60 just past the Top-of-the-World community and before the Pinto Creek bridge.

Downstream from the mine is the Pinto Creek Bridge

At about the same time that this announcement was being made, the US Supreme Court denied Carlota’s petition to review the 9th Circuit Court of Appeals decision from 2007 that struck down the mines’s Clean Water Act permit. This permit issued by the EPA, known as the National Pollutant Discharge Elimination System (NPDES) permit, allows the mine to discharge pollutants into Pinto Creek. After years of litigation, a decision has been made and it is now resolved that new pollution cannot be added to already polluted streams - waterways have to be cleaned up. Pinto Creek exceeds the standard for dissolved copper, most likely due to numerous abandoned mines in the area.

The implications of the court decision are not entirely clear, but it appears that if production is to continue Carlota will now - at a minimum - have to upgrade its mine to a zero-discharge facility and produce a compliance schedule to clean up the rest of the creek.

Also, while all this has been happening, Carlota announced an agreement with the nearby Pinto Valley Mine to obtain up to 200 gallons of water per minute when that mine has an excess. While the agreement might provide only intermittent low-quality water, there is now some hope that the effects of groundwater pumping on vegetation at the confluence of Pinto Creek and Haunted Canyon might be reduced if the wellfield can be pumped at less than what was originally planned. Despite a mitigation system designed to restore lost flows into the creek, numerous trees in Haunted Canyon have already died due to lower groundwater levels.

What will happen next is unclear. The sudden recession and low copper prices have caused many layoffs and some closures in the industry. The Sierra Club and our conservation partners will continue to monitor events in Pinto Creek and Haunted Canyon in the hope that this spectacular waterway remains so for a long time.