EPA orders Sunnyside to begin groundwater probe
The Environmental Protection Agency ordered Sunnyside Gold Corp. to begin a costly investigation of complicated underground water flows as part of the federal government’s Superfund cleanup of toxic mining sites above Silverton.
Figuring out where contaminated water flows through a maze of mining tunnels and natural cracks has emerged as a challenge for moving forward in one of the most ambitious toxic mining clean ups attempted in the West.
Sunnyside’s properties are included in the 48- site Bonita Peak Mining District cleanup launched in 2016 after the Gold King Mine spill that was accidentally triggered on Aug. 5, 2015 by EPA contractors investigating a collapsed portal. That high- profile disaster worsened toxic mine contamination of the Animas River, sending a mustard- yellow plume as far west as the mouth of the Grand Canyon.
Local officials have raised concerns that EPA officials are studying the problem to death without getting the actual clean up done.
The EPA on Thursday issued “a unilateral order” to Sunnyside, owned by Canada- based Kinross Corp., “to begin investigation of the Bonita Peak groundwater system,” said Rebecca Thomas, the Superfund project manager.
“We need to understand how water moves through the mining system — not only the man- made structures, the adits and stopes, but also how it moves through natural faults and fissures,” she said. “This is so we can understand how best to improve water quality in the tributaries of the Animas River.”
Sunnyside Gold Corp. will review the order, reclamation operations director Kevin Roach said.
“Sunnyside is not the cause of water quality issues in the Animas River and its activities in the area, including spending $ 30 million on reclamation over the past 30 years, have resulted in less metals in the Animas basin than would have otherwise been the case,” Roach said. “We are hoping that our remaining assets can be efficiently utilized in timely, proven and effective solutions to improve water quality rather than pointless studies or litigation.”
EPA Administrator Scott Pruitt has declared Superfund cleanups here and elsewhere to be a federal priority.
Mining that began in the late 19th century, churning out minerals that propelled the United States as a rising world power, left tens of thousands of abandoned tunnels leaking acidic metalslaced water into Western watersheds. Every couple of weeks in Colorado, the equivalent of the Gold King spill happens again as thousands of gallons of the acidmetals mine water trickles into creeks where few fish or even aquatic bugs can survive.
Sunnyside ran the last producing mine until 1991 in an area above Silverton riddled with underground tunnels. Until 2002, Sunnyside ran a water- treatment plant below the Gold King Mine along Cement Creek that filtered contaminants from leaking old mines in the area.
When Sunnyside fulfilled its legal obligations, Colorado Department of Natural Resources regulators let the company stop running the treatment plant. Sunnyside also had installed bulkhead plugs in their mine workings to back up millions of gallons water inside a mountain.
After the Gold King spill, Sunnyside officials agreed to cooperate with the EPA on investigation of contamination flowing into waterways from the Mayflower Mill tailings along the Animas River.
But no cooperative deal was reached for investigation of groundwater.
“Conversations didn’t lead to a consent decree for investigation of the groundwater systems, so we are taking this step to issue the order,” Thomas said. “We anticipate hearing from Sunnyside within the next week or so.”
EPA officials want Sunnyside to drill a well into the American Tunnel — Sunnyside owns parts of it — and to test water from seeps on mountainsides.
Drilling wells to study underground water flows typically ranks among the most expensive tasks in mine cleanups. This could cost Sunnyside tens of millions of dollars.
The order means Sunnyside likely will have to present EPA officials with a work plan for investigating groundwater.
The overall Superfund cleanup above tourism- dependent Silverton remains in the study stages.
“This groundwater system is very complicated,” Thomas said. “It is certainly true that the EPA and others have collected a lot of data to understand what happens on the surface,” she said. “But until we understand how water moves through the system, it won’t be possible for us to come up with a good, solid remediation plan.”