The Palmer Project’s application for two separate permits that would regulate subsurface exploration are pending two state agencies’ approval after a required 30-day public comment period, ending May 15.
In March, Constantine Metal Resources submitted a waste management permit application to Department of Environmental Conservation and reclamation plan to Department of Natural Resources to move forward with advanced exploration for copper, zinc, gold and silver 35 miles north of Haines.
Since 2006, the company has focused on surface drilling and road construction while they assessed the economic viability of the project in phase one, but these permits indicate the beginning of phase two, which aims to: excavate an underground tunnel to build a drill platform, drill a cumulative 10,000 feet into the ground and construct a subsurface disposal system of pipes that would lead to discharge areas underground.
“These two permits essentially complement each other,” Alaska Department of Natural Resources director Kyle Moselle said. “By constructing that exit adit (or tunnel), they are going to generate waste rock (and waste water) which will need to be managed according to the waste management plan,” Moselle said. “The reclamation plan approval ensures that the area that has been disturbed is put back into stable condition post-mining.”
The waste management permit involves disposal of both solid and water waste.
For potentially acid generating rock (PAG), Constantine has proposed a storage pad, though two preliminary reports indicate rock in the exploration area is not acid- generating. “However, in the event that PAG rock is encountered, it must be stored on the surface, covered when not being handled, runoff contained and hauled to the underground ramp for final disposal,” the application says.
Discharge water in the tunnel will be collected and temporarily stored in underground tanks. It will then move through a piping system to either the upper or underground discharge station, or move to one of two settling ponds. In the settling ponds, seepage water will be separated from rock waste before discharged underground.
Surface water will be monitored at four sites in potential wastewater drainage risk sites: upper and mid-Glacier Creek, two sites in Waterfall Creek and in Hangover Creek.
These sites are the most relevant sites for detecting any significant change in water quality, the permit says.
There will also be three groundwater monitoring sites by the settling ponds, and above and below the lower perforated pipe water release site. Department of Environmental Conservation regulates quarterly monitoring requirements and has set trigger limits for allowable mineral amounts in the water before the company is out of compliance with their permit.
Constantine’s 2018 water quality tests show an excess of aluminum, manganese and vanadium at the groundwater monitoring site.
On Wednesday, Constantine vice president of external affairs Liz Cornejo, presented updates to the Alaska Chilkat Bald Eagle Preserve advisory council.
“You’re predicting 200 gallons per minute potentially coming out of that tunnel, and that’s not going to leach water quality standards for aluminum, manganese and vanadium?” Takshanuk Watershed Council scientist Derek Poinsette asked on Wednesday.
Cornejo said in some areas the natural groundwater does not meet water quality standards, but that the water will be settled in ponds and is not expected to meet surface water.
Poinsette said that the lower underground diffuser is 30 feet from Hangover Creek, as per Constantine’s drawn maps. “It seems almost inevitable that the water is going to go right into the creek,” he said.
Constantine has prepared reclamation plans for both temporary closure and permanent closure to ensure mineral activities are reclaimed according to state standards.
The reclamation plan mandates cost estimates and guidelines the company must abide by for temporary closure or permanent closure. If the mine was closed for a three-year period, it would cost the company an estimated $100,000 and require site cleanup, bi-weekly site inspections and monthly reporting.
Constantine’s estimated reclamation cost for the permanent closure of the site is $1 million including equipment removal and constructing a plug to the tunnel.
According to Moselle, DNR requires 100 percent upfront bonding before exploration activities occur. That is intended to make sure the public doesn’t bear the cost of reclamation.
The bond for the Palmer Project in the draft permit is roughly $1 million, which would cover the estimated cost of permanent mine closure.
Moselle said that both state agencies have reviewed Constantine’s applications and found them to be complete.
“Right now, we have not pre-determined an outcome to the permitting process,” he said this week. “What often happens through the public comment process is new information is made available to the agencies.”
DNR has not yet received any public comment. Residents can send comments by mail, email, or fax to Kyle Moselle at the Department of Natural Resources’ project and permitting office in Juneau. Deadline for comment is May 15 at 5 p.m.
At the Wednesday meeting, assembly member Tom Morphet asked how close Constantine is to moving ahead with a mine. Cornejo said they are still years away from determining.
“There are still a couple more stages to go,” she said. She said a conceptual mine plan will be published in the company’s preliminary economic assessment, which will detail where the mill site might be, how tailings would be stored and the amount of minerals the company might produce.