Comment period extended for Lisbon Valley Mine request to use well water to extend mining
A Utah environmental regulatory agency is preparing a request to the federal government to allow a mine to inject diluted sulfuric acid solutions into a San Juan County aquifer.
If approved, the Utah Division of Environmental Quality’s (DEQ) aquifer exemption request to the federal Environmental Protection Agency (EPA) would allow the Lisbon Valley Mining Company to conduct in situ mining to extract copper from the Burro Canyon Aquifer in Lower Lisbon Valley.
Lisbon Valley Mining Company has been operating an open pit and heap leach copper mine in northeastern San Juan County for 13 years. The mine reports that it has recovered 65 to 75 percent of the available copper using those methods and now hopes to extend the life of the mine operation by using In-Situ Recovery.
The In-Situ mining process involves injection of a lixiviant, in this case groundwater with sulfuric acid and oxygen, to draw out copper from portions of the Burro Canyono Aquifer.
The proposal was met with pushback in 2020 from Lisbon Valley residents, environmental groups, and the San Juan County Commission.
The DEQ says that the proposed permitting area at depths of 200 to 900 feet into the Burro Canyono aquifer will not impact the drinking water from two nearby wells, due to confinement of the proposed permit area. But the neighbors are not convinced.
At a public hearing held on January 19, the Stevenson family – owners of 3-Step Hideaway resort – and the Wilcox family – a five-generation ranching family – both expressed fear of losing drinking water should the in-situ mining move forward.
While the public has through February 8 to provide written comment to the DEQ via mail or email, the hearing was an opportunity for the public to provide oral comments to the DEQ regarding their aquifer exemption request to the EPA.
At the hearing, neighbor Scott Stevenson, owner of 3-Step Hideaway, asked the DEQ to consider the scarcity of water in the area. Stevenson said they are not making any more water in Lisbon Valley or San Juan County.
“We believe we are pretty darn good stewards of what the good Lord has given us,” said Stevenson. “And it it just it’s very disheartening to think that we could lose our our small well. There’s just not much water there.”
The DEQ cites a technical report prepared by the Lisbon Valley Mining Company that shows that the Stevenson well is outside the Aquifer Exemption boundary.
The Wilcox well penetrates the top of the aquifer just outside the Aquifer Exemption boundary on the southeast.
The DEQ argues that the portions of the Burro Canyon aquifer that would be subject to in situ mining would meet an exemption from the EPA, because those portions do not currently serve as a source of drinking water.
In their exemption request, the DEQ says the area cannot serve as a potential future source of drinking water because Lisbon Valley Mining Company has demonstrated that it contains minerals that are expected to be commercially producible.
In a public hearing, Lisbon Valley landowner David Roccaforte asked how the aquifer can be exempt based on its ability to produce minerals.
“If the water at issue is already proven drinkable, how does the opportunity for copper extraction make drinkable water, which you’re supposed to protect, undrinkable?” asked Roccaforte. “Sure after they’re done with it it’ll be undrinkable, if there’s any left, but it sure is drinkable now.”
The DEQ also provided an update on the financial assurance amount for the process. A 2019 estimate provided by the mining company put the bonding at $4.5 million, with three years operation liability accrual and two years post closure well-field rinsing and monitoring, as well as plugging the wells after rinsing.
An updated bond estimate from a third-party Clear Creek associates in August 2021 put the estimate at $6.2 million, with the aforementioned requirements and 20 years post closure monitoring of Lisbon Valley, as well as Division of Oil Gas and Mining Labor Rates and escalation for inflation and well-field rinsing with a bicarbonate solution.
While the financial assurance covers the eventual closure of the in-situ operations, county resident RL Wilcox asked about the potential cost of the destruction of his family’s well.
“The employees and the investors at Lisbon Valley mining company only want to get as much as they can as cheap as they can out of the natural resources that God has put into this wonderful part of the world,” said Wilcox. “As soon as the copper is gone, they will be gone and we will be left with the disaster that they created.”
Should the in-situ process be approved, the mining company anticipates the copper ore deposits will be commercially produced for approximately 20 years.
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