The city’s Open Space and Trails Board on Thursday unanimously approved drilling a test well to explore geothermal energy potential underneath Aspen.

The temporary test-drilling site is on the gravel parking lot of the city-owned Prockter Open Space, beside the Roaring Fork River and across Neale Avenue from Heron Park.

The board voted 4-0 for the drilling project, following a brief presentation by Lauren McDonnell of the city’s Canary Initiative, which is spearheading the initiative.

“If we’re sitting on top of a clean, renewable source of energy, I think we have a responsibility to explore it,” she told the board members.

They agreed.

“I am a massive proponent of geothermal and I wish you the best of luck,” said board member Gyles Thonely, reflecting the board’s collective enthusiasm.

Board member Charlie Eckart asked how many truckloads of dirt and rocks would be produced from drilling. Just one every three to four days during drilling, McDonnell said. All the board members encouraged her to continue communicating proactively with neighbors about noise and other impacts from the test.

The city held a neighborhood meeting on Monday seeking feedback on the geothermal project from adjacent homeowners. Twelve neighbors attended that meeting. None attended Thursday’s meeting to oppose or support the project.

The city has promised to keep drilling noise below 55 decibels. Any higher would violate the local noise ordinance.

McDonnell will now begin searching for a drilling company to do the work. The contract for drilling will be subject to City Council approval later this summer. Drilling is scheduled to take place in mid- to late-September, McDonnell told the open space board. The parking lot will be closed up to 45 days during drilling and the subsequent testing of the hole.

The drill hole will be up to 1,000 feet deep. McDonnell said they would have to drill on a second successful site in the city before going into actual energy production. McDonnell added that even if the tests are successful, production of geothermal energy isn’t a given.

“It could be that we hit gold and then this isn’t economically or politically feasible for five or 10 years,” she said.

Based on a 2008 geothermal feasibility study, the temperature of local underground water ranges in temperature from 90 to 140 degrees. To heat or cool buildings with geothermal energy, 100-degree water is required. To generate electricity, the city would need water of at least 220 degrees.

The city has dedicated $150,000 to the exploration project. Earlier this year the city also won a $50,000 grant from the Governor’s Energy Office to help fund the test drill.

andrew@aspendailynews.com [1]