"There is no doubt," Johnson told Utah Division of Oil, Gas and Mining director John Baza on Tuesday. "If I put the results in front of 100 hydrologists, they would say there is a path [for water] from the ridge tops to the canyon bottoms."
Baza convened a special hearing to hear Johnson, who spoke as an expert for the group Living Rivers, and residents and activists opposed to tar sands mining.
He also heard from U.S. Oil Sands executives.
The Calgary-based company would like to expand the test site from 64 acres to 316 acres, using a citrus-based solvent to separate out a viscous crude called bitumen.
"It is a much more logical mining plan," operations chief Barclay Cuthbert said. "It's an optimization by which we improve the method for extracting bitumen. We have shown we can extract the bitumen with a minimum impact to the environment and we will continue to do so."
Baza will make a decision whether to allow the mine expansion within the next 10 days, but his findings will likely be appealed to the state Board of Oil, Gas and Mining.
Activists staged a rally on the steps of the building before the hearing, denouncing foreign companies' plans to strip-mine tar sands and oil shale.
Utah holds some of North America's largest deposits of the "unconventional" fossil hydrocarbons, but many people prefer them left in the ground because extracting and processing them requires lots of energy and rearranges the landscape.
"It is unconscionable for the state to allow operations at all," said Kathy Albury of Peaceful Uprising. "They had a permit, but they got greedy and wanted more. They opened the can of worms. They came back for more. They should not get it."
A private security guard shot video of the Peaceful Uprising and Utah Tar Sands Resistance speakers and asked press photographers for their identification.
The groups regularly conduct vigils and demonstrations at PR Springs on the line between Grand and Uintah counties, where 26 protesters were arrested last summer after some activists locked themselves to mine equipment and others obstructed vehicle traffic.
Authorities labeled the action a "riot" that shut down mine operations for the day.
Uintah County officials support the project because of its projected economic impact — expected to total $1.2 billion.
Over 10 years, the project is estimated to generate $160 million in royalties for the state's school fund and provide 200 to 300 full-time, high-paying jobs, according to the County Commission's letter asking Baza to expedite permitting.