Tensions over hydraulic fracturing in Alaska were underscored at a Thursday hearing when the chair of a state regulatory agency called one person's testimony "bulls—," and the governor's top oil and gas adviser attacked the same person for insulting the state.

The target of the comments were Bob Shavelson, executive director of Cook Inletkeeper, a group asking the Alaska Oil and Gas Conservation Commission to issue public notice and allow a public comment period before oil and gas wells are hydraulically fractured.

Hydraulic fracturing, or fracking, has occurred for more than five decades in Cook Inlet and the North Slope, without reports of harm to groundwater or other damage, officials have said.

But plans by Texas oil company BlueCrest Energy to conduct hydraulic fracturing from a well that will start 6 miles north of Anchor Point have heightened fears on the Kenai Peninsula.

The effort has been called the region's first large-scale, long-distance operation with multistage fracking in a well extending 3 miles from shore. The hydraulic fracturing will occur more than a mile beneath the Inlet seafloor and will occur in stages along the well, with the fractures traveling about 200 feet.

Some residents fear the operation could pollute groundwater or cause other problems. Supporters of the project say that won't happen in part because of the state's strict regulatory oversight and design requirements for wells. Alaska's fracking rules were strengthened in 2014, following extensive opportunities for public comment.

Shavelson said he agrees the agency, which oversees oil and gas drilling on state lands, has some of the nation's strictest regulations to prevent accidents from fracking, including that landowners within half a mile of a planned well-bore be notified of foreseen operations.

But Shavelson and several supporters of the change said the general public has a right to be notified and comment on proposed fracking operations associated with each well. He requested the Thursday hearing to discuss the issue.

The agency currently does not issue public notices or hold hearings when an operator applies for a permit to drill a well and use hydraulic fracturing. The information is made available to the general public after the agency approves the operation.

Deborah Limacher, a longtime Inlet fisherman living in Homer, said the agency is tasked with protecting the public's interests and needs to allow public comment before fracking operations are approved.

"We need to be part of the decision-making. We are the ones who have to live with your decision," she said.

A handful of speakers opposed the change. John Hendrix, chief oil and gas adviser to Gov. Bill Walker, said the existing rules require ample notification for interested parties. A public hearing before each fracture stimulation would delay operators and increase expenses.

"Alaska's oil industry must be competitive to survive and fuel our economy," he said.

The hearing grew tense after Shavelson suggested he's not surprised the state or the Kenai Peninsula Borough oppose the rule change, since the state faces multibillion-dollar deficits and doesn't want delays to potential development. He suggested the change could happen without public hearings, and his group's concerns would be met if people can submit letters or emails during a 30-day public comment period.

Hendrix, shooting icy looks at Shavelson, said he found it "appalling" and "degrading" that he would suggest the state's views are based on the economy, rather than facts and careful evaluation of the issues.

"We also find it amazing you will stand up here and say you respect AOGCC and then you want them to change things," Hendrix said.

Shavelson also got crosswise with the AOGCC chair when he shared an analysis from a Natural Resources Defense Council official who said Bluecrest's well design was flawed and could contribute to leaking fluids that threatens groundwater.

AOGCC Chair Cathy Foerster, who early in the meeting had told speakers not to use foul language, said the analysis is "steeped in ignorance and totally false."

"We work really, really hard to ensure good mechanical integrity, and when someone says, 'You know, well you are not doing your job because,' and then the stuff they say is, excuse my French — I said nobody could cuss — is bulls—. I find it arrogant," she said.

Shavelson shot back, saying the differing opinions on what is safe, and the complexity involved in fracking operations, are why public comment should be allowed.

Foerster said the public comment period on the proposed change will extend through Dec. 27. The commission is expected to decide whether to change its rules within 30 days of that date.