In this March 25, 2014 photo, a worker oils a pump during a hydraulic fracturing operation at an Encana Corp. well pad near Mead, Colo. The National Petroleum Council estimates that up to 80 percent of natural oil wells drilled in the next decade will require hydraulic fracturing. 

(AP Photo/Brennan Linsley)
District Court Judge D.D. Mallard struck down the city of Longmont's ban on hydraulic fracturing, also known as fracking, in an order issued Thursday.

The judge stayed her order though, pending an appeal.

"There shall be no hydraulic fracturing activity in the City of Longmont until further order of Court, either from this Court or a higher court," Mallard's ruling states.

Opponents said late Thursday that they will file an appeal. Kaye Fissinger, president of Our Health, Our Future, Our Longmont, said while they’re disappointed by the ruling, the court’s decision to immediately stay the decision gives her hope.

“We’re expecting this all the way along the line that this would be a back and forth kind of issue that would not be settled by a district court," Fissinger says. "We ... have vowed to take this all to the Supreme Court if that’s what’s required.”

Mallard ruled that existing state law, the Colorado Oil and Gas Conservation Act, pre-empts the city's ban. In 2012, Longmont voters passed an amendment to the city charter that banned fracking and the storage and disposal of fracking waste within city limits. Since then, four other cities, Boulder, Lafayette, Broomfield and Fort Collins, have passed similar restrictions.

The two laws are "irreconcilable," the judge wrote:

There is no way to harmonized [sic] Longmont’s fracking ban with the stated goals of the Oil and Gas Conservation Act. As described above, the state interest in production, prevention of waste and protection of correlative rights, on the one hand, and Longmont’s interest in banning hydraulic fracturing on the other, present mutually exclusive positions. There is no common ground upon which to craft a means to harmonize the state and local interest. The conflict in this case is an irreconcilable conflict.

In a statement, Attorney General John Suthers said "the court got it right."

“Under the current law, local governments can’t ban fracking,” Suthers says. 

Tisha Schuller, president and CEO of the Colorado Oil and Gas Association, one of the plaintiffs in the case, supports the judge's decision.

“The judge’s decision reaffirms that local jurisdictions can’t ban fracking," she said. "That’s something to celebrate for the industry, but also for the state of Colorado, because oil and gas development is an activity of statewide interest.”

CPR News' Mark Bevis and KUNC reporter Nathan Heffel contributed to this report.