LONGMONT, Colo. -

A district judge has struck down Longmont's voter-approved ban on hydraulic fracturing, but stayed her decision while the city considers an appeal.

Judge D.D. Mallard ruled Thursday that the ban conflicted with state regulations and Colorado's interest in efficiently developing oil and gas deposits.
    
Longmont voters passed an amendment to the city charter in November 2012 that banned the practice. Hydraulic fracturing, also known as fracking, involves blasting underground rock formations with water, sand and chemicals so oil and natural gas can escape.
    
The Colorado Supreme Court ruled in 1992 that cities can't entirely ban drilling, although the court said they weren't completely forbidden from regulating oil and gas development.
    
Supporters of the ban say fracking is environmentally risky.