Oil and gas companies doing business in Northern Colorado are increasing their investments in water recycling in an effort to cut their consumption, reduce costs and perhaps dampen criticism from environmentalists and others.

The issue is rooted in hydraulic fracturing, a practice that consumes large amounts of water during drilling. Fracking can involve pumping millions of gallons of water into a drilled hole to release oil and gas trapped in shale.

Western Slope operators tend to recycle a greater percentage of their water, though experts believe Northern Colorado operators recycle greater volumes because drilling activity has slowed in the Piceance Basin.

At the moment, there's no way to know exactly how much recycling actually takes place in Northern Colorado, though the issue could come into focus when the Colorado Oil and Gas Conservation Commission begins to analyze data it has gathered since June on the amount of water recycled in the state.

That's expected to happen "in the coming months," said Todd Hartman, spokesman for the Colorado Department of Natural Resources.

Already, however, "we know that industry is aggressively pursuing recycling opportunities for water, both on the