It's called fracking and it's a popular drilling method used to unearth natural gas and oil. Fracking involves injecting fluid, sometimes consisting of a mixture of chemicals and water, thousands of feet underground to expand existing cracks in rocks.

There are more than 45,000 oil and gas wells in Colorado. Most of them are in the mountains and in more rural areas. In a populated area like Aurora, drilling wells could be popping up in the Cross Creek Community soon.

The Houston-based petroleum company Anandarko leased the mineral rights to most of the land around the subdivision and has expressed interest in fracking for oil.

"When we built our house and bought land out here this was probably the last thing we'd ever think of that would come around us," Eric Neeley, who lives in the subdivision, said.

"There's no reason why it has to start so close to us," Tracy Cook, a neighbor, said.

Ninety percent of the wells drilled in Colorado are hydraulically fractured.

"We can assure you we take the protection of the environment, the protection of public health and safety very seriously," David Neslin, director of the Colorado Oil and Gas Conservation Commission, said.

Neslin's job is to regulate the drilling companies and to approve their permits.

Neslin says Anandarko hasn't applied for any permits in Cross Creek area yet, but has acquired most of the land. Neighbors who've met with him say they don't believe Neslin understands their concerns, seeing as how his department is funded by the oil companies he regulates.

"In one form or another, all of our funding comes from the industry," Neslin said.

Neslin says proximity to communities does play a role in the permit process. More than that, he wants to assure people about the safety procedures taken. Especially when it comes to concerns about water contamination.

"You know what surprised me the most? Is the amount of ground water data the state of Colorado has," Neslin said.

Neslin says oil and gas companies are required to take water samples before and after digging occurs. Residents say there's also concern about property devaluation, loud noise and large vehicles passing through around the clock.

"The whole laundry list of things," Neeley said.

Neighbors are also concerned about the chemicals used in fracking. Companies aren't required to release the ingredients they use.

However, the Colorado Oil and Gas Conservation Commission says it's in the process of drafting a bill requiring the companies to share their ingredients.

A vote is scheduled for Dec. 5. If it's approved, the law would go in to effect in January.

Some companies already share the information on a website called www.frackfocus.org.

(KUSA-TV © 2011 Multimedia Holdings Corporation)