Weld County resident Renee McClure said she couldn't believe it when her son turned on the kitchen faucet then held a cigarette lighter next to the running water.The water ignited.The flammable water phenomenon is affecting at least three homeowners west of Hudson. Those homeowners want to know why."We were shocked," McClure told 7NEWS. "My horses and animals drink it. My kids drink it. I want to know if it's safe."Stephen Flaherty, of Noble Energy, one of several energy firms with wells in the area, said that water has been tested at one of the homes about a half-mile away from the McClure's, and that methane gas was found in the water well.He said some methane gas is naturally occurring in the aquifer, but that tests show the methane in the water at that home was not naturally occurring.A spokeswoman at the state health department said, generally speaking, methane gas itself is not a major concern in drinking water."If there was something else in the water, like benzene, there would be a concern," said Lori Maldonado.Anadarko Petroleum also has wells in the area.A spokesman for Anadarko told 7NEWS that they are working with Noble Energy to notify families about the situation. He said they don't know the precise source of the contamination."We've offered to help secure temporary housing for that (neighboring) family," John Christiansen said.Flaherty said they dont know if the flammable water at the other homes is also methane related, and if so, whether it's from the same source. He said those tests will be conducted this week.Christiansen said it's possible that methane is leaking from an operational well, one maintained by existing energy companies.He said it's also possible that it's leaking from an historic well that's no longer operational. He said if thats the case, the Colorado Oil and Gas Conservation Commission is responsible for the fix.The Commission did not return phone call seeking comment.Environmentalists say the flammable water points to the need for effective regulation of the oil and gas industry."This isn't an isolated incident, by any means," said Gavin Clark, of Environment Colorado. "Our reports tell us there are about two dozen, if not more, similar incidents of oil and gas drilling not only affecting people's drinking water but health in general."Clark gets no argument from McClure, who said she had no idea methane was naturally occurring in the area until after she and her husband bought their house three years ago. She said her safety questions go beyond just drinking the water.When asked if she felt comfortable using tap water to extinguish a small kitchen fire, she shook her head, threw up her hands and said, "Exactly! Thats one of my questions, too."So far, the ignitable gas has only shown up in private water wells.Hudson Town Administrator Joe Racine said the municipal water supply is not affected.