GLENWOOD SPRINGS, Colo. (AP) — The director of the Colorado Oil and Gas Conservation Commission says the mystery of the flammable water from a Fort Lupton-area well has been partially solved.

Director David Neslin told the commission Tuesday that nearby gas wells were replugged and tests showed methane gas was not to blame.

"I don't know that we solved the mystery, but we evaluated all the wells in a half-mile radius and determined that the wells are operating properly. The wells were not the source of the gas," Neslin said. "We don't believe there is a current leak or problem that endangers public safety."

Neslin said he will meet with residents and deliver a full report to the commission next month.

Neslin said the owner of the wells installed a water treatment system on the water wells, and that should clear up problems that attracted national attention when tap water in nearby homes caught fire.

Anadarko Petroleum Corp. and Noble Energy Inc., which own the wells near Amee Ellsworth's Fort Lupton-area home, also tested the wells and haven't found where the gas is coming from.

The Ellsworths first noticed problems with the water last fall. They went public with their plight with videos of their tap water catching fire when a lighter was held nearby.

State health officials have said the levels of methane gas in the water aren't high enough to cause health problems.

Neslin said there is a history of naturally occurring methane in groundwater in Weld County, but further studies may be needed to determine the source.

Another of the hot topics on the agenda for the two-day hearings that got under way Tuesday is proposed drilling close to an underground nuclear blast site.

Commissioner Tresi Houpt said Garfield County is "ground zero" for drilling issues and environmental issues, and the natural gas industry is still showing interest in developing resources, despite a decline in drilling activity.

A full hearing from public health officials, county officials and opponents of Rulison drilling is scheduled Wednesday.

Garfield County commissioners sent a letter this spring to Colorado's congressional delegation and the U.S. Department of Energy seeking field tests so companies drilling for natural gas near the site in Rulison don't end up releasing radioactive contamination.

The DOE has said models show that chances of contamination releases are slim. The department has released a draft management plan for the site recommending that energy companies can drill closer to the area if done in a conservative, staged approach.