

FIRESTONE – A fatal house explosion was caused by odorless gas seeping from a cut-off underground pipeline into the house through French drains and a sump pit, Frederick-Firestone Fire Protection District chief Ted Poszywak said.

Fire investigators found a 1-inch diameter black plastic pipeline running from an Anadarko Petroleum well near the house that had been cut when a tank battery was moved before the Oak Meadows subdivision was built, Poszywak said. That pipeline leaked the gas from a point 6 feet from the southeast corner of the house at 6312 Twilight Ave. in Firestone. Investigators said they found the gas valve at the Anadarko well in the “on” position.

Poszywak said leaking gas “saturated the soil and migrated into the French drains of the home.”

Soon after the firefighters released their report Tuesday, Gov. John Hickenlooper ordered oil and gas companies statewide to inspect and pressure-test oil and gas flowlines within 1,000 feet of occupied buildings.

Hickenlooper said companies must make sure flowlines not in use are properly marked and capped, and that any abandoned flowline cut off underground is sealed.

Frederick investigators found “prerefined gas” — gas that had not been odorized for safety — in the basement sump pit and French drains, Poszywak said. “Those inside the home would not have smelled it.”

The gas was a volatile mix of methane and propane, he said. It “found an ignition source inside the home. It erupted into a sudden and violent explosion” that killed homeowner Mark Martinez and his brother-in-law Joey Irwin and critically injured Martinez’s wife, Erin.

Family members have said Martinez and Irwin were working on a water heater in the basement of the house.

The Anadarko Petroleum oil and gas well sits 178 feet from the house that burned and collapsed in the fiery explosion April 17. Colorado Oil and Gas Conservation Commission regulators announced last week they were supporting the local firefighters’ investigation, and Anadarko officials said they voluntarily were shutting down 3,000 of their older, vertical oil and gas wells in northeastern Colorado as a precaution.

“It was the pipeline rather than the wellhead that caused the buildup related to the explosion,” Poszywak said.

Anadarko had left the well dormant in 2016 and restarted it in January. Anadarko operators may not have pressure-tested underground flow lines to detect leaks, one of many issues the COGCC regulators said they would review.

COGCC chief Matt Lepore said Tuesday afternoon that the commission will consider adopting new rules to require pressure testing for smaller flow pipelines. He added that rules regarding mapping of pipelines throughout the state also will be reviewed as well as other matters.

The house explosion on Twilight Avenue has re-ignited concerns about oil and gas industry operations close to where people live along Colorado’s booming Front Range.

While the COGCC requires companies drilling new oil and gas wells to stay 500 feet from homes (unless companies make deals with landowners and get special permission), state officials leave it to local governments to determine how close to industry facilities new houses can be built.

Firestone’s municipal code allows new house construction as close as 150 feet to existing oil and gas facilities.

“We do not have any definitive answer for what happened,” Oak Meadows subdivision builder Century Communities spokesman Andy Boian said. “We are 100 percent committed to finding out what happened.”

Environment and public safety groups this week were focused on the issue of underground industry pipelines that carry oil and gas away from wells — like the one that leaked gas into the Martinez family home.

State Sen. Matt Jones, a Boulder County Democrat, on Tuesday warned of “a recipe for disaster that could cause people to get hurt.”

“As more information has come to light, it has become clearer that these oil wells, pipes, and tanks are simply too dangerous to be in close proximity to homes, businesses, and schools,” Jones said. “We need to take steps to ensure a tragedy like this doesn’t happen again.”

The Sierra Club is urging state leaders to stop permitting new oil and gas operations until the COGCC overhauls its current process to make sure public health and safety and the environment are protected.

Pointing to the recent Colorado Court of Appeals ruling that oil and gas production can only be done if it does not hurt people and the environment, Sierra Club “Beyond Oil and Gas” campaign director Harv Teitelbaum said COGCC regulators too often waive rules and approve projects “in service of drilling operator convenience and economic expediency

“As a result of these loopholes and rubber-stamped waivers, homeowners and prospective buyers in newer housing developments are not adequately informed of the potentially fatal risks they face,” he said.

Sierra Club members “are very concerned about this, and suspect that this is not an isolated situation,” Teitelbaum said. “Even if not right on top, corrosion in nearby lines, combined with various pathways for gas migration, present a serious, ongoing, widespread risk. … All operators in Colorado should be required to immediately suspend operations at similar wells, fully inspect and report on those wells — not on a voluntary basis — with monitoring systems put in place to alert authorities to any leaks. Long-term, this problem will only get worse as corrosion, geologic action and age affect the integrity of all old wells.”