Editor’s note: Daniel Glick and Ted Wood of The Story Group, along with Kelsey Ray of The Colorado Independent, have been reporting on oil and gas issues for our ongoing series: Fractured. Fractured examines the science, politics and humanity of oil and gas development and explores its impacts on Coloradans around the state.

The agency tasked with regulating Colorado’s oil and gas industry has no record of the abandoned storage and processing site to which the severed gas line that caused last month’s fatal home explosion in Firestone originally led, The Colorado Independent has learned.

Nor does the Colorado Oil and Gas Conservation Commission, or COGCC, have paperwork for the same kind of site, called a tank battery, currently connected to the well responsible for the blast — nor for most battery sites connected to wells throughout the state.

The state started requiring such documentation in the spring of 2009, but did not apply the rule retroactively, leaving older equipment that was or even remains connected to most of Colorado’s more than 54,000 existing wells unrecorded.

Without requirements to keep track of infrastructure that was in place before the regulation took effect, the COGCC’s main proof that the now-abandoned battery site existed are old satellite images. There’s no state documentation indicating when that battery site – owned by Anadarko Petroleum – was disconnected from the line that later caused the Twilight Avenue explosion. Likewise, there’s no record showing why that line was abandoned without apparently having been capped on both ends, when and by whom it was severed right near the home on Twilight Avenue, or why, over the course of more than a decade, no one seemed to notice. An investigation led by the National Transportation Safety Board (NTSB) is underway.

The COGCC’s lack of documentation raises a broader question about the state’s ability to protect Coloradans from the vast underground, unmapped and unregulated webs of oil and gas infrastructure around which homes, schools, parks and business are being built.

Bruce Baizel, energy program director for environmental watchdog group Earthworks, says it’s “classic agency behavior” for the COGCC to enact regulations that do not apply retroactively. With so much older infrastructure in place throughout the state, he adds, that can lead to a worrisome lack of oversight.

“If you don’t measure it, if you don’t regulate it, you just ignore it,” Baizel says. “And in this kind of industrial activity, the logical outcome of that is that it comes back to haunt you with this kind of an accident.”

A tale of two wells

Understanding the deadly explosion on April 17 requires familiarity not only with the well located 178 feet from the home at 6312 Twilight Ave. and its attached lines, but also with the oil and gas infrastructure spanning the once-open patch of land that became the Oak Meadows neighborhood starting in 1999.

Officially, the well responsible for the explosion is called Coors V 6-14Ji. For simplicity’s sake, let’s call it “Well A.” Hydrocarbons flowed underground from Well A, drilled in 1993, through flowlines to storage tanks on a battery site about 2,000 feet to the northwest. That battery site also served other wells, including one immediately to its east. We’ll refer to this second well, officially named Coors Fee 3-6, as “Well B.”

In 1999, development company Century Communities started building roads and houses in the area. As a result, sometime between 1999 and 2002 — the COGCC can’t say exactly when because it didn’t require paperwork at that time — the flowlines needed to be reconfigured so that they didn’t run for more than a quarter mile underneath the new subdivision.

The oil and gas extracted from southern Well A was rerouted, through new flowlines, to a new battery site built to the west, rendering the old flowlines that had connected Well A to the old battery site near Well B obsolete.

These abandoned lines, about seven feet underground, remained intact, as is standard practice in the industry. Rather than remove the buried pipes, oil and gas operators instead abandon such lines “in place” by removing all hydrocarbons, capping both ends and conducting pressure tests to ensure that they are no longer connected to any drilling activity.

In the case of a two-inch diameter flowline connecting Well A to the old battery site, such precautions appear to have been properly followed. But with the line that would eventually leak the highly explosive gas into the home of Mark and Erin Martinez — a smaller, low-pressure, one-inch return line, which ran parallel to the larger line — such protocol apparently was ignored. (Return lines move small amounts of natural gas from wells to the tank battery to power the machines, called “separators,” which separate oil from natural gas. They are a kind of flowline, which move hydrocarbons from wells to the battery sites.)

Mark and his brother-in-law, Joey Irwin, were killed in the resulting explosion as they were replacing the hot water heater in the basement. Mark’s wife, Erin Martinez, was severely injured and remains hospitalized.

The results of the Frederick-Firestone Fire Protection District’s investigation showed that at the time of the explosion in mid-April, Well A was still connected to a few hundred feet of that smaller underground line, which at some unknown time had been neatly severed where the Martinez home was built in 2015.

After the blast, inspectors found the southern end of the line, at the wellhead, was topped not with a cap, but with a valve.

Inexplicably, that valve was found in the “on” position.

No looking back

COGCC officials can’t explain why a line that was abandoned as far back as 1999 was still connected to an active well more than 15 years later. And the agency’s massive database offers no clues.

Until 2005, COGCC rules mandated that oil and gas companies follow a particular procedure for abandoning flowlines, but did not require paperwork documenting the process. Not only does the agency not know for sure when the return line that once ran through the Twilight Avenue property was abandoned — “between 1999 and 2002,” says spokesman Todd Hartman — but there is no documentation explaining why one end of the line remained attached to Well A after the line was no longer in use, or why the valve was left on.

In 2008, the state legislature increased the COGCC’s authority to enact new regulations addressing a wide swath of issues related to reclamation, permitting and abandonment of oil and gas sites. The overhauled rules, which became effective in the spring of 2009, were intended to “protect public health, safety, and welfare… from the impacts resulting from the dramatic increase in oil and gas development in Colorado.”

Those regulations require, among other things, that operators record battery sites built after spring of 2009 in documents that are made public on the COGCC database. They also mandate that each time oil and gas companies drill a new well, they submit an inventory of all related infrastructure equipment, such as battery sites, pits and flowlines so that when the well is ultimately shut down and abandoned, there’s a full accounting of what remains and what doesn’t. But those safeguards don’t apply to the battery sites for Wells A and B, because that infrastructure was in place well before the new rules took effect.

Ownership of both Well A and Well B changed multiple times, as is often the case given the volatile fluctuations in the oil and gas market. Records show that in the three decades since it was drilled in 1983, Well B has had six different owners and operators; Well A has had five since being drilled in 1993. It’s unclear what each of those companies knew about the detailed histories of each part of the systems they bought. The Colorado Independent asked both Anadarko and former owner Noble Energy about the history of the abandonment processes, but spokesmen from both companies declined comment, citing the ongoing investigation.

Operator responsibility lies at the heart of the lawsuit that Jeffrey and Karla Baum, owners of the house two doors from the Martinez home, filed Monday. The suit against Anadarko Petroleum, Noble Energy, land developer ST-Firestone LLC and home builders Hearth at Oak Meadows LLC and CC Communities LLC, seeks damages for alleged negligence, saying both the oil and gas companies and the developers had a responsibility to “confirm the existence, proper abandonment and removal of all oil and gas production related facilities so as not to endanger residents of Oak Meadows, generally and including the Plaintiffs.”

The lawsuit argues that the defendants either knew or had the ability to know about the potential dangers presented by the unmapped and improperly abandoned line. Their failure to adequately protect the neighborhood, the plaintiffs say, has caused them damages including “physical injuries, post-traumatic stress, mental anguish and severe anxiety, damages to personal and real property,interference with their use and enjoyment of property, annoyance…loss of peace of mind, and diminution of real estate property value.”

Colorado has more than 54,000 active wells, but COGCC’s database records only 1,400 battery sites. Even taking into account that wells often share battery sites, and that some wells don’t require them at all, the numbers nonetheless convey a large discrepancy.

That discrepancy leaves prospective homebuyers and current residents in the Oak Meadows neighborhood and elsewhere throughout Colorado’s gas patches in the dark about the history of oil and gas activity around them and whether, as was the case on Twilight Avenue, equipment was recklessly abandoned.

The COGCC says it has taken steps to document “a lot” of older battery sites in floodplain areas since massive flooding hit some of those sites in the Front Range floods of 2013. But there are no state efforts on the books to record all battery sites that were in place before 2009.

“We’re working through that as we progress forward,” says COGCC engineering manager Stuart Ellsworth.

The industry may not embrace the agency’s efforts. In a direct reaction to public outcry after the Firestone explosion, Reps. Mike Foote of Boulder and Steve Lebsock of Thornton proposed a bill requiring the mapping of all flowlines in Colorado. In the final week of this year’s legislative session, a Republican filibuster spurred by heavy opposition from the oil and gas industry managed to kill it.

RELATED: FRACTURED: Roughneck politics

A line to nowhere

In the aftermath of the April 17 blast in Firestone, and the revelation that an abandoned flowline had caused it, The Independent went searching for documentation about the line itself. Finding none, we then searched for records of the battery site to which the line once carried oil and gas from Well A, thinking that those documents might offer insight into the capping and abandonment of the line years earlier.

Not finding them in the COGCC’s database, we asked the agency for help.

Agency spokesman Hartman and engineering manager Ellsworth directed us to open the agency’s GIS mapping software and zoom in on the area in question. Satellite images from 2009, 2011 and 2013 showed two white cylinders in a dirt field.

“So there you go. That’s it,” Ellsworth said as he guided The Independent through the imagery. “That’s the facility.”

The mapping software’s most recent satellite photos, from 2015, show the same patch of brown dirt, sans cylinders. In 2014, Anadarko officially abandoned Well B, citing poor production. Today, all that exists on land where the battery site stood is a single metal pole etched with the words Coors Fee 3-6 in the middle of a patch of prairie above the neighborhood park.

COGCC rules require companies to follow and document a specific set of safety precautions when abandoning wells. Anadarko did so, filing the paperwork in November 2014. But the company wasn’t required to document the abandonment of the nearby battery site — again, because COGCC regulations did not apply to batteries built before 2009. Beyond the “after” satellite photos, the COGCC’s only confirmation that Anadarko abandoned the site itself comes from a single form, completed by an agency inspector, showing that he visited the location and eyeballed no tanks, trucks or other equipment.

As Ellsworth explains it, “He went out there and he saw no pieces of equipment, he saw no pits, everything looked great, so he was done.” The COGCC gives operators three months to remove tanks and other related equipment after abandoning a well. The inspector filed his form on Jan. 25, 2016, 14 months after Anadarko formally abandoned the well.

COGCC regulations on the books today would have offered multiple opportunities for keen-eyed operators and inspectors to notice the problematic flowline, from mandating documentation of the abandonment process to requiring a thorough inventory of everything surrounding the tank battery site.

Earthworks’ Baizel argues that a required inspection of the old battery site likely would have alerted Anadarko to the wayward line. “Common sense says to ask, ‘Where does this pipeline go?’” he says. But, he says, “If it’s not on the checklist, it becomes invisible.”

COGCC’s Hartman and Ellsworth disagree. They say that an inspector at the battery site would have no reason to believe that anything unusual was happening with the return line. When Well B was abandoned, Hartman says, workers would have assumed that the line that once connected the tank battery to Well A had been long defunct, “so work in 2014 would not have likely raised a flag.”

Workers may not have even seen the old flowline when abandoning the tank battery, though that’s unknown. Again, Anadarko and Noble did not respond to questions about the abandonment process at the tank battery. But COGCC protocol did not require operators to cut off abandoned flowlines below ground level at the time Well A’s flowlines were abandoned around 1999, Ellsworth says, so the problematic line likely was left sticking out of the ground.

Still, Hartman says that it could have been chopped off to ground level at any point after 1999. Without documentation, it’s impossible to tell. He says it even could have been removed entirely at some point throughout the neighborhood construction process, leaving no trace at all.

Fatal assumptions

The investigation into the explosion in Firestone is ongoing, and answers remain elusive. But questions are plentiful: What happened during the original flowline abandonment process? Who turned the valve on after Well A was reactivated in January 2017? Why did nobody notice the problem over the course of more than a decade?

Anadarko spokesman John Christiansen referred The Independent’s questions on these matters to the National Transportation Safety Board, which is leading the investigation because pipelines are considered a mode of transportation. NTSB spokesman Eric Weiss in turn told The Independent that Anadarko could answer any questions that “could have been answered the day before the accident,” but Anadarko did not respond to follow-up requests. Noble also referred questions to the federal agency.

The NTSB expects to conclude its investigation into the accident in 12 to 18 months, and hopes to have a publicly available “accident docket” on its website, with interviews, inspection records and other materials, in about six months.

In the wake of the tragedy on Twilight Avenue, Gov. John Hickenlooper called for a rapid-fire inspection of every well and flowline within 1,000 feet of a home. The COGCC has ordered operators to detail the coordinates of all flowline endpoints and to properly abandon any lines no longer in use.

But for many Coloradans, these measures are inadequate. Earthworks’ Baizel bluntly contends that because the COGCC routinely allows regulatory exemptions for existing infrastructure, “we have two dead people.” At a COGCC hearing on May 1, concerned residents packed the meeting room, clamoring for the state to do something about safety.

“Why are you allowing this?” one woman shouted at the commissioners. “Why are you putting my children at risk? And your own?”

For these and other residents in oil and gas patches throughout the state, the vast network of decades-old infrastructure represents a frightening web of threats.

“FIGURE THIS OUT,” the woman at the commission meeting yelled, “before you allow more wells and more ticking time bombs to go off under another person’s home. And don’t tell me this had nothing to do with oil and gas. It’s not the first time, and it’s not the last.”

Ellsworth says he can’t speculate about what happened with the line in question. But he can say that, given all the housing construction in the Oak Meadows neighborhood, it would have been reasonable for operators, years later to assume that the line was defunct and abandoned. “I want you to realize,” he says, “that when this subdivision was built, there was no line that fully connected all the way, because of the numerous amounts of basements, sanitary sewer lines, all that construction when it occurred throughout from 1999 to current.”

In other words, for more than a decade, builders and drillers working near Twilight Avenue did so assuming that with so much construction taking place in the area, an active line couldn’t possibly remain underneath.

On Tuesday, Anadarko announced that it will permanently sever all of its one-inch return lines in the Oak Meadows neighborhood. The company also says it will be paying for methane detection equipment for homeowners and for the cleanup and upgrade of the neighborhood park. The company shut down 3,000 wells in northern Colorado while it conducts its own safety inspections.

The scene in the neighborhood remains surreal. A pile of blackened debris marks is all that remains of the Martinez house. A chainlink fence laced with limp crime scene tape envelops the lot, the park on one side and a neighbor’s home on the other. A sidewalk memorial of drying flowers leans against the fence in front of the home.

The well from which the deadly return line once led sits to the southeast. From it runs a trail of fluttering yellow flags marked ANADARKO FLOW LINE that heads west along the back fences of neighbors to the tank battery.

A neighbor working on his yard across the street from the Martinez home Tuesday morning says he heard that another neighbor had filed a lawsuit against Anadarko, Noble and the home builders, but he says he has no interest in doing the same. Nor does he have any interest in having his name in the paper.

He says he went to the homeowners’ association meeting a couple weeks back and Anadarko answered questions to his satisfaction. And, he adds, the fire department has assured everyone that the neighborhood is safe.

“I have no reason to doubt them.”

Just behind the Martinez house, construction continues on an apartment complex. The beep and roar of bulldozers, the sound of hammering and the workers’ shouts all carry in a breeze that still smells faintly of charred wood.

Cover image by Susan Greene.

Susan Greene and Tina Griego contributed to this report.