AURORA | Even before a deadly house explosion in Firestone last month, questions swirled about the intersection between energy development and Colorado’s considerable housing boom.

Diane Kocis, the oil and gas specialist for Arapahoe County, said she regularly received those calls from savvy home buyers wanting to know more about a parcel’s oil and gas past — details title companies and real estate agents generally don’t offer up. And many are shocked to learn that a property they are interested in, or even may already own, sits on top of or adjacent to an abandoned oil well.

“People still don’t think there was drilling where there isn’t anything going on today,” she said.

After the deadly Weld County explosion — which investigators say was caused by an abandoned nearby gas well — state and local officials are looking at the risks posed by the often tiny distances between abandoned wells and new homes.

And Kocis said she expects even more calls from local residents wanting answers about just how close energy development past and present may have come to their homes.

“It also makes people think this is a pervasive problem, which it isn’t. The new wells have been done so much better than the old ones,” she said. Those improvements include tougher regulations and rules that mandate concrete casings around wells.

In general though, Kocis said while there are rules requiring drilling operations to be a certain distance from existing homes, the state doesn’t have regulations that dictate how close a home can be built to an old well.

Aurora has hardly been the hotbed of oil and gas development that Weld County and some other regions of the state have been in recent years. What little development that Aurora has seen has been limited to swaths of land east of the E-470 toll road, and even that has been minimal compared to neighboring Weld.

Still, the otherwise barren plains to the east of the city’s center have seen some energy development in recent years. And going back decades, a handful of wells — many of which proved dry when developers first explored them — dot the landscape.

There are 113 known wells located within Aurora city limits, according to data provided by city spokeswoman Julie Patterson. Of those 113, there are 37 that are “permitted,” 30 that are “dry and abandoned,” 17 that are “producing,” 16 that are “plugged and abandoned,” 11 that are simply deemed “abandoned,” and two that are “shut-in.” The semantics of those definitions remain somewhat vague, according to Patterson.

“We are working to get a better sense of the definitions of each status, and working with the (Colorado Oil and Gas Conservation Commission) to confirm each status,” she wrote in a May 9 email.

There are 40 different oil companies who lay claim to the various wells spread throughout Aurora, according to city data. The majority of the firms only own one well in the city. Burlington Resources Oil & Gas controls the vast majority of Aurora-based wells with 31. The next company on the list, Bison Exploration, controls 18 wells in Aurora.

Anadarko, the oil giant that agreed to halt operations at 3,000 wells in Colorado following the Firestone blast, does not operate any wells in Aurora, according to the city.

On top of the 113 wells within Aurora city limits, there are an additional 165 known wells within 1,000 feet of city boundaries. Nearly one third of those nearby wells are “dry and abandoned.”

In Aurora, the city largely defers to the baseline regulations set by the Colorado Oil and Gas Conservation Commission (COGCC).

But in 2012, the city drafted an ordinance solidifying its specific rules for oil and gas. They mirror the minimums set forth by the state.

According to the ordinance that took effect in July 2012, any new home built in Aurora must be at least 150 feet away from an existing well, and any new well cannot be closer than 350 feet from an existing structure in a “high density” area. There are additional distance requirements for schools, nursing homes, hospitals and jails, and any drilling application that is less than 1,000 feet from a residential lot, city park, reservoir, open space or golf course must go through the city’s planning commission and undergo a public hearing. Any drilling applicant drilling within 1,000 feet of the aforementioned areas must also mail notice of their application to property owners within a half-mile, and registered neighborhood groups like homeowners associations within one mile, according to the ordinance.

Sonia Skakich-Scrima, who represents local anti-fracking group “What The Frack? Arapahoe,” said the distance regulations set in the city are far too lenient.

“One hundred and fifty feet is not far at all — it’s a ridiculous distance,” she said. “And the city now, in light of this tragedy in Firestone, should be reconsidering this distance.”

Skakich-Scrima said her group is in the process of gathering signatures for a petition they plan to send to the city asking city council and the city’s oil and gas advisory committee to reconsider the 150-foot rule for new homes.

“There should be a minimum distance of at least 1,000 feet if not 2,000 feet,” she said. “The explosions can send debris flying 800 feet, and hydrogen sulfide plumes can go up to two miles.”

The abandoned well that caused the late-April explosion in Firestone was nearly 180 feet from the home that was damaged.

On top of passing that ordinance in 2012, the city in 2015 signed off on creating an oil and gas advisory committee meant to aid city council with deciding how to efficiently extract oil and gas in Aurora. The committee comprises 11 members: Five Aurora residents, three oil industry representatives and three surface or property owners in Aurora who hold mineral rights. Members serve for three-year terms and cannot serve for more than three consecutive terms.

Councilwoman Renie Peterson, who represents the city’s massive Ward II stretching into the eastern plains, said she recently asked Steve Rodriguez, the city staffer who acts as the liaison between council and the oil and gas committee, to provide council an update on wells in Aurora in light of the explosion in Firestone. It remains unclear if or when that update will occur.

Peterson said she’s heard from constituents, mostly near the Murphy Creek neighborhood, asking about their safety following the Firestone incident.

“I’m very concerned,” she said.

She added she supported House Bill 1372, which would have required the state to map out all gas flow lines — like the one that acted as the fuse in the Firestone explosion — for public use. But that late-session measure died in the wake of strong Republic opposition on the House floor late evening May 1.