Colorado cities are responding to concerns over the safety of oil and gas wells after news that the cause of a home explosion in Firestone that killed two people and critically injured another was an abandoned, severed gas line.

On Tuesday Gov. John Hickenlooper ordered inspections for every gas and oil line in Colorado that lies within 1,000 feet of an occupied building.

Although the governor gave oil and gas line operators 30 days to assess their lines and 60 days to make appropriate adjustments, Broomfield announced Wednesday the city's oil and gas operators must immediately comply with the governor's request.

The city also asks all operators submit copies of their updated emergency preparedness plans for all well sites in Broomfield, including location maps and types of above ground and below ground facilities, to include flowlines and isolation valves and including any abandoned known flowlines.

One of these operators, Extraction Oil and Gas, told 9NEWS that as of Tuesday, they had tested "100 percent of our well flowlines and facilities." Read their full statement here.

Broomfield resident Tonja Sjerven has an oil well right near her front door, something she didn't think much about until the FIrestone tragedy. And though there's no indication anything is wrong with that well near Aspen Creek Elementary, it's now a little too close for comfort.

"The school is right here, and all these homes," Sjerven said. "There's not a lot of space in between, so if something were to happen, it would be a lot of damage, and it's concerning."

Broomfield leaders share those concerns.

"We wanted to make absolutely certain that no similar situation existed in Broomfield," Broomfield City and County Manager Charles Ozaki told 9NEWS.

Sharon Tessier, Broomfield City Council member for Ward 2, echoed Ozaki's sentiment, but worried it took too long for this kind of action.

"It is unfortunate that it took the lives of Mr. Martinez and Mr. Irwin to inspect the health and safety that is presumed to be a part of the protocol," Tessier said in a statement.

"Of course we are concerned," Mike Shelton, another Broomfield City Council member for Ward 2, said in a statement. "In fact, Broomfield hired an independent inspector last year to inspect all legacy wells for leaks to fix." Read Tessier and Shelton's full statements here.

Shelton is referring to the inspector Broomfield hired to look at the city's 38 active well sites between February and December 2015. At the time, 22 of them had gas leaks.

According to the report published on the Broomfield City and County website, all but one well has been repaired and one was shut down.

Broomfield doesn't have the largest number of active wells: Boulder has more than 300 and Weld County has more than 22,000.