Colorado House Republicans late Monday blocked a bill that would have required operators to provide the location of all their oil and gas subsurface systems in the state.

House Bill 1372, introduced last week by state Democrats Steve Lebsock and Mike Foote, followed a fatal house explosion in Firestone last month. The explosion, linked to a severed gas flowline from a vertically drilled well about 170 feet from the house, killed two men and critically injured the wife of one man.

In response, Anadarko Petroleum Corp., which owns the well, shut in more than 3,000 vertical wells in the northeastern part of the state; Great Western Oil and Gas Co. followed suit, shutting in 61 wells pending inspections.

The late session bill in the House, which is controlled by Democrats, needed to be approved before midnight Monday to make it to Gov. John Hickenlooper’s desk in time for a signature before the legislature is adjourned for the year. However, the bill was filibustered by House Republicans. It also would have faced likely opposition in the GOP-controlled Senate.

As written, the legislation would have required oil and gas operators to provide the location of each flowline, gathering pipeline and transmission pipeline installed, owned or operated. The information was to be submitted under deadlines set by the Colorado Oil and Gas Conservation Commission (COGCC) and each local government affected. The COGCC also was to establish a searchable database of the subsurface equipment.

Although there is no central database of subsurface systems, critics argue access to well information is available using geographic information systems, or GIS.

“You’d have to go back to the ’50s to find lines that aren’t mapped out,” Republican Rep. Phil Covarrubias said, according to the Associated Press. “It’s ridiculous to say we don’t know where they are.”

Opponents also argued that a safety review of Colorado’s wells, which number close to 54,000, already has begun. Hickenlooper on May 2 ordered operators to inspect and pressure test oil and gas flowlines located within 1,000 feet of occupied buildings. The existing flowlines have to be tested within 30 days, while the integrity tests are required within 60 days. Lines abandoned or not in use have to be inspected within 30 days and abandoned within 60 days.