COLUMBIANA — An uncontrolled gas flow incident at Hilcorp Energy’s natural gas pad outside of Columbiana has been neutralized, the broken wellhead capped off and the evacuation order lifted, Columbiana Assistant Fire Chief Frank Nulf reported Wednesday.

Approximately 450 residents were evacuated in a 1-mile radius around Fairfield School Road after a contractor vehicle struck a wellhead at the Tarka location, causing a release of natural gas around 9 a.m. Tuesday.

The residents were given the all clear to return to their homes over 24 hours later when the well was secured at 12:25 p.m. Tuesday.

The area between state Route 558 and Crestview Road will remain closed until heavy equipment used to cap the well is removed. Residents who live in that area have permission to travel to their homes, but are asked to be mindful of the truck and equipment traffic.

“We want people to be safe when they are returning home and to respect the barricades that are in place,” said Peggy Clark of the Columbiana County Emergency Management Agency.

Fred Romeo, Regional Emergency Operations and Response manager at the Ohio Department of Natural Resources, said Wild Well Control — the specialized contractor brought in by Hilcorp — removed debris around the wellhead and freshwater was pumped into the casing to reduce the flow of gas. A back-pressure valve and two other valves were installed on top of the wellhead.

Romeo said ODNR’s Oil and Gas Division also will remain on the scene during that phase.

The Ohio Environmental Protection Agency also responded to the incident and provided baseline air monitoring throughout the situation. The Ohio EPA was tracking explosive gas methane and volatile organic compound levels on and around the pad.

Ohio EPA On-Scene Coordinator Wade Balser reported data collected did not indicate dangerous air quality at any time during the uncontrolled gas flow. He also said that there was no impact on water within the evacuation zone.

Balser added the gas that escaped from the compromised wellhead already has or will dissipate. He said weather and wind conditions helped disburse the released gas.