Update 2:30 p.m.
The Centennial Ice Arena was turned back over to staff Friday afternoon after a Billings HAZMAT response team located and capped an ammonia leak inside the building. Levels measured around 17 parts per million during the team's final walk-through, well within the safe range of 25 parts per million.
Readings had been over 100 parts per million before officials discovered the additional leak Friday morning.
Update 1:25 p.m.
Billings Firefighters on the HAZMAT team have located a leak within the Centennial Ice Arena that was preventing ammonia levels from dropping.
They would like to see ammonia levels at or below 25 parts per million (ppm) before releasing the building back to arena staff, according to Victoria Hill, a public information officer for the City of Billings.
On Thursday night levels were as high as 200 ppm. Friday morning levels were still above 100 ppm despite overnight mitigation efforts.
Shortly after the HAZMAT team located and stopped the leak Friday afternoon, ammonia levels drastically dropped.
The main area of concern was the compressor room, but the rest of the building has been deemed safe.
A remote monitoring system is now being used to monitor the compressor room. As long as the ammonia levels stay below 25 ppm over the next hour, the fire department will be able to release the facility back to staff.
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Original Report
BILLINGS - A Billings Fire Department HAZMAT team returned to the Centennial Ice Arena in Billings Heights on Friday morning following an ammonia leak that forced the evacuation and closure of a nearby park.
The team entered the building to take measurements of the ammonia levels inside to determine whether the chemical has dissipated enough to reopen the facility.
The leak was first reported Thursday evening when a building alarm at the ice arena off Bench Boulevard alerted the fire department to an issue at the arena.
The ammonia leak was discovered and officials closed the arena, Two Moon Park and the bike path near the arena. The park and bike bath were reopened Friday morning.
Ammonia is used at the arena to create ice and keep it cold. it is a toxic industrial chemical, and if exposed a person will experience severe skin and lung irritation.
No one was inside of the ice arena when its alarm system alerted dispatchers of the issue.
RELATED: Two Moon Park in Billings evacuated after ammonia leak
