Another explosion at American Iron and Metal's Saint John Harbour scrapyard halted operations briefly Thursday afternoon, the Department of Environment and Local Government has confirmed.
The "contained explosion" occurred at about 4:50 p.m. in the metal shredder, department spokesperson Erika Jutras said in an email statement.
The noise level measured at the shredder was 109.4 decibels, above the 109-decibel level that requires the company to shut down operations and inform the province and Saint John Fire Department.
Jutras said AIM followed the required process and an inspection by the fire department revealed no fire, smoke or visible damage. The department gave AIM the go-ahead to resume operations at 6 p.m.
Environment Minster Jeff Carr said he believes the explosion was caused by a propane tank or similar material hidden inside a vehicle that was shredded.
"That was a problem we faced early on, that a lot of material was brought on site that had these combustible materials in them, and they were not being inspected properly," Carr said.
He said until old inventory material is cycled through, there may be some minor explosions, but the company has told the government it should be gone by the end of March.
On March 7, Carr granted AIM a further three months of operation in an amendment to a ministerial order.
He said this would allow the department to continue monitoring the operations.
"We want to be able to make improvements from now until June."
The department said it is working with AIM and the Port of Saint John to address explosions and excessive noise that have upset some of AIM's neighbours on the lower west side of the city.
AIM environmental director Ann Marcotte said in an email statement that what happened Thursday "was an infrequent impulse noise that resulted from a contained single burst of pressure following the shredding of some material."
The company said it followed the operating protocol.