What caused an explosion in Breslau, Ont.?

A huge explosion near Breslau, Ont. could be seen and heard on video from a home's security camera.

An explosion Thursday night in Breslau, Ont. is being blamed on the weather.

Video from a home security system showed a bright ball of light, followed by thick white smoke rising into the air, not far from a residential area and the Region of Waterloo International Airport.

CTV News reached out to the Woolwich Fire Department for an explanation.

“The incident in Breslau... was the result of a pressure relief valve freezing due to our current weather, causing a small buildup of pressure in an empty tank,” Chief Dennis Aldous explained in a email.

Both Aldous and Sandy Shantz, the mayor for the Township of Woolwich, confirmed it happened at Safety-Kleen Canada, a waste management and used oil refinery at 300 Woolwich Street South.

Shantz said there was no danger to the public.

The Region of Waterloo’s Emergency Management Office said they were not aware of an explosion. They told CTV News they would not have been alerted if the township dealt with the problem on its own and did not escalate the matter to the region for additional support which, they noted, would have been the normal procedure during an emergency situation.

CTV News also contacted the Ministry of Environment about the explosion.

Previous incidents at facility

The Breslau facility has been the subject of previous environmental and safety-related incidents over the years.

In 2022, the Ontario government fined Safety-Kleen Canada $140,000 after the company was convicted of one violation under the Environmental Protection Act. The province said the conviction was for discharging a contaminant into the environment that was likely to cause “an adverse effect.”

One year later, Safety-Kleen Canada said black smoke seen coming from the refinery did not pose a health risk to the public, following concerns raised by nearby residents.

Residents in the area have also previously reported strong odours. In 2019, people living in Breslau complained of an “intense” natural gas smell, while similar odour complaints were reported in parts of Waterloo Region in 2017.

The facility has also experienced fire-related incidents. In 2018, emergency crews responded to a fire at the Safety-Kleen plant, though no injuries were reported at that time.

Officials have not indicated whether any of those past incidents are connected to the most recent explosion.