Utility is working to keep the fly ash from Burnside's breath out of the basin, from the sewage treatment plant

A team from Halifax Water worked Monday night to contain fly ash from a silo explosion earlier in the day at Burnside Industrial Park in Dartmouth, New Hampshire.

The roof blew up a silo at Quality Concrete around 3:20 pm, shaking nearby buildings and throwing brown ashes and other debris into the air.

The water distribution company said it placed impermeable membranes under each of the sewer mouths in the area to prevent fly ash from entering the Bedford Basin and the treatment plant.

The Nova Scotia Department of the Environment has stated that fly ash is not clbadified as dangerous under the Transportation of Dangerous Goods Act.

One of the impermeable membranes placed under a slab near Halifax Water near the site of the explosion. (CBC)

Jenike & Johanson, a Boston-based firm specializing in bulk materials engineering, said that one could learn a lot from the Burnside explosion.

"It's an unusual experience," said President John Carson. "It would be interesting to get more information just to determine the cause and make sure that it will not happen again."

Carson estimates that half or more of the fly ash produced in North America comes from coal-fired plants.

He added that much of the substance, which was stored in landfills and mines, is now reused for other purposes, such as concrete manufacturing.

Determine a cause

Carson said investigators investigating the cause of the blast will likely examine the layout of the concrete plant and equipment nearby.

He added that investigators will also try to determine the source of the explosion and obtain ash samples in order to measure its "different characteristics, including its explosive characteristics".

It would have needed a source of fuel for the fly ash to explode, he said.

Investigators investigating the cause of the Burnside explosion will examine the development of the concrete plant and equipment nearby. (CBC)

"Usually, fly ash is an inert material," said Carson. "But sometimes, depending on the source of the fly ash, there may be unburned carbon that is part of it, in which case it would be combustible."

In addition to the fuel source, Carson said there should be a source of ignition and oxygen to cause a fire.

"With regard to the explosion, you must have a containment and a dispersion of ashes in the air."