Fire officials have identified the liquid that leaked from an underground tank into the Don River Sunday evening as mineral oil, kerosine and aviation fuel.

A construction crew ruptured the tank at the rear of the Staples store on Eglinton Avenue near Brentcliffe Road, west of Leslie Street.

“The tank was not leaking at the time…so the construction company had made arrangements to have the tank pumped out (Monday),” said Toronto Fire Services Capt. Mike Strapko. “However, after the heavy rainfall the material in the tank started to leak.”

The hazardous material got into the storm sewers and into the Don River. Fire crews set up containment booms at the Keating Channel at the foot of the Don River to prevent the material from getting into Lake Ontario.

“While we’re not certain of the name of the company that left the tank in the ground, we know that there was an airstrip in that location decades ago,” Strapko said. “It’s possible that when the airstrip was shut down that the tank was left in the ground at that time.”

The airfield, known as Leaside Aerodrome, opened in 1917 and was the site of Canada’s first airmail delivery a year later. It closed in 1931.

Toronto Police Const. Wendy Drummond said the spill was contained and that the cleanup was successful.

“There were no road closures, there were no evacuations, there were no injuries.”

via InsideToronto Article: Contents of Don spill identified.