The company has been storing PCB-laden oil illegally at the Hymus Boulevard site for the past 15 years.
The ministry confirmed last week it found out about the presence of PCBs (polychlorinated biphenyls) last March, after public works employees in Pointe-Claire detected an unknown substance leaking into the city's storm drains.
Provincial environment officials were called in to investigate that leak of 800 to 1,200 litres of oil containing the chemical compound — long-used as a coolant and insulating fluid but banned decades ago because of its environmental toxicity and danger to human health.
Officials have been waiting for a cleanup plan from Reliance Power Equipment for weeks. Last week, Environment Minister Yves-François Blanchet issued an ultimatum: submit a cleanup plan, or the province will move in, do the work and send the company the bill.
Blanchet said Wednesday that an acceptable plan was delivered on Tuesday.
The company now has until Sept. 13 to transfer its holding equipment to a safe facility.
"The subcontractors doing the work are highly experienced people who have the experience to do the job," Blanchet said. "The plan is complete. The plan is satisfactory. The plan permits us to achieve our objectives in a safe way."
Blanchet said the environment officials will oversee the work and will continue to pay close attention to Reliance's undertakings.
"If, in terms of execution, it's not completely up to our expectations, we will take control of the site instantly," he said.
The company's site is being guarded, and Blanchet said residents who live near the company's site have nothing to worry about.