In October 2001, the Supreme Court of Canada released its decision on this matter. The final determination of the Supreme Court was that the action could not proceed as a class action. Because of decision of the Supreme Court, the action did not proceed to trial.
Before a class action is allowed to proceed the plaintiffs must first be certified as a class. To certify a class action in Ontario under the Class Proceedings Act, 1992 , the plaintiffs must demonstrate: there is an identifiable class that may be defined by reference to objective criteria; the claims of the class members raise common issues; and a class proceeding would be the preferable procedure for resolution of the common issues. The action was certified as a class action by the motion court of the Ontario Court (General Division), but the defendant (the City of Toronto) appealed to the Ontario Divisional Court. The Divisional Court overturned the lower court's decision to certify the action. The plaintiffs appealed first to the Ontario Court of Appeal and then the Supreme Court of Canada on the issue of certification. The Supreme Court of Canada affirmed the decision of the Court of Appeal and Divisional Court, and refused to certify the class. As a result, the action was not able to proceed.
The Supreme Court of Canada held that there was an identifiable class and there were common issues among members of the class, but that the preferred route for bringing the action was not by class action. Instead, the plaintiffs could pursue their individual claims through the Small Claims Trust Fund established by the City of Toronto to compensate people who live close to the landfill. The Supreme Court also stated that, if the plaintiffs wanted to ensure the defendant took full account of their actions, they could apply for a review or an investigation under parts IV or V of the Environmental Bill of Rights.
While the Supreme Court of Canada concluded that the action should not have been certified to proceed as a class action, the Court expressly stated that other environmental nuisance actions might be able to proceed as class actions. Each case is to be determined on its own merits and facts.