In a recent decision by the Ontario Superior Court of Justice, a class action was decertified on the basis that the common issue as certified was not a necessary and a substantial ingredient of each class members’ claim. In Plaunt v. Renfrew Power Generation Inc., 2017 ONSC 1868, the defendant was successful in presenting sufficient new evidence to warrant the decertification of the class action.

Class action certified on the basis of common property line

The class action was certified on the basis that the approximately 400 class members owning property surrounding a lake had their shoreline eroded because the defendant (or its predecessors) had raised the water level onto their land, and as such, was trespassing on their land by storing water on their property.

At the certification motion, the plaintiffs’ evidence was that there was a fixed dividing line between the public land of the lake and the private land owned by all the class members. On the basis of this evidence, Justice Smith found that the determination of whether the fixed dividing line “did or did not create a boundary line between public lands and private lands, or was only a flooding easement, would have affected all class members and would have moved their action for trespass forward in a substantial manner.” This common issue was certified.

New Evidence: No fixed property line

After certification, the defendant obtained a report from a land surveyor indicating that not all of the class members’ lands surrounding the lake were in fact impacted by the fixed boundary line, or were even defined by the fixed boundary line.

As a result of this new evidence, Justice Smith found that many class members did not have a property boundary that was defined by any reference to the fixed boundary line. Therefore, “resolution of the common issue does not form a substantial ingredient [of these class members’ claims] and it is not necessary to decide the certified common issue.”

Rather, each class member would have to present specific evidence with regards to his/her individual property to establish whether there has been any erosion affecting the property such that the defendant is storing water on their land. Thus, the test for certification was no longer met.

Certification once not certification for all

If a defendant can present sufficient evidence subsequent to certification to establish that there is no commonality between the class members that creates a substantial common ingredient in the class action, the court may conclude that a class action is no longer the preferable procedure and decertify the action.

While decertification motions have been relatively rare in Ontario, this decision serves as a reminder to defence counsel to keep a decertification motion on the menu of strategic options if new evidence, subsequent facts or developments are obtained in the lead up to a common issues trial that demonstrate a lack of commonality amongst the class.