On January 17, 2014 the United States Court of Appeals for the Seventh Circuit reversed a district order certifying a class of Illinois property owners who claimed that a nearby refinery had leaked benzene and other contaminants into the groundwater under the class members’ homes.  The suit sought damages measured primarily by the effect of the groundwater contamination on the value of the class members’ properties.   The defendants argued that the District Court’s class certification order did not establish the predominance of issues common to the entire class over issues that vary among the members of the class.  The Seventh Circuit agreed, stating:   “Mere assertion by class counsel that common issues predominate is not enough.  That would be too facile. . . [W]hen factual disputes bear on issues vital to certification (that is, to whether the suit should be allowed to be litigated as a class action), such as predominance, the court must ‘receive evidence . . . and resolve the disputes before deciding whether to certify the case.’”     In reaching this conclusion, the Seventh Circuit concluded that the potential existed for a host of individual issues that will vary from homeowner to homeowner, including whether the presence of the benzene reduced the value of an individual’s property and, if so, how great has the reduction been.    Parko v. Shell Oil Co., Nos. 13-8023 & 8024 (7th Cir. Jan. 17, 2014).