The Commonality and Numerosity Requirements in Missouri Class Action Certification – Doyle v. Fluor Corp.

“Commonality” and “Numerosity” are two of a handful of factors that most courts consider in deciding whether to allow a toxic dumping lawsuit to proceed as a class action. In Doyle v. Fluor Corp., a Missouri appellate court explains these requirements and how they should be applied in a particular matter.

Plaintiffs brought the action alleging that Defendants, owners and operators of a smelting (the process by which metal is extracted from ore) business in Herculaneum, Missouri, released lead, heavy metals and other toxic substances into the air, which in turn caused damage to real property in the surrounding area. Plaintiffs sought damages under theories of negligence, private nuisance, strict liability, and trespass. The trial court granted Plaintiffs’ motion to certify the matter as a class action with the class representatives suing on behalf of nearly 400 people who “own and occupy” residential real property in the area near Defendants’ operation.

On appeal, the Court of Appeals for Missouri’s Eastern District upheld the decision to certify the class. A class may be certified under Missouri law where: 1) the class is so numerous that joinder of all members is impracticable; 2) common questions of law or fact exist among the class; 3) the claims or defenses of the representative parties are typical of that of the class; and 4) the representative parties are able to fairly and adequately protect the class’ interest. In addition, a court considering certification must also determine that the common factual or legal questions “predominate over any questions affecting only individual members” and that a class action is more suitable than other methods to fairly and efficiently adjudicate the issue.

In affirming the trial court’s decision, the court noted that the “commonality” requirement does not mean that all issues in a particular action be common to all class members, but instead that the common issues predominate over the others. “A single common issue may be the overriding one in a matter, despite the existence of numerous remaining individual questions,” the court ruled. In this case, several of the action’s central issues were shared among the class, including whether Defendants were responsible for emitting toxic metals in to the air; whether such an act constitutes negligence; and whether the pollution caused property in Herculaneum to be contaminated.


Furthermore, the court rejected Defendants’ contention that the class failed to meet the “numerosity” requirement because the class, as defined, was vague and Plaintiffs did not show that a group of persons exists that both want and need the requested relief. “[T]hat a class may initially include persons who do not have claims or who do not wish to assert claims against Defendants is not important at this stage of the litigation,” the court ruled, unless Defendants could show that this was true for most or all of the class.

Contamination by dumping is believed to cause a broad range of health and medical problems and can also wreak havoc on real property by reducing its value. The dumping and contamination lawyers at Lubin Austermuehle represent plaintiffs in dumping and contamination class action litigation at state and federal levels. We are pleased to assist clients throughout the Chicagoland area, including Naperville, Wheaton, Vernon Hills and many other cities throughout Illinois as well as in Indiana and Wisconsin. To speak with a dumping and contamination lawyer at our firm, contact our law office in Oakbrook Terrace or Chicago, Illinois by calling 630-333-0333 or (630) 333-0333. You may also contact us by e-mail.

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