A Florida federal district court recently denied a petition for class certification by a group of property owners that allegedly suffered health risks and diminished property values due to contamination at Pratt & Whitney’s neighboring aerospace testing and manufacturing plant. Cotromano v. United Techs. Corp., Civ. No. 13-80928, Opinion Memorandum and Order (S.D. Fla. May 2, 2018). The district court decision illustrates some of the issues of proof that a putative class encompassing a large geographic area may encounter.

The proposed class covered a 60-mile square area that encompassed what the Florida Department of Health had once designated as a “cancer cluster.” The parties’ experts disputed whether groundwater and soil contamination in the class area could be traced to the Pratt & Whitney facility.

Plaintiffs’ experts, however, conceded that it was unlikely that the entire class area was contaminated. This evidentiary gap proved decisive to the court which found that the plaintiffs’ proposed class area was overbroad, and alternatively, that they failed to meet their burden on Rule 23(b)’s predominance and superiority requirements.

On the issue of whether the plaintiffs’ proposed class was ascertainable, the court found that there were no objective criteria to define the class area. Without evidence of the boundaries of the contamination, the court found it “impossible to re-draw the geographic boundaries of the proposed class.” Further, the “stigma” attached to the proposed class area was not an objective criterion because it was unconnected to any conduct by the defendant.

Alternatively, the court found that the plaintiffs would be unable to meet their burden of proving the superiority of a class action and that common issues predominated over individual issues. For those issues, the plaintiffs had relied on an expert who proposed to calculate class-wide lost property values, based on a sales trend analysis and contingent valuation survey. But the court excluded the expert’s testimony under Daubert, and the plaintiffs otherwise lacked proof that the nearly 18,000 properties, which varied significantly in scale, were affected the same way by environmental stigma.