District Judge Considers Proffered Expert Testimony in Air Pollution Case Against Pennsylvania Coal-Fired Electric Generating Facility

The U.S. District Court for the Western District of Pennsylvania considered multiple challenges to proffered expert testimony in its cases dealing with air pollution events from a coal-fired electric generating facility in 2006 and 2007 that allegedly caused property damage and adverse health effects.  The judge determined that the plaintiffs’ environmental engineering expert could not opine on the legal issue of whether the defendant’s operations violated regulations governing coal-fired power plants or medical issues such as the effect of the emissions on health.  However, the plaintiffs’ expert could testify that the soil contamination on the plaintiffs’ property was caused by the “black rain” emissions from the plant, in part based on soil samples containing high levels of arsenic.  The judge explained that the defendant’s assertions that the sampling was flawed and that other properties also exposed to the emission showed no signs of arsenic goes to weight (for the jury to consider) and not to admissibility.  The judge also determined that the defendant’s challenged expert, a professional geologist, could testify about the methods he used to evaluate the soil affected by the black rain, which relied on the sampling of sycamore leaves, and also could provide his opinion about the background concentrations of arsenic that normally exist in southwestern Pennsylvania.  The judge, however, did preclude the defense expert from opining that the variation of levels of arsenic contained in the plaintiffs’ expert’s soil sampling could be attributable to treated lumber because there was no evidence in the record supporting the theory that the lumber on the property was ever treated with copper, chrome, or arsenic.