The opinion of the court was delivered by: H. Bruce Guyton United States Magistrate Judge
This civil action is before the Court pursuant to 28 U.S.C. § 636(b), the Rules of this Court, and by the Orders [Docs. 137, 158] of the Honorable Thomas A. Varlan, United States District Judge, for disposition of the defendant's Motion in Limine to Exclude the Opinion Testimony of Alan Michael Hekking [Doc. 130] and Motion in Limine to Exclude the Opinion Testimony of Robert H. Koppe [Doc. 132], and the plaintiffs' Motion in Limine to Preclude the Introduction of Certain Testimony from TVA's Expert Witness Jerry L. Golden and the Admission of Related Information. [Doc. 156] On August 12, 2008, the parties appeared before the Court for a hearing on the instant motions. Attorneys Wade Davies, George E. Hays, and William J. Moore, III, appeared on behalf of the plaintiffs, and attorneys Frank H. Lancaster, Harriet A. Cooper, and Maria Victoria Gillen appeared on behalf of the defendant. After the hearing, the Court took the motions under advisement and they are now ripe for adjudication.
Both parties challenge the admissibility of the opposing party's expert(s) under Rule 702 of the Federal Rules of Evidence and Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579 (1993), with the defendant challenging the expert qualification of Alan Michael Hekking, the plaintiffs' expert on the issue of what constitutes routine maintenance, repair, and replacement, and Robert H. Koppe, the plaintiffs' expert on the issue of emissions increases, and the plaintiffs challenging the qualification of Jerry L. Golden, the defendant's expert on the issue of what constitutes routine maintenance, repair, and replacement. Rule 702 of the Federal Rules of Evidence governs the admissibility of expert testimony:
If scientific, technical, or other specialized knowledge will assist the trier of fact to understand the evidence or to determine a fact in issue, a witness qualified as an expert by knowledge, skill, experience, training, or education, may testify thereto in the form of an opinion or otherwise, if (1) the testimony is based upon sufficient facts or data, (2) the testimony is the product of reliable principles and methods, and (3) the witness has applied the principles and methods reliably to the facts of the case.
The trial judge must act as a gatekeeper, admitting only that expert testimony that is relevant and reliable. Daubert, 509 U.S. at 589. With regard to scientific knowledge, the trial court must initially determine whether the reasoning or methodology used is scientifically valid and is properly applied to the facts at issue in the trial. Id. To aid the trial court in this gatekeeping role, the Supreme Court has listed several key considerations: (1) whether the scientific knowledge can or has been tested; (2) whether the given theory or technique has been published or been the subject of peer review; (3) whether a known error rate exists; and (4) whether the theory enjoys general acceptance in the particular field. Id. at 592-94. The Court's focus "must be solely on principles and methodology, not on the conclusions that they generate." Id. at 595. "[T]he test under Daubert is not the correctness of the expert's conclusions but the soundness of his methodology." Daubert v. Merrell Dow Pharmaceuticals, Inc., 43 F.3d 1311 (9th Cir. 1995).
Although Daubert centered around the admissibility of scientific expert opinions, the trial court's gatekeeping function applies to all expert testimony, including that based upon specialized or technical, as opposed to scientific, knowledge. Kumho Tire Co. v. Carmichael, 526 U.S. 137, 147-48 (1999); Berry v. City of Detroit, 25 F.3d 1342, 1350 (6th Cir. 1994). The trial court's objective "is to make certain that an expert, whether basing testimony upon professional studies or personal experience, employs in the courtroom the same level of intellectual rigor that characterizes the practice of an expert in the relevant field." Kumho Tire, 526 U.S. at 152. The trial judge enjoys broad discretion in determining whether the factors listed in Daubert reasonably measure reliability in a given case. Id. at 153. With this framework in mind, the Court will now address the instant motions.
The defendant moves the Court to exclude the expert report and testimony of Alan Michael Hekking, the plaintiffs' expert on the issue of what constitutes routine maintenance, repair, and replacement. The defendant contends that Hekking's opinions are not reliable because they are predicated on a methodology of Hekking's own design, because his methodology is governed by no objective standards, does not emanate from his own field of study, and is rife with material errors. The defendant further argues that Hekking's opinions are not relevant because they stem from an enforcement initiative launched by the EPA several years after the events in issue. The plaintiffs oppose the motion, arguing that Hekking's opinions are reliable, relevant, and admissible.
As to the issues of relevance and the WEPCO test,*fn1 the Court notes that the issue of whether the WEPCO test applies in this matter, or whether some regulation or rule predating WEPCO should be applied, is a central issue before the District Court on summary judgment. Given that only the Daubert issues have been referred to the undersigned, the Court finds that it must leave the decision of what law will control to the District Court. Accordingly, the Court leaves the issue of the relevance of testimony relying on the WEPCO test to the District Court's determination.
As to the issue of reliability, the Court finds that Hekking's opinions are sufficiently reliable to satisfy Daubert. The Court finds that the methodology relied upon by Hekking was not created by Hekking, but instead is based in part on the common sense analysis set forth by the WEPCO test. The Court further finds that, while Hekking has not set forth a metric for determining what weight should be given to each of the WEPCO factors, in this instance, the absence of such a metric is a matter that affects the weight of Hekking's testimony, not its admissibility. The drafters of the Federal Rules of Evidence recognized that "[i]n certain fields, experience is the predominant, if not sole, basis for a great deal of reliable expert testimony" Fed. R. Evid. 702 Adv. Comm. Note (2000), and the Court finds that Hekking's twenty plus years of experience in this area provides a sufficient basis for him to opine on the WEPCO test and the weight the factors should be given.
The defendant also argues that Hekking formed his opinions solely for the purpose of this litigation, arguing that Hekking did not utilize the WEPCO test when he previously worked for TVA. However, the Court finds that while Hekking may not have specifically utilized the WEPCO test during his time at TVA, Hekking's experience at TVA includes the areas of expertise necessary for him to opine on the factors of the WEPCO test, and thus Hekking's experience with TVA provides a reliable basis for the application of the WEPCO test. The defendant also takes issue with Hekking's application of the WEPCO factors, but the Court again finds that the defendant's arguments go to the weight of Hekking's testimony, not its admissibility.
As to the defendant's arguments as to the correctness of Hekking's opinions, the Court's focus "must be solely on principles and methodology, not on the conclusions that they generate." Daubert, 509 U.S. at 595. "[T]he test under Daubert is not the correctness of the expert's conclusions but the soundness of his methodology." Daubert v. Merrell Dow Pharmaceuticals, Inc., 43 F.3d 1311 (9th Cir. 1995). The Court finds that the methodology utilized by Hekking meets Daubert's reliability standard. To the extent that the defendant takes issue with Hekking's calculations and opinions, "[v]igorous cross-examination, presentation of contrary ...