## Facts

- A chemical mixture used in coal processing (primarily 4-methylcyclohexanemethanol, “Crude MCHM”) leaked into the Elk River on January 9, 2014, from a storage facility owned by a nonparty.
- The chemical infiltrated a public water system’s treatment plant serving the Charleston, West Virginia area, triggering a “Do Not Use” order and interrupting potable water service for hundreds of thousands of people.
- Plaintiffs included residents, employees, and business owners who alleged economic losses (lost wages, lost revenue, replacement-water and travel costs) and, for some, physical injury and medical-monitoring needs.
- Defendants included the local water utility and related corporate entities (collectively, the “water company defendants”) and the chemical supplier.
- Plaintiffs alleged that defendants could have prevented or mitigated the event through reasonable care, regulatory compliance, adequate warnings, and proper design, operation, and emergency response.
- The operative consolidated complaint asserted multiple theories, including negligence, gross negligence, negligence per se based on statutory/regulatory violations, and breach of warranty.
- Plaintiffs moved to (i) certify a Rule 23(b)(3) damages class and (ii) certify a Rule 23(c)(4) issues class focused primarily on liability, fault, and comparative fault; defendants filed Daubert motions challenging plaintiffs’ experts, particularly economic damages experts.

## Issues

1. Whether plaintiffs could satisfy Rule 23(b)(3) predominance and superiority for a damages class given individualized loss variation and the need for a reliable classwide damages method.
2. Whether Rule 23(c)(4) permits certification of common liability issues (including fault and comparative fault) even if an overall Rule 23(b)(3) damages class is not certifiable.
3. Whether plaintiffs’ proposed damages experts used reliable, admissible methodologies under Daubert sufficient to support class certification.

## Decision

- The court denied certification of a Rule 23(b)(3) damages class.
- The court granted certification in part under Rule 23(c)(4) for common issues concerning fault and comparative fault among defendants.
- The court excluded or declined to rely on the principal economic damages opinions offered to support classwide damages, finding the methodologies unreliable under Daubert for certification purposes.
- The court denied without prejudice a Daubert motion directed at an expert whose opinions were not relied upon to support class certification.
- The court granted plaintiffs’ request to exceed page limits for their class-certification reply.

## Legal Principles

- Class certification requires a “rigorous analysis,” and plaintiffs bear the burden to prove compliance with Rule 23 requirements.
- For a Rule 23(b)(3) damages class, plaintiffs must show predominance; when damages are central, plaintiffs must present a reliable method for proving damages on a classwide basis consistent with admissible evidence.
- Expert evidence offered to establish Rule 23 requirements may be tested under Daubert at the certification stage; unreliable expert damages models cannot support predominance.
- Rule 23(c)(4) authorizes certification “with respect to particular issues,” and an issues class may be appropriate where common liability questions can be resolved with common proof even if individualized damages inquiries later remain.
- Common issues appropriate for (c)(4) treatment include questions centered on defendants’ conduct and comparative fault that can be decided in a single proceeding using shared evidence.

## Conclusion

The court refused to certify a damages class because plaintiffs lacked admissible, reliable classwide damages methodologies, but it permitted an issues class to resolve common liability questions—especially fault and comparative fault—through a classwide proceeding, leaving individualized damages for later adjudication.


Good v. Am. Water Works Co., 310 F.R.D. 274 (S.D.W. Va. 2015)