## Facts

- Residents living near an Exxon Mobil-operated refinery plant sued Exxon Mobil Corp. and related entities, alleging the plant failed to meet regulatory standards.
- The residents alleged that the noncompliance resulted in dozens of chemical leaks over roughly a 12-month period, including a naphtha leak, a hydrochloric acid (HCl) release, and a sulfur dioxide leak.
- The residents sought damages for nuisance and odors, varying degrees of physical respiratory symptoms allegedly tied to the releases, and loss of use and enjoyment of their property.
- The residents moved to certify a damages class under Federal Rule of Civil Procedure 23(b)(3).
- The proposed class consisted of all individuals living within a defined geographic area near the plant for any length of time between June 2012 and the present.
- The residents argued that causation and fault could be resolved with common proof for the class, while acknowledging that damages would require individual determinations.
- To address individualized damages, the residents proposed a bifurcated approach: a class trial on liability and causation first, followed by separate proceedings to determine damages for individual class members if liability were found.
- Exxon opposed class certification.

## Issues

1. Whether the proposed class met the requirements for certification under Rule 23(b)(3), including whether common questions would predominate over individualized questions in a case alleging multiple releases and varying alleged symptoms.
2. Whether the residents’ proposed bifurcated trial plan (classwide liability/causation followed by individual damages) satisfied Rule 23(b)(3)’s predominance and superiority requirements.

## Decision

- The court denied the residents’ motion to certify a Rule 23(b)(3) class.
- The court concluded that individualized issues—particularly those tied to exposure, causation, and the nature and extent of each resident’s alleged harm—prevented a finding of predominance under Rule 23(b)(3).
- The court also found the residents did not establish that a class action would be a superior method for resolving the dispute given the individualized proof that would still be required.
- After certification was denied, the litigation proceeded on an individual-claim basis rather than as a certified class action.

## Legal Principles

- A party seeking class certification bears the burden to prove the Rule 23 requirements are met.
- Rule 23(b)(3) requires (1) that common questions predominate over individual questions and (2) that a class action is superior to other available methods for fairly and efficiently adjudicating the controversy.
- In cases involving alleged chemical releases and resulting nuisance or personal-injury-type symptoms, predominance may fail where determining causation depends on person-by-person evidence about exposure circumstances, timing, and the type and severity of alleged effects.
- A proposed trial plan that separates liability/causation from damages does not, by itself, satisfy Rule 23(b)(3) when individualized questions meaningfully affect proof of causation or injury and not merely the calculation of damages.
- Superiority may be lacking when the case would still require many individualized determinations, creating substantial case-management difficulties that reduce the efficiency gains expected from class treatment.

## Conclusion

In Nolan v. Exxon Mobil Corp., the court denied Rule 23(b)(3) certification for residents living near an Exxon refinery plant who alleged repeated chemical leaks caused nuisance conditions, odors, respiratory symptoms, and loss of property enjoyment. Even with a proposed bifurcated trial structure, the need for individualized proof on exposure and causation—and the resulting management problems—meant common issues did not predominate and the class mechanism was not shown to be the best method for resolving the claims.


Nolan v. Exxon Mobil Corp., 2015 WL 2338336 (2015)