## Facts

- The State of New Hampshire sued Exxon Mobil Corporation and other gasoline-related companies in New Hampshire state court, alleging that defendants’ use of methyl tertiary butyl ether (MTBE) in gasoline contaminated groundwater throughout the state.
- New Hampshire alleged that MTBE, once released, spread readily through groundwater and created widespread cleanup and remediation costs.
- Because gasoline containing MTBE from multiple suppliers was commingled in distribution and sale, New Hampshire could not identify which defendant’s gasoline caused contamination at particular sites.
- New Hampshire proceeded under a market-share liability theory, seeking to allocate damages among defendants based on each defendant’s share of the relevant New Hampshire gasoline market during the period of injury.
- A jury found defendants liable and awarded total damages of roughly $800 million; Exxon’s approximate 30% market share resulted in a judgment of about $230+ million against Exxon.
- The trial court permitted damages to be allocated using market-share liability.
- The trial court also imposed a trust over a substantial portion of the award (about $195 million), restricting how the State could use that portion of the damages.
- Exxon appealed, challenging (among other issues) the use and application of market-share liability and trial rulings affecting liability and damages.
- The State cross-appealed, challenging the trial court’s imposition of the trust.

## Issues

1. Whether New Hampshire law permits recovery under a market-share liability theory for MTBE groundwater contamination when the State cannot identify which defendant’s product caused contamination at specific locations.
2. Whether, on this record, the trial court properly allowed the jury to allocate damages among defendants based on market share.
3. Whether the trial court had authority to restrict the State’s use of a large portion of the damages award by placing it into a trust.

## Decision

- The New Hampshire Supreme Court affirmed the trial court’s rulings on the merits, including the application of market-share liability and the judgment holding Exxon liable for its share of the MTBE-related harm.
- The court reversed the portion of the judgment imposing a trust over a substantial part of the damages award, holding that the trial court erred by limiting how the State could use that money.

## Legal Principles

- Market-share liability may be used where a plaintiff proves a prima facie case on all elements except identification of the specific tortfeasor, and product identification is impracticable because products from multiple makers were fungible and commingled.
- Under market-share liability, liability is several (not joint) and is apportioned according to each defendant’s proven share of the relevant market at the time of injury.
- In deciding whether market-share liability is appropriate, courts may consider factors reflected in the Restatement (Third) of Torts, including: whether the product is generic or interchangeable, whether the harm has a long latency period, the plaintiff’s inability to identify the source, the clarity of the causal link, the presence of other likely contributing causes, and the adequacy of market-share data.
- A defendant’s market share may be established through competent evidence sufficient to permit a rational allocation of responsibility, even if the plaintiff cannot trace contamination at a given location to a particular supplier.
- A trial court may not, absent proper legal authority, restrict a sovereign plaintiff’s use of a money judgment by ordering that damages be placed into a trust or otherwise earmarked for particular expenditures.

## Conclusion

State v. Exxon Mobil Corporation held that New Hampshire could recover for statewide MTBE groundwater contamination using market-share liability when commingling made supplier identification impossible, affirming Exxon’s liability in proportion to its market share while reversing the trial court’s separate order that placed a major portion of the damages into a trust.


State v. Exxon Mobil Corporation, 126 A.3d 266 (2015)