## Facts

- Homeowners Catherine Martin and Dorinda Frugé used private drinking-water wells near a gasoline service station with underground storage tanks in Wilton, Connecticut.
- Plaintiffs alleged gasoline constituents, including MTBE, migrated from the station and contaminated their wells, causing bad-tasting water, property damage, health problems, and increased cancer risk.
- State regulators identified groundwater pollution with gasoline components at the station site, and the area was the subject of years of hydrogeologic investigation and monitoring.
- Available monitoring data for shallow groundwater indicated flow generally north-northwest from the station, away from plaintiffs’ homes, which were located east and south of the station.
- Plaintiffs relied on two experts: (1) an environmental/hydrogeology expert to link the station to plaintiffs’ wells via a deep-groundwater migration theory, and (2) a toxicology/medical expert to link alleged exposure to plaintiffs’ symptoms and increased cancer risk.
- Defendants moved to exclude both experts under Fed. R. Evid. 702 and Daubert/Kumho Tire and moved for summary judgment on negligence, negligence per se, strict liability, gross negligence, private nuisance, and trespass.

## Issues

1. Whether plaintiffs’ environmental and toxicology experts were admissible under Fed. R. Evid. 702 and Daubert/Kumho Tire (qualification, reliability, and fit).
2. Whether plaintiffs had sufficient admissible evidence of environmental causation (source and pathway to plaintiffs’ wells) and medical causation (dose/exposure causing the alleged health effects).
3. Whether the court should shift the burden of proving causation to defendants, or apply a lower expert-admissibility threshold, based on public-policy arguments concerning allegedly “untested” products.
4. Whether any of plaintiffs’ tort claims could survive summary judgment without admissible expert evidence on causation and damages.

## Decision

- The court granted defendants’ motion in limine and excluded both plaintiffs’ experts.
- The court found the environmental expert’s pathway opinions unreliable and lacking fit because they depended on unsupported assumptions about deep groundwater flow, failed to reconcile contrary monitoring data, and did not provide a reliable quantitative link between the station and plaintiffs’ wells.
- The court found the toxicology/medical expert’s causation opinions unreliable because they lacked adequate scientific support for the claimed effects at relevant exposure levels and did not adequately analyze dose, duration, and related factors.
- The court rejected plaintiffs’ request for burden-shifting and a relaxed admissibility standard, holding that Rule 702 and Daubert govern and are not lowered by policy concerns about product testing.
- The court granted summary judgment for defendants on all claims because plaintiffs lacked admissible evidence establishing causation and related damages elements necessary for the asserted tort theories.

## Legal Principles

- Under Fed. R. Evid. 702 and Daubert/Kumho Tire, the court must act as gatekeeper to ensure expert testimony is both reliable (sound methods and sufficient supporting data) and fits the facts of the case.
- Expert opinions that rest on untested assumptions, fail to address contrary data, or do not reliably apply methods to the case-specific facts may be excluded as unreliable or lacking fit.
- In toxic-tort cases, medical causation opinions generally require scientifically supported general causation and a reasoned, case-specific analysis of dose and exposure sufficient to support specific causation.
- Federal courts do not shift the burden of proving causation to defendants, nor apply a lower admissibility threshold for expert testimony, based solely on policy arguments that a product was insufficiently studied.
- When expert testimony is necessary to prove essential elements such as environmental and medical causation, exclusion of that testimony can require summary judgment for the defendant.

## Conclusion

The court excluded plaintiffs’ environmental and medical causation experts under Rule 702 and Daubert for lack of reliable methodology and fit, declined to adopt a policy-based burden shift or reduced admissibility standard, and entered summary judgment for defendants because plaintiffs could not prove causation and related elements across their tort claims.


Martin v. Shell Oil Co., 180 F. Supp. 2d 313 (D. Conn. 2002)