## Facts

- Grain Processing Corporation (GPC) operated a corn wet-milling facility in Muscatine, Iowa, near residential neighborhoods.
- Nearby homeowners alleged GPC emitted harmful pollutants and noxious odors that entered their properties, reduced use and enjoyment, and caused health risks and property damage.
- Plaintiffs asserted claims for common-law nuisance, statutory nuisance, trespass, and negligence.
- Plaintiffs sought compensatory damages, punitive damages, injunctive relief, and class certification on behalf of similarly situated residents.
- Before any class was certified, GPC moved for summary judgment asserting federal preemption under the Clean Air Act (CAA), state preemption under Iowa Code chapter 455B, and dismissal under the political-question doctrine.
- The district court granted summary judgment for GPC on all asserted grounds and dismissed the case.

## Issues

1. Whether the Clean Air Act preempted state-law nuisance, trespass, and negligence claims based on alleged air emissions from a permitted facility.
2. Whether Iowa Code chapter 455B preempted common-law tort claims addressing localized harms from air pollution.
3. Whether the claims were nonjusticiable political questions because they implicated technical and policy-laden emissions regulation.

## Decision

- The Iowa Supreme Court reversed the grant of summary judgment and remanded for further proceedings.
- The court held the CAA did not preempt plaintiffs’ state-law tort claims.
- The court held Iowa Code chapter 455B did not impliedly preempt plaintiffs’ common-law claims.
- The court held the political-question doctrine did not bar adjudication of nuisance, trespass, and negligence claims involving emissions evidence.

## Legal Principles

- Federal environmental regulation under the CAA generally permits state regulation and preserves traditional state-law remedies; absent clear congressional intent, state tort claims for property-specific harms are not displaced.
- Compliance with regulatory permits may be relevant evidence in tort litigation but does not automatically defeat nuisance, trespass, or negligence liability.
- State air-quality statutes do not abrogate common-law actions by implication without clear legislative intent; regulatory enforcement and private tort remedies can operate concurrently.
- The political-question doctrine is limited; courts may resolve technically complex disputes when the claims are traditional tort causes of action with manageable legal standards and no constitutional commitment to another branch.

## Conclusion

The Iowa Supreme Court allowed homeowners’ air-pollution tort and nuisance claims against an industrial facility to proceed, rejecting federal and state preemption defenses and holding the dispute was suitable for judicial resolution despite its technical subject matter.


Freeman v. Grain Processing Corp., 848 N.W.2d 58 (Iowa 2014)