## Facts

- Dow Chemical Company operated a heavily secured, 2,000-acre chemical manufacturing facility in Midland, Michigan, consisting of covered buildings and extensive outdoor equipment and piping.
- Dow used perimeter security to block ground-level views, but the outdoor portions of the facility were visible from the air.
- The Environmental Protection Agency (EPA) sought a follow-up on-site inspection under its enforcement responsibilities; Dow refused entry.
- Without seeking an administrative warrant, EPA hired a commercial aerial photographer to photograph the facility from various altitudes within lawful navigable airspace.
- The photographer used a standard precision aerial mapping camera commonly used for mapmaking; the photographs showed the layout of outdoor equipment and structures but did not reveal building interiors or intimate activities.
- Dow sued, alleging (1) the aerial photography exceeded EPA’s statutory authority and (2) the warrantless photography was an unreasonable search under the Fourth Amendment.
- The district court granted summary judgment to Dow; the Sixth Circuit reversed; the Supreme Court affirmed the Sixth Circuit.

## Issues

1. Whether EPA’s aerial observation and photography of an industrial facility from lawful navigable airspace exceeded the agency’s statutory investigatory authority.
2. Whether warrantless aerial photography of the exposed outdoor areas of an industrial complex constitutes a “search” under the Fourth Amendment.

## Decision

- The Court held that EPA’s use of aerial observation and photography was within its statutory enforcement and investigatory powers.
- The Court held that the warrantless aerial photography from lawful navigable airspace of the exposed outdoor areas of Dow’s facility was not a Fourth Amendment “search.”
- The Court emphasized that state trade-secret or unfair-competition norms do not define Fourth Amendment limits.
- The Court distinguished protected privacy interests in building interiors from reduced privacy expectations in exposed outdoor industrial areas.
- The Court affirmed the judgment for the United States.

## Legal Principles

- When Congress grants an agency enforcement and investigatory authority, the agency need not have an explicit statutory enumeration of every permissible investigative technique.
- Government observation from a lawful public vantage point generally does not become a Fourth Amendment search merely because the target attempted to block some views (e.g., from the ground) while remaining visible from the public vantage point.
- Exposed outdoor areas of an industrial complex are more analogous to “open fields” than to the curtilage of a home; a business generally lacks a reasonable expectation of privacy against aerial observation of such areas from public navigable airspace.
- Use of commonly available photographic equipment to record what is visible from lawful airspace ordinarily does not transform observation into a search.
- A business retains a legitimate expectation of privacy within the interiors of covered buildings; surveillance that penetrates interiors or uses unusually revealing technology may raise different Fourth Amendment questions.

## Conclusion

The Court upheld EPA’s authority to use commercially available aerial photography from lawful navigable airspace to document exposed outdoor areas of a secured industrial facility, ruling that this method neither exceeded statutory powers nor constituted a Fourth Amendment search, while recognizing stronger privacy protection for building interiors and potentially for more technologically invasive surveillance.


Dow Chemical Co. v. United States, 476 U.S. 227 (1986)