How we did this story

A worst-case scenario for each refinery is filed by its owner with the U.S. Environmental Protection Agency. Specifically, companies include what’s known as an “Offsite Consequences Analysis,” part of a larger plan that details how they manage myriad risks involved in manufacturing usable fuel from crude oil.

The EPA keeps close tabs on the documents and who views them because of the vulnerabilities of refineries, chemical plants and other facilities to accidents or acts of terrorism, and the potential for harm to millions of people living nearby. Particularly since the terrorist attacks of 2001, the government has spread a veil over such sensitive information – a veil that makes it difficult for members of the public to learn about risks in their midst.

A citizen can view Offsite Consequences Analyses only by visiting an EPA “reading room.” They cannot be photocopied. They cannot be obtained on the Internet or from libraries.

After identifying 50 refineries that use hydrofluoric acid, five reporters from the Center for Public Integrity visited EPA headquarters in October 2010, scrutinized the relevant reports, and recorded the information in a spreadsheet. The reporters then contacted each company, giving it an extended opportunity to dispute or urge corrections to the reports. None of those who responded challenged the data.

On several occasions while filming outside refineries, journalists with the Center and ABC News were confronted and questioned by law enforcement authorities or refinery security personnel.

Download the full spreadsheet.