Librarians and government databases are a great source of information. Our client needed to know chemical plants of a certain production power and NAICS code in a certain location. ReferenceUSA and Hoovers not cutting it? Try the EPA!

http://iaspub.epa.gov/triexplorer/tri_release.facility

A search on an EPA database which records chemical emissions can deliver location, industry, size of plant by emissions released – as well as names and contact numbers. Don’t forget Uncle Sam!