One listing is provided for each state/regional agency referenced in this category (with an average of over 10 agencies per U.S. state). Listings include the primary environmental agency for each U.S. state (i.e. the "State EPA"), other agencies and the Home Page for each U.S. state.

Each listing includes a locator/operator contact, and when possible, director's office and public affairs type contacts. The abstracts for each listing discuss the agency's purpose and identify each group in the agency (divisions, bureaus, sections, departments, etc.) that provide assistance or regulation in a particular subject area.