Visible Emissions Evaluation (VEE) is a method for quantifying a pollution stream based on its visibility to the human eye. In 1974, the U.S. Environmental Protection Agency (EPA), promulgated U.S. EPA Reference Method 9 (Method 9), which contains both the required method for performing a VEE as well as the procedures for certifying VEE readers. In order to determine compliance with federal, State, and local air pollution regulations containing a visible emission limitation, VEE readers must be certified according to Method 9. Additionally, many local air districts stipulate on an issued Permit to Operate that a certified VEE reader be onsite when the permitted equipment operates.

VEE is a two-part training and certification program that includes an online prerequisite. The online course provides instruction on the evaluation on visible plumes for the purpose of determining compliance with air pollution regulations. After successfully completing the online courses, students attend the VEE field session to earn the Method 9 VEE certification. Certifications are valid for six months.