The Board hears evidence from the applicant, government agencies, non-governmental organizations, and citizens. In most cases, the evidence is brought forward in a public hearing. Hearing participants, including the Board and Board staff, have an opportunity to test the evidence put forward by other participants through questioning.

The Board must then weigh the evidence and decide what, in its view, is in the public interest. The Board documents the matters considered and the conclusions it reached in order to approve or deny a project.