DOT Rule 49 CFR Part 40 Section 40.385
Subpart R - Public Interest Exclusions
§ 40.385 Who bears the burden of proof in a PIE proceeding?
(a) As the proponent of issuing a PIE, the initiating official bears the burden of proof.
(b) This burden is to demonstrate, by a preponderance of the evidence, that the service agent was in serious noncompliance with the requirements of this part for drug and/or alcohol testing-related services or with the requirements of another DOT agency drug and alcohol testing regulation.