Cal. Pub. Util. Code § 100310
(b)
(1) An exclusive representative for employees of the VTA may select to move one or more of its represented bargaining units to the jurisdiction of the Public Employment Relations Board for unfair practice charges. A selection for Public Employment Relations Board jurisdiction pursuant to this paragraph with regard to a bargaining unit shall be irrevocable for that unit. The exclusive representative shall file notification of such a selection with the general counsel of the Public Employment Relations Board, or a designee, and serve one or more of the following: