(a) The commissioner may temporarily suspend a license to transport school pupils under contract with a school district, subject to a hearing conducted pursuant to Chapter 5 (commencing with Section 11500) of Part 1 of Division 3 of Title 2 of the Government Code, when, in the commissioner`s opinion, the action is necessary to prevent an imminent and substantial danger to the public health. (b) The commissioner may, following a hearing, suspend a license to transport school pupils under contract with a school district, for a period of at least 30 days but not more than 90 days, if the holder of the license knowingly permits the transportation of school pupils by a person who does not possess the appropriate driver`s license and driver`s certificate. (c) The suspensions authorized pursuant to subdivisions (a) and (b) may, at the discretion of the commissioner, be enforced for all operations of a schoolbus contractor, or for the operations of the contractor in the school district in which the alleged violations occurred, or for the operations of the contractor in the contractor`s terminal in which the alleged violations occurred. (d) The commissioner shall provide notification of a suspension hearing to those school districts whose terminals would be affected by the suspension.