(a) A county fire mutual aid plan upon adoption by the county board of supervisors may be admitted into the State fire mobilization and mutual aid plan provided it meets minimum standards as established and published by the bureau of fire mobilization and control.

(b) Upon adoption of such county fire mutual aid plan by the county board of supervisors and admission into the State fire mobilization and mutual aid plan, certified copies of the plan are deposited with these agencies as a permanent file: