The Department shall serve a copy of the objection or complaint on each Applicant, Petitioner or Defendant listed in the pleading personally or by first-class or certified mail. Written proof of such service shall be filed with the Department. Each Applicant or Defendant who chooses to file a responsive pleading must do so within 30 days from the date of personal service or the date of Department mailing of the objection or complaint
454 Neb. Admin. Code, ch. 7, § 006