A Notice to Abate or Remedy shall be served in the following manner:
(a) Personal Service. In any case, where a Notice to Abate is issued:
(1) The Agricultural Commissioner or his designee shall attempt to locate and personally serve the Responsible Person and attempt to obtain the signature of the Responsible Person on the Notice to Abate.
(2) If the Responsible Person served refuses or fails to sign the Notice to Abate, the failure or refusal to sign shall not affect the validity of the Notice to Abate or of subsequent proceedings.
(b) Service of Notice to Abate by Mail and Posting. If the Agricultural Commissioner is unable to locate the Responsible Person after reasonable efforts, the Notice to Abate shall be mailed by certified mail, postage prepaid with return receipt to the owner of the land as shown on the last equalized County assessment roll, to the last registered legal owner of record, and any other address that is reasonably calculated to give the Responsible Person actual notice of the Notice to Abate. The Agricultural Commissioner shall also post the Notice to Abate on the subject real property within the County. Service shall be effective upon mailing or posting, whichever is later.