The notice of suspension and intention to dismiss, shall be in writing and be served upon the employee personally or by United States registered mail addressed to the employee at his or her last known address. A copy of the charges filed, together with a copy of the provisions of Section 87736, shall be attached to the notice. If the employee demands a hearing within 30 days, the matter shall proceed to arbitration or hearing, as the case may be, as specified in Article 4. If the employee does not demand a hearing within the 30-day period, his or her dismissal shall be effective upon the expiration of 30 days after service of the notice.