All ordinances shall become effective 30 days from the date of final passage, except the following ordinances, which shall take effect immediately:

1. (a) Those calling or otherwise relating to an election.
2. (b) Those specifically required by this code or by any other law to take immediate effect.
3. (c) Those fixing the amount of money to be raised by taxation, or the rate of taxes to be levied.
4. (d) Those for the immediate preservation of the public peace, health, or safety, which shall contain a declaration of the facts constituting the urgency, and shall be passed by a four-fifths vote of the board of supervisors.
5. (e) Those specifically relating to the adoption or implementation of a memorandum of understanding with an employee organization.
6. (f) Those relating to salaries and other compensation of officers, other than elected officers, and employees.