Whenever the public safety requires the use of police officers in excess of those normally available and the use is at the request of a private person, firm, corporation, or institution, the Chief of Police, with the approval of the City Manager, may detail off-duty officers to perform police- related functions such as traffic control, protection of life and property, and security provided that the person, firm, corporation, or institution reimburses the city the cost of providing the additional police officers. Prior to assigning off-duty police officers to such duty, the Chief of Police shall ascertain the total cost thereof, including overtime, fringe benefits, the use of city equipment, and prepare a contract to be executed by the party requesting the service and by the City Manager or his or her designee, the terms of which contract shall enumerate the services to be provided, the number of officers to be assigned, and the cost to be paid therefor.