DISTRIBUTION OF TRIPS. In the event no on-duty CFOs are available for prisoner or mental patient transport as determined by the Sheriff or his/her designee, the Sheriff or his/her designee may, at his/her discretion, assign trips to qualified off-duty CFOs. The Employer may use qualified non- bargaining unit members for prisoner and mental patient transport. An employee of the bargaining unit is prohibited from transporting a prisoner if the employee has been working sixteen (16) hours. A person on sick leave or vacation must return to work for an eight (8) hour shift in order to be eligible for prisoner transport on an overtime basis. If an error is made by the Employer, then the officer shall be offered the next overtime prisoner transport.