Effective December 30, 2018, a salary differential of seventy dollars ($70) biweekly shall be paid incumbents or positions requiring bilingual proficiency as designated by the appointing authority and HRD Director. Said differen­tial shall be prorated for employees working less than full‑time or who are in an unpaid leave of absence status for a portion of any given pay period. Designation of positions for which bilingual profi­ciency is required is the sole prerogative of the County and the decision of the HRD Director is final. The Association shall be notified when such designations are made.