Per the Contract if you work a 2 hours of overtime you must have a 3rd break of 10 minutes.

AFGE/SSA NATIONAL AGREEMENT (Contract)

Article 10 -Hours of Work, Flextime, Alternate Work Arrangements and Credit Hours

Section 1 — Hours of Work

A. Hours of work for employees shall be in accordance with applicable law and regulations.

B. A rest period of fifteen (15) minutes duration will be allowed each employee twice a day provided the employee works seven hours and once a day provided the employee works four hours. A rest period of ten (10) minutes duration will be allowed each employee during each period of extended shift overtime of at least 2 hours duration.

On days when all work is overtime and/or credit hours, a rest period of fifteen (15) minutes will be allowed for each period of 4 hours worked. Rest periods will not be appended to periods of leave or the beginning or end of the employee’s work shift. Management will not restrict employee mobility during rest breaks.

C. The occurrence of holidays shall not affect the designation of the basic workweek.