So how did Atlantic City, Avalon and Stone Harbor fail to pay lifeguards over 400,000 dollars in overtime? Investigators found lifeguards were only paid overtime after they reached 48 hours of work per week, not the 40-hour per week mark required by law. In addition, 14 minors were working without a proper employment certificate, the DOL said, and their time-in/time-out was not being documented as the law requires.