(1) If an employee files a complaint with the department alleging that employer has violated a requirement of this chapter or any rule adopted under this chapter resulting in a rest or meal period violation, the department will investigate the complaint pursuant to the procedures outlined in RCW 49.84.045, WAC 296-136-100, and 296-136-130.

(2) During an investigation, if the department discovers information suggesting additional violations of chapter 49.84 RCW or associated rules, the department may investigate and take appropriate enforcement action without any additional complaint in accordance with WAC 296-136-100. The department may also conduct a consolidated investigation for any alleged violation identified under chapter 49.84 RCW in accordance with WAC 296-136-100.

(3) If the department determines that the employer has violated a requirement of this chapter or any rule adopted under this chapter resulting in a rest or meal period violation, the employer must pay the employee one additional hour of pay at the employee's regular rate of pay for each day there is a violation. The employer must pay the employee at the employee's regular rate of pay for rest and meal periods where the employee is required to remain on duty or on the employer's premises at the employer's direction subject to call. The regular rate of pay is the hourly rate at which the employee is paid, but may not be less than the established minimum wage rate. The regular rate of pay is determined by dividing the amount of compensation received per week by the total number of hours worked during that week.

(4) If the department determines that an employer has violated a requirement of this chapter or any rule adopted under this chapter resulting in a rest or meal period violation, the department may order the employer to pay to the employee interest of one percent per month on all amounts owed. The interest owed must be calculated from the first date amounts were owed to the employee, except that the department may not order the employer to pay any interest that were owed more than three years before the date the complaint was filed with the department.