The Labor Department said Tuesday that 674 Capitol Hill cafeteria workers would receive more than $1 million in back wages, or about $1,500 per person, after an investigation found that their employers failed to meet wage guidelines for federal contractors.

The department’s Wage and Hour Division Administrator David Weil said that Restaurant Associates, a New York-based company, and its subcontractor, Personnel Plus, improperly classified the workers, denying them the minimum hourly rate required by the government as well as overtime pay. The workers were food service employees in Capitol Hill’s various cafeterias. The department is considering whether to bar the contractors from future contracts with the government.