Parkside Landscaping of Littleton has paid more than a half million dollars in back wages and penalties to settle allegations it underpaid the foreign workers it brought in to fill seasonal jobs, the U.S. Department of Labor’s Wage and Hour Division said Tuesday. The Littleton landscaping firm paid $524,063 in back wages to 53 employees and $26,104 in penalties to resolve violations of the Fair Labor Standards Act and H-2B non-agricultural visa program provisions. Landscapers in Colorado and other states depend heavily on the H-2B nonimmigrant visa program.