DHS says that employers are free to use Private Wage Surveys as along as they are on par with OES wage levels. They would need to select appropriate wage level based on relative OES wage level and the Salary offered.  If the wage is lower than Wage Level 1, then they should select “Wage Leve 1 and below”.  The employer has the burden to prove that the wage levels are on par with equivalent OES wage level.