The average operator salary at Prosser was $18,156 , which is 57 percent lower than the average salary for this job in Washington, and 63 percent lower than the national average for this job . Operator salaries at Prosser typically range from $14,487 to $20,492 (25th to 75th percentile). The highest reported operator salary was $30,618. There are 31 employees at Prosser with the job title operator.