Can employers make employees pay for drug testing in NJ?

http://individual.com/story.php?story=75691381

My union is enforcing mandatory drug testing for its 4000 members. The cost is approximately $750,000 for the first year. The cost for the first year is going to be split between the members and the contractors. I have been on the NJ Dept of Labor website, and it says employers can not make possible employees pay for pre-employment drug testing. Does this count for employees that are already employed? The reason they give us for the testing, is to save the contractors money on workers compensation premiums. Is it legal to charge the employees to pay to save the contractors money? Something doesnt seem right here.