http://www.samhsa.gov/newsroom/advisories/0811213700.aspx
A Final Rule will be published in the Federal Register, Thursday, November 20, 2008, dealing with 40.67(b) - direct observation for return-to-duty and follow-up testing.
You can access that document by clicking here or copy and paste the following: http://federalregister.gov/OFRUpload/OFRData/2008-27617_PI.pdf