Found in the first part of the storage & mixing vats area to the left of the computer that activates the nearby protectron robot, i.e. before you enter the flooded area.
Hello, Larry. On behalf of the Nuka-Cola Corporation, I'd like to welcome you to the Shipping Department at our Bottling Facility in Washington D.C. Your official job posting is Shipping Clerk and your employee ID number is NCSD-701G. Please keep this information handy at all times. Thanks again, and welcome aboard!