How to Join Membership in USI Federal Credit Union is open to all employees of Millennium  Chemicals, Equistar Chemicals,   and Linde Gas, Inc. who work in or are supervised from the Deer Park LaPorte Complex in Deer Park, Texas. Employees of Industrial Security Services Corporation who work at the Deer Park LaPorte Complex in Deer Park Texas and  Basic Industries who work at the Deer Park LaPorte Complex in Deer Park Texas, their immediate families and organizations of such persons are also welcome to join. If you are interested in becoming a member, please visit our office or send us an email requesting a new member package. We look forward to serving you.