Grey Water Tank??

[smithmiller6]

I have 1972 Land Yacht Trade Wind, 25 or 27'. When I run the sink water comes out the discharge hook up tube in the back? I have been told that Airstreams this old do not have grey tanks, and that I need a tote. but I have also heard of trailers with two tanks. How do I find out if I have an auxilary tank with a leak, or just no auxilary tank. Thanks.