Originally Posted by Milo Dolezal
In my region of operation, air gap is mandated by Plumbing Code. However, I am puzzled over the fact that you have dedicated drain just for D/W. Typically D/W is connected to air gap which drains to either Garbage Disposer - or in absence of G/D - it drains to "branch T" fitting located right above the trap.
Some States don't require Air Gap. In these States you are allowed to connect D/W discharge hose directly to " branch T" or G/D. Every D/W includes installation manual that covers both types of installation.
So to answer your question: No, you don't need air gap. Dishwasher will operate just fine w/o it. Just keep the discharge hose high, right bellow the countertop before it drops down toward the drain.
But in any case, it is good practice to check with your local Building Department before you do anything.