It's called an air gap, and it's there to prevent dirty drain water from siphoning back down into the dishwasher and contaminating your clean dishes. I have one, and I'm in CA - it may be a building code requirement.

I've never seen that in Florida.

is that soms type of vent?

- I actually call this a “California “ thing as I never had one in Texas or Connecticut. We had a plumber re-do it so I now only have a button on my sink for the garbage disposal. Looks much better and easier to use. I’m sorry I can’t be more explicit how it was done, but it was pretty inexpensive, under $100. I’ll try to post a pic.

This is the button for garbage disposal. I believe it is an issue of building codes here and when we sell the home we may have to switch it back. I’m okay with that. Simple procedure.

Code in California. No worse than a soap dispenser.

It has nothing to do with a disposer that I know of. Strictly the dishwasher.

Ok, so I’m afraid I was not clear. We took the air gap out and had plumber install something under sink that replaces it. Formerly, my disposal button was located under sink, far back on the cabinet wall. The air gap was where this button is. Truly irritating and ridiculous.

I live in Texas and I’ve never seen such a thing.

Yup, we got them here in Washington state.

My husband is a building inspector (also a licensed plumbing contractor)in the capital of California ...an air gap/vent on the counter is not code here but a choice. Beth H’s specs are correct. The high loop is the normal practice around here, but you see both.

Thank you, everyone. You gave me the plan - no weird thingy with the remodel! Woohoo!

I should clarify... an air gap is universal code, but the high loop is acceptable in many places...requirements can differ in cities, counties, and states...call your building department if you want a definite answer though I doubt many places would require a permit for replacing a dishwasher. ♀️

Go with the high loop, then get an extra hole drilled for a soap dispenser- no more ugly dish soap bottle on the counter and you refill easily from above :)

https://www.thespruce.com/dishwasher-venting-2718654