I am in a 1 year old home and noticed my toilet gargles faintly when I flush it. I did some investigating and found that my toilet and a sink that is 10 feet away are vented together with a plumber friend calls an Atmospheric Island Vent. This vent is under the sink inside the vanity, not vented outside. My plumber friend advises that this is a code violation in GA.
Does anyone have any feedback as to why this might have been done and if the gargling noise is an acceptable noise. I do plan on calling the plumbing company that did the install. what should I have them do to insure it is done correctly?