We have lived in our home for about three years. At some point during this last year, our kitchen sink has begun making a very violent gurgling noise. It only happens in the kitchen sink, and the noise only occurs between 9-11 am, never any other time. The gurgling normally only last for 15 mins or so, though some days it is longer. After reading various articles on plumbing, we thought maybe it had something to do with our septic tank needing pumped. We had that done about six months ago, and the problem is still occurring. While it does only happen during the morning hours, it does not happen every day. That is more random. We have a well, and as mentioned early, have a septic tank. It is a one story house with a small basement, which houses all our plumbing components. We also checked the two vent pipes outside to see if they were somehow obstructed, but there was nothing there. Does anyone have any suggestions on what the problem might be?