I this a vent or a cleanout?

Sounds like your main drain line is backed up but it's hard for me to say as your question was unclear (not posted right).

If your main drain line is backed up you can call a plumber or rent a large sewer snake machine and purchase some leather gloves and snake the drain line until cleared.

Back to you...

Mark

Hi Mark

Here's a diagram of my vent pipe. Hopefully this answers your question. http://en.wikipedia.org/wiki/File:SoilStack.PNG

Does that change your answer at all

Thanks again

Steve

Nope... still not clear. The pictureonly showed a pic. Of a vent pipe with fixtures connected... doesn't help me understand your setup.

Is water coming out the vent pipe in the yard (?)

Is water backing up at any fixtures inside the home?

Is the vent pipe higher or lower than the fixtures connected?

Let me know...