In my SMP world I have large Buildcraft quarries operating and I wish to ensure that they keep on operating even when I'm not around. I know that I can use the [Teleport Tether](http://thetekkit.wikia.com/wiki/Teleport_Tether) to keep chunks loaded, however I'm not sure how many chunks I need to keep loaded in order for my quarry to continue operating.

Do I need to keep all chunks containing the quarry loaded, or do I only need to keep the chunk containing the quarry block itself loaded? Also if I am piping items back from the quarry will anything bad happen if the chunks containing those items are not loaded?