Three stubs; kitchen sink; why?

[mikebuild]

Installing a kitchen sink in new construction. The plumbers roughed in 3, 1 1/2", abs, drain stubs. Why? Whats the proper way to hook this up?
(double bowl sink, dishwasher, no disposal)
Thanks.

[jimbo]

One is probably a cleanout, and the other two give you the option to drain the sinks with separate traps. I have heard some folks say that some area require that. Here the two always come together in a san tee.

[BAPlumber]

how are they oriented, are they all side by side?

[mikebuild]

Two are inline vertically on one side and the other is adjacent to them. They form a "right triangle". I suspect that, one is for the " p trap", one is for the clean out and the third is for "?". (future use maybe?) Could it be set up this way for the potential use of a "3 bowl" sink? I'm using a "2 bowl" sink, so I'm going to use a "p trap", a "clean out" and "?". Should I just leave the third one alone or "?".

[GrumpyPlumber]

This an island sink?

[BAPlumber]

the highest may be for a AAV.

[markts30]

One is probably for the first sink, another (below it) for the cleanout...
And the third is probably for the garbage disposal and second sink...

[BAPlumber]

ask the plumbers who roughed this in.

[JeffH]

there are three basin sinks, where the smallest basin is specifically for a disposal. The thought was that each basin will have its own drain going into the wall. Usually the basins form a diamond pattern with the small disposal basin closest to the user.