Hey just wanted to know something:
With the fallout 3 add-on Broken Steel which i've played i just was curious. With the add-on enabled what happens if you side with the Enclave and poison the water source?
Thanks

The water at the Purifier is toxic and will kill you, Rivet City is overflowing with patients dying of the toxic water, and the ghouls are implied to be all becoming sick and will soon perish.

In short, the game is set before the ending slide where everyone in the Capital Wasteland dies horribly.

Oh and the Brotherhood of Steel is still wiping out all of the Enclave's remnants and you have the option of finishing them off.

The Enclave has no friendly fuzzy feelings to you, though, probably because no one liked John Henry Eden.