teh google search tips
water intoxication site:.edu
water intoxication site:.gov
water intoxication site:webmd.com
usually i find it easier to look it up in encyclopedia
and then follow up on the references
http://en.wikipedia.org/wiki/Water_intoxicationbasically, liters of water, without electrolytes , bad for you
if its got flavor, its usually chock full of electrolytes
on a related note,
http://en.wikipedia.org/wiki/Oral_rehydration_therapy