There is a myth thats prgressed from the 70's and 80's that you cant drink spanish tap water. Well having done a bit of research it appears that you can. there are several sources of spains water, one being from the mountains, from underground reservoirs and the other is the sea.
most people are concerned about the sea water source, which in actual fact goes through a purification process that makes it drinkable. this process is one that is used on cruise ships to provide sufficient water to its passenges.
what you will find is that spanish water can taste slightly different which sometimes isnt very pallitable for those visiting, and also our stomachs might need to get used to it.
now as spain is a very dry place and therefore i do suspect that much of the supply that goes to the hotels will possibly be from the sea process, i dont know that for a fact, but it makes sense that it would be considering spanish potential for droughts.
though personally i dont drink the tap water because i dont like its different taste, i do brush my teeth and gargle with it without worry.
i realised i was wasting money on water just to brush my teeth.
I havent had an upset tummy yet so thought id pass on my findings.Edited: 8 years ago