Whoever came up with the idea of carrying potable water within your backpack is or was a genius, that's all we have to say on the matter. Other than that you can make sure that you're kept hydrated the whole day long with clean and safe water with one of these backpacks from such great brands as Osprey and Camelbak.
Camelbak Lobo 100oz Hydration Pack 62390
Camelbak Rim Runner 22 Hydration Pack 62237
Camelbak Kids Scout 50 Oz Hydration Pack 62082
Camelbak Rogue 70oz Hydration Pack 62239
Camelbak Lobo 100oz Hydration Pack 62387
Camelbak Rogue 70 Oz Hydration Pack 62241
Camelbak Childrens Scout 50 oz Hydration Pack 62081