Getting stuck outdoors without clean water is not idea. The LifeStraw Family 1.0 Water Purifier is a handy solution that can purify up to 18000 liters of water. It removes 99.99% of virsues and bacteria. It can purify water to 0.02 microns.
The LifeStraw Family 1.0 comes with a 2L reservoir bucket.
[where to get it]