As a general rule, many know that you can live 3 minutes without oxygen, 3 days without water, and 3 weeks without food (under normal conditions. It is important to procure nourishment for your body in this particular order. Not to say you shouldn't take advantage of readily available food should you come across it, but understand that breathing and water are equally important, and lack of oxygen and water will likely kill a person, and fast.
There are many options available for obtaining water and making it safe to drink. There are chemical tablets, water filters, ultraviolet light, to name a few. You can, of course, also boil the water to make it safe, and this is an almost foolproof method. But I would highly advise you to consider adding a water purification set up to your survival and camping pack. Not just one of the above options, but several options are best.
With a small kit it is very convenient to have some chemical tablets, as they are small and will fit in the kit. However, if you have a good amount of space to work with, I would recommend a quality water filtration system. These filters can be bottles which filter as you drink, or pumps that filter the water from the course, The bottles generally have a smaller filtering capability and will requiring changing the filters often. The pumps will displace a large amount of water safely and quickly, but they are generally large and require a good amount of room.
I have ordered a Katadyn Vario water filtration system to add to my kit. I am also trying to get a hold of a Steripen, as I would like to conduct a side by side comparison of the differences between the two. Though the Steripen utilized UV light to kill harmful viruses, it does not get rid of foul taste, however, it is very small and can be taken anywhere. A side by side comparison will allow you to see the differences between the two in terms of size, quantity of water to be purified, east of use, and maintenance. More to come.