Remember, there are two issues with water, filtration and purification. While both can be fairly easy, they are different steps. Water is too valuable in any serious situation to be considered unusable. You can filter wate with lots of options. Purification requires some additional step, the simplist and cheapest of which is unscented chlorine bleach. Once you have the sediment and garbage out of the water, proper use of the bleach will do the trick. Put some resources into proper containers to do this and you will feel more confident, regardless of the size of your household.
The more creative you can be, the better you will feel and the better off you will be!
Get an old milk can and make it into a still. That will be one of the best options you can use. While it won't remove volatile chemicals, it will get most everything else out, including salts of all descriptions.
I am still a big advocate of storing large volumes of dry goods,both grains and beans. You can cook them or sprout them as long as you have water, but the storage of them is the most efficient for any long term considerations. Oils are the next most valuable item because you need them to survive,regardless of how much grain and beans you have.
Hope this helps!
Trim sends
//BT//