Agreed. Filtration systems are cheap, and even if you don't have one with you it's pretty easy to boil water to be sure.

In the extreme case that you can't boil the water, try collect rain water or water closest to an in-ground source (top of a stream where it comes out of the ground or a natural spring).

The biggest risk factor imo (outside of personal hygiene) is not knowing what lies further upstream. Only takes one dead animal to make you have a real bad time.

Iodine water treatment is even cheaper, more effective against viruses, and you don't have to guess about the age of the filter. I've been using the same bottle of Polar Pure for about a decade.