Some of the most common water filters for backpacking are inadequate for purifying water that is contaminated with chemicals or heavy metals. Here is a review of one that does.
Here's the sum of it all: we are born, we live, we die. That's it. At some point we will take action on what we need to do with whatever is left of our lives. Own yours.
The fullness of a completed task is the reward. It consumes all the hardship and doubt experienced along the way. It owns the moment. So, hike on and do the hard thing. It's worth it.