Drinking Fountain from Pond Water

There is a nice lake about two miles from my house.  Many people get some exercise by walking around the lake several times. A complete loop is just under a full mile.  I take my two Beagle dogs there about every other day.  I sure wish they had a drinking fountain there. In the summer it can get rather hot.  But, I’m sure part of the problem is that there is no nearby city connection for clean drinkable water.  The lake water itself is not clean enough for drinking. But, I’m wondering if some solution might be devised. Suppose one were to install a custom drinking fountain near the lake. It could be powered by a pole mounted solar panel.