Unless I am high in the mountains I try to avoid streams etc. I've never had any problems with getting water from cafes, pubs, churches, farmyard taps, etc and when I'm in the middle of nowhere I also find cattle troughs are great! BUT! I always ensure that I collect my water at the point where it comes out of the ballcock, never from the trough itself. Depending on the design of the troughs some are easier to get at the water than others. I have a small plastic cup hanging from my rucksack and if necessary I use this to collect the water, then transfer it to my water bladder in the back of my rucksack. If I'm worried about the water quality I just use my Lifestraw water filter. It must work because I'm still here to tell the tale. Sometimes when I'm feeling desperate I will also knock on a random door, most people in my experience are very helpful.