Water quality is really important so you need to know if your Spring has been tested for purity (ours hadn’t so we had to throw our collected water away!). So I was therefore very interested to read Elwin Robinson’s useful overview on water quality in which he grades different types of water based on the quality. At the top, you have fresh spring water, with no water at all at the very bottom:
I’ve included edited descriptions of each water type below. There’s also a useful video on Elwin’s website if you’re interested in finding out more.