We are surrounded by water. We float on it, we wash in it. But we cannot drink it - not the local stuff. There is a source for spring water and the first time our tank ran we out - we got our water there, but we could only get 15 gallons at a time and we had to drive to get it. So a couple days ago, the last time we ran out and were very thirsty (4 PM and 85 degrees out), we decided to fill our water tank with dock water. We treated it with bleach (100 gallons water to 1.5 Tbsp bleach) and now we are drinking it. It tastes a little like chewing metal - kind of like water from Northern Minnesota - just like what we grew up with. The kids get a little taste from home.
Not sure if we will fill it again with dock water, but for now we can use water freely which in itself is worth the poor taste.