[JonnyNova]

I once drank lake water in Iceland during winter. The only reason I could be convinced to do so was because it was Iceland during the winter. It was absolutely fantastic. Easily the best tasting water I've had by an order of magnitude.

[13of40]

I once drank water from a natural spring in Kolomenskoye Park in the middle of Moscow. Tasted great with no ill effects. Don't know if it's safe for chronic consumption though.

[mantas]

95% it is safe. If it wasn't, it'd be marked as such. The spring doesn't need much space. Rain drops, gets filtered by sand and soil, comes out from a spring down bellow. A park of few hundred square meters is more than enough to be a safe filter.

Source: drink frequently from springs in/around towns.