Re: drinking your doom
Jane doe - couldn't tell you if they do use mountain water sources for tap water. Considering how much water is used by the populous in general for things such as washing, gardening, toilets, etc, I highly doubt fresh water is used as I'm sure supply is time limited and wouldn't be enough.
More likely a reservoir like most places, where the water is recycled from toilets etc. Hence my initial posts that if you don't want poo in your water, drink bottled as it comes from pure rain water, limestone filtered and not recycled at some sewage processing plant.
For instance, there's a fresh water spring a few miles from me. This spring water collects from the surrounding hills and emerges at its source, a valley. Logical enough and no it's not tap water (as there's not enough to supply large infrastructure) and no it doesn't contain poo particles as it has come from the sky!
I don't know my european laws on bottled water, but I'd be surprised if a bottle labelled as spring water, was anything but.