The build

So no additives like chlorine etc? Sounds good to me.  

I have lived in two houses with spring fed water, one was what my Gran called 'Adams ale' sparkling and cold even in summer (not sure what filters used) the other house had horrible water, used bottled water to drink as it was distasteful.
I was drinking unfiltered water off the mountain on the Isle of Rum last week and still lived to tell the tale!

Tangential tale, I went to buy a house by sealed tender but Lord Lampdon said he would stop the spring water supply which ran over his land if he didn't get the house. After a lengthy legal ramble it was agreed he couldnt stop the water and the new owner would need to pay 50 pper annum for it's use.! As it happened he bid a ridiculous ammount in his tender and got the house for a shooting lodge anyway!

Think it’s only been in the last 15/20 years that water has needed any sort of filler. People have been drinking it for years and are still here. 

Unfortunately there are lot of arrogant, self righteous people like lord lampoon around.