Apologies, I didn't note that you were using surface water.
My boreholes are about 35 and 60 metres away from my house. The boreholes are both fed by the underground streams. I don't have any other sources of water on the land.
I tested the borehole water for 16 different properties (total alkalinity, carbonate, hardness, cyanuric acid, copper, mercury, total chlorine, free chlorine, bromine, nitrate, nitrite, iron, chromium, lead and fluoride) and it was low or normal for all except hardness.