In my country, a borehole is to be found in nearly a radius of about every 5 kilometers, in at least every village. That popular are boreholes.
This a good detail of borehole drilling, one caveat I thought you might want to make, is that given selected sites must, besides satisfying the condition of being located in topographically favorable areas where there is a wide zone of weathering with deep rock fracturing, must also – and this is very important – meet environmental criteria, ie.e. located away from groundwater pollutants.
But of course that, as you finally indicate, depends on the purpose for which the borehole is being drilled. It wouldn't probably matter much if it is being drilled for agricultural purposes, but if for human consumption like in my country, it matters a great deal.