I thought that adding lime was the standard method for keeping weeds down?
Not heard of that. Makes sense. I have an old bag of lime and a weedy area (despite a foot of hardcore, the lack of traffic means the adjacent planted area soon colonizes it)
I shall report back next year
It doesn't work - we've got weeds growing on 18 inch of limestone.
Depends on what 'lime' you are using. Calcium hydroxide will raise the pH and is not a good idea for drinking water. For anyone living in an acid soil area, it will be neutralised, but slowly.
Chalk or limestone are basically a mixture of calcium carbonate, calcium bicarbonate and calcium sulphate with a few other things thrown in. They are a lot less alkaline, and will only affect plants that are lime intolerant.
From what you have posted Nick, I don't think any sort of lime on your drive is going to stop the weeds, and won't be good for your well.