I've looked into all this. Borehole with pump £10K assuming the spoil is left on site and depth is around 100 metres. The main cost is just getting the equipment on and off the site. You can extract 40,000L per day without licence now apparently, but we'd never use that much. Running costs are just the filters and electric pump, so great if you generate your own electricity. It really depends on how much you use, but Chlorinated water is no good for food crops with delicate flavour unless it stands in open tanks for at least 4 days to release the Chlorine. It wrecks the taste of raspberries and strawberries. Spoils cherries a bit as well.