I have a farm in West Bengal, Purulia and we have dug a borewell of 720 feet and an 8-inch diameter. The entire bore is through stone so the casing could only be provided till 10 feet and we hit water at around 550 feet and gushing water at 650 so the bore was only possible till 720. We have made an overhead tank at 20 feet above ground, please suggest an optimum pumping solution and depth at which it should be hung.