Changes

If required, the upper part of the well can be reamed and cased with larger diameter pipe (3 or 5 inches), to accommodate larger pumps. A shallow (large diameter) [[rope pump]], for example, may require a wider well (although small-diameter rope pumps can fit in a 2" borehole), and submersible pumps commonly need at least 4".  Note that there is no need to enlarge the entire depth of the borehole: reaming until slightly below the lowest expected water table (the pump's water intake) is sufficient.