Revision history [back]
I would start by reiterating the need for drainage to ensure that contamination is minimised. This is particularly important where livestock watering or clothes washing is encouraged or permitted at the well. Often some suitable crop, such as banana is planted at the termination of the drain
Having consulted a hydrogeologist colleague it would seem that the usual recommendation is to provide a 5 m deep seal, provided that the productive aquifer is deeper than this. One useful document is: https://schneiderwater.com/pdf/Hydrophilanthropy_Well_Guidelines.pdf
Other useful stuff can be found on RWSN: https://www.rural-water-supply.net/en/