Sustainable Groundwater ...

Sustainable Groundwater Resource

Dear Hussein,

As previous people noted, the lack of water in the wells is probably due to a decline in the water table.  This decline could be due to a combination of over-pumping in the region/area and/or decreased precipitation (drought?).  Geophysics can help you delineate major hydrogeologic units.  To be honest, I am not overly familiar with these methods.  I do know, however, that electrical resistivity is often used after the well has been drilled to further define the lithologic layers (to augment the cores collected during installation of the well).  And I believe ground penetrating radar can help detect geologic layering, etc.  However, nothing is as accurate as the information collected during drilling of a well.

What I would suggest is that you not only drill the wells deeper, but if possible, screen them (and double case them) within a semi-confined aquifer that is relatively prolific.  In addition, I would also suggest groundwater analysis of the water quality to ensure there are no problems, either due to anthropogenic sources and/or natural (e.g., high arsenic).

It may be more cost effective to drill smaller diameter pilot holes for hydrogeologic delineation.  You can then convert these wells to observation wells.  If possible, after confirming the water quality is acceptable,  I would then conduct an aquifer pumping test using a larger diameter well (e.g., possible supply well) to estimate aquifer parameter values like transmissivity and storatviity.  From these values, you could perform some relatively simple hydrogeologic modeling to project potential impacts of pumping, based upon expected water use/demand.  This can help you assess the long term feasibility of the supply, and also help you in spacing wells appropriately (preventing excessive overlapping of cones of depression).

As far as performing recharge to augment groundwater supply, you would likely need to perform a feasibility study, which would include hydrogeologic delineation of the groundwater system and groundwater modeling.  Alternatively, can you use the water that you would recharge as a direct source of water?

If you need any further suggestions or assistance, feel free to contact me directly.

Sincerely,

Emery