Question

A farmer is analyzing cross sections of his land to determine where to build a well.



Which phrase describes the best area to dig down to the groundwater?

where the saturated zone is 15 meters deep
where the water table is at 100 meters deep
where the unsaturated zone is 50 meters thick
where there is a 25-meter thick clay layer at the surface

Answer 1

Where the saturated zone is 15 meters deep.

Reason: the saturated zone is where groundwater is found, so a 15 m deep saturated zone (i.e., a shallow water table) requires the least digging. The other choices describe much deeper water (100 m or 50 m unsaturated thickness) or a thick clay layer at the surface that would make drilling harder.