The important point is that they would have formed in the unsaturated zone, which means there is not permanent water there.

The part of the aquifer that lies above the water table is termed the unsaturated zone.

It separates the saturated part of the aquifer from the unsaturated zone above it.

The nitrate problem has taught us that to protect our drinking water, we must monitor the unsaturated zone.

In the dry or growing season, plants take water from the unsaturated zone.

There are also problems in characterising the vadose zone (unsaturated zone).

In addition the repeat profiles provide valuable information on the mechanisms and rates of water movement in the unsaturated zone.

The air is then vented through the unsaturated zone.

Direct discharges (no unsaturated zone) of List I substances must be prevented.

The water table and unsaturated zone are also illustrated.