Description:

The measurement of water depth (in feet).  This measurement is made from the reference point that is the elevation from the top of the casing where it is notched (MPELEV) to the top of the liquid in the well bore.

OWL:  DYNAMIC LIQUID DEPTH THE depth from the measuring point to the top of the liquid in the well bore. These measurements will include the water level at the beginning of the test (time=0). These measurements are used to calculate drawdown.

TWI:   DYNAMIC LIQUID DEPTH or recovery depth, dynamic depth of water after recovery from purge, measured in feet from the measuring point elevation.