ter 0 if IOWS = 2. Default: 10.0, but 0 if iows = 2.</p></td>
    </tr>
    <tr>
      <th>xll</th>
      <td><p>Length of screened interval of observation well or piezometer, in units 
of length. Must be 0 if IDPR = 0. Default: z2 - z1, but 0 if idpr = 0.</p></td>
    </tr>
    <tr>
      <th>zp</th>
      <td><p>Depth below top of aquifer or initial water table to center of piezometer, 
in units of length. Use for IOWS = 2. Enter 0.0 if IOWS = 0 or 1.
Default: 3.0, but 0.0 if iows not equal to 2.</p></td>