Cement is then again placed in the borehole (and inside the surface casing pipe that was placed at the top of the hole and cemented in during drilling) all the way to the surface. At the top it is required that a “monument” be placed at the surface to mark the well’s plugged location. Usually this is a four-foot metal pipe stuck in the surface cement job and itself is filled with cement. This monument is so the future user of the surface or sub-surface will know it is there, and just exactly where it is in the event it might interfere with or limit a future use. The well’s API number has to be permanent shown somehow on the monument in case someone wants to find more information on the well – such as what was required by the plugging permit.