Q746. What is the best way to determine the surface area of my landfill if there is significant surface topography?

A746. For the purposes of reporting under subpart HH, the surface area should be determined considering a single horizontal plane and the areas on that plane below which waste has been or will be disposed.  Easements should not be considered as part of the landfill area.  If the landfill disposal area has a significant mound, it is acceptable to determine the surface area as the product of the width and length of the base of the mound (rather than calculating the area of the exposed surface of the mound).  In other words, topography (change in height) does not need to be considered when determining the surface area of the landfill.