In theory, there is an elevation that they were allowed to dig the hole to and another elevation that will be the top. Every cubic yard of airspace is worth lots of money, so will try to make it as high as they can get away with. Also, when it is all filled up, they will seed and mulch it and make the top into a plateau so it will eventually look like another giant hill. The solid waste business is big business and a little slimey, kinda like recruiting, so this will be sports related................