It shall be the duty of each permittee under this chapter to clean up the premises where his or her Christmas tree sales business was conducted within fifteen days after Christmas and remove all leftover trees, branches, paper, waste and debris therefrom and any temporary structures. The permittee's cash deposit shall not be refunded until after certification by the Building Official that the premises have been properly cleaned up. If the premises are not properly cleaned up as herein required within fifteen days after Christmas, the City may cause such premises to be cleaned up, and the costs thereof shall be certified by the Department of Engineering and Building to the City Treasurer, and such costs shall be deducted from the cash deposit before refund to the permittee. Such cash deposit, or the balance thereof, shall be refunded within thirty days after certification by the Building Official.