The applicant (and the landowner in the instance of a leased property) shall provide a performance bond and/or other assurances satisfactory to the planning board, in a form approved by the borough attorney, that will cause the antennas, any supporting tower, the electric equipment cabinets, any building enclosing the electronic equipment shelters, and all other related improvements to the land to be removed, at no cost to the borough, when the antennas are no longer operative. Any wireless communication facility not used for its intended and approved purpose for a period of six months shall be considered "no longer operative" and shall be removed by the responsible party within 60 days thereof.