D.C. Code § 10-1121.09: Restoration of airspace upon expiration or termination of lease.

If, upon the expiration or termination of a lease of airspace under this subchapter: (1) the Mayor determines that any structure constructed or erected in such airspace should be removed or such airspace should be restored to its condition prior to the construction or erection of such structure; and (2) the lessee or his successor in interest, upon the request of the Mayor, fails, after a reasonable time, to remove such structure or to restore such airspace to its condition prior to the construction or erection of such structure; the Mayor may remove such structure and restore such airspace. The cost of such removal and restoration shall be assessed against the abutting properties as a tax. Such tax shall be collected in the manner prescribed by § 6-806, for the collection of amounts assessed as a tax under that section.