requesting the covered materials made available under this section must certify, in writing, that the materials it accepts will be exclusively used for the refurbishment or maintenance of ports of entry along the southwest border or construction projects aimed at stopping illicit human and vehicle traffic along the border of the United States with Mexico. (d) Execution of plan Not later than 100 days after the date of submission of the plan required by subsection (a), the Secretary of Defense shall commence execution of such plan until the date on which the Department of Defense is no longer incurring any costs to maintain, store, or protect the covered materials. (e) Report Not later than 90 days after the date of the enactment of this Act, the Secretary of Defense shall submit to Congress a report containing the following: (1) A detailed description of the decision process of the Secretary to forgo the excess property disposal process of the Department of Defense and instead pay to store the covered materials. (2) A list of entities the Department is paying for use of their privately owned land to store the covered materials, with appropriate action taken to protect personally identifiable information, such as by making the list of entities available in an annex that is labeled as controlled unclassified information. (3) An explanation of the process through which the Department contracted with private landowners to store the covered materials, including whether there was a competitive contracting process and whether the landowners have instituted an inventory review system. (4) A description of any investigations by the Inspector General of the Department that have been opened related to storing the covered materials. (f) Definitions In this section, the term covered material means all remaining construction materials currently possessed by the United States Government that were purchased under section 2808 and 284 of title 10, United States Code, from fiscal years 2017 through 2021, including bollards and