An agency holding unneeded land withdrawn or reserved from the public domain must submit to the appropriate GSA Regional Office a Report of Excess Real Property (Standard Form 118), with appropriate Schedules A, B, and C, only when -
(a) It has filed a notice of intention to relinquish with the Department of the Interior (43 CFR part 2372 et seq.) and sent a copy of the notice to the appropriate GSA Regional Office;
(b) The Department of the Interior has notified the agency that the Secretary of the Interior has determined that the lands are not suitable for return to the public domain for disposition under the general public land laws because the lands are substantially changed in character by improvements or otherwise; and
(c) The Department of the Interior provides a report identifying whether or not any other agency claims primary, joint, or secondary jurisdiction over the lands and whether its records show that the lands are encumbered by rights or privileges under the public land laws.