D.C. Code § 10-616
The Federal Emergency Administration of Public Works, or its successor, shall be repaid 55 per centum of any moneys advanced under § 10-614 in annual instalments over a period of not to exceed 25 years with interest thereon at such rate as is agreed upon by the Mayor of the District and the Federal Emergency Administration of Public Works, or its successor, for the period of amortization; provided, that such sums as may be necessary for the reimbursement herein required of the District of Columbia, and for the payment of interest, shall be included in the annual estimates of the Mayor of the District of Columbia, the 1st reimbursement with interest to be made not later than June 30, 1944; provided further, that whenever the District of Columbia is under obligation by virtue of the provisions of § 4 of Public Act No. 284, 71st Congress, 46 Stat. 482, ch. 354, reimbursement under that Act shall not be less than $300,000 in any 1 fiscal year.
D.C. Code § 10-616