D.C. Mun. Regs. tit. 3, § 704
704.1 Polling places in which elections are to be held shall be opened at 7:00 a.m. on the date required by law for the election and shall remain open for voting until 8:00 p.m., except in instances when the time established for closing the polls is extended pursuant to a federal or District of Columbia court order or Board order.
704.2 All persons standing in line at a polling place at the close of polls shall be permitted to vote, if otherwise qualified.
704.3 At the close of polls, a polling place official shall take a position at the end of any existing line of prospective voters, and only persons standing in front of the official at that time shall be permitted to vote.
704.4 The Board may extend polling hours at a precinct in order to resolve unforeseen emergency situations on Election Day. If voting at a precinct is interrupted on Election Day by an emergency situation, the Board will convene an emergency meeting to consider whether the situation warrants the extension of polling place hours and, if applicable, how long polling place hours will be extended.
SOURCE: Final Rulemaking published at 39 DCR 2467, 2480 (April 10, 1992); as amended by Final Rulemaking published at 51 DCR 7403 (July 30, 2004); as amended by Final Rulemaking published at 57 DCR 4245, 4248 (May 14, 2010).