D.C. Mun. Regs. tit. 29, § 2309
2309.1 Any notice required by this chapter may be served either personally or by certified mail, return receipt requested, directed to the applicant, facility or program at the last known address as shown in the records of the Department.
SOURCE: Final Rulemaking published at 47 DCR 9341 (November 24, 2000), adopting Emergency and Proposed Rulemaking published at 47 DCR 7708, 7718 (September 22, 2000).