D.C. Mun. Regs. tit. 3, r. 3-5524
A subpoena or notice of deposition may be served by any person who is not a party and is not less than eighteen (18) years of age. Service of a subpoena or notice upon a person named therein shall be made by delivering a copy of the subpoena to the person and, if the person's attendance is commanded, by tendering to that person the fees for one day's attendance and the mileage allowed by law. When the subpoena is issued on behalf of the United States or the District of Columbia or an officer or agency thereof, fees and mileage need not be tendered.
Witnesses are entitled to a witness fee of forty dollars ($40) per day and the cost of public transportation to the proceeding or a mileage fee calculated at seventeen cents (17¢) per mile.
Service of a subpoena or notice and fees to an individual may be made by any of the following means:
When the person to be served is not an individual, a copy of the subpoena or notice of the deposition and fees shall be delivered by one (1) of the following ways:
The individual serving a subpoena shall file with the Board a return of service setting forth the facts establishing proper service.
The Board may, upon the failure by any person to obey a subpoena served upon that person, apply to the D.C. Superior Court for an order requiring the person to appear before the Board to give testimony, produce evidence, or both. If a person fails to obey the order without an adequate excuse, the Board may apply for an order that the person be held by the court for contempt.
D.C. Mun. Regs. tit. 3, r. 3-5524