D.C. Code § 43-123
No grave in said District shall be reopened, except for the purpose of disinterment, within 10 years after burial of a person above 12 years of age, or within 8 years after the burial of a child under 12 years of age, unless the grave has been, in the first instance, of sufficient depth to permit subsequent interments, in which case a layer of earth of not less than 1 foot thick shall be left undisturbed over the previously buried coffin, unless such coffin has been separately entombed in properly cemented stone or brick work; but if on reopening any grave the soil be found to be offensive, such soil shall not be disturbed. In no case shall a grave be opened in which has been buried the body of any person who has died of Asiatic cholera, yellow fever, typhus fever, smallpox (including varioloid), leprosy, the plague, tetanus, diphtheria, or scarlet fever; provided, that the Director of the Department of Health of the District of Columbia may, in his discretion, authorize the opening, under sanitary precautions, of any such grave, and the disinterment and reinterment in the same grave or other suitable burial ground, of the dead body of any person who has died of any of the contagious diseases enumerated above.
D.C. Code § 43-123