D.C. Code § 9-421.10
Any property owner, aggrieved by any assessment levied under this subchapter, may, within 60 days after service of notice of such assessment, file with the Mayor of the District of Columbia a protest in writing against such assessment, accompanied by affidavits if he so desires, and if said Mayor finds that the property of such owner so protesting is not benefited by the improvement for which said assessment is levied, or is benefited less than the amount of such assessment, or is unequally or inequitably assessed with relation to other property abutting such improvement, said Mayor shall abate, reduce, or adjust such assessment in accordance with such finding. In computing the 60 days provided in § 9-401.06, within which such assessment may be paid without interest, there shall be excluded therefrom the time between the date of the filing of any such protest and the date of action thereon by the Mayor.
D.C. Code § 9-421.10