D.C. Code § 34-1103

The Commission shall have power, after hearing and notice by order in writing, to require and compel every public utility to comply with the provisions of this subtitle, and with other laws of the United States applicable, and any municipal ordinance or regulation relating to said public utility, and to conform to the duties upon it thereby imposed or by the provisions of its own charter, if any charter has or shall be granted it; provided, that nothing herein contained shall be held to relieve any public utility, its officers, agents, or servants, from any punishment, fine, forfeiture, or penalty for violation of any such law, ordinance, regulation, or duty imposed by its charter, nor to limit, take away, or restrict the jurisdiction of any court or other authority which on March 4, 1913, had or which may thereafter have power to impose any such punishment, fine, forfeiture, or penalty.