D.C. Code § 34-1408

The Mayor of the District of Columbia is hereby authorized, in his discretion, to permit the Potomac Electric Power Company to make connections between its conduits and the conduits of the Washington Railway and Electric Company and all other companies controlled by the Washington Railway and Electric Company for the purpose of furnishing electric current through the said conduits for public and private uses, the use of said railway companies’ conduits to be upon such terms as may be agreed upon between the said companies.