The Department of Transportation, subject to the powers of the Board of Estimates, shall make all contracts:for furnishing, operating, and maintaining lamps and lamp standards; for furnishing steam for public buildings; and for furnishing illuminating gas and electric current for street lamps and public buildings. The Department of Transportation must:regulate the lighting and cleaning of the City lamps and see that they are kept in proper repair; erect new lamp standards and lamps for lighting the highways, streets, lanes, alleys, bridges, parks, and squares in the City; remove or relocate any lamp standards and lamps whenever and wherever, in its judgment, convenience and necessity of the public may require; make monthly statements of the street gas lamps and ascertain the correct rate or rates of gas consumption for all such lamps; and ensure that, on or before June 30^th 2013, all City electric street lamps are equipped with energy efficient light emitting diode lights or similar cost-effective technology. City Code, 1893, art. 28, §3 1927, art. 28, §27 1950, art. 22, §20(1st - 3rd sens.) 1966, art. 17, §20(1st - 3rd sens.) 1976/83, art. 17, §19(1st - 3rd sens.) Ord. 1880-104 Ord. 46-590 Ord. 76-056 Ord. 11-567