Amending Section 11-506 of The Philadelphia Code, entitled "Alleys, Driveways, and Retaining Walls," by providing additional methods by which the City may pay contractors the City hires to pave or repave alleys or driveways or to construct or reconstruct retaining walls pursuant to orders to abate nuisances, and by providing a maximum amount that property owners may be assessed for the costs of such work; all under certain terms and conditions. — Open Common Ground