The Commissioner In Charge of any particular parcel of real property owned by the City is hereby authorized to grant permission in writing to any governmental body to install on said real property on a temporary basis an air quality measuring station; provided, however, that no such written permission shall be granted unless and until the requesting governmental body has stated in writing that the temporary installation will be accomplished without injury or damage to the City property and that said governmental body will reimburse City for all costs or expenses to City incident to the installation.