While a declaration of public health nuisance for an affected site is in effect and has been posted at the site, no persons are permitted to be inside the site, or on the site property without prior written consent of the City Building Official or as otherwise authorized by this subchapter. To confirm compliance with this subchapter and to execute their duties under this subchapter, law enforcement officers, the City Building Official, and any persons designated by the Building Official may enter onto the site property or enter into the site at any time while a declaration of public health nuisance is in effect for the site.