EPA is taking direct final action to approve Philadelphia Department of Public Health Air Management Services's (AMS's) request for delegation of authority to implement and enforce its hazardous air pollutant regulations which have been adopted by reference from the Federal requirements set forth in the Code of Federal Regulations. This approval will automatically delegate future amendments to these regulations. For sources which are required to obtain a Clean Air Act operating permit, this delegation addresses all existing hazardous pollutant regulations. For sources which are not required to obtain a Clean Air Act operating permit, this delegation presently addresses the hazardous air pollutant regulations for perchloroethylene drycleaning facilities, hard and decorative chromium electroplating and chromium anodizing tanks, ethylene oxide sterilization facilities, halogenated solvent cleaning and secondary lead smelting. In addition, EPA is taking direct final action to approve of AMS's mechanism for receiving delegation of all future hazardous air pollutant regulations which it adopts unchanged from the Federal requirements. This mechanism entails submission of a delegation request letter to EPA following EPA notification of a new Federal requirement. EPA is not waiving its notification and reporting requirements under this approval; therefore, sources will need to send notifications and reports to both AMS and EPA. This action pertains to affected sources, as defined by the Clean Air Act's (CAA or the Act's) hazardous air pollutant program. EPA is taking this action in accordance with the CAA.