Philadelphia’s Air Management Services (AMS) currently regulates toxic air contaminants (TAC) per Air Management Regulation VI “Control of Emissions of Toxic Air Contaminants (TACs)”. On April 28, 2022, Philadelphia Air Management Services (AMS) proposed revisions to Air Management Regulation VI to require a robust health risk assessment for sources that emit certain levels of TACs. The current regulation regulates 99 chemicals, while the revised regulation will be expanded to include 217 chemicals and will borrow heavily from the New Jersey Department of Environmental Protection air toxic requirements.
The proposed revisions to Regulation VI modify the definition of what is considered a TAC to include all Hazardous Air Pollutants (HAPs) based upon Section 112 of the Clean Air Act and air toxics as specified by the New Jersey Department of Environmental Protection. These TACs are specified in the Appendix to Regulation VI. Additionally, new reporting thresholds for each TAC are proposed, which are specified in the new Technical Guidelines for Air Management Regulation VI document. AMS has also created a Health Risk Assessment Technical Support document (as Exhibit B to the regulation). The technical guidelines explain how to conduct the risk screening analysis for applicable sources and facilities.
The proposed Regulation VI requires that facilities filing for an Installation Permit or Plan Approval need to conduct a health risk assessment if emissions of TACs exceed the reporting thresholds as specified in the Technical Guidelines document for the specific emission source. This health risk assessment requires the use of either the AMS Risk Screening Workbook or US EPA AERSCREEN to demonstrate compliance with cancer risk and hazard index requirements. If the potential cancer risk for each TAC from an emissions source is less than one in a million, then no further evaluation is needed. If the cancer risk is above one in a million from an emissions source, then a refined risk assessment will need to be conducted. The revised Regulation VI allows for certain sources to be exempt from notice requirements such as parking facilities, demolition activities, and non-Title V (major source) operation/renewal permits. Certain sources such as smaller/limited use internal combustion engines (under 2,500 hp and operate less than 500 hours/year), smaller autobody shops (using less than 250 gallons/year), and natural gas-fired boilers with a maximum heat input capacity below 50 mmBtu/hr (with certain stack restrictions) are exempt from performing a health risk assessment.
Additionally, the revised regulation requires that initial Title V operating permits include a facility-wide health risk assessment based upon US EPA’s air quality dispersion modeling guidelines. If the health risk assessment conducted for an initial Title V permit application does not demonstrate compliance, then a Risk Mitigation Plan must be developed. The revised regulation also requires AMS to review the current surrounding concentration of each evaluated TAC prior to issuing a Plan Approval of a Title V operating permit.
Previously, Regulation VI has only required sources to report the amount of TAC emissions, however due to these proposed revisions, facilities submitting permit applications will have to conduct a more complex analysis as a part of the air permitting process. The proposed regulation was approved by the Philadelphia Air Pollution Control Board on April 28, 2022 and is expected to be available for public comment in the future.
If you would like to discuss the new revised TAC regulations and how they may impact your facility, please contact Trinity’s Philadelphia office, or call 610.280.3902.
