Pennsylvania Department of Environmental Protection (PADEP)

The Environmental Quality Board (EQB) is moving forward on the Reasonably Available Control Technology (RACT) III rule that was proposed to the Pennsylvania Department of Environmental Protection (PADEP) on October 17, 2019. The purpose of this rule was to revise the State Implementation Plan (SIP) for compliance with the primary and secondary National Ambient Air Quality Standard (NAAQS) for ozone. RACT applies to major sources of nitrogen oxides (NOx) and/or volatile organic compounds (VOCs) emitted statewide. This revision to the rule will provide additionally reduced emissions limits for NOx and VOCs from the previous PA RACT rules. The compliance deadline for RACT III will be January 1, 2023.


PADEP is revising the RACT standards in response to EPA’s lowering of the NAAQS 8-hour ozone standards in 2015.  The proposed RACT requirements would apply to all sources in the Commonwealth that emit or have a potential to emit 100 tons per year (TPY) or more of NOx or have a potential to emit at least 50 TPY of VOCs.  It will only affect sources that commenced construction on or before August 3, 2018.


RACT III Changes

The DEP proposed changes that would lower the emissions limits on the RACT II sources. The averaging periods would now be daily during the ozone season (new) and 30 day-rolling year-round. Please see Table 1 below for more specifics on simple cycle (SC) or combined cycle (CC) turbines. Table 2 shows the changes for engines. The rule includes operating practices for sources equipped with a selective catalytic reduction system (SCR) or selective non-catalytic reduction (SNCR) required for each operating day to limit NOx emissions by optimizing all installed air pollution control devices.

Table 1.  RACT II and RACT III Limit Changes for Natural Gas-fired turbines

Table 2.  RACT II and RACT III Limit Changes for engines

Public Comments Period

The Environmental Quality Board (EQB) is currently accepting public comments on the proposed RACT III rule.

Comments may be submitted online at, via email to, or mailed to Environmental Quality Board, PO Box 8477, Harrisburg, PA 17105-8477.  The deadline for comment submittals is October 21, 2021.


Looking Forward

Sources will need to determine a strategy for compliance with the new RACT-III limits.  These strategies may necessitate installing additional emissions controls and/or modifications to monitoring equipment (e.g. adding or re-ranging analyzers) which may trigger changes to the PADEP Monitoring Plan (i.e. Phase I-II-III).

VIM Technologies urges affected sources to assess their compliance options to stay ahead of the curve. We are ready to help. Our state-of-the-art DAS is fully equipped to comply with the monitoring, recordkeeping and reporting requirements. Our regulatory experts (COMPAS Division) have over 125 years of combined CEMS and regulatory experience and have extensive experience complying with the PADEP requirements.

Contact us today for a FREE consultation at

Lastly, we will be announcing upcoming webinars and training courses tailored to PADEP processes and reporting.  Please stay tuned.