Final Air Quality Source Category Permits to Operate Emergency Engines Exempt from NSPS Subparts IIII and JJJJ but Subject to NESHAP Subpart ZZZZ

PUBLIC NOTICE

Final Air Quality Source Category Permits to Operate Existing Stationary Diesel and Natural Gas-Fired Emergency Engines Exempt from NSPS Subparts IIII and JJJJ but Subject to NESHAP Subpart ZZZZ

On Thursday, April 24, 2025, the Air Quality Division (AQD) of the Department of Energy and Environment (DOEE) issued two source category air quality permits (Nos. 7115-SC-R2 and 7116-SC-R2) covering most stationary diesel and natural gas-fired emergency engines not subject to New Source Performance Standards (NSPS) Subparts IIII or JJJJ (40 CFR §60, Subparts IIII and JJJJ), but subject to National Emissions Standards for Hazardous Air Pollutants (NESHAP) Subpart ZZZZ (40 CFR § 63, Subpart ZZZZ), in the District of Columbia. These permits were issued pursuant to 20 DCMR § 200.8.

On March 14, 2025, DOEE issued a public notice soliciting comments on draft versions of the two permits and the associated application forms. Comments were accepted through April 14, 2025.

AQD received two sets of comments providing similar comments on both draft permits during the public comment period.

DOEE has considered these comments and has prepared a response document. A summary of the comments and the associated responses can be found in the attachments section below. The comments resulted in several changes to each of the permits.

Questions should be addressed to Stephen Ours, Chief, DOEE Air Quality Permitting Branch at (202) 498-8143 or by email at [email protected].