The Utah Department of Air Quality (UDAQ) asked Barr’s confidential client to prepare a reasonably available control technology (RACT) analysis to support their development of an updated state implementation plan (SIP). A SIP update is required when an area does not achieve the national ambient air quality standard for a particular pollutant by a regulatory deadline. When the severity of the non-attainment changes, a new SIP is required. The RACT analysis was for nitrogen oxides (NOx) and volatile organic compounds (VOC) emissions from a refinery in Salt Lake City to support of the UDAQ's moderate ozone SIP published in 2023.
The analysis relied on prior control evaluations under RACT and best available control technology (BACT) completed under Utah’s moderate and severe PM2.5 (particulate matter) SIPs dating back to 2012. The historical analyses conducted for the PM2.5 SIP evaluated NOx, VOC, sulfur dioxide (SO2), and PM2.5 controls. Barr refreshed the historical analysis and evaluated all refinery equipment, including the fluid catalytic cracking unit, wastewater treatment plant, fuel gas combustion devices, storage tanks, and transfer racks. Controls evaluated included selective catalytic reduction, selective non-catalytic reduction, ultra-low NOx burners, LoTOx, closed-vent vapor recovery systems with carbon or combustion, secondary seals on internal floating roof tanks, and retrofitted domes on external floating roof tanks. Barr worked with refinery staff to confirm that their feasibility arguments for possible future controls were technically sound and their cost estimates were defensible and took into account site-specific nuances. Due to the depth of the analysis, the UDAQ had very few questions regarding the RACT report.
Barr’s support of the client did not end there. Similar to the work conducted for the PM2.5 SIP, Barr helped the refinery address agency proposals, reviewed the draft SIP, and prepared public comments on behalf of the refinery. Given Barr’s technical experience with refinery design and operations and the resulting air quality impacts, Barr was able to prepare public comments that addressed the technical, economic, and legal feasibility of “beyond RACT” controls proposed by the draft ozone SIP.