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December 14, 2018  |  Written by Alyson E. Ackerman

New Technological Standards for Internal Combustion Engines Up for Review by the Sacramento Metropolitan Air Quality Management District – Comment Period Open

Minor source stand-by gas-fueled spark-ignited internal combustion engines with less than 500 brake horse power (BHP), as well as those with greater or equal to 500 BHP (collectively, “covered engines”) may soon have new Best Available Control Technology (BACT) standards.  The Sacramento Metropolitan Air Quality Management District (SMAQMD) recently drafted and noticed two BACT determinations for the covered engines, which are generally emergency generators, such as those used by grocery stores to maintain refrigeration or tall buildings to keep elevators running during power outages.  The BACT determinations (#208 and #209, respectively), if approved, will replace the current BACT determinations for the covered engines.

BACT standards are one of the primary methods used by regulatory agencies to regulate air emissions.  These standards set the required minimum emissions rates and/or required control technology for the day-to-day operation of emissions-generating equipment of all kinds, across all industries.  In the Sacramento area, SMAQMD sets the BACT standards every two years and, typically, adopts the newly available technologies.  This trend results in gradually more stringent standards.  Importantly, BACT standards can and do differ from local air quality management district to local air quality management district.  Currently, there are 35 local air districts in California.

The BACT Determinations for the covered engines address a range of pollutants:  VOC; NOx; SOx; PM10; PM2.5; and CO.  However, when compared to their respective, previous BACT standards, the new determinations differ only in regard to VOC emissions:

Regulated entities and members of the public are encouraged to submit comments on these draft BACT determinations.  An effective comment should include the BACT reference number (#208 or #209) and clearly state the commenter’s specific concerns with the applicable determination.  Such concerns may include the detrimental impact the new standards may have on the regulated entity, or perceived oversights in the determination process.  SMAQMD is required to provide written response to written comments timely submitted.In reaching these new BACT standards, the SMAQMD considered other BACT determinations for equivalently sized and alternatively-fueled engines issued by other local air districts.  Specifically, SMAQMD considered the BACT determinations imposed by the following local air districts:  the South Coast Air Quality Management District, Bay Area Air Quality Management District, and San Joaquin Valley Unified Air Pollution Control District.  SMAQMD also considered the U.S. Environmental Protection Agency BACT determinations.  Furthermore, SMAQMD considered whether the suggested standards were technologically feasible and cost-effective for the regulated community.  Notably, SMAQMD rejected the use of an add-on Selective Catalytic Reduction (SCR) system to reduce NOx emissions because of operational constraints, e.g., temperature and operational duration, as well as cost-effectiveness.  Indeed, the technology would cost approximately $181,576/ton NOx removed for a 499 BHP engine, and approximately $152,555/ton NOx removed for a 1,000 BHP engine.In reaching these new BACT standards, the SMAQMD considered other BACT determinations for equivalently sized and alternatively-fueled engines issued by other local air districts.  Specifically, SMAQMD considered the BACT determinations imposed by the following local air districts:  the South Coast Air Quality Management District, Bay Area Air Quality Management District, and San Joaquin Valley Unified Air Pollution Control District.  SMAQMD also considered the U.S. Environmental Protection Agency BACT determinations.  Furthermore, SMAQMD considered whether the suggested standards were technologically feasible and cost-effective for the regulated community.  Notably, SMAQMD rejected the use of an add-on Selective Catalytic Reduction (SCR) system to reduce NOx emissions because of operational constraints, e.g., temperature and operational duration, as well as cost-effectiveness.  Indeed, the technology would cost approximately $181,576/ton NOx removed for a 499 BHP engine, and approximately $152,555/ton NOx removed for a 1,000 BHP engine.

Comments on BACT Determinations #208 and #209 are due by December 17, 2018. They may be submitted by email [addressed to bactdeterminations@airquality.org] or by mail, to:

777 12th Street, 13th Floor
Sacramento, CA 95814
ATTN: Jorge DeGuzman

A copy of the Notice of Determination for #208 and #209, including specific standards for each covered pollutant, is here.

The SMAQMD’s website with general BACT information is here.

For additional information on the new BACT determinations, how to effectively submit public comments, and other air-related issues, please contact Alyson E. Ackerman at aackerman@somachlaw.com or 916-469-3843, or Michael E. Vergara at mvergara@somachlaw.com or 916-469-3824.

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