As you may have heard by now, in anticipation of
Phoenix-Mesa’s redesignation to “serious” ozone nonattainment, expected to occur in the first quarter of 2025, Maricopa County Air Quality Department (MCAQD) has
finalized the changes to Adopted Rules 330, 331, and 338. Finalized on September 25, 2024, these three adopted rules regulate volatile organic compounds (VOCs) and nitrogen oxide (NO
x) emitting facilities. Serious non-attainment areas are required to comply with stricter federal emissions standards for VOCs and NO
x, both of which are precursors to the formation of ground level ozone. Complying with these more stringent regulations may affect users of VOC containing materials, VOC containing cleaning solvents, and semi-conductor manufacturers.
With these three (3) rulemakings being formally adopted, implementation of VOC and NOx emissions limits are fast approaching. So, what exactly do these new regulations mean for your facility?
Changes to Adopted Rules 330 & 331 are Finally Done
The newly adopted changes to Rules 330 and 331 are interrelated. Rule 330 was revised so that all VOC-containing solvents previously regulated by the rule are now regulated under Rule 331. With the update, all operations using VOC-containing solvent must familiarize themselves with the recently adopted changes to Rule 331 to ensure compliance with the regulation. Since the revisions to Rule 331 remain unchanged from the notice of final rulemaking,
Trinity’s July breakdown of Rule 331 revisions remains an excellent resource for facilities to learn how to adapt to the new VOC-containing solvent regulations.
Looming Changes to Thresholds for All VOC and NOX Emitting Facilities
Once the inevitable reclassification of Phoenix-Mesa to “serious” ozone nonattainment under the 2015 8-hour ozone National Ambient Air Quality Standard (NAAQS), the MCAQD VOC and NOx permitting thresholds will subsequently change in the following manner:
- The major source threshold for VOC and NOx emissions will drop from 100 tons potential to emit (PTE) per year to 50 tons per year (tpy);
- The significant emissions increase threshold that triggers a Nonattainment New Source Review (NNSR) will decrease from 40 tons of VOC and/or NOx to 25 tons, aggregated over 5 years; and
- The NNSR emission offset ratio will change from 1.15:1 to 1.2:1.
Existing sources with a Potential to Emit (PTE) between 50 and 100 tpy of VOC and/or NOx emissions will either need to voluntarily reduce these emissions to below 50 tpy or convert their non-Title V permit to a Title V permit within 12 months of the effective date. Existing sources with non-Title V permits must abide by the 50 tpy of VOC and/or NOx PTE emission limit to maintain their non-Title V permits. Once the new NNSR emission offset ratio goes into effect, new operations or modifications that exceed the 50 tpy VOC and/or NOx PTE emission limit must offset the excess emissions at the new ratio of 1.2:1.
Changes to Adopted Rule 338 Seal Your Fate
The newly adopted changes to Rule 338 bring semiconductor manufacturing facilities into the Maricopa County world of regulatory updates. Rule 338 now includes NOx emissions for the first time! Point-of-use (POU) combustion devices are defined as sources of combustion that generate NOx, meaning semiconductor manufacturing facilities must now;
- Either operate POU devices in accordance with the manufacturer’s or manufacturer’s authorized service provider’s written good combustion practices or submit their own good combustion plan to the control officer; and
- Maintain records of any POU device malfunctions that could result in increased NOx emissions and the corrective actions taken to remediate the malfunctions.
Semiconductor manufacturers should start reviewing and/or coordinating with their POU device manufacturers to acquire the necessary good combustion practices document. Semiconductor manufacturers should also begin building the necessary recordkeeping tools for tracking POU device malfunctions related to NOx emissions. If you wish to learn more about writing POU good combustion plans or maintaining POU malfunction records in Maricopa County, please reach to Trinity’s Phoenix office to get in contact with many of our in-house semiconductor subject matter experts.
Conclusion
Regulatory updates are always emerging and it’s important to stay on top of the changes that may affect your facility. The information detailed above provides a high-level overview of the myriads of changes occurring in the MCAQD Adopted Rules due to the approaching ozone nonattainment reclassification. The final adoption of the changes to Rules 330, 331, and 338 and the imminent decrease of the VOC and NO
x permitting thresholds starts a countdown to regulatory compliance for a wide range of facilities! If you would like to
discuss and further understand the implications of these adopted rules to your facility and permit, please email Trinity’s
Phoenix office or call
602.274.2900. We look forward to working with one another to ensure your facility has the most reasonable air permit possible!
