The Maricopa County Air Quality Department (MCAQD) is continuing the rulemaking efforts to issue and amend local rules for the purpose of meeting Reasonably Available Control Technology (RACT) stringency levels due to Maricopa County ozone nonattainment status. Maricopa County is located within the Phoenix-Mesa nonattainment area, which was redesignated by EPA from “marginal” to “moderate” nonattainment classification for the 2015 8-hour ozone National Ambient Air Quality Standard (NAAQS) following a final rule in October 2022.
On February 5, 2024, the MCAQD issued two (2) briefing notifications addressed to the County Manager to propose amending the following regulations:
- Ordinance P-21 (Vehicle Idling Restriction): MCAQD seeks to add a provision requiring all persons subject to basic or comprehensive dust control training under Rule 310 (Fugitive Dust from Dust-Generating Operations) and/or Rule 316 (Nonmetallic Mineral Processing) to also complete idle reduction training. Many existing facilities in Maricopa County contain Rule 310 and 316 permit conditions that will be subject to change following final action.
- Rule 335 (Architectural Coatings): MCAQD seeks to lower many of the volatile organic compounds (VOC) content limits and add additional coating limitations to reflect standards in the Ozone Transport Commission (OTC) Model Rule “Architectural and Industrial Maintenance (AIM) Coatings.”
If you would like to discuss these proposed regulatory updates and how they may impact your facility, please email Camille Ponce in Trinity’s Phoenix office or call 517.285.4118. Additional details of the proposed rulemaking are noted below.
Additional details of the proposed rulemaking are noted below.
Background
The proposed updates to Ordinance P-21 and Rule 335 are part of the County’s effort to demonstrate compliance with ozone nonattainment Reasonably Available Control Technology (RACT) requirements imposed by the Clean Air Act (CAA) for stationary sources. Ozone is regulated by its precursors, VOCs, and nitrogen oxides (NOx). RACT constitutes the “floor-level” of control applicable to existing categorical sources covered by an EPA Control Techniques Guideline (CTG) document as well as all existing major sources of VOCs and NOx.
Prior to the ozone nonattainment redesignation, MCAQD Rules were considered by EPA to meet ozone nonattainment RACT for the “marginal” classification. However, following the redesignation to a more severe classification of nonattainment for the 2015 NAAQS, MCAQD reviewed all rules associated with a CTG source category and determined that these rules needed to be revised to meet RACT. This includes EPA categorical requirements and any other design, equipment, work practices, or operational standards that MCAQD determines are stringent enough to attain the standard by the regulatory deadline, which is August 3, 2024, for the Phoenix-Mesa nonattainment area, including Maricopa County.
Ordinance P-21 (Vehicle Idling Restriction)
This ordinance, last revised on June 26, 2002, is applicable to vehicle idling within Maricopa County. The ordinance currently restricts devices meeting the following criteria (typically heavy-duty diesel vehicles) from idling for longer than five (5) consecutive minutes:
- designed with a gross vehicle weight rating of more than 14,000 pounds; and
- required under Arizona law (Arizona Revised Statute [ARS] Title 28 Chapters 7 and 9) to be registered; and
- designed to operate on public highways; and
- powered by a diesel engine.
In addition to the changes described below, MCAQD is considering other revisions to improve and clarify the ordinance.
Key changes that may affect your operations:
- Upon revised rule adoption, sources which are subject to MCAQD Rule 310 (Fugitive Dust from Dust-Generating Operations) and/or Rule 316 (Nonmetallic Mineral Processing) will be required to have all persons currently subject to basic or comprehensive dust control training to also undergo idle reduction training.
- Upon revised rule adoption, new permit conditions citing Rules 310 and 316 will likely require the additional training for affected sources.
Rule 335 (Architectural Coatings)
Rule 335, last revised on September 25, 2013, applies to VOC emissions from the use of architectural coatings. The MCAQD proposed revisions to Rule 335 for the purpose of achieving potential VOC emissions reductions towards attainment of the ozone NAAQS.
In addition to the changes described below, MCAQD plans to update and restructure the rule for consistency with other existing rules.
Key changes that may affect your operations:
- Lowering of the VOC limits contained in the Rule.
- Addition of new coating limitations to reflect standards in the Ozone Transport Commission (OTC) Model Rule “Architectural and Industrial Maintenance (AIM) Coatings.”
- Upon revised rule adoption, the language in permit conditions for affected sources would be updated for consistency with the revised Rule.
Next Steps
It is anticipated that initial drafts for the revised rules will be issued in Spring 2024. Initial stakeholder workshops followed by a public comment period are also anticipated to occur in Spring 2024.
