Air Quality Permitting Data Centers in Pennsylvania

The construction and air permitting of data centers continues to be a growing industry worldwide. Each country and state have their own set of requirements as part of the construction and permitting process. Currently, Pennsylvania is a hotbed for data center growth given the recent news regarding 90 billion dollars of investment in data center construction. A critical component of meeting construction schedules and avoiding costly delays in obtaining the air permit required to start project-related construction. Typical aspects of air permitting include preparing an air permit strategy to evaluate construction phases and proposed equipment, collaboration with the regulatory agency, and evaluation of Environmental Justice considerations surrounding the development and establishment of data centers.

ALL4 Air Quality experts review the process of strategizing for and obtaining an air quality permit in Pennsylvania in a data center-specific white paper.

This white paper reviews:

• Emission calculations and the nuances pertinent to data centers,
• Types of air permits available to data center companies and associated timeline,
• Process of identifying the Best Available Technology (BAT),
• Environmental Justice process in Pennsylvania, and,
• Best practices for permitting data centers.

If you have any questions or would like assistance in evaluating how your facility may be subject to air permitting requirements as a data center, please reach out to Merritt McGlynn at mmcglynn@all4inc.com, Sharon Sadler at ssadler@all4inc.com, and Colleen Nagel at cnagel@all4inc.com. ALL4 will continue to track updates to additional guidance or rulemaking regarding the construction and permitting requirements for data centers not only in Pennsylvania, but for other U.S. states as well; check out our website routinely or subscribe for our newsletter to stay up-to-date.

U.S. EPA Extends Compliance Deadlines for Oil and Natural Gas Sector

On July 31, 2025, the United States Environmental Protection Agency (U.S. EPA) issued an interim final rule to extend compliance deadlines established for crude oil and natural gas facilities that are subject to the provisions of 40 Code of Federal Regulations (CFR) Part 60, Subpart OOOOb – Standards for Performance for Crude Oil and Natural Gas Facilities for Which Construction, Modification, or Reconstruction Commenced After December 6, 2022 (Subpart OOOOb). With these changes, the U.S. EPA is amending compliance deadlines and timeframes based on multiple petitions for reconsideration, allowing affected facilities additional time to meet the compliance deadlines under Subpart OOOOb. Likewise, the U.S. EPA has determined that multiple states are still in the early stages of developing state plans under 40 CFR Part 60, Subpart OOOOc – Emissions Guidelines for Greenhouse Gas Emissions from Existing Crude Oil and Natural Gas Facilities (Subpart OOOOc). The U.S. EPA has received many inquiries from state regulatory agencies regarding extensions to the state plan submission requirements under Subpart OOOOc. Therefore, the U.S. EPA has extended the state plan submission deadline for Subpart OOOOc, allowing more time for states to submit their respective plans.

These extensions come on the heels of U.S. EPA’s March 12, 2025 announcement that they would reconsider specific provisions of Subparts OOOOb and OOOOc pertaining to vent gas net heating value (NHV) monitoring for flares and enclosed combustion devices and temporary flaring provisions for associated gas under certain conditions. According to the recently released Spring 2025 Unified Agenda, U.S. EPA plans to issue a proposed reconsideration of the subparts in November 2025 and a final rule in July 2026.

Key Deadline Extensions under Subpart OOOOb

U.S. EPA published 40 CFR Part 60 Subpart OOOOb, which finalized air quality regulations for greenhouse gas (GHG) and volatile organic compound (VOC) emissions from affected sources constructed, modified, or reconstructed after December 6, 2022. Affected sources regulated under Subpart OOOOb include wells, centrifugal compressors, reciprocating compressors, process controllers, storage vessels, process units, sweetening units, pumps, and fugitive emissions components, at a well site, centralized production facility or compressor station. In response to the final Subpart OOOOb, the U.S. EPA received petitions from stakeholders and affected facilities regarding specific provisions within the rule that present challenges to achieving and maintaining compliance within the final time frames. Petitioners raised concerns about supply chain constraints, limited emissions testing resources, and limited laboratory analytical capacity related to the ability to demonstrate compliance with control device testing and monitoring requirements. Petitioners also cited conflicting regulatory language and technical guidance from the U.S. EPA that imposed compliance deadlines perceived to be too stringent by many affected facilities and stakeholders within the sector.

In response to the concerns that were raised in the petitions, the U.S. EPA issued an interim final rule on July 31, 2025, in which multiple Subpart OOOOb compliance deadlines were extended to January 22, 2027, providing affected facilities with an additional 18 months to procure equipment, coordinate performance testing schedules, and to implement monitoring systems into facility operations and project plans. The deadline extensions align with U.S. EPA’s plan to issue a final reconsideration of Subparts OOOOb and OOOOc in July 2026, where certain provisions will be reviewed and likely revised. By specifying deadlines that allow sufficient lead time for affected facilities to comply with applicable Subpart OOOOb provisions, U.S. EPA aims to ensure a structured ‘transition period’ that providing regulatory certainty across the sector During the reconsideration process. The table below outlines several important compliance requirements promulgated within Subpart OOOOb that have been granted deadline extensions within the issuance of the interim final rule.

¹ The provisions of the Super Emitter program under 40 CFR Part 60, Subparts OOOO and OOOOa were also suspended until January 22, 2027.

Extensions to State Plan Requirements under Subpart OOOOc

On March 8, 2024, emissions guidelines for existing sources in the crude oil and natural gas source category were finalized under 40 CFR Part 60, Subpart OOOOc. The final rule includes a deadline of March 9, 2026 for state regulatory agencies to submit their respective state plans for the implementation of Subpart OOOOc. Since the rule was finalized, the U.S. EPA has received many inquiries from state regulatory agencies regarding extension of the deadline and the subsequent consequences of late state plan submissions. These inquiries ultimately prompted the U.S. EPA to reassess the submission deadline for state plans, allowing states more time to develop their plans in accordance with the final emissions guidelines. The July 31, 2025 interim final rule extended the State’s deadline to January 22, 2027. This deadline extension also grants the U.S. EPA sufficient time to conduct their reconsideration of Subpart OOOOc prior to a submittal deadline.

What is Next?

The interim final rule became effective immediately (without formal notice and comment) upon publication, citing the ‘good cause’ exemption under the Administrative Procedure Act. The interim final rule provides targeted extensions to facilitate realistic and achievable compliance with GHG and VOC control requirements under Subparts OOOOb and OOOOc. On August 15, 2025, the U.S. EPA extended the deadline for the public to submit comments on the interim final rule through October 3, 2025. Until then, the U.S. EPA is accepting public comments on all aspects of the interim final rule under Docket ID. No. EPA-HQ-OAR-2025-0162. While the extended compliance deadlines offer relief, facilities can take advantage of the extensions to develop compliance strategies and plans, including procurement of long-lead equipment and services, to comply with the rule. The interim final rule was issued in the shadow of U.S EPA’s March 12, 2025 announcement of their planned reconsideration of specific provisions under Subparts OOOOb and OOOOc. U.S EPA is also considering certain provisions under Subparts OOOOb and OOOOc related to NHV monitoring at flares and enclosed combustion devices and flaring of associated gas. Until a reconsideration rule is proposed, affected facilities should remain engaged in the rulemaking process and maintain communication with their respective legal, technical, and environmental professionals.

Need help understanding how this affects you?

ALL4’s oil and natural gas experts are well-versed in all aspects of evaluating applicability to the federal regulations, developing plans for compliance, and implementing practical strategies aligned with the U.S. EPA’s evolving regulatory landscape. If you are wondering how the U.S. EPA’s final rule will affect your facility or ongoing projects directly, please reach out to your ALL4 project manager or contact Daniel Hickey at dhickey@all4inc.com.

Who is SCAQMD and Why Industrial Facilities Should Care

Every industrial facility in the Greater Los Angeles Area is touched by South Coast Air Quality Management District (SCAQMD or District) rules, and with dozens of regulations and permitting requirements, it can be difficult to see the full picture of what the District actually does. SCAQMD has jurisdiction over stationary sources of air pollutants in Orange County and the urban areas of Los Angeles, Riverside, and San Bernadino Counties, commonly referred to as the South Coast Air Basin. The South Coast Air Basin is home to more than 17¹ million people, representing more than 40% of California’s populations and more total residents than every U.S. State² except for Texas, Florida, and New York. Facilities located in SCAQMD’s jurisdiction are subject to some of the most stringent air quality regulations in the United States.

This article is the first in a series designed to demystify SCAQMD rules, policies, and programs. Our goal is to explain what the District does, why it matters for industrial facilities, and how companies can navigate their requirements without unnecessary surprises or delays.

Authority and Origins

In the late 1940s, the California State Legislature passed legislation that allowed counties to create unified air pollution control districts. Los Angeles County established the nation’s first air quality district and required major industry to obtain permits for emissions of air pollutants. Orange, Riverside, and San Bernadino Counties established their own districts in the 1950s, and by the late 1970s, the four county agencies were consolidated to form SCAQMD by the Lewis Presley Air Quality Management Act (Lewis Presley Act). The Lewis Presley Act granted SCAQMD the authority to:

• Regulate stationary sources of air pollution in the South Coast Air Basin.
• Adopt and enforce rules stricter than federal standards if needed.
• Prepare air quality management plans to demonstrate compliance with both state and federal clean air requirements.
• Issue permits and enforce conditions on industrial facilities.

While the Lewis Presley Act grants SCAQMD its local authority, the work of the District is driven by state and federal legislation. The federal Clean Air Act requires the U.S. Environmental Protection Agency (U.S. EPA) to set National Ambient Air Quality Standards (NAAQS) that every region must meet. The California Clean Air Act requires that each air district adopt the most stringent feasible controls to achieve the California Ambient Air Quality Standards (CAAQS). The California Air Resources Board (CARB) supports this process by compiling and submitting the State Implementation Plan (SIP), setting mobile source standards, and reviewing district plans. This framework requires SCAQMD to adopt strict rules for stationary sources so that the South Coast Air Basin can make progress toward meeting state and federal air quality goals.

Agency Structure and Governance

To understand how SCAQMD makes and enforces its rules, it helps to first look at how the District is structured and governed.

Governing Board

SCAQMD is directed by a 13-member Governing Board who meet monthly to establish policies, and approve, reject, or amend rules. The Governing Board is comprised of 10 elected officials from communities located in the South Coast Air Basin and three political appointees.

Hearing Board

The SCAQMD Hearing Board is a quasi-judicial body authorized under the California Health and Safety Code to provide relief from SCAQMD regulations under certain circumstances.

District Operations

SCAQMD is organized into functional teams responsible for day-to-day operations of the District.

Executive Office

The Executive Office is appointed by the Governing Board and is responsible for management and the development and implementation of strategies to attain the NAAQS.

Legal

The Legal Department advises the Governing Board and District Staff on all aspects of operations, enforcement, and litigation. The Legal Department represents the District in proceeding before the Hearing Board.

Monitoring and Analysis

The Monitoring and Analysis Division (MAD) is responsible for maintaining SCAQMD’s air quality monitoring network and managing the District’s source testing program.

Technology Advancement

The Technology Advancement Office (TAO) partners with private industry and local, state, and federal agencies to co-sponsor projects that develop and demonstrate low- and zero-emissions technologies. TAO also manages incentive programs that help local fleets adopt cleaner equipment.

Engineering and Permitting

The Engineering and Permitting (E&P) group is responsible for administering SCAQMD’s permitting program, including the REgional CLean Air Incentives Market (RECLAIM) permits, Permits to Construct and Permits to Operate equipment for non-RECLAIM facilities, and the Federal Title V Operating Permit Program.

Compliance and Enforcement

The Compliance & Enforcement (C&E) group is responsible for verifying compliance with permit conditions and air quality regulations through inspections and record reviews. The C&E group has the authority to issue Notices to Comply (NTC) and Notices of Violation (NOV) which are then adjudicated by the Legal Department. The C&E group is also responsible for responding to public complaints.

Planning, Rule Development, and Implementation

The Office of Planning, Rule Development, and Implementation manages SCAQMD’s air quality planning and develops new rules or amendments to existing ones. Key programs include emissions reporting, air quality modeling, health risk assessments, California Environmental Quality Act (CEQA) review, socioeconomic analysis, and air quality management plans.

Legislative, Public Affairs and Media

The Office of Legislative, Public Affairs and  Media handles community outreach, small business assistance, government relations, and media communications. Its mission is to promote public participation and understanding of SCQMD’s rules, plans, and policies.

Finance

The Finance Office administers all financial functions of the District, including managing permit fees, annual emissions fees, and other payments required from regulated facilities.

Information Management

The Information Management Office handles SCAQMD’s technology systems, including public records requests, records management, and online tools such as the FIND system that provide access to permits, compliance, and emissions data.

So What Does All This Mean?

You may be thinking, this all sounds important, but why should I care?

Compliance is not optional

SCAQMD issues hundreds of permits each year and conducts countless inspections. The District has the legal authority to penalize any industrial facility for violations of their rules. Noncompliance can trigger civil penalties of up to $75,000 per day³. In certain cases, SCAQMD may also refer violations to the local District Attorney for criminal prosecution.

Compliance and permitting records are public

Permits and compliance records are available to your neighborhood, your business partners, and the general public through online databases and public records requests. Staying ahead of compliance issues not only limits operational and financial risk but also protects your reputation and brand.

Looking at the long term

SCAQMD consistently reviews and updates its rules to meet state and federal air quality standards. Identifying these changes early and participating in the rule development and comment process can help companies avoid being caught off guard, incorporate compliance into capital planning, and position sites to take advantage of incentive programs where available.

Closing Thoughts

The South Coast Air Basin faces some of the United States’ most significant air quality challenges. SCAQMD has been tasked with meeting those challenges through one of the most complex regulatory and administrative frameworks in the country. Navigating this regulatory regime not only requires an understanding of the District’s rules, but its planning, enforcement, and incentive frameworks. For industrial facilities in the South Coast Air Basin, compliance is not just about meeting today’s requirements, it is about anticipating tomorrow’s changes, protecting your reputation, and positioning for long-term success.

Stay tuned for future 4 the Record articles where we will dive deeper into specific SCAQMD rules and programs. If you are interested in learning how to navigate SCAQMD’s rules and structure, please reach out to Michael McHale at 610.422.1131 or mmchale@all4inc.com.

¹ https://www.aqmd.gov/nav/about

² Population data as of the 2020 U.S. Federal Census (https://www.census.gov/data/tables/time-series/demo/popest/2020s-state-total.html)

³Penalty ranges established by the California Health & Safety Code §42402.3. Penalties range from $5,000 per day for general violations up to $75,000 per day for knowing and willful violations, adjusted annually for inflation. Willful and intentional release of air pollutants that causes injury to any person can result in greater penalties.

U.S. EPA Proposes Revised Standards for Open Burning/Open Detonation of Waste Explosives

On March 20, 2024, the U.S. Environmental Protection Agency (EPA) proposed amendments to the standards governing the open burning and open detonation (OB/OD) of waste explosives. While OB/OD of hazardous waste was initially prohibited in 1980, an exception was made for waste that “cannot safely be disposed of through other modes of treatment” (40 CFR §265.382). However, in 2019, reports discussing new, safer disposal technologies prompted the U.S. EPA to issue updated standards in a June 2022 memorandum. They have now proposed further clarifications and revisions.

Key Revisions

The proposed changes clarify and expand upon several aspects of the Resource Conservation and Recovery Act (RCRA) requirements for OB/OD operations. The U.S. EPA’s goal of these proposed amendments is to improve implementation of requirements for how facilities must evaluate and use alternative technologies determined to be safe and available for treating waste explosives in lieu of OB/OD:

• Alternative Technology Evaluations: Revised criteria, timing, and required documentation
• Applicability: Including a de minimis exemption and provisions for emergency response scenarios
• Technical Standards: Updated monitoring and operational standards for OB/OD units
• Prohibited Wastes: Specific waste types are no longer eligible for OB/OD treatment
• Mobile Treatment Units (MTUs): New permitting framework

What Does This Mean?

The U. S. EPA continues to emphasize that OB/OD should be a last resort. Where safe and available alternatives exist, they must be prioritized. However, the agency acknowledges that OB/OD may still be necessary in certain situations and has proposed targeted exceptions.

Alternative Technology Evaluations
Expanding upon the 2022 memo, the proposed U.S. EPA amendments clarify guidelines regarding timing, definitions of “safe” and “available,” and specific content requirements. Facilities must demonstrate why alternative technologies are not viable in order to qualify for OB/OD permitting. If an alternative technology evaluation finds that alternative technology is available, the facility may be required to phase out their OB/OD activities through off-site waste disposal or installation of alternative technology. In addition, a facility-specific compliance schedule may be included in their permit by the responsible regulatory agency. Installation of new disposal devices require RCRA permit modifications. New minimum technical standards for OB/OD operations will also be incorporated into existing permits.

De Minimis Exemption
Facilities generating 15,000 pounds or less of net explosive weight (NEW) annually may qualify for a de minimis exemption, provided they can meet demonstration and documentation requirements. This exemption allows continued OB/OD operations at lower-volume facilities.

Emergency Treatment Provisions
For emergency scenarios requiring expedient responses to immediate threats exempt from permitting, OB/OD is allowed, but post-incident reporting is required. For emergencies under a permit, facilities must first assess whether safe alternative treatments are available within a reasonable timeframe. This assessment must be documented and submitted to the proper regulatory agency within five days of beginning treatment.

Prohibited Wastes
The U.S. EPA proposes to prohibit OB/OD treatment of certain waste types that pose unacceptable risks or are not effectively treated by OB/OD. These wastes include:

• Mixed wastes containing more than trace amounts of depleted uranium (DU)
• White and red phosphorus
• PAX-21 (Picatinny Arsenal Explosive 21)
• Polychlorinated biphenyls (PCBs)
• Improved Conventional Munitions (ICMs)/cluster munitions
• Chemical weapons as defined by the U.S. EPA

These prohibitions do not apply during emergencies that are exempt from RCRA permitting.

Mobile Treatment Units
A new permitting framework for MTUs has been proposed. MTUs may provide faster, more cost-effective treatment for small waste volumes and reduce the need to transport hazardous materials off-site.

What You Can Do

Facilities that employ OB/OD can prepare for the implementation of these proposed changes by starting alternative technology analyses and strategizing ways to comply with the proposed amendments.

How ALL4 Can Help?

As organizations prepare for these regulatory changes, ALL4 is here to help navigate the revised OB/OD permitting requirements, assess eligibility for exemptions, evaluate alternative waste treatment options, and guide you through any required regulatory processes. Our goal is to support your compliance efforts while prioritizing environmental and occupational safety. To learn more, contact the ALL4 team through Meredith Pedraza at mpedraza@all4inc.com.

Updates on the California Air Resources Board SB 253/261 Climate-Related Legislation

On Thursday, August 21, 2025, the California Air Resources Board (CARB) hosted a public workshop on Senate Bills (SB) 253 and 261, also known by CARB as the 200’s. The workshop provided important clarification on California’s corporate climate disclosure laws, also known as the Climate Accountability Package. For more information about the laws’ applicability, timeline, and enforcement, refer to ALL4’s previous blog on this topic. CARB is currently developing implementation regulations for these laws and is seeking public feedback. The update below summarizes CARB’s announcements and outlines the next steps to help companies doing business in California prepare for compliance.

Key Takeaways from the August 21^st Workshop:

• Applicability of the Climate Accountability Package
  • SB 253 applies to entities (public or private) with $1 billion+ in annual revenue doing business in California.
  • SB 261 applies to entities with $500 million+ in annual revenue doing business in California.
  • “Doing business in California,” and “revenue,” remain under review, with CARB continuing to request stakeholder input.
• SB 253 – The Climate Corporate Data Accountability Act
  • CARB has proposed a submittal deadline of June 30, 2026 for reporting Scope 1 and Scope 2 greenhouse gas (GHG) emissions from Fiscal Year 2025 data, with limited assurance.
  • The draft report format template is to be released for public comment in September 2025.
  • The annual CARB fee for SB 253 is proposed to be set at $3,106 per year, per reporting entity.
  • Scope 3 GHG emissions reporting timelines will be established by CARB through a future rulemaking.
  • Scope 1, Scope 2, and Scope 3 GHG emissions reporting may be consolidated at the parent company level.
• SB 261 – Climate-Related Financial Risk Disclosure
  • The reporting deadline for the climate-related risk assessment disclosure remains January 1, 2026, for subject entities.
  • SB 261 does not specify Calendar Year or Fiscal Year data. CARB states that covered entities should use the most recent or best available data for their first report.
  • Reporting entities must publish disclosures on their websites and submit them to CARB’s public docket, which will open on December 1, 2025. On that date, CARB will begin posting a docket where entities must provide the location of their public link to their initial climate-related financial risk report under this program. The docket will remain open until July 1, 2026, serving as a centralized, transparent resource for the public to access all climate-related financial risk reports.
  • The annual CARB fee for SB 261 is proposed to be set at $1,403 per year, per reporting entity.
  • Scenario analysis will not be required in Year 1 reporting; qualitative analysis will be sufficient in later years, though quantitative analysis is encouraged.
  • GHG emissions reporting will not be required in Year 1.
• Fee Structure and Applicability
  • The CARB fees for SB 253 and SB 261 are cumulative for entities subject to both laws.
  • The CARB fees are to be paid annually per reporting entity (even though SB 261 reporting is biennial).
  • The CARB fees will be adjusted for inflation as necessary.
• Assurance Standards
  • CARB is working to finalize the assurance requirements in the rulemaking process.
  • The assurance standards under consideration include International Standard on Sustainability Assurance (ISSA) 5000, AccountAbility AA1000, the International Organization for Standardization (ISO) 14060 family of standards, and Association of International Certified Professional Accountants (AICPA).
  • Stakeholder feedback on assurance standards is actively being solicited by CARB.

Enforcement and Compliance

• CARB will exercise enforcement discretion in 2026, recognizing the challenges of early implementation. Entities that demonstrate good-faith efforts to comply will not face penalties for incomplete reporting.
• In subsequent years, CARB will provide additional enforcement guidance as regulations mature.

Next Steps for Businesses

1. If you need a refresher on CARB’s Climate Accountability Package, go back and review ALL4’s blog from earlier this year for clarification and guidance.
2. Companies should determine whether either of California’s climate laws apply to them.
3. Companies subject to SB 253 should begin collecting Scope 1 and Scope 2 GHG emissions data for Fiscal Year 2025 now to meet the June 30, 2026 reporting deadline.
4. Companies subject to SB 261 should prepare their first climate-related financial risk report by January 1, 2026 focusing on the most recent or best available data for their first report.
5. Entities should anticipate annual CARB fees ($3,106 per year for SB 253; $1,403 per year for SB 261), with adjustments for inflation.
6. Companies are encouraged to provide feedback on definitions, assurance standards, and draft report formats utilizing CARB’s public comment solicitation board.

How ALL4 Can Help

ALL4 is closely monitoring CARB’s implementation of SB 253 and SB 261, as well as developments in GHG emissions disclosure, climate-risk reporting, and enforcement guidance, to help businesses prepare for California’s climate-accountability requirements. Our team of sustainability experts can support your company by developing GHG emissions inventories and conducting climate-related risk assessments to ensure accurate and compliant disclosure.

For questions about these legislations, please contact James Giannantonio, Managing Consultant (jgiannantonio@all4inc.com) or Daryl Whitt, Technical Director (dwhitt@all4inc.com).