DEPARTMENT OF NATURAL RESOURCES AND ENVIRONMENTAL CONTROL

Division of Air Quality

FINAL

Secretary's Order No.: 2025-A-0003

RE: Approving Final Regulations to Amend 7 DE Admin. Code 1109 -

Emissions of Sulfur Compounds from Industrial Operations

Date of Issuance: January 7, 2025

Effective Date of the Amendment: February 11, 2025

1109 Emissions of Sulfur Compounds From Industrial Operations

Under the authority vested in the Secretary of the Department of Natural Resources and Environmental Control ("Department" or "DNREC"), pursuant to 7 Del.C. §§6006 and 6010, and all other relevant statutory authority, the following findings of fact based on the record, reasons and conclusions are entered as an Order of the Secretary in the above-referenced promulgation.

Background, Procedural History and Findings of Fact

This Order relates to the proposed amendments ("Amendments") to 7 DE Admin. Code 1109 - Emissions of Sulfur Compounds from Industrial Operations ("Regulation"). The Department is proposing amendments to address the regulation of particulate emissions during startup, shutdown, and malfunction ("SSM") of industrial process equipment. These Amendments are necessary to ensure compliance with the U.S. Environmental Protection Agency's (EPA) 2015 Startup, Shutdown, and Malfunction State Implementation Plan Call ("2015 SSM SIP CALL").

Pursuant to the Clean Air Act ("CAA") the Department established 7 DE Admin. Code 1109 to establish air emission limits for sulfur dioxide (SO2) in alignment with the National Ambient Air Quality Standards ("NAAQS") for industrial process operations. This regulation sets specific SO2 emission limits for sulfuric acid manufacturing and sulfur recovery operations.

Delaware currently has only one sulfuric acid manufacturing facility, the Veolia Red Lion Plant, and one sulfur recovery operations, the Delaware City Refinery. In alignment with NAAQS, the Regulation limits SO2 emissions from sulfuric acid manufacturing operations to 0.5 lb/ ton for acid mist and sets a maximum SO2 emission rate of 2,000 parts per million (ppm) for sulfur recovery operations.

Further, the regulation addresses emission limits during startup, shutdown, and malfunction ("SSM") periods. For the purposes of this regulation, "startup" is defined as the initiation of a source's operation, "shutdown" as the cessation of operation, and a "malfunction" as a sudden and unavoidable breakdown of process or control equipment. During SSM periods, equipment does not operate at optimal efficiency, resulting in excess emissions. These emissions can negatively impact public health, contribute to smog formation, and adversely affect downwind communities.

The Department established emission limits for SSM events that require facilities that operate continuously or in an extended steady state when SSM occurs, to obtain an operating permit pursuant to the provisions of 2.0 of 7 DE Admin. Code 1102, to limit emissions during these events. These permits are subject to environmental review and public scrutiny and must demonstrate that they will not violate NAAQS.

Additionally, the Department's regulations are also part of Delaware's State Implementation Plan ("SIP") because they implement, maintain, and enforce the NAAQS. A SIP is a state-created, federally enforceable plan that outlines how the state will fulfill CAA requirements to enhance air quality. It includes regulations and supporting documentation that demonstrate the state's efforts to safeguard public health and the environment.

On June 30, 2011, the Sierra Club petitioned the EPA to address how excess emissions during SSM events were being handled in SIPs that had been approved by the EPA. In response, on June 12, 2015, the EPA issued a final rule known as the 2015 SSM SIP Call [80 FR 33840]. Under Section 110(k)(5) of the CAA, the EPA has the authority to issue a 'SIP Call' to states, requiring them to correct state plans that fail to meet federal standards. The 2015 SSM SIP Call included 36 state SIPs, including Delaware's SIP for 7 DE Admin. Code 1109. The EPA found Subsection 1.4 of Delaware's regulation to be deficient because it potentially allowed exemptions from the emission limits established in Section 2.0 and 3.0, during SSM events. The 2015 SSM SIP Call mandated that state's establish plans that require industrial facilities to follow air pollution rules during periods of SSM; specifically, how these emissions are treated in SIPs, with corrections due by November 22, 2016.

On November 22, 2016, the Department revised its regulations governing particulate emissions from industrial process equipment (7 DE Admin. Code 1109) and submitted a SIP revision to the EPA, in response to the 2015 SSM SIP Call. The SIP revisions included the removal of the problematic exemption stated in subsection 1.4.

As part of the response to the 2015 SIP CALL, the Department also adopted a separate "state-only" version of 7 DE Admin. Code 1109. The "state only" version as cited in the Delaware Registrar of Regulations, maintained the language that was removed in the SIP revisions (subsection 1.4). Delaware believed the conditions set forth in the "state only" version was necessary to administer good air quality management.

On October 23, 2023, the EPA issued a final rule (88 FR 72688), disapproving Delaware's SIP revision submission and determined that the revisions failed to fully resolve the deficiencies identified in the 2015 SSM SIP Call.

In response to the EPA's disapproval, the Department is proposing the amendments, herein, to rectify the deficiencies cited in the 2015 SSM SIP Call. The proposed amendments address Section 1.0 ("General Provisions") of 7 DE Admin. Code 1109. To ensure compliance with EPA standards, the Department proposes to strike the regulatory language in subsection 1.4, in its entirety. The Amendment aims to remove language that could potentially allow exemptions in SSM events and hold industrial operations to the emission limits in Regulation 1109, apply at all times.

The Department has conducted a review of the impact of the proposed Regulation and found that more stringent federal regulations, are applicable to the sources covered by this Regulation. The EPA regulation at 40 CFR Part 60, Subpart H (Section 60.83(a)(1)), Standards of Performance for Sulfuric Acid Plants, establishes an acid mist limit of 0.15 lb/ton. Furthermore, EPA's regulation at 40 CFR Part 60, Subpart J (Section 60.104), Standards of Performance for Petroleum Refineries, sets the least stringent SO2 emission limit at 300 ppm.

In conclusion, the applicable federal regulations impose more stringent emission limits than those proposed under Delaware's Regulation for the two affected facilities. Additionally, both facilities currently comply with the SSM emission limits, ensuring that no new controls or additional resources will be required for compliance with the proposed amendments.

The Department published its proposed amendments in the August 1, 2024, Delaware Register of Regulations. The virtual public hearing regarding this matter was held on August 27, 2024. There were seven (7) members of the public in attendance at the Department's virtual public hearing. Pursuant to 29 Del.C. §10118(a), the Hearing Record ("Record") remained open for receipt of written comment for 15 days following the public hearing. The Record formally closed for comment in this matter on September 11, 2024, with no comment received by the Department.

Thereafter, Hearing Officer Theresa Smith prepared her report dated September 12, 2024 ("Report"), which expressly incorporated into the Record the proposed Amendment, attached thereto as Appendix "A." Mrs. Smith's Report set forth the procedural history, summarized and established the record of information ("Record") relied on in the Report and provided findings of fact, reasons, and conclusions that recommend the approval of the proposed amendments pending before the Department.

The Department has the statutory basis and legal authority to act with regard to the formal promulgation of these proposed amendments, pursuant to 7 Del.C. §§ 6001(c) & 6010. All notification and noticing requirements concerning this matter were met by the Department and proper notice of the hearing was provided as required by law.

Reasons and Conclusions

Currently pending before the Department are the proposed regulatory amendments to 7 DE Admin. Code 1109 - Emissions of Sulfur Compounds from Industrial Operations. Based on the record developed by the Department's staff in the Division of Air Quality, and established by the Hearing Officer's Report, I find that the proposed regulatory amendments are well-supported and will enable the Department to ensure compliance with the EPA 2015 SSM SIP Call by removing Section 1.4, in its entirety. I also find that under Section 110(k)(5) of the CAA, the EPA will review the proposed amendments and if approved, these Amendments will become part of Delaware's SIP for 7 DE Admin. Code 1109 and will be enforceable under federal law (40 CFR Part 52, Subpart I - Delaware). Lastly, I find that the proposed amendments comply with all applicable federal and state laws and regulations. Further, the proposed amendments as published in the August 1, 2024, Delaware Register of Regulations, are reflective of the Department's authority under 7 Del.C. §§ 6001(c) & 6010, to ensure continued protection of public health and the environment by regulating emissions and reducing air pollution and air contaminants.

The following reasons and conclusions are hereby entered:

1. The Department has the statutory basis and legal authority to adopt and enforce these proposed regulatory amendments pursuant to 7 Del.C. §§ 6001(c) & 6010;

2. The Department has jurisdiction under its statutory authority, pursuant to 7 Del.C. Chapter 60, to issue an Order adopting these proposed amendments as final;

3. The Department provided adequate public notice of the proposed amendments and all proceedings in a manner required by the law and regulations, and provided the public with an adequate opportunity to comment on the proposed amendments, including at the time of the virtual public hearing held on August 27, 2024, and during the 15 days subsequent to the hearing (through September 11, 2024), before making any final decision;

4. Promulgation of the proposed amendments to 7 DE Admin. Code 1109 - Emissions of Sulfur Compounds from Industrial Operations, will enable the Department to ensure compliance with the EPA 2015 SSM SIP Call by removing Section 1.4, in its entirety;

5. The Department has reviewed the proposed amendments in light of the Regulatory Flexibility Act, consistent with 29 Del.C. §104, and believes the same to be lawful, feasible and desirable, that it will not establish reporting requirements or substantive additional costs for individuals or small businesses, and that the recommendations as proposed should be applicable to all Delaware individuals or small businesses equally;

6. The Department has reviewed this proposed regulatory promulgation in the light of 7 Del.C. §10003 and 29 Del.C. §10118(b)(3), and has determined that any impact of this regulation on the achievement of the State of Delaware's greenhouse gas emissions reduction targets will be de minimis;

7. The Department's Hearing Officer's Report, including its established record and the recommended proposed amendments as set forth in Appendix "A," are hereby adopted to provide additional reasons and findings for this Order;

8. The Department's proposed regulatory amendments, as published in the August 1, 2024, Delaware Register of Regulations, as set forth in Appendix "A" hereto, are adequately supported, are not arbitrary or capricious, and are consistent with the applicable laws and regulations. Consequently, they are approved as final regulatory amendments, which shall go into effect ten days after their publication in the next available issue of the Delaware Register of Regulations;

9. The Department has an adequate Record of its decision, and no further public hearing is appropriate or necessary;

10. The Department shall submit this Order approving the proposed amendments as final regulations to the Delaware Register of Regulations for publication in its next available issue, and provide such other notice as the law and regulation require, and the Department determines is appropriate; and

11. The Department shall serve and publish its Order on its internet site.

Shawn M. Garvin

Secretary

1109 Emissions of Sulfur Compounds From Industrial Operations

05/09/1985

1.1 The emission of sulfur dioxide from process operations shall be controlled to a limit that shall meet the ambient air quality requirements.

1.2 For all tables in this regulation, unless otherwise indicated, the emission limitation for a production rate between any two consecutive production rates shall be determined by linear interpolation.

1.3 For all tables in this regulation, unless otherwise indicated, the emission limitation for a production rate above the maximum production rate or below the minimum production rate shall be determined by linear extrapolation.

1.4 The provisions of this regulation shall not apply to the start-up and shutdown of equipment which operates continuously or in an extended steady state when emissions from such equipment during start-up and shutdown are governed by an operation permit issued pursuant to the provisions of 2.0 of 7 DE Admin. Code 1102.

02/01/1981

2.1 No person shall cause or allow the emission of sulfur dioxide in the tail gases from any existing sulfuric acid manufacturing operation to exceed either a concentration of 1,000 parts per million by volume or a mass emission rate as specified in Table 2-1 of this regulation.

2.2 No person shall cause to be discharged into the atmosphere from any existing sulfuric acid plant any gases which contain acid mist, expressed as H2SO4, in excess of 0.25 g per kg of acid produced (0.5 lb per ton) the product being expressed as 100% H2SO4.

2.3 The provisions of 2.2 of this regulation shall not apply to acid plants used as sulfur dioxide control systems, to chamber process plants, to acid concentrators or to petroleum storage and transfer facilities.

2.4 The reference methods used to determine compliance with standards prescribed in 2.2 of this Regulation shall be those set forth in 1.5 of 7 DE Admin. Code 1120.

02/01/1981

3.1 No person shall cause or allow the emission of sulfur dioxide in the tail gases from existing sulfur recovery operations to exceed either a concentration of 2,000 parts per million by volume or a mass emission rate as specified in Table 3-1 of this regulation.

ALLOWABLE MASS EMISSION RATE OF SULFUR DIOXIDE

FROM SULFUR RECOVERY OPERATIONS

3.2 Except as provided in 11.0 of 7 DE Admin. Code 1120, NEW SOURCE PERFORMANCE STANDARDS, no person shall cause or allow the emission of sulfur dioxide in the tail gases from new sulfur recovery operations to exceed either a concentration of 2,000 parts per million by volume or a mass emission rate as specified in Table 3-1 of this regulation.

02/01/1981

Minimum stack heights for new sources of sulfur dioxide will be determined by the Department on an individual basis. Such stack height requirements will be based on considerations such as, but not limited to, existing ambient levels of sulfur dioxide, local sources, atmospheric dispersion calculations, land use, and population density. The provisions of 7 DE Admin. Code 1127 shall apply to these calculations.