SUPPLEMENTARY INFORMATION:

Preamble acronyms and abbreviations. Throughout this document the use of “we,” “us,” or “our” is intended to refer to the EPA. We use multiple acronyms and terms in this preamble. While this list may not be exhaustive, to ease the reading of this preamble and for reference purposes, the EPA defines the following terms and acronyms here:

APCD air pollution control device

CAA Clean Air Act

CBI Confidential Business Information

CEDRI Compliance and Emissions Data Reporting Interface

CEMS continuous emission monitoring system

CFR Code of Federal Regulations

CPMS continuous parameter monitoring system

CO₂ e carbon dioxide equivalent

D/F dioxin/furan ( i.e., polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans)

dscm dry standard cubic meter

EDL estimated detection limit

EFB electrified filter bed

EPA Environmental Protection Agency

ESP electrostatic precipitator

°F degrees Fahrenheit

FR Federal Register

gr/dscf grains per dry standard cubic foot

HAP hazardous air pollutant(s)

HCl hydrogen chloride

Hg mercury

IBR incorporation by reference

ICR information collection request

kPa kilopascals

lb/MSF  3/4 ” pounds of pollutant per thousand square feet of 3/4 -inch thick board

lb/MSF  3/8 ” pounds of pollutant per thousand square feet of 3/8 -inch thick board

lb/ODT pounds of pollutant per oven-dried ton of wood

LVL laminated veneer lumber

MACT maximum achievable control technology

MDF medium density fiberboard

MDI methylene diphenyl diisocyanate

MDL method detection limit

mg/dscm milligrams of pollutant per dry standard cubic meter of air

NAICS North American Industry Classification System

NESHAP national emission standards for hazardous air pollutants

ng/dscm nanograms of pollutant per dry standard cubic meter of air

Non-Hg non-mercury

NRDC Natural Resources Defense Council

NTTAA National Technology Transfer and Advancement Act

O&M operation and maintenance

OCAP Office of Clean Air Programs

OMB Office of Management and Budget

OSB oriented strandboard

PAH polycyclic aromatic hydrocarbons

PBCO production-based compliance option

PCWP plywood and composite wood products

PDF portable document format

PM particulate matter

PRA Paperwork Reduction Act

ppmvd parts per million by volume, dry

psia pounds per square inch absolute

RATA relative accuracy test audit

RCO regenerative catalytic oxidizer

RDL representative detection limit

RFA Regulatory Flexibility Act

RMH resinated material handling

RTC Response to Comments

RTO regenerative thermal oxidizer

RTR residual risk and technology review

SBA Small Business Administration

SSM startup, shutdown, and malfunction

TEQ toxic equivalency (relative the toxicity of 2,3,7,8-tetrachlordibenzo dioxin)

THC total hydrocarbon

tpy tons per year

UMRA Unfunded Mandates Reform Act

VCS voluntary consensus standards

WESP wet electrostatic precipitator

3xRDL three times the representative detection limit

Table of Contents

I. General Information ( printed page 41411)

A. Executive Summary

B. Does this action apply to me?

C. Where can I get a copy of this document and other related information?

D. Judicial Review and Administrative Reconsideration

E. Severability

II. Background

A. What is the statutory authority for this action?

B. What is the PCWP source category and how does the current NESHAP regulate its HAP emissions?

C. What changes did we propose for the PCWP source category in our May 18, 2023, proposal?

III. What is the rationale for our final decisions and amendments to the PCWP NESHAP?

A. Analytical Procedures

B. MACT Standards for Direct-Fired PCWP Dryers

C. MACT Standards for Lumber Kilns

D. MACT Standards for Process Units With Organic HAP Emissions

E. MACT Standards for Process Units With MDI Emissions

F. Requirements for Performance Testing, Monitoring, and Recordkeeping and Reporting

G. Other Actions

H. What are the effective and compliance dates of the standards?

IV. Summary of Cost, Environmental, and Economic Impacts and Additional Analyses Conducted

A. What are the affected sources?

B. What are the air quality impacts?

C. What are the cost impacts?

D. What are the economic impacts?

E. What are the benefits?

V. Statutory and Executive Order Reviews

A. Executive Order 12866: Regulatory Planning and Review and Executive Order 13563: Improving Regulation and Regulatory Review

B. Executive Order 14192: Unleashing Prosperity Through Deregulation

C. Paperwork Reduction Act (PRA)

D. Regulatory Flexibility Act (RFA)

E. Unfunded Mandates Reform Act (UMRA)

F. Executive Order 13132: Federalism

G. Executive Order 13175: Consultation and Coordination With Indian Tribal Governments

H. Executive Order 13045: Protection of Children From Environmental Health Risks and Safety Risks

I. Executive Order 13211: Actions Concerning Regulations That Significantly Affect Energy Supply, Distribution, or Use

J. National Technology Transfer and Advancement Act (NTTAA) and 1 CFR part 51

K. Congressional Review Act (CRA)

I. General Information

A. Executive Summary

In this final rule, the EPA is amending the PCWP NESHAP in response to multiple actions: the partial remand and vacatur of the 2004 final rule that promulgated the “2004 rule”, the petition for reconsideration of the 2020 RTR, and to address previously unregulated HAP in the PCWP source category.^[1 2] This final rule establishes new emission limitations and work practices as appropriate that reflect MACT for HAP emitted by process units that are part of the PCWP source category. This action is an amendment to the previous technology review, not a new technology review as required under CAA section 112(d)(6).

The EPA promulgated the PCWP NESHAP on July 30, 2004. In the 2004 rule, for several process units, the EPA concluded that the MACT floors were represented by no emission reduction (or “no-control” emission floors). In 2007, the U.S. Court of Appeals for the D.C. Circuit vacated and remanded those portions of the 2004 rule.^[3] On August 13, 2020, the EPA took final action on the RTR of the PCWP NESHAP as required by Clean Air Act (CAA) sections 112(d)(6) and (f)(2). The EPA acknowledged in the preamble to the proposed RTR that there were unregulated sources with “no-control” MACT determinations in the PCWP source category, and we stated our plans to address those units in a separate action subsequent to the RTR.^[4] The EPA also received a petition for reconsideration following promulgation of the 2020 RTR, which argued that the EPA failed to set limits for unregulated HAP, among other issues.

On May 18, 2023, the EPA proposed revisions to the PCWP NESHAP (“May 2023 proposal”) to set MACT standards for total HAP (including acetaldehyde, acrolein, formaldehyde, methanol, phenol, propionaldehyde), MDI, and combustion-related HAP. The proposed standards for combustion related HAP include non-Hg HAP metals, mercury, HCl, PAH, and D/F).^[5] We proposed setting total HAP and MDI standards for sources with previously vacated no-control floor determinations, MDI standards for processes that use MDI resins and coatings, and standards to limit combustion-related HAP from direct wood- and other fuel-fired dryers. See section II.C of this preamble for additional details and other proposed changes that were included in the May 2023 proposal.

The public comment period for the May 2023 proposal closed on July 18, 2023. We summarize some of the more significant comments we timely received regarding the proposed rule and provide our responses in section III of this preamble. A summary of all other public comments on the proposal and the EPA's responses to those comments is available in the docket for this rulemaking along with a redline strikeout version of the regulatory language that incorporates the changes.^[6 7] The EPA is finalizing MACT standards largely as proposed to address sources with previously vacated no-control floor determinations and unregulated HAP in the PCWP source category. Changes from the proposed rule are listed in Table 1 and include setting D/F emission limitations for direct wood-fired green rotary dryers, adding a definition for PAH, technical corrections to emissions data analyses, refinement to work practice standards for sources including lumber kilns, fiber washers, log vats, and wastewater operations to address comments on technical feasibility or clarity, and other changes to improve clarity such as revising the definition for non-HAP resin. Section III.G.4 of this preamble contains our responses to the issues raised by the petition for reconsideration that the EPA received on the 2020 RTR final rule.

The EPA estimates that this final rule will result in the reduction of approximately 720 tons per year (tpy) HAP and 8,500 tpy volatile organic compounds (VOC) at a total annualized cost of $53 million (2024 dollars) to 219 affected major source facilities. Section IV of this preamble describes in more detail the final costs, emissions reductions, and economic impacts of this final rule. ( printed page 41412)

B. Does this action apply to me?

Regulated entities. Table 2 of this preamble presents categories and entities that this action potentially regulates.

The EPA does not intend table 2 of this preamble to be exhaustive but rather to provide a guide for readers regarding the entities that this final action is likely to affect. To determine if this action affects your facility, you should examine the applicability criteria in title 40 of the Code of Federal Regulations (CFR), part 63, subpart DDDD. If you have any questions regarding the applicability of any aspect of this NESHAP, please contact the appropriate person listed in the preceding FOR FURTHER INFORMATION CONTACT section of this preamble.

C. Where can I get a copy of this document and other related information?

In addition to being available in the docket, an electronic copy of this action is available on the internet. In accordance with 5 U.S.C. 553(b)(4), a brief summary of this rulemaking may be found at www.regulations.gov, Docket ID No. EPA-HQ-OAR-2016-0243. Following signature by the EPA Administrator, the EPA will post a copy of this final action at https://www.epa.gov/​stationary-sources-air-pollution/​plywood-and-composite-wood-products-manufacture-national-emission. Following publication in the Federal Register , the EPA will post the Federal Register version of the final rule and key technical documents at this same website.

D. Judicial Review and Administrative Reconsideration

Under CAA section 307(b)(1), judicial review of this final action is available only by filing a petition for review in the United States Court of Appeals for the District of Columbia Circuit (D.C. Circuit) by September 4, 2026. CAA section 307(b)(2) prohibits a party from challenging this final rule separately in any civil or criminal proceedings brought by the EPA for enforcement.

CAA section 307(d)(7)(B) further provides that only an objection to a rule or procedure that was raised with reasonable specificity during the period for public comment (including any public hearing) may be raised during judicial review. This section also requires the EPA to reconsider the rule if the person raising an objection can demonstrate to the Administrator that it was impracticable to raise such objection within the period for public comment or if the grounds for such objection arose after the period for public comment (but within the time specified for judicial review) and if such objection is of central relevance to the outcome of the rule. Any person seeking to make such a demonstration should submit a Petition for Reconsideration to the Office of the Administrator, U.S. EPA, Room 3000, WJC South Building, 1200 Pennsylvania Ave. NW, Washington, DC 20460, with a copy to both the person(s) listed in the preceding FOR FURTHER INFORMATION CONTACT section, and the Associate General Counsel for the Air and Radiation Law Office, Office of General Counsel (Mail Code 2344A), U.S. EPA, 1200 Pennsylvania Ave. NW, Washington, DC 20460.

E. Severability

This final rule contains several discrete components, which the EPA views as severable as a practical matter ( i.e., they are functionally independent and will operate in practice independently of the other components). These discrete components are detailed in sections III.A through III.G of this preamble and ( printed page 41413) the technical memoranda available in the docket. For example, the final requirements for direct-fired PCWP dryers, lumber kilns, process units that use MDI resins or coatings, monitoring of process unit bypass stacks, and performance testing generally function independently of one another and would not be impacted if a reviewing court were to vacate one or more of the other final provisions. In addition, as this final rule revises an existing NESHAP, the EPA notes that if a reviewing court were to vacate one or more of the standards finalized here, the affected standards will revert to those present in the 2020 RTR final rule.

II. Background

A. What is the statutory authority for this action?

CAA section 112, as amended (42 U.S.C. 7412) provides the statutory authority for this action. CAA section 112 establishes a two-stage regulatory process to develop standards for emissions of HAP from stationary sources. Generally, the first stage involves establishing technology-based standards that reflect MACT or an appropriate alternative.^[8] The second stage involves evaluating those standards within eight years to determine whether additional standards are needed to address any remaining risk associated with HAP emissions.^[9] The EPA commonly refers to this second stage as the “residual risk review.” In addition to the residual risk review, CAA section 112 also requires the EPA to review the standards at least every eight years and “revise as necessary” taking into account “developments in practices, processes, or control technologies.” ^[10] This review, commonly referred to as the “technology review,” is the subject of this final rule. The discussion that follows identifies the most relevant CAA section 112 statutory sections and briefly explains the contours of the methodology used to implement these statutory requirements.

In the first stage, the EPA promulgates technology-based standards under CAA section 112(d) for categories of sources identified as emitting one or more of the HAP listed in CAA section 112(b). “Major sources” are those that emit, or have the potential to emit, any single HAP at a rate of 10 tpy or more, or 25 tpy or more of any combination of HAP.^[11] For major sources, these standards are commonly referred to as MACT standards; CAA section 112(d)(2) provides that these must reflect the maximum degree of emission reductions of HAP achievable (after considering cost, energy requirements, and non-air quality health and environmental impacts). In developing MACT standards, CAA section 112(d)(2) directs the EPA to consider the application of measures, processes, methods, systems, or techniques, including, but not limited to, those that reduce the volume of or eliminate HAP emissions through process changes, substitution of materials, or other modifications; enclose systems or processes to eliminate emissions; collect, capture, or treat HAP when released from a process, stack, storage, or fugitive emissions point; are design, equipment, work practice, or operational standards; or any combination of the above.

CAA section 112(d)(3) establishes a minimum control level for MACT standards, known as the MACT “floor,” based on emission controls achieved in practice by the best performing sources. For new sources, the MACT floor cannot be less stringent than the emission control achieved in practice by the best-controlled similar source. The MACT standards for existing sources can be less stringent than floors for new sources, but they cannot be less stringent than the average emission limitation achieved by the best-performing 12 percent of existing sources in the category or subcategory (or the best-performing five sources for categories or subcategories with fewer than 30 sources).

In certain instances, as provided in CAA section 112(h), the EPA may set work practice standards in lieu of numerical emission standards. Under CAA section 112(h), the EPA may adopt a work practice standard in lieu of a numerical emission standard if it is “not feasible in the judgment of the Administrator to prescribe or enforce an emission standard for control of a hazardous air pollutant or pollutants.” ^[12] CAA section 112(h)(2) defines the phrase “not feasible to prescribe or enforce an emission standard” to mean any situation where the Administrator either determines that a HAP or HAPs “cannot be emitted through a conveyance designed and constructed to emit or capture such pollutant, or that any requirement for, or use of such a conveyance would be inconsistent with any Federal, State or local law” ^[13] or determines that “the application of measurement methodology to a particular class of sources is not practicable due to technological and economic limitations.” ^[14] The EPA considers a measurement to be not technologically practicable within the meaning of CAA section 112(h)(2)(B) if the majority of the measurements are below the detection limit. Such measurements raise issues of questionable reliability, feasibility, and enforceability.

The EPA also considers control options that are more stringent than the floor and may establish standards more stringent than the floor, based on the consideration of the cost of achieving the emissions reductions, any non-air quality health and environmental impacts, and energy requirements.^[15] Standards more stringent than the floor are commonly referred to as “beyond-the-floor” standards. In the second stage of the regulatory process, the CAA section 112(d)(6) requires the EPA to undertake a technology review no less frequently than every eight years. Under the technology review, the EPA must review the technology-based standards and revise them “as necessary (taking into account developments in practices, processes, and control technologies).” ^[16] In conducting this review, the EPA is not required to recalculate the MACT floors that were established in earlier rulemakings.^[17] The EPA may consider cost in deciding whether to revise the standards pursuant to CAA section 112(d)(6).^[18] Following the D.C. Circuit's decision in Louisiana Environmental Action Network (LEAN) v. EPA,^[19] the EPA also reviews available data to determine if there are unregulated HAP within the source category and evaluate these data for use in developing new emission standards. The D.C. Circuit held in LEAN that the EPA is required to address unregulated HAP from a major source category when the Agency conducts a technology review of a NESHAP that previously left such HAP unregulated.^[20]

( printed page 41414)

In the 2004 rule, the EPA concluded that the MACT floors for several process units were represented by no emission reduction (or “no control” emission floors) and declined to set standards for those units. In 2007, the D.C. Circuit held that the EPA's use of “no-control” emission floors to avoid setting emissions standards in another source category was unlawful.^[21] In response, the EPA requested a voluntary remand and vacatur of the portions of the 2004 rule that included these “no-control” emission floor determinations.^[22] The D.C. Circuit remanded and vacated those portions of the 2004 rule to the EPA to set emission standards for those units to replace the unlawful “no-control” floor determinations.^[23] On August 13, 2020, the EPA took final action on the RTR of the PCWP NESHAP as required by CAA sections 112(d)(6) and (f)(2). The EPA acknowledged in the preamble to the proposed RTR that there are unregulated sources with “no-control” MACT determinations in the PCWP source category, and we stated our plans to address those units in a separate action subsequent to the RTR.^[24]

This final rule responds to the partial remand and vacatur of the 2004 rule, the petition for reconsideration of the 2020 RTR, and addresses previously unregulated HAP in the PCWP source category. This final rule establishes new standards that reflect MACT for HAP emitted by process units that are part of the PCWP source category, pursuant to CAA sections 112(d)(2) and (3) and, where appropriate, CAA section 112(h). The EPA is setting “total HAP” standards (defined in the PCWP NESHAP as acetaldehyde, acrolein, formaldehyde, methanol, phenol, and propionaldehyde) for sources with previously vacated “no-control” MACT determinations. In addition to total HAP, the EPA is setting standards for previously unregulated HAP present in the PCWP source category, including non-Hg HAP metals, Hg, HCl, PAH, and D/F as a result of combustion in direct-fired dryers and MDI from processes that use MDI resins and coatings.

B. What is the PCWP source category and how does the current NESHAP regulate its HAP emissions?

The EPA originally promulgated the PCWP NESHAP on July 30, 2004.^[25] The standards are codified at 40 CFR part 63, subpart DDDD. The PCWP industry consists of facilities engaged in the production of PCWP or kiln-dried lumber. PCWP are manufactured by bonding wood material (fibers, particles, strands, etc.) or agricultural fiber, generally with resin under heat and pressure, to form a structural panel or engineered wood product. PCWP manufacturing facilities also include facilities that manufacture dry veneer and lumber kilns located at any facility. PCWP includes (but are not limited to) plywood, veneer, particleboard, oriented strand board (OSB), hardboard, fiberboard, medium density fiberboard (MDF), laminated strand lumber, laminated veneer lumber (LVL), wood I-joists, kiln-dried lumber, and glue-laminated beams. There are currently 219 major source facilities that are subject to the PCWP NESHAP, including 93 facilities manufacturing PCWP and 126 facilities producing kiln-dried lumber. A major source of HAP is a plant site that emits or has the potential to emit any single HAP at a rate of 9.07 megagrams (10 tons) or more, or any combination of HAP at a rate of 22.68 megagrams (25 tons) or more per year from all emission sources at the plant site.

The affected source under the PCWP NESHAP is the collection of dryers, refiners, blenders, formers, presses, board coolers, and other process units associated with the manufacturing of PCWP. The affected source includes, but is not limited to, green end operations, refining, drying operations (including any combustion unit exhaust stream routinely used to direct fire process unit(s)), resin preparation, blending and forming operations, pressing and board cooling operations, and miscellaneous finishing operations (such as sanding, sawing, patching, edge sealing, and other finishing operations not subject to other NESHAP). The affected source also includes onsite storage and preparation of raw materials used in the manufacturing of PCWP, such as resins; onsite wastewater treatment operations specifically associated with PCWP manufacturing; and miscellaneous coating operations. The affected source includes lumber kilns at PCWP manufacturing facilities and at any other kind of facility.

The PCWP NESHAP contains several compliance options for process units subject to the standards: (1) installation and use of emissions control systems with an efficiency of at least 90 percent; (2) production-based limits that restrict HAP emissions per unit of product produced; and (3) emissions averaging that allows control of emissions from a group of sources collectively (only at existing affected sources). These compliance options apply for the following process units: fiberboard mat dryer heated zones (at new affected sources); green rotary dryers; hardboard ovens; press predryers (at new affected sources); pressurized refiners; primary tube dryers; secondary tube dryers; reconstituted wood product board coolers (at new affected sources); reconstituted wood product presses; softwood veneer dryer heated zones; rotary strand dryers; and conveyor strand dryers (zone one at existing affected sources, and zones one and two at new affected sources). In addition, the PCWP NESHAP includes work practice standards for dry rotary dryers, hardwood veneer dryers, softwood veneer dryers, veneer redryers, and group 1 miscellaneous coating operations (defined in 40 CFR 63.2292).

The 2020 RTR found that the risk associated with air emissions from the PCWP manufacturing industry (including those from lumber kilns and other process units and HAP for which we had not yet responded to the 2007 partial remand and vacatur) are acceptable and that the current PCWP NESHAP provides an ample margin of safety to protect public health. In the 2020 RTR, the EPA concluded that there were no developments in practices, processes, or control technologies that would warrant revisions to the specific standards already promulgated in 2004. In addition to conclusions with respect to the RTR, the 2020 action contained amendments to remove exemptions from the standards during periods of startup, shutdown, and malfunction (SSM). The 2020 RTR amendments added work practices so there would be standards in place of the former startup and shutdown exemptions for three specific events that occur during PCWP production: safety-related shutdowns, pressurized refiner startup/shutdown, and softwood veneer dryer gas-burner relights. Lastly, the 2020 RTR amendments included provisions requiring electronic reporting and repeat emissions testing. In the 2020 RTR, the EPA did not address and reached no conclusions regarding unregulated HAP. The 2020 RTR did not address ( printed page 41415) establishing MACT emissions limits or work practices for the process units or HAP that were the subject of the 2007 D.C. Circuit's partial remand and vacatur of the 2004 rule's “no-control” MACT determinations. Consequently, this is the first rulemaking in which the EPA has addressed emission limits and work practices for these process units and HAP, since the 2007 ruling.

C. What changes did we propose for the PCWP source category in our May 18, 2023, proposal?

On May 18, 2023, the EPA published a proposal in the Federal Register for the PCWP NESHAP, 40 CFR part 63, subpart DDDD to set MACT standards for total HAP, MDI, and combustion-related HAP including non-Hg HAP metals, Hg, HCl, PAH, D/F. Total HAP limits were proposed for fiberboard mat dryers at existing sources, hardboard press predryers at existing sources, and atmospheric refiners at existing and new sources. Limits for non-Hg HAP metals in the form of particulate matter (PM), Hg, HCl, and PAH were proposed for direct wood- and other fuel-fired dryers at existing and new sources. MDI limits were proposed for reconstituted wood product presses using MDI, tube dryers blow-line blending MDI, and miscellaneous coating operations. The proposed rule also included the addition of burner tune-up requirements for all direct-fired PCWP dryers, direct-fired lumber kilns, and associated combustion unit bypass stacks. Work practice standards were also proposed for lumber kilns, stand-alone digesters, fiber washers, log vats, wastewater operations, and resinated material handling (RMH) units, including resin tanks, blenders, formers, reconstituted wood products board coolers at existing sources, plywood presses, engineered wood product presses and curing chambers, finishing sanders, finishing saws, panel trim chippers, humidifiers, and wastewater operations.

The proposed rule included the removal of the emissions averaging compliance option for existing affected sources (not available for new affected sources). The proposed rule also included a requirement for mixed PCWP process streams at existing sources currently meeting the compliance options present in Table 1B of this subpart to continue doing so. Additionally, the proposed rule included a requirement to monitor process unit bypass stack usage at all times; plus, the proposal added emissions testing; monitoring, reporting, and recordkeeping requirements relevant to the standards being added. The proposal incorporated a revised definition of “pressurized refiner” to clearly distinguish between stand-alone digesters and pressurized refiners. Lastly, the proposed rule included the removal of obsolete date language associated with amendments finalized on August 13, 2020, that are now implemented.

III. What is the rationale for our final decisions and amendments to the PCWP NESHAP?

This action finalizes the EPA's determinations pursuant to the technology review provisions of CAA section 112 for the PCWP source category and amends the PCWP NESHAP based on those determinations. This action also reflects several changes to the May 2023 proposal in consideration of comments received during the public comment period described in section III of this preamble.

Section III.A describes the analytical procedures used to develop the MACT standards we are finalizing. Section III.B discusses the MACT standards we are finalizing for combustion-related HAP from direct-fired PCWP dryers, including rotary strand dryers, green rotary dryers, dry rotary dryers, tube dryers, and softwood veneer dryers. Section III.C discusses the MACT standards we are finalizing for all HAP emitted from lumber kilns. Section III.D discusses the MACT standards we are finalizing for total HAP from various process units other than lumber kilns that also had “no-control” MACT determinations in the 2004 rule that were vacated and remanded. Section III.E discusses the MACT standards we are finalizing for process units with MDI emissions, including reconstituted wood product presses, blow-line blend tube dryers, and miscellaneous coating operations. Section III.F discusses the final requirements for performance testing, monitoring, and recordkeeping and reporting. Section III.G discusses other actions we are finalizing. Section III.H discusses the effective and compliance dates of the amendments we are finalizing. Each of these discussions include a summary of what we proposed, a summary of key comments we received on what we proposed and our responses, and a summary of our final decisions and rationale. Comment summaries for all other comments and the EPA's specific responses can be found in the response to comments (RTC) document.^[26]

A. Analytical Procedures

The MACT standards finalized in this action were developed pursuant to CAA sections 112(d)(2) and (3) or, when appropriate, CAA section 112(h). When developing MACT standards, the “MACT floor” for existing sources is calculated based on the average performance of the best performing units in each category or subcategory and on a consideration of the variability of HAP emissions from these units. The MACT floor for new sources is based on the emissions levels that are achieved by the best performing similar source, with a similar consideration of variability. For existing sources, the MACT floor is based on the average emission limitation achieved by the best performing 12 percent of sources (for which the EPA has emissions information) for source categories or subcategories with 30 or more sources, or the average emission limitation achieved by the best performing five sources (for which the EPA has or could reasonably obtain emissions information) for categories or subcategories with fewer than 30 sources. The EPA does not consider costs when determining the MACT floor. To account for variability in PCWP manufacturing operations and resulting emissions, we calculated the MACT floors using the 99 percent Upper Prediction Limit (UPL) using performance data collected from two CAA section 114 surveys of PCWP facilities in 2017 and 2022.^[27] We note that the MACT floors for certain existing and new units are based on limited data sets.^[28]

Once the UPL is calculated for a pollutant, the representative detection limit (RDL) for the pollutant measurement method is considered, if necessary. The RDL is representative of the laboratory instrument sensitivity and lowest industry-standard method detection limits (MDL) achieved when analyzing air pollutant samples. Consideration of the RDL is necessary when pollutants are measured near or below the detection limit of the analysis method, which was the case for some HAP measured in the 2022 survey. The EPA compares a value of three times the RDL (3xRDL) of the pollutant to UPL ( printed page 41416) values to ensure that the calculated MACT floors account for measurement variability.^[29] If the 3xRDL value exceeds the MACT floor UPL, the 3xRDL value is substituted as the MACT floor emission limit to ensure that the standard is set no lower than the minimum level at which emissions can reliably be measured. We applied an established procedure for cases where we had low detection data to handle below detection level (BDL) data and develop RDL data when setting MACT emission limits.^[30]

In addition, under CAA section 112(d)(2), the EPA must examine more stringent “beyond-the-floor” regulatory options to determine MACT. Unlike the floor minimum stringency requirements, the EPA must consider various impacts of the more stringent regulatory options in determining whether MACT standards are to reflect beyond-the-floor requirements. These impacts include the cost of achieving additional emissions reduction beyond that achieved by the MACT floor, any non-air quality health and environmental impacts that would result from imposing controls beyond the floor, and energy requirements of such beyond floor measures. If the EPA concludes that the more stringent regulatory options have unreasonable impacts, the EPA selects the MACT floor as MACT. However, if the EPA concludes that impacts associated with beyond-the-floor levels of control are reasonable considering additional HAP emissions reductions achieved, the EPA selects those beyond-the-floor levels as MACT.

For some process types, it is not feasible to prescribe or enforce a numerical emission standard using the MACT floor and MACT determination approach described in CAA sections 112(d)(2) and (3). According to CAA section 112(h)(1), MACT standards may take the form of design, equipment, work practice, or operational standards if it is not feasible in the judgment of the Administrator to prescribe or enforce an emission standard for control of HAP. To support a determination that it is not feasible to prescribe or enforce an emission standard for control of HAP, CAA sections 112(h)(2)(A) and (B) require the EPA to determine that either: (A) a HAP or pollutants cannot be emitted through a conveyance designed and constructed to emit or capture such pollutant, or that any requirement for, or use of, such a conveyance would be inconsistent with any Federal, State or local law, or (B) the application of measurement methodology to a particular class of sources is not practicable due to technological and economic limitations.

B. MACT Standards for Direct-Fired PCWP Dryers

As proposed, the EPA is finalizing standards for two subcategories of PCWP direct-fired dryers: (1) wood and other fuel-fired dryers; and (2) natural gas fuel-fired dryers. We subcategorized PCWP direct-fired dryers by fuel type because wood and other fuel-fired dryers have different design and combustion-related HAP emissions profiles from those firing natural gas (or propane). We are finalizing the addition of the following definitions to the PCWP NESHAP to delineate the different types of direct-fired PCWP dryers: PCWP dryer, Direct wood-fired PCWP dryer, and Direct natural gas-fired PCWP dryer. In addition, we are finalizing the same definition of natural gas used in the NESHAP codified at 40 CFR part 63, subpart DDDDD (“Boiler MACT”).

As proposed, the EPA is finalizing a work practice standard requiring annual burner tune-ups for the combustion unit(s) that fire new and existing direct-fired PCWP dryers. The purpose of the annual burner tune-ups is to control all combustion-related HAP that may be emitted from direct natural gas-fired PCWP dryers and control D/F emissions from direct wood-fired dryers. In addition to requiring annual burner tune-ups for all direct-fired dryers, we are also finalizing the proposed requirement for new and existing direct-fired PCWP dryers to continuously monitor an indicator of their combustion unit bypass stack usage such as flow damper position or temperature to address any HAP emitted from combustion bypass stacks associated with direct-fired PCWP dryers. As explained in the preamble, work practice standards for direct-fired dryer bypass stacks are justified because emissions are not technically and feasibly measurable.

1. What combustion HAP standards did we propose for direct wood-fired dryers?

For direct wood-fired PCWP dryers, emission limits for combustion HAP were developed following the approach described in section III.A. The MACT emission limits were developed in mass per production and concentration units to provide compliance options for the various dryer configurations subject to the standards. Mass per production units are pounds of pollutant per thousand square feet (lb/MSF) for softwood veneer dryers and pounds per oven dried ton (lb/ODT) for all other dryer types. Concentration units include grains per dry standard cubic foot (gr/dscf) for PM and milligrams per dry standard cubic meter (mg/dscm) for non-PM pollutants.

The EPA proposed MACT standards for combustion-related HAP (non-Hg metals, Hg, HCl, PAH, and D/F) from direct wood-fired PCWP dryers, which include rotary strand dryers, green rotary dryers, dry rotary dryers, tube dryers, softwood veneer dryers (heated zones), fiberboard mat dryers (heated zones), and hardboard ovens. The EPA proposed PM numerical limits to serve as a surrogate to control non-Hg metals and proposed numerical limits for both mercury and HCl. Additionally, the EPA proposed PAH numerical limits for all direct wood-fired dryers based on an aggregate of 19 PAH compounds which serve as a surrogate for all PAHs in the PCWP source category. Lastly, the EPA proposed a D/F work practice to address D/F emissions from direct wood-fired dryers in the PCWP source category. Some, but not all, changes to the direct-fired standards from the May 2023 proposal are discussed in the remainder of this section.^[31] A complete discussion of changes is provided in the RTC document and a docketed memorandum.^[32]

2. What comments did we receive on combustion HAP standards for direct wood-fired dryers?

Comment: The EPA received comments on specific data and production values used in our calculations of the proposed PM emission limit for green rotary dryers.

EPA Response: After reevaluating the production values used in the PM UPL calculations for green rotary dryers, and ( printed page 41417) reviewing the technical errors raised by commenters, the EPA agreed with commenters and found that the new and existing source limits for PM required correction due to technical errors. See section 3 of the RTC document located in the docket for this rulemaking for these specific comments and our responses regarding revisions.

Comment: With regards to the proposed PAH limits for wood-fired dryers, commenters argued that data quality issues with the PAH data collected in the 2022 survey render the data unsuitable for setting these limits. The commenters requested that the EPA remove the PAH limits based on the collected data and instead rely on the annual burner tune-up work practice to control PAH emissions. The commenters noted the annual burner tune-up work practice to reduce D/F formation would also reduce the formation of PAH.

EPA Response: The EPA agrees, in part, with the commenter's concern over data quality. The EPA has reevaluated the PAH data and concluded the data were acceptable for setting MACT limits after two adjustments. First, we removed one 3-run test with excessive contamination from the final MACT analysis (in addition to a single test run with lab analysis problems we had already removed from the proposed MACT analysis). Second, we removed naphthalene from the MACT floor analysis and from the rule specific definition of PAH at 40 CFR 63.2292 to preemptively address naphthalene contamination issues in future compliance demonstrations.^[33] The EPA received sufficient data in the 2022 survey to demonstrate that the remaining 18 PAH congeners serve as an appropriate surrogate for polycyclic organic matter and naphthalene, the listed HAP that PAH standards are intended to regulate.

Comment: Some commenters argued that our proposal to use the 3xRDL value of 3.3E-05 mg/dscm as the PAH limit for wood-fired softwood veneer dryers in the absence of PAH test data was arbitrary and capricious.

EPA Response: The EPA agrees that we lacked adequate data to establish a numerical MACT limit for softwood veneer dryers. Performance data were not collected from direct-wood fired softwood veneer dryers in the CAA section 114 survey because softwood veneer dryers were not expected to have the same potential for formation of detectable PAH emissions as direct wood-fired rotary and tube dryers, which operate at higher temperatures under more turbulent conditions. Upon further consideration in response to these comments, we are not finalizing the proposed 3xRDL limit for wood-fired softwood veneer dryers and instead are relying on the burner tune-up standards included in the rule to limit the potential for PAH emissions from wood-fired softwood veneer dryers. However, we require that wood-fired softwood veneer dryers conduct performance testing for PAH emissions along with the compliance tests required for other combustion-related HAPs. Although we do not expect to find detectable PAH emissions, if PAH are detected, these test results could be used during the next eight-year technology review to determine if revision to a numerical standard is warranted.

Comment: One commenter questioned our analysis of D/F toxic equivalency (TEQ) emissions data and proposed that a work practice is justified for D/F from wood-fired dryers because emissions cannot reliably be measured due to the prevalence of non-detects in more than 55 percent of TEQ runs.^[34] The commenter suggested that the EPA reevaluate the RDL as a result of D/F test method improvements in recent years and questioned if the EPA should have compared detected TEQ to the 3xRDL value as was done for the proposal.

EPA Response: We maintain that use of the current RDL is appropriate for this rulemaking. The EPA may consider updating the RDL as additional lab experience and data sets become available for a broader set of emission sources using the revised EPA Method 23, which was not finalized at the time of the PCWP CAA section 114 data collection. However, the EPA agrees with commenters that the RDL is not the appropriate detection value when determining the number of non-detect TEQ runs. We updated our analysis of the detected TEQ to compare to the estimated detection limit (EDL) of 1.8E-02 nanograms per dry standard cubic meter (ng/dscm) instead of 3xRDL to adhere to guidance for evaluating when to establish numerical MACT limits versus establishing work practices.^[35] Upon reanalysis, the percentage of non-detect TEQ runs remained the same as proposed for wood-fired rotary strand dryers (100 percent non-detect), dry rotary dryers (100 percent non-detect), and tube dryers (80 percent non-detect). We no longer found that a substantial majority of green rotary dryer TEQ runs were non-detect upon comparison with the EDL. As a result, we are revising the rule to add a numerical limit for D/F from direct wood-fired green rotary dryers based on the emissions data sets available at proposal.

Emissions data for D/F (in terms of TEQ) are available for three out of six direct wood-fired green rotary dryer systems. The UPL MACT floor calculations for existing sources were based on all three systems because fewer than 30 direct wood-fired green rotary dryer systems exist. The UPL MACT floor calculation for new sources was based on the best performing system. The TEQ MACT floor for existing direct wood-fired green rotary dryer systems is 1.3E-09 lb/ODT or 1.7E-01 ng/dscm based on the UPL. The TEQ MACT floor for new direct wood-fired green rotary dryers is 4.4E-10 lb/ODT or 3.7E-02 ng/dscm based on 3xRDL. The 3xRDL value was substituted for the UPL in the new source MACT floor to ensure that the standards are established at the minimum level at which emissions can be measured reliably. The TEQ MACT floors are based on dryers that already have PM and organic HAP controls in series. The burner tune-up requirements required for all direct-fired PCWP dryers are expected to help with meeting the TEQ MACT floors. No options more stringent than the MACT floors were identified for existing or new sources. No reductions in TEQ emissions were estimated for existing or new wood-fired green rotary dryer systems because they are expected to meet the MACT floor with baseline controls and proper tuning.

3. What Combustion HAP Standards Are We Finalizing for Direct Wood-Fired Dryers

Table 3 of this preamble summarizes the MACT emission limits being finalized for direct wood-fired PCWP dryers. ( printed page 41418)

We are modifying the proposed PAH limits to not include naphthalene. We are not finalizing the proposed PAH limits from softwood veneer dryers and instead are requiring PAH testing to be included in the performance tests of these dryers in addition to the burner tune-up standard. In addition to the limits presented in Table 3 of this preamble, we are revising the rule to add D/F limits for direct wood-fired green rotary dryers based on reanalysis of the D/F data. In addition to adjustments stemming from public comments, we removed data from MACT floor calculations if they were collected from systems that ceased operations since the pre-proposal analysis was completed. This adjustment affected some limits and some mass per production based 3xRDL values. We also updated PM 3xRDL values to reflect the most recent revision to these values.

C. MACT Standards for Lumber Kilns

As explained in the May 2023 proposal, the EPA did not identify any lumber kilns with add-on air pollution controls.^[36] We explained that the EPA, as well as State permitting authorities, have evaluated the possibility of capturing and controlling emissions from lumber kilns and in each case concluded that capture and control of lumber kiln emissions is not technically feasible or cost effective for VOC emissions from batch or continuous kilns, and that these previous conclusions are equally relevant for capture and control of HAP. The EPA proposed a work practice standard for lumber kilns based on the criteria in CAA section 112(h), which states that if it is not feasible in the judgment of the Administrator to prescribe or enforce an emission standard for control of a HAP, the Administrator may, in lieu thereof, promulgate a design, equipment, work practice, or operational standard, or combination thereof, which in the Administrator's judgment is consistent with the provisions of CAA section 112(d).

1. What lumber kilns standards did we propose?

To reduce HAP from lumber kilns, we proposed a work practice consisting of four elements: (1) operation and maintenance (O&M) plan for all kilns to maintain the integrity of lumber kiln internal air flow and heat distribution components ( e.g., baffles, fans, vents, heating coils, temperature sensors) to provide as uniform a temperature and air flow as reasonably possible; (2) annual burner tune-up for direct-fired kilns to reduce the potential for combustion-related HAP emissions beyond the reduction in these emissions that results from minimizing lumber over-drying; (3) a work practice option in which all kilns limit over-drying by operating below a temperature set point, conducting in-kiln moisture monitoring, or following a site-specific plan (for temperature and lumber moisture monitoring); and (4) minimum kiln-dried lumber moisture content limits below which lumber is considered to be over-dried lumber for all kilns for purposes of the PCWP NESHAP. The May 2023 proposal described each of these elements in detail.^[37]

2. What comments did we receive on the proposed lumber kiln standards?

Comment: One commenter argued that the EPA has not shown infeasibility to justify work practice standards over numeric standards for limiting over-drying of lumber at lumber kilns. Other commenters agreed with the EPA's determination that it is not feasible to prescribe or enforce emissions standards for lumber kilns.

EPA response: The EPA determined work practice standards are appropriate because the total volume of emissions cannot be emitted through a conveyance that is designed and constructed to emit or capture HAP emissions. Furthermore, direct measurement of flow rate from batch kilns is not technically feasible because of the numerous vents and changing flow direction. Similarly, continuous dry kilns (CDKs) have fugitive emissions from their openings that cannot be eliminated while allowing for lumber to enter and exit the kiln. Therefore, the EPA maintains work practice standards for kilns are justified and establishing numerical limits for kilns is not feasible. The work practices included in the final rule are justified under CAA section 112(h) and reflect the maximum degree of emission reduction achieved by existing lumber ( printed page 41419) kilns and the degree of reduction that is achievable based on the EPA's review and analysis of available information.

Comment: Commenters supported the inclusion of O&M plans for kilns but suggested edits to plan requirements. Commenters noted components covered by the O&M plan should not be limited to those listed in the May 2023 proposal; objected to the proposed charge optimization practices to promote uniformity in lumber charged into the kiln ( e.g., sizing, sorting, stickering, conditioning); requested to be allowed additional time to complete corrective actions; and requested that the annual kiln inspection be conducted within 13 months of the previous inspection.

Similarly, a commenter requested that the EPA allow burner tune-ups to be performed every 13 months instead of every 12 months to help with process operation or personnel scheduling issues. The commenter also requested that additional language be added to 40 CFR 63.2271(c)(2) to specify that any cleaning, repairs, or replacements must be initiated within 30 days, to remove any interpretation that corrective action must be initiated immediately. This timeframe is consistent with 40 CFR 63.2253(a)(3)(ii) for initiation of the corrective actions identified during the annual lumber kiln integrity inspection in the O&M plan. The commenter did not propose a specific completion timeframe.

EPA response: The EPA agrees that facilities may need an additional month to perform corrective action and in the burner tune-up compliance schedule to accommodate process operations and personnel scheduling issues. In response to these comments, the EPA revised the O&M plan language. We also revised the rule to allow inspections to occur no later than 13 months after the previous inspection and added language for allowing submittal of a written request to the delegated authority for completing corrective actions after 180 days In response to the commenter's requests, the EPA revised the final rule to allow annual tune-ups and burner/grate inspections to be performed no more than 13 months after the previous tune-up, instead of every 12 months. To address the commenter's concerns regarding the current rule language being silent on the required timeframe of corrective actions and potential delays due to availability of parts, the EPA revised 40 CFR 63.2271(c)(2) to clarify that any corrective action taken as part of the tune-up/inspection must be initiated within 30 days and completed within 180 days following the annual tune-up/inspection identifying the need for the corrective action. The EPA also added language specifying if additional time is necessary to complete corrective actions, an extension request may be submitted through the delegated authority consistent with the O&M requirements.

Comment: Commenters stated that the “temperature set point” option under the proposed work practices should be referred to as the “temperature limit” option. According to the commenter, the EPA has proposed these temperature limits as “temperature set points” but compliance with the proposed temperature set point option would be based on the actual kiln dry bulb temperature readings according to 40 CFR 63.2269(m) and 40 CFR 63.2270(h)(1).

Commenters also requested that compliance with the maximum dry bulb temperatures under this work practice option be demonstrated with a longer averaging period of at least 24 hours, daily or batch to accommodate temperature variation instead of with a three-hour block average as proposed. The commenters noted that shorter averaging periods are impacted by routine temperature fluctuations in the kiln, such as temperature increases during fan reversals, which are a normal part of kiln operation and not indicative of over-drying. They also noted that facilities hold title V operating permits with 24-hour averaging periods for temperature monitoring.

Commenters requested that the EPA replace the “in-kiln moisture measurement” option with a hybrid option involving both temperature and moisture measurement. The commenters stated that most facilities monitor lumber moisture content after the lumber exits the kiln and cools, per industry guidance. The commenters suggested a hybrid option could apply to most lumber kilns conducting higher temperature drying such as those in the U.S. Southeast. The commenters recommended maximum dry bulb temperature limits of 240 degrees Fahrenheit (°F) for batch indirect-fired kilns, 250 °F for batch direct-fired kilns, and 260 °F for indirect- and direct-fired continuous kilns. Because the hybrid work practice option would include higher temperature limits, commenters suggested that facilities could also monitor moisture content to meet the minimum moisture content limits in the rule. However, under the hybrid option, the moisture content could be measured either in the kiln or after the lumber has exited the kiln ( e.g., at the planer).

EPA response: As a result of these comments, to avoid confusion and clarify intent of the proposed standard, the EPA modified the name of this option in the final rule to refer to a “temperature limit” rather than a “temperature set point”. The EPA is revising the final rule to require a batch cycle average for batch kilns and a daily (24-hour) block average for continuous kilns for the maximum dry bulb temperature to demonstrate compliance with the work practice standard.

The EPA also agrees with the commentator's request for a hybrid compliance option involving both temperature and moisture measurement. Using the large amount of monitoring data generated at the planer, along with kiln dry bulb temperature is a robust approach to reduce over-drying and is consistent with practices in place at lumber mills. Therefore, we revised the final rule to replace the in-kiln moisture measurement option with the requested hybrid option.

Comment: Relative to the “site-specific plan” work practice option, commenters requested that the EPA extend the deadline to submit site-specific plans from the 180 days (as proposed) to 18 months to allow time for facilities to properly develop an effective site-specific plan and gather data to support the elements of the plan. One commenter noted that developing a site-specific plan for lumber kilns could reasonably take more than 12 months.

EPA response: The EPA agrees with the commenter that 18 months will allow facilities to properly develop a site-specific plan, therefore, the deadline is being extended to 18 months versus the proposed 180 days (6 months) in the final rule. The EPA acknowledges this extension will shorten the period for delegated authorities to review and approve the plans for over 140 lumber kilns in operation.

Comment: One commenter supported the EPA's general methodology of defining over-dried lumber through the proposed lumber minimum moisture content limits of the proposed Table 11 to Subpart DDDD of Part 63 (“Table 11”). The commenter also agreed with the EPA's description of maximum lumber moisture grade in principle but requested that the term “moisture specification” be used throughout the rule rather than “moisture grade.”

EPA response: The EPA agreed and changed the term “moisture grade” to “moisture specification” to eliminate potential confusion. ( printed page 41420)

3. What lumber kiln standards are we finalizing?

After considering comments,^[38] we are finalizing work practice standards for lumber kilns in 40 CFR 63.2241(e) to reduce HAP emissions by minimizing lumber over-drying. The final work practice consists of four elements: (1) O&M plan for all kilns; (2) annual burner tune-up for direct-fired kilns; (3) a choice of three work practice options including a temperature limit option, hybrid option involving higher temperature limit and lumber moisture monitoring, or site-specific plan for temperature and lumber moisture monitoring; and (4) minimum kiln-dried lumber moisture content limits below which lumber is considered to be over-dried lumber for all kilns for purposes of the PCWP NESHAP.

D. MACT Standards for Process Units With Organic HAP Emissions

The EPA is finalizing MACT standards for organic HAP emissions from process units that had “no-control” MACT determinations in the 2004 rule that were vacated in 2007. In addition to lumber kilns, these process units include various RMH process units, atmospheric refiners, stand-alone digesters, fiber washers, fiberboard mat dryers at existing sources, hardboard press predryers at existing sources, and log vats. Some of these process units are already subject to new source HAP standards in the PCWP NESHAP, including fiberboard mat dryers, hardboard press predryers, and reconstituted wood product board coolers (which are a type of RMH unit) at new and reconstructed sources. Therefore, limits for these new and reconstructed sources do not need to be established in response to the partial remand and vacatur. Mixed PCWP process streams routed to HAP control devices subject to the current HAP emission limits in Table 1B are also already subject to the PCWP NESHAP. Sections III.D.1 through 6 summarize the final standards for process units with unregulated organic HAP emissions that were subject to the partial remand and vacatur, the key comments received and our responses, and our final decisions and rationale on the standards for this final action.^[39]

1. RMH Process Units

RMH process units within the PCWP affected source include resin tanks, softwood and hardwood plywood presses, engineered wood product presses and curing chambers, blenders, formers, finishing saws, finishing sanders, panel trim chippers, reconstituted wood product board coolers (at existing affected sources), hardboard humidifiers, and onsite wastewater treatment operations specifically associated with PCWP manufacturing. These process units handle resin or resinated wood material downstream of the point in the PCWP process where resin is applied. The potential for HAP emissions from RMH process units relates to the material being processed ( i.e., resin and wood).

a. What RMH standards did we propose?

As explained in the proposal, RMH process units are not designed and constructed in a way that allows for HAP emissions capture or measurement. Therefore, the EPA proposed work practice standards for RMH process units under CAA section 112(h) to address their resin-related emissions and wood-related emissions.

We proposed work practice standards to require new and existing facilities with RMH process units to (i) use only a non-HAP resin,^[40] or (ii) use a resin with a maximum true vapor pressure of less than or equal to 5.2 kilopascals (kPa), which is equal to 0.75 pounds per square inch absolute (psia),^[41] or (iii) use a combination of resins meeting either (i) or (ii). Facilities with RMH process units would also be required to process wood material that was purchased pre-dried to a moisture content of no more than 30 percent (weight percent, dry basis) or that has been dried in a dryer located at the PCWP facility. The proposed requirement to process dried wood did not apply for wet formers and wastewater operations.

No options more stringent than the RMH process unit work practices were identified for resin tanks, softwood and hardwood plywood presses, engineered wood product presses and curing chambers, blenders, formers, finishing saws, finishing sanders, panel trim chippers, or hardboard humidifiers at new or existing affected sources, or for reconstituted wood product board coolers at existing affected sources. Reconstituted wood product board coolers at new affected sources are already subject to standards under the PCWP NESHAP, so were not addressed by our proposal.

For RMH wastewater operations, the EPA proposed a work practice in addition to the process unit work practice standards that would require facilities with wastewater operations to implement one of the following measures:

• Follow the plan required in40 CFR 63.2268 for wet control devices used as the sole means of reducing HAP emissions from PCWP process units; or
• Reduce the volume of wastewater to be processed by reusing or recirculating wastewater in the PCWP process or air pollution control system; or
• Store wastewater in a closed system; or
• Treat the wastewater by using an onsite biological treatment system, or by routing the wastewater to an offsite POTW or industrial wastewater treatment facility.

b. What comments on our proposed RMH standards did we receive?

Comment: One commenter questioned the justification of work practice standards for RMH process units.

EPA response: We maintain that work practices developed under CAA section 112(h) are legally justified and are the appropriate format of standard for RMH process units, because it is not feasible to prescribe or enforce an emission standard for RMH process units.^[42 43]

Comment: Other commenters agreed that work practices are justified under CAA section 112(h) but expressed significant concern about the proposed definition of “non-HAP resin.” To reduce implementation uncertainty, the commenters stated that the EPA should focus application of the weight percent limits (0.1 percent for carcinogens and 1 percent for non-carcinogens) on known resin-related HAP and clarify that the limits, which are based on OSHA hazard communication thresholds for reporting, are not cumulative. One commenter also requested that the EPA apply the tiered approach from the amino/phenolic resin NESHAP (based on storage tank capacity) for purposes of setting the vapor pressure limits in the PCWP NESHAP. The commenters asserted that these changes are needed to properly scope the standards to avoid unintended consequences and unaccounted for ( printed page 41421) market impacts to upstream suppliers of resins. Commenters also requested whether the process under 40 CFR 63.6(g) for approval of an alternative non-opacity emission standard could be used in specific situations where it is not feasible to use a non-HAP resin or a resin that meets the vapor pressure standards.^[44]

EPA response: The EPA agrees that the definitions around non-HAP resin and the resin requirements require further clarification. The EPA also agrees that the vapor pressure requirements should account for different tank sizes, as suggested by commenters. In this final action we are clarifying the definition of “non-HAP resin” and “maximum true vapor pressure” and incorporating a tiered limits for vapor pressure based on resin tank size.

Comment: We received numerous comments opposing the proposed wastewater work practice options. Among other issues, commenters asserted that the definition of “wastewater operations” as proposed goes beyond the PCWP affected source, the EPA did not account for the costs associated with this overly broad definition, and the EPA lacked emissions information to justify the wastewater work practice.

EPA response: The EPA also agrees that, given the broad set of operations included under the proposed wastewater work practice, most of which are not part of the affected source as defined in the current rule, we lacked the authority to impose requirements beyond the defined affected source.

c. What RMH standards are we finalizing?

As a result of the comments, we are updating the proposed definition of “non-HAP resin” in the final rule to focus on the known resin-related HAP and to clarify how the weight percent limits are to be applied. In the final rule, non-HAP resin is defined as “a resin that contains less than 0.1 percent by mass of formaldehyde and less than 1.0 percent by mass each of phenol, methanol, and MDI.” Using this definition and following the intent of the May 2023 proposal for the weight percentages to be applied for each HAP, an example resin with 0.5 weight percent phenol and 0.7 weight percent methanol would be considered a non-HAP resin because the 1.0 weight percent threshold is applied to each HAP. Under the vapor pressure option, the final standard contains tiered limits for vapor pressure based on resin tank size consistent with the amino/phenolic resin NESHAP and updating the definition of “maximum true vapor pressure” for the final rule.^[45] The final vapor pressure limits for resins received at the PCWP facility are 5.2 kPa (0.75 psia) for resins stored in resin tanks with capacity greater than or equal to 40,000 gallons and 13.1 kPa (1.9 psia) for resins stored in one or more resin tanks with capacity less than 40,000 gallons. Finally, we note that under the PCWP NESHAP facilities can already request approval of an alternative standard following the process set forth under 40 CFR 63.6(g).^[46]

Considering the EPA's proposed overly broad definition of wastewater operations that extends beyond the affected source and that no HAP emission reductions are estimated to be achieved with the wastewater work practices, the EPA is not finalizing the four work practice options for “wastewater operations” that were proposed in addition to the work practice standards for RMH process units. For the final rule, the term “wastewater operations” is being replaced with the wording from the definition of affected source “onsite wastewater treatment operations specifically associated with PCWP manufacturing,” in the definition of RMH process units. The resin-related RMH process unit standards apply for “onsite wastewater treatment operations specifically associated with PCWP manufacturing.”

2. Atmospheric Refiners

Atmospheric refiners operate with continuous infeed and outfeed of wood material and under atmospheric pressure for refining (rubbing, grinding, or milling) wood material into fibers or particles used in particleboard or dry formed hardboard production. Atmospheric refiners are further characterized based on their placement before or after dryers in the PCWP production process. In addition to a definition of “atmospheric refiner,” we proposed definitions of “dried wood atmospheric refiner” and “green wood atmospheric refiner” to distinguish atmospheric refiners following dryers in the PCWP process ( e.g., dried wood atmospheric refiners) from other atmospheric refiners ( e.g., green wood atmospheric refiners).

a. What atmospheric refiner standards did we propose?

We proposed numerical emission limits for existing and new atmospheric refiners of each type developed pursuant to CAA sections 112(d)(2) and (3) using performance data collected from the CAA section 114 survey of PCWP facilities in 2022. The proposed standards were based on the MACT floor. More-stringent beyond-the-floor options were analyzed and rejected due to the high costs relative to the emission reductions that would be achieved, energy usage, and other non-air quality environmental impacts. Although the more stringent beyond-the-floor options were not proposed, we proposed to include a provision in 40 CFR 63.2240(d)(6) to give facilities the option of complying with the more stringent limits in Table 1B in place of the proposed limits in the proposed Table 1C to Subpart DDDD of Part 63 (“Table 1C”) if they choose to meet the more stringent option.

b. What comments on the proposed atmospheric refiner standards did we receive?

Comment: We received several comments noting that the numerical standards were not necessary and suggested using a work practice. Commenters also requested a concentration-based compliance option as well as revisions to the proposed definitions and classifications for atmospheric refiners.

EPA response: The EPA maintains that work practice standards cannot be established for atmospheric refiners under CAA section 112(h) because emissions can be captured, conveyed, and measured. However, the EPA agrees that an additional concentration-based compliance option and clarifying language is needed to reduce uncertainty and confusion with the proposed atmospheric refiner standards.

c. What atmospheric refiner standards are we finalizing?

Due to the requirement for EPA to establish emission standards for atmospheric refiners under CAA sections 112(d)(2) and (3), we are finalizing the numerical standards for atmospheric refiners as proposed. In response to comments received, we are adding concentration-based standards, in addition to the lb/ODT standards. We are modifying the proposed definition for atmospheric refiners to remove reference to wet-formed hardboard and fiberboard. We are also redefining the proposed “green wood atmospheric” and “dried wood atmospheric refiner,” ( printed page 41422) terms as “multipurpose atmospheric refiner” and “post-dryer atmospheric refiner,” respectively, to eliminate confusion surrounding references to “green” and “dried” wood when the distinction to be made hinges on placement of a subset of refiners after dryers in the PCWP process. In the revised rule, all atmospheric refiners that are not “post-dryer atmospheric refiners” are defined as “multipurpose atmospheric refiners.” These definitional changes do not alter the proposed MACT floors for green and dried wood atmospheric refiners because they are consistent with how the MACT floors and MACT were determined.

The final total HAP standards for multipurpose atmospheric refiners are 1.2E-01 lb/ODT or 15 parts per million volume, dry (ppmvd) for existing units and 2.4E-03 lb/ODT or 3.3 ppmvd for new units. The final standards for existing post-dryer atmospheric refiners are 4.1E-03 lb/ODT or 8.5E-01 ppmvd, and 3.3E-03 lb/ODT or 6.5E-01 ppmvd for new units.^[47]

3. Stand-Alone Digesters and Fiber Washers

Stand-alone digesters are used to steam or water soak wood chips so that they may be easily rubbed apart or ground into fibers in atmospheric separate refiners that operate downstream from the digesters. Stand-alone digesters have batch operating cycles that differ from pressurized refiner steaming vessels (sometimes called “digesters”) used to preheat wood chips prior to pressurized refining. Pressurized refiner steaming vessels have continuous infeed and outfeed without pressure release between the steaming vessel and refiner part of the pressurized refiner.

Fiber washers are units in which water-soluble components of wood (hemicellulose and sugars) that have been produced during digesting and refining are removed from the wood fiber before the fiber is used in fiberboard or hardboard production. In a fiber washer, wet fiber leaving a refiner is further diluted with water and then passed over a filter, leaving the cleaned fiber on the surface.

One wet/dry process hardboard facility operated a batch stand-alone digester and a fiber washer at the time of the May 2023 proposal. This facility has since ceased operations. No PCWP affected sources are expected to operate stand-alone digesters or fiber washers, but the possibility cannot be entirely ruled out. Thus, standards for these process units are being finalized in this action. Both process units meet the criteria under CAA section 112(h)(2)(B) for establishing a work practice standard because there are technological and economic limitations to measuring emissions.

a. What standards for stand-alone digesters and fiber washers were proposed?

The potential for HAP emissions from stand-alone digesters is reduced when: (1) clean steam from the boiler is used for the digestion process (as opposed to steam potentially contaminated with HAP being reused from another process); and (2) HAP-containing or wood pulping chemicals ^[48] are not added to the digestion process. Thus, we proposed a work practice requiring clean steam to be used in the digesters and prohibiting addition of HAP-containing or wood pulping chemicals to the digestion process. No regulatory options more stringent than the work practice were identified for further consideration for existing or new stand-alone digesters.

We proposed a work practice for PCWP fiber washers to use fresh water for washing and processing fiber without addition of wood pulping or HAP-containing chemicals.

b. What comments on the proposed stand-alone digester and fiber washer standards did we receive?

Comment: One commenter explained their wet end process uses a large amount of water, which is recycled to optimize the volume of water discharged from the process and balance pH. The commenter requested the EPA eliminate the requirement to use only fresh water for washing because it is technically infeasible.

EPA response: The EPA agrees with the commentator's argument that using fresh water is infeasible due to process design and the increase in volume of wastewater that would result. Therefore, we are not finalizing the requirement to use only fresh water for washing in the work practice standards for fiber washers.

c. What standards for stand-alone digesters and fiber washers are we finalizing?

We are finalizing the proposed definition of “stand-alone digester” and an amendment to the definition of “pressurized refiner” in 40 CFR 63.2292 to distinguish between these two process units. Pressurized refiners are already subject to emission standards in the PCWP NESHAP. We are amending the current definition of pressurized refiner to state that: “Pressurized refiners include steaming vessels that operate under pressure to continuously feed and vent through the pressurized refiner.” We are finalizing the stand-alone digester work practice requiring clean steam to be used in the digesters and prohibiting addition of HAP-containing or wood pulping chemicals to the digestion process. Initial and continuous compliance with the stand-alone digester work practice must be demonstrated through recordkeeping.

We are finalizing the work practice requirement to process fiber without addition of HAP-containing or wood pulping chemicals. Initial and continuous compliance with the fiber washer work practice must be demonstrated through recordkeeping. No regulatory options more stringent than the work practice were identified for further consideration for existing or new fiber washers. No new fiberboard or hardboard mills are projected. Therefore, no new PCWP affected sources are expected to use fiber washers.

4. Fiberboard Mat Dryers and Press Predryers at Existing Sources

Fiberboard mat dryers are conveyor-type dryers used to dry wet-formed fiber mats. Press predryers are used in the wet/dry hardboard process to remove additional moisture from the hardboard mat after it exits the fiberboard mat dryer before the mat enters the hardboard press. The PCWP NESHAP already contains standards for fiberboard mat dryers (heated zones) and hardboard press predryers at new sources.

a. What Fiberboard mat dryers and press predryers did we propose for existing sources?

The EPA proposed standards for the heated zones of existing fiberboard mat dryers and hardboard press predryers. For the fiberboard mat dryer (heated zones), the proposed MACT floor is 4.9E-02 lb total HAP per MSF on a 1/8-inch thickness basis. The MACT floor ( printed page 41423) for the press predryer is 8.0E-02 lb total HAP per MSF on a 1/8-inch thickness basis. The emission limit for each dryer was calculated using HAP test data collected in 2022 through a CAA section 114 survey. These MACT floor calculations were based on limited data sets.^[49] The units that were tested in the 2022 survey were at the same wet/dry hardboard facility discussed in section III.D.3, which has ceased operations since the May 2023 proposal was published. The EPA considered beyond-the-floor regulatory options for both dryers, but these options were rejected because of the high costs relative to the HAP emission reduction that could be achieved, energy usage, and other non-air quality environmental impacts.

b. What comments did the EPA receive on the proposed standards for Fiberboard mat dryers and press predryers?

Comment: The EPA received comments supporting and opposing the proposed emission limits for fiberboard mat dryers and press predryers. One commenter recommended that the EPA rely on data from sources with controls that have ceased operation to set MACT standards instead of data from the only remaining units in operation at the time of proposal, which were uncontrolled. The commenter argued that the EPA contravenes the CAA by setting weaker standards using data from this single source when previously existing sources were better performing. A different commenter supported the proposed MACT analysis and emission limits and requested a change to the definition of fiberboard mat dryer to clarify applicability for units producing wet/dry hardboard. Another commenter asked the EPA to specify the emission standards for existing fiberboard mat dryers and press predryers in Table 1C on both a 1/8-inch and 1/2-inch basis for consistency with Table 1A to Subpart DDDD of Part 63 (“Table 1A”) and asked the Agency to clarify the dates in Table 1C.

EPA Response: We disagree with the commenter's statement that development of these limits contravenes the CAA. According to CAA section 112(d)(3)(B), the MACT floor for existing sources is the average emission limitation achieved by the best performing five sources (for which the Administrator has or could reasonably obtain emissions information) in a category or subcategory with fewer than 30 sources. The D.C. Circuit has affirmed that CAA section 112 “says nothing about what data the Agency should use to calculate emission standards.” ^[50] The EPA followed the law when developing the MACT floors for fiberboard mat dryers and hardboard press predryers based on the emission data from the source remaining in operation at the time of the 2022 section 114 survey.^[51] The most complete and relevant data on fiberboard mat dryer and press predryer emissions were collected during this survey. As noted in this section, the EPA did consider beyond-the-floor measures for both the fiberboard mat dryer and press predryer based on control technology and rejected these options for both dryers because of the high costs relative to the HAP emission reduction that could be achieved, energy usage, and other non-air quality environmental impacts.

c. What standards for Fiberboard mat dryers and press predryers are we finalizing?

After considering comments, we are finalizing the proposed standards for existing source fiberboard mat dryers and press predryers as proposed. We modified the proposed Table 1C to include the 1/8-inch limits converted to equivalent values in terms of 1/2-inch. We added a footnote to the table to clarify that the existing source limits are not applicable to new sources, which have their own limits from the 2004 rule in Tables 1A or 1B to Subpart DDDD of Part 63. Regarding the other changes requested by commenters, we clarified the definition fiberboard mat dryer applies to dryers in the wet/dry hardboard process.

5. Log Vats

Log vats are used to condition logs before they are cut into veneer or wood strands. Hot water vats in which logs are immersed are often open to the atmosphere. In log steaming or “chest” vats, logs are placed in the vat in batches, the door is closed, and steam (which condenses in the vat) along with hot water sprays are used to condition the logs for a specified time before the logs are removed for veneer production. The EPA is finalizing the proposed definition for “log vat” in 40 CFR 63.2292 that applies to both hot water and log steaming vats.

a. What log vat standards did the EPA propose?

We proposed a work practice standard based on CAA section 112(h)(2)(A) and (B) for log vats at existing or new sources because log vats have neither the proper emissions capture and conveyance ductwork nor stacks where emissions testing could be conducted. The proposed work practice standard would require facilities to: (a) operate each vat using a site-specific target log temperature that does not exceed 212 °F, measured in the water used to soak the logs or in the wood cut at the lathe or stranders; and (b) operate each vat to reduce the potential for fugitive emissions by either: (1) covering at least 80 percent of the vat hot water surface area for soaking vats in which logs are submerged; or (2) keeping doors closed while steam or hot water showers are being applied inside log steaming vats.

b. What comments on the proposed log vat standards did we receive?

Comment: One commenter opposed distinguishing between hot water vats and log steaming vats and questioned the EPA's justification for using work practice standards over numeric standards for log vats. Other commenters agreed log vats are eligible for work practice standards but recommended changes in the proposed work practice standards pertaining to the potential for fugitive emissions. The commenters stated that covering logs in log vats can create health and safety concerns and hinder operations. They noted operators with steam vats already close the doors during steaming/spraying as standard procedures, making this requirement redundant.

EPA Response: As discussed in a docketed memorandum, the EPA has concluded that work practice standards for log vats are justified given the technical limitations and measurement infeasibilities.^[52] The EPA has also noted the safety concerns raised by commenters, and agrees that requiring an 80 percent log vat cover would interfere with operations and potentially lead to health and safety concerns.

( printed page 41424)

c. What log vat standards are we finalizing?

As a result of the concerns raised by commenters on the proposed work practice standards, we are finalizing the temperature limitation work practice but not the requirement to cover at least 80 percent of the hot water surface or keep doors of log steaming vats closed. This change also eliminates the distinction in hot water and steaming vats.

6. Mixed PCWP Process Streams Regulated at Existing Sources

Some PCWP facilities route emission streams from multiple process units of the same or different types into one shared HAP control system such as a regenerative thermal oxidizer (RTO), regenerative catalytic oxidizer (RCO), biofilter, or process incineration system to meet the compliance options in Table 1B. In a few mixed process arrangements, an emissions stream from a remanded unit was mixed at the inlet to a HAP control device and co-controlled with other process units listed in Table 1B such that the combined emission stream became subject to the Table 1B limits when the control system was initially installed to meet the PCWP NESHAP or as part of the PCWP plant design. Due to the mixing of emissions from each individual type of process unit, the PCWP process stream cannot be distinguished at the inlet or outlet of the control device.

a. What standards did we propose for mixed process streams?

We proposed a requirement that mixed PCWP process streams from remanded units meeting the compliance options in Table 1B be treated as a separate type of emission stream that remains subject to the Table 1B limits. Mixed PCWP process streams are defined in 40 CFR 63.2292 as an emission stream from a process unit subject to the final amendments that was commingled with emissions stream(s) from process unit(s) subject to the compliance options in Table 1B before July 6, 2026 at an affected source that commenced construction (or reconstruction) on or before May 18, 2023. The definition of “mixed PCWP process stream” refers specifically to a “stream” as opposed to a whole process unit because there can be uncaptured or uncontrolled emissions from a remanded process unit in addition to the captured emission stream from the remanded unit that is routed to the HAP control device as part of a mixed PCWP process stream.

b. What comments on the proposed mixed PCWP process stream limits did we receive?

Comment: Two commenters agreed with the EPA's proposal that mixed PCWP process streams continue to meet compliance options in Table 1B. One commenter requested the Notice of Compliance Status (NOCS) for mixed PCWP process streams be due within a short timeframe after publication in the Federal Register ( e.g., 30 or 60 days) rather than on the date of publication.

EPA Response: We acknowledge commenters support for the proposed requirement that mixed PCWP process streams comply with options in Table 1B. We agree that 30 days would allow facilities the necessary time to create and submit their NOCS.

c. What mixed PCWP process stream limits are we finalizing?

In response to these comments, we are finalizing requirements for the mixed PCWP process streams as proposed with the exception that the NOCS shall be due no later than 30 days after the date of publication.

E. MACT Standards for Process Units With MDI Emissions

The EPA is finalizing standards to regulate MDI emissions from reconstituted wood product presses using MDI, tube dryers that blow-line blend MDI resin, and miscellaneous coating operations. Sections III.E.1 through 3 summarize the final standards, the key comments received and our responses, and our final decisions and rationale on the standards for this final action. A complete discussion of changes from the May 2023 proposal can be found in the RTC document and a docketed memorandum.^[53]

1. Reconstituted Wood Product Presses

a. What reconstituted wood product press MDI standards did we propose?

The EPA proposed MDI emission standards for reconstituted wood product presses that produce OSB and for reconstituted wood product presses that produce particleboard or MDF (PB/MDF). We developed separate standards because product differences affect MDI emissions.

For OSB presses, the proposed MACT standards for both new and existing sources are based on 3xRDL for MDI, which exceeded the calculated MACT floor. The 3xRDL values were substituted for the calculated MACT floor to ensure that the standards are established at the minimum level at which emissions can be measured reliably. The proposed MACT standards for new and existing OSB presses are 2.5E-04 lb MDI/MSF 3/4” (1.3E-04 lb/MSF 3/8”) or 2.7E-02 mg MDI/dscm.

The proposed MACT floor for existing PB/MDF presses using MDI is 8.4E-04 lb/MSF 3/4” or 2.0E-01 mg MDI/dscm. For new sources, the 3xRDL values exceeded the calculated MACT floor concentration and emission rate. Therefore, the 3xRDL values were used in place of the calculated MACT floor for new source PB/MDF presses using MDI to ensure that the standards are established at the minimum level at which emissions can be measured reliably. For new PB/MDF presses the MDI proposed MACT limit based on the 3xRDL values is 2.3E-04 lb MDI/MSF 3/4” or 2.7E-02 mg MDI/dscm.

Considering the low levels of MDI emitted and that reconstituted wood product presses already meet HAP limits in the PCWP NESHAP using robust HAP controls, no regulatory options more stringent than the existing or new source MACT floors for MDI were identified for OSB or PB/MDF reconstituted wood product presses.

b. What comments on the proposed MDI reconstituted wood product press standards did we receive?

Comment: The EPA received comments supporting and opposing subcategorization of reconstituted wood product presses for purposes of limiting MDI.

EPA response: The EPA maintains subcategorizing reconstituted wood product presses using MDI by product is within the EPA's authority in CAA section 112(d)(1), which states, “The Administrator may distinguish among classes, types, and sizes of sources within a category or subcategory in establishing standards.” The manner and type of press operation are distinct between products. Depending on the product type ( i.e., OSB, or PB/MDF), presses require different operating temperatures ( e.g., OSB is pressed at higher temperature) and feed stocks ( e.g., OSB are created with larger wood strands), which affect emission rates. Therefore, subcategorizing by product is appropriate.

Comment: The EPA also received a comment stating that it is unnecessary for the EPA to set numerical standards for MDI, and that MDI emissions would be more appropriately regulated under ( printed page 41425) the work practice for RMH process units.

EPA response: We maintain that the EPA is required to set standards for HAP such as MDI that are known to be emitted from reconstituted wood products presses. Reconstituted wood products presses do not meet the criteria under CAA section 112(h) for establishing work practices.

c. What MDI reconstituted wood product press standards are we finalizing?

The EPA is finalizing the proposed MDI MACT limits for reconstituted wood product presses. The EPA is maintaining the designated subcategorization based on the product type, as described above. Reconstituted wood product presses operating HAP controls are expected to meet the MACT floor for existing and new sources. However, it is currently unknown whether presses at two particleboard facilities that meet the PCWP production-based compliance option (PBCO) using pollution prevention measures would meet the MDI MACT floor.^[54 55]

2. Tube Dryers

Primary tube dryers often incorporate blow-line blending in which resin is added to wood fibers as they enter the primary tube dryer. The resin and wood fibers mix with the turbulent conditions in the primary tube dryer as the wood fiber is dried. Primary and secondary tube dryers are often co-controlled. Primary tube dryers may also be co-controlled with a reconstituted wood product press.

a. What MDI standards did the EPA propose for tube dryers?

The proposed MACT standard for MDI from new and existing tube dryers is 1.7E-02 lb/ODT or 0.68 mg MDI/dscm. This standard is based on the MACT floor. No regulatory options more stringent than the MACT floor were identified for tube dryers that blow-line blend MDI.

b. What comments on the proposed MDI standard for tube dryers did we receive?

Comment: One commenter indicated MDI standards for tube dryers are not necessary because all tube dryers with blow-line blending MDI resin are equipped with HAP emissions controls and the standard will only serve to incur an additional cost of emissions testing every five years with no environmental benefit.

EPA response: The EPA disagrees with the commenters claim that MDI standards for tube dryers are not necessary. Tube dryers blow-line blending MDI were identified as one of the primary sources of MDI emissions in the PCWP source category in the 2020 RTR.^[56] Further, source testing in 2022 identified MDI emissions from an RTO-controlled tube dryer to be above the detection limit. For these reasons, establishing standards for tube dryers is appropriate.

c. What MDI standards are we finalizing for tube dryers?

The EPA is finalizing the proposed MACT standard for MDI from new and existing tube dryers. The MACT standard for tube dryers is 1.7E-02 lb/ODT or 0.68 mg MDI/dscm.

3. Miscellaneous Coatings Operations

a. What MDI standards did we propose for miscellaneous coatings operations?

The EPA proposed MDI emission standards for miscellaneous coating operations in which MDI moisture sealants are applied to engineered wood products such as parallel strand lumber or LVL.

b. What comments did the EPA receive on the proposed MDI standards for miscellaneous coatings operations?

Comment: Commenters questioned the necessity of the MDI numerical limit and requested reduced testing frequency for the MDI coating operation.

EPA response: The EPA maintains the standard is required to ensure MDI is properly regulated across miscellaneous coatings operations. Emissions from this source are measurable and capturable; therefore, they do not meet the criteria under CAA section 112(h) for establishing a work practice. See section III.F for an explanation of EPA's performance testing, monitoring, and recordkeeping and reporting requirements

c. What MDI standards did we finalize for miscellaneous coatings operations?

The final MACT limit for existing and new sources is 1.9E-03 lb MDI emitted/lb sealant applied, or 1.4E-05 lb MDI/ft² surface area coated based on coating HAP content. The limit is based on the MACT floor. No options more stringent than the MACT floor emission level were identified for further analysis. The EPA is finalizing the five-year testing frequency, as proposed.

F. Requirements for Performance Testing, Monitoring, and Recordkeeping and Reporting

1. Performance Testing

No comments were received on the proposed emission test methods included in Table 4 to Subpart DDDD of Part 63 (“Table 4”). We are finalizing the proposed methods without change. The final emissions test methods for total HAP include EPA Method 320,^[57] NCASI Method IM/CAN/WP-99.02,^[58] NCASI Method ISS/FP-A105.0,^[59] or ASTM D6348-12e1 ^[60] with the conditions discussed in section V.J of this preamble. EPA Method 326 ^[61] is required for MDI emissions measurement, in which a minimum sample of 1 dscm must be collected. For PM as a surrogate to HAP metals, either EPA Method 5 ^[62] or EPA Method 29 ^[63] is required with a minimum sample volume of 2 dscm. For Hg, EPA Method 29 or EPA Method 30B ^[64] are required, with a minimum sample volume of 2 dscm for EPA Method 29. EPA Method 26A ^[65] was proposed for HCl emissions measurement with a minimum sample volume of 2 dscm. The recently updated EPA Method 23 ^[66] is required for PAH and D/F emission measurement with a minimum sample volume of 3 dscm. Consistent with the treatment of non-detect data used to establish the emission standards, we are finalizing a requirement that non-detect data be treated as the MDL in test averages used to demonstrate compliance with the standards in Table 1C, Table 1D to Subpart DDDD of Part 63 (“Table 1D”), or Table 1E to Subpart DDDD of Part 63 (“Table 1E”). We are revising the rule to add Table 12 to Subpart DDDD of Part 63 (“Table 12”) to provide the toxic equivalence factors (TEFs) to multiply by the individual D/F congener test results to determine TEQ.^[67] In addition, we are adding EPA Method 9 ^[68] to the ( printed page 41426) rule for use in conjunction with pressure drop monitoring across mechanical collectors and other dry control devices.

a. What performance testing frequency did we propose?

For the new and existing source emission limits being added to the PCWP NESHAP, we proposed that performance testing would be required every 5 years (60 months).

b. What comments did we receive on the proposed performance testing frequency?

Comment: Multiple commenters expressed concern about the proposed five-year frequency of emissions testing. One commenter argued that testing every five years is too infrequent to ensure compliance and recommended semiannual testing or a continuous emission monitoring system (CEMS). Other commenters requested the EPA allow performance testing of PAH, HCl, and Hg be one time sampling events rather than repeated every five years considering the high costs of testing, complexity of test methods, and lack of laboratory availability for these trace compounds.

EPA response: Regarding the assertion that stack testing every five years cannot ensure compliance, we note that demonstration of compliance is not accomplished by performance testing alone but is paired with ongoing parametric monitoring established during performance testing to show compliance with the emission limits. Routine performance testing is necessary to provide periodic verification of the operation of control devices and to ensure the parametric monitoring remains relatable to actual emissions. We maintain that the proposed testing frequency, in combination with required parametric monitoring, is sufficient to ensure compliance and that CEMS are unnecessary for PCWP standards being finalized.

c. What performance testing requirements are we finalizing?

The final rule requires initial performance tests to be completed within 180 days after the compliance date for the new standards and subsequent performance testing every five years (60 months), thereafter.

2. Parameter Monitoring

The preamble for the May 2023 proposal described the proposed parametric monitoring requirements in detail.^[69] After reviewing public comments, we are finalizing the parametric monitoring requirements substantially as proposed with the following key changes:

• We are allowing the owner or operator to monitor pressure drop weekly opacity observations in lieu of continuous opacity monitoring system (COMS) for mechanical collectors (or other dry control devices not otherwise mentioned in Table 2 to Subpart DDDD of Part 63 [“Table 2”]) to demonstrate continuous compliance with PM limits.
• We are clarifying language in Table 10 to Subpart DDDD of Part 63 “Table 10” to require the notification and reporting requirements for performance evaluations for only COMs and CEMS, although we are retaining the requirement to perform performance evaluations on other continuous parameter monitoring systems (CPMS).
• We have corrected typographical errors related to electrified filter bed (EFB) monitoring by clarifying that only voltage monitoring is required for EFB.
• We changed the semiannual flow sensor calibration to an annual calibration, which is consistent with other calibration requirements throughout the rule.
• We are amending the rule to include language specifying when pressure drop is to be monitored.

For more details and our rationale surrounding these changes and other minor changes to the monitoring requirements, please see the RTC document in the docket for this action. The final monitoring requirements are summarized in this section.

Continuous compliance with the standards proposed in Tables 1C, 1D, or 1E must be demonstrated through control device parameter monitoring coupled with the proposed periodic emissions testing described in section III.F.1. The parametric monitoring already required in Table 2 for thermal oxidizers, catalytic oxidizers, or biofilters to demonstrate continuous compliance with the compliance options in Table 1B is also required to demonstrate ongoing compliance with the standards in Tables 1C, 1D, or 1E. In addition to the parametric monitoring currently specified for thermal oxidizers, catalytic oxidizers, or biofilters, the amendments to Table 2 as revised by this final action include the following parameter monitoring requirements for the types of air pollution control devices (APCDs) that we expect to be used to comply with the standards in Tables 1D or 1E:

• For wet electrostatic precipitator (WESP), secondary electric power input and liquid flow rate;
• For dry electrostatic precipitator (ESP), secondary electric power input or opacity;
• For wet PM scrubbers, liquid flow rate and pressure drop;
• For wet acid gas scrubbers, liquid flow rate and effluent pH;
• For EFBs, ionizer voltage or current and pressure drop; and
• For mechanical collectors (e.g., cyclone or multiclone) or other dry control devices, a choice of opacity monitored using a COMS or pressure drop with weekly opacity observations.

The operating limits for these parameters must be established consistently with the existing provisions of 40 CFR 63.2262, as the average of the three test run averages during the performance test. Continuous compliance with the parameters for WESP, dry ESP, wet scrubbers, and EFB must be determined by comparing the three-hour block average parameter average to the limit established during the performance test.

Consistent with existing provisions in Table 2, the rule is amended to require that a source owner choosing to rely on a control device other than a thermal oxidizer, catalytic oxidizer, or biofilter used to meet a compliance option in Table 1C petition the Administrator for site-specific operating parameters to be monitored or to maintain the three-hour block average total hydrocarbon (THC) concentration within the limits established during the performance test. The source owner of process units that meet a compliance option in Tables 1C, 1D, or 1E without using a control device must maintain on a daily basis the process unit controlling operating parameter(s) within the ranges established during the performance test or maintain the three-hour block average THC concentration within the limits established during the performance test.

For control devices where opacity is used as an operating parameter, a COMS is required, and the 24-hour block average opacity must not exceed 10 percent (or the highest hourly average measured during the performance test). Table 10 indicates that the requirements for opacity standards in 40 CFR 63.6(h)(2) through (9) do not apply because opacity is an operating limit and not an emission standard.

Continuous monitoring requirements associated with the work practices in Table 3 to Subpart DDDD of Part 63 (“Table 3”) include combustion unit bypass stack usage monitoring ( e.g., temperature or bypass damper position), lumber kiln dry bulb temperature ( printed page 41427) monitoring for comparison with the batch average or daily block average dry bulb temperature limit, monitoring of lumber moisture (with semiannual averaging) for comparison to lumber minimum moisture content limits in Table 11, or monitoring of lumber kiln temperature (with 3-hour block averaging) and lumber moisture (with semiannual averaging) for comparison to limits in an approved site-specific plan.

We are finalizing as proposed a requirement to continuously monitor process unit bypass stack usage at all times while the process units are operating, including times when the process unit is undergoing startup or shutdown, and during the operating conditions as specified in 40 CFR 63.2250(f)(2) through (4). This requirement is included to ensure that reliable data are available to evaluate continuous compliance with the PCWP NESHAP requirements.

Consistent with NESHAP general provisions at 40 CFR part 63, subpart A, a source owner is required to operate and maintain the source, its air pollution control equipment, and its monitoring equipment in a manner consistent with safety and good air pollution control practices for minimizing emissions, to include operating and maintaining equipment in accordance with the manufacturer's recommendations. Owners are required to prepare and keep records of calibration and accuracy checks of the continuous monitoring system (CMS) to document proper operation and maintenance of the monitoring system.

3. Recordkeeping and Reporting

The EPA received no significant comments on the recordkeeping requirements, so they are being finalized as proposed. A source owner is required to submit semi-annual compliance summary reports that document both compliance with the requirements of the PCWP NESHAP and any deviations from compliance with any of those requirements, consistent with existing requirements in the PCWP NESHAP. Owners and operators are required to maintain the records specified by 40 CFR 63.10 and, in addition, are required to maintain records of all monitoring data, in accordance with the PCWP NESHAP.^[70]

G. Other Actions

We are finalizing revisions to the PCWP NESHAP to remove obsolete rule language including the emissions averaging compliance option for existing affected sources, dates, and startup/shutdown provisions that are no longer in effect. Removing the outdated language from the PCWP NESHAP streamlines the rule and makes it easier to read. We are also finalizing updates and clarifications of the electronic reporting requirements. In addition, we reviewed issues raised by reconsideration petitioners following the 2020 RTR. The final revisions and rationale are presented in this section.

1. Emissions Averaging

Emissions averaging was included in the 2004 rule as a compliance option for use at existing affected sources. We proposed to remove the emissions averaging compliance option in the May 2023 proposal because no existing facilities are using it, and emissions averaging is not an option for new affected facilities. The only facility to use the option has now ceased PCWP production. Also, the new emission standards being added for process units and HAP subject to the 2007 partial remand and vacatur with this action further diminish opportunities for emissions averaging, and removing the emission averaging language simplifies the rule. Two commenters agreed with removing the emissions averaging option and no commenters objected. Therefore, we are removing the emissions averaging option from the PCWP NESHAP in this final action.

2. Obsolete Dates and Provisions

On August 13, 2020, the EPA published several amendments to the PCWP NESHAP with corresponding compliance dates for transitioning from obsolete provisions that have since passed.^[71] This final rule contains additional amendments with multiple associated dates discussed in section III.H of this preamble. We proposed in the May 2023 proposal to remove the obsolete dates and provisions that are no longer in effect to improve clarity of the PCWP NESHAP, including:

• In40 CFR 63.2233(1) through (3), cross-references to specific paragraphs needed to implement the 2020 RTR amendments were proposed to be removed and replaced with a reference to the proposed 40 CFR 63.2233(e), which provides compliance dates for the rule requirements proposed in this action.
• Paragraphs40 CFR 63.2250(a) through (c) were proposed to be removed and reserved because their requirements no longer apply.
• Date language was proposed to be removed in paragraphs40 CFR 63.2250(f) and (g), which are paragraphs that replaced the obsolete paragraphs 40 CFR 63.2250(a) through (c) in the 2020 RTR amendments.
• Paragraphs40 CFR 63.2280(b) and (d) contained dates for when electronic submittal of initial notifications and performance test results became effective. 40 CFR 63.2281(b)(6) contained dates for when electronic submittal of semiannual reports became effective. These dates have passed, and the electronic reporting requirements are in full effect, so we proposed to remove dates to make the rule easier to read.
• The first part of paragraph40 CFR 63.2281(c)(4) contains dates for language that was phased out as well as dates for when electronic reporting requirements were phased in. Similarly, 40 CFR 63.2282(a)(2) contains obsolete dates and language intended to phase out some records and phase in other records. We proposed to remove the obsolete language to simplify the rule because the dates have now passed.
• Row 2 in Table 9 to Subpart DDDD of Part 63 was proposed to be removed and reserved because the requirement for an SSM report is no longer in effect.
• The 2020 RTR amendments added a column to Table 10 to clarify which general provisions in40 CFR part 63, subpart A applied before and after August 13, 2021, for existing sources. The now obsolete column pertaining to requirements before August 13, 2021, was proposed to be removed. Those amendments pertain to SSM provisions that were removed and to reporting provisions that were added on August 13, 2020.

For clarity, we are retaining date language from the 2020 RTR that specified compliance dates for standards and electronic reporting provisions added with that rulemaking. We have also taken care to insert compliance date language for the new standards finalized in this action as discussed further in section III.H of this preamble.^[72]

We received no substantial comments on removal of the obsolete dates and provisions. Therefore, we are finalizing the changes as proposed.

3. Electronic Reporting Updates and Clarifications

On November 19, 2020, the EPA published a final rule incorporating standard electronic reporting language into the general provisions at 40 CFR ( printed page 41428) 63.9(k). We proposed to update the electronic reporting language in 40 CFR part 63, subpart DDDD, to refer to the provisions in 40 CFR 63.9(k) in addition to other revisions. The proposed revisions are as follows:

• We proposed to require that initial notifications and notifications of compliance status be submitted in a user-specified format such as PDF in40 CFR 63.2280(b) and (d) instead of 40 CFR 63.2281(h).
• General provisions pertaining to submittal of CBI were proposed to be removed from40 CFR 63.2281(h), (i)(3), and (j)(3).
• In40 CFR 63.2281(k), we proposed to replace language pertaining to Compliance and Emissions Data Reporting Interface (CEDRI) outageswith additional detailed procedures for submitting CBI in electronic format.^[73] The update provides an email address that source owners and operators can use to electronically mail CBI to the Office of Clean Air Programs (OCAP) CBI Office when submitting compliance reports.

• In40 CFR 63.2281(l), we proposed to remove the provisions related to force majeure claims which are now in 40 CFR 63.9(k).
• We proposed to remove the provision in40 CFR 63.2283(d) that states that records submitted to CEDRI may be maintained in electronic format, because 40 CFR 63.10(b)(1) already allows the retention of all records electronically.
• In Table 10, we proposed to indicate that all of the provisions in40 CFR 63.9(k) apply to 40 CFR part 63, subpart DDDD.

In addition, we proposed to amend 40 CFR 63.2281(c)(4) to clarify the compliance reporting requirements for the work practices in Table 3 (rows 6, 7, or 8). The EPA proposed to clarify that the requirement to report the date, time, and duration of every instance in which one of the work practices is used applies only if that individual work practice is used for more than 100 hours during the reporting period. The EPA's original intent was for the 100-hour reporting threshold to be compared to the semiannual usage of each of the three work practices individually, not for the total usage of all three work practices combined. As stated in 40 CFR 63.2281(c)(4), when one of the work practices is used for less than 100 hours per semiannual reporting period, a summary of the number of instances and total amount of time that work practice was used is required to be reported. As noted in section III.F.2 of this preamble, we also proposed to require continuous monitoring and recording of process unit bypass stack usage at all times including during the operating conditions specified in 40 CFR 63.2250(f)(2) through (4) and Table 3 (rows 6, 7, or 8) to ensure that reliable data are available to evaluate continuous compliance with the PCWP NESHAP requirements.

One commenter offered comments on the updated CEDRI reporting template provided with the May 2023 proposal and requested an additional opportunity to review the template before it is finalized.^[74] The commenter's recommendations and the EPA's responses are provided in the RTC located in the docket. The EPA's revised CEDRI reporting template for this final rule is available in the docket but will not be required until implemented in CEDRI.^[75]

4. Issues Raised by Petitioners Following the RTR

Following publication of the 2020 RTR,^[76] the EPA received a petition for reconsideration (Petition) from Earthjustice on behalf of Greater Birmingham Alliance to Stop Pollution, Louisiana Environmental Action Network, and Sierra Club (“Petitioners”). The Petitioners asked the EPA to reconsider certain aspects of the 2020 RTR and other amendments under the authority of CAA section 307(d)(7)(B), arguing that the EPA's rationale for four decisions all appeared for the first time in the 2020 RTR and RTC document accompanying the final rule.^[77] This section summarizes the four issues raised by the Petitioners, the EPA's proposed revisions to the PCWP NESHAP to address some of these issues, comments received on the proposed revisions and our responses, and our final decisions and rationale on the issues for this rulemaking.

a. What were the issues raised by the Petitioners and what were our proposed revisions?

In the first issue raised, the Petitioners alleged that the EPA failed to set limits for unregulated HAP. Although we do not agree that the Petitioners met their burden under CAA section 307(d)(7)(B) to show that it was impracticable to raise this objection during the public comment period for the proposed 2020 RTR, and thereby compel reconsideration of this issue, the May 2023 proposal contained new standards for unregulated HAP that are being finalized in response to the 2007 partial remand and vacatur of the 2004 rule and to address unregulated HAP, such that the Petitioners' concern regarding this issue is resolved with this final action.

In the second and third issues raised by the Petitioners, they disagreed with two work practices the EPA finalized on August 13, 2020, for safety-related shutdowns and pressurized refiner startup and shutdowns, and objected to what they perceived to be the EPA's changed or new rationale for these work practices between proposal and finalization of the 2020 RTR, claiming that they did not have an opportunity to raise their objections during the public comment period. The Petitioners disagreed with the EPA's use of CAA section 112(h) to develop work practice standards for safety-related shutdowns and pressurized refiner startup and shutdown events. For safety-related shutdowns, the Petitioners took issue with the EPA's rationale that facilities cannot capture and convey HAP emissions to a control device during these periods for safety reasons, saying that whether emissions can be conveyed to a control device is irrelevant under CAA section 112(h)(2)(A).^[78] In response to this critique, and to ensure that there is a full opportunity for all stakeholders to comment on the EPA's rationale for these work practices, the EPA requested comment in the May 2023 proposal on the relevance of the ability of facilities to capture and convey emissions to a control device to CAA section 112(h)(2)(A), given that CAA section 112(h)(2)(A) explicates CAA section 112(h)(1), which explicitly refers to the EPA's judgment as to when it is not feasible to prescribe or enforce an emission standard for control of a HAP.

( printed page 41429)

Regarding the EPA's rationale under CAA section 112(h)(2)(B) for the safety-related shutdown and pressurized refiner startup and shutdown work practices, the Petitioners expressed discontent with the EPA's conclusion that stack tests (which typically take one to three hours) cannot be conducted for events lasting only minutes. The Petitioners asserted that the EPA should have considered the practicability of other measurement methodologies including CEMS or continuous parameter monitoring. In response to the Petitioners' concerns, in the May 2023 proposal we maintained that stack testing is not feasible for safety-related shutdown events lasting only minutes or for pressurized refiner startup/shutdown events lasting less than 15 minutes. We requested comment in the May 2023 proposal on how the EPA could feasibly prescribe or enforce a numeric emission limit for such short-term events without the ability to conduct stack testing. Further, continuous operation of CEMS on bypass stacks that are unused for the majority of process operating time is not technically ( e.g., because of the calibration drift likely to occur while the CEMS goes unused) or economically practicable. The source testing required for conducting a relative accuracy test audit (RATA) of CEMS would not be possible without requiring the use of the bypass during the RATA. Obtaining emissions data to correlate with parameters to establish continuously monitored parameter limits also necessitates stack testing. Although CEMS or specific continuously monitored parameter limits are not an appropriate measurement methodology for safety-related shutdowns and pressurized refiner startups and shutdowns themselves because of technical and economic limitations, in 2023 we proposed additional continuous parameter monitoring of bypass stack usage in addition to the work practices for safety-related shutdowns and pressurized refiner startup/shutdown events to address the Petitioners' concern. As discussed in section III.B of this preamble, we proposed to require continuous monitoring of combustion unit bypass stacks and to require annual tune-ups of combustion units used to direct-fire dryers. As discussed in section III.F of this preamble, we also proposed to require continuous monitoring of process unit bypass stack usage at all times while the process units are operating, including times when the process unit is undergoing startup or shutdown, and during safety-related shutdowns and pressurized refiner startup/shutdown events to ensure that reliable data are available to evaluate continuous compliance with the PCWP NESHAP requirements.

The Petitioners also took issue with inclusion of measures that facilities have developed to protect workers and equipment in the safety-related shutdown work practice. The Petitioners argued that the steps an operator takes to protect workers and equipment are not necessarily the steps needed to prevent excess emissions or to remove raw materials and the heat source from the process as expeditiously as possible. We disagree with the Petitioners that the phrase “to protect workers and equipment” detracts from the safety-related shutdown work practice requirements to ensure that the flow of raw materials (such as furnish or resin) and fuel or process heat (as applicable) ceases, and that material is removed from the process unit(s) as expeditiously as possible given the system design to reduce air emissions. However, we requested comment in the May 2023 proposal on inclusion of measures facilities developed to protect workers and equipment from the safety-related shutdown provision. We also requested comment on all aspects of the work practice provisions (which appear in Table 3, rows 6 and 7) based on operational experience now that these narrowly defined provisions have been implemented in place of the broader SSM exemptions that were removed from the PCWP NESHAP.

In their fourth issue raised, the Petitioners disagreed with the EPA's statement in the September 6, 2019, proposed technology review and 2020 RTR that use of low-HAP resins is a development under CAA section 112(d)(6), claiming the EPA must revise standards for any development identified to require the maximum degree of reduction that is achievable through its application. In the 2019 proposed and 2020 final technology reviews, when noting that low-HAP resins may be a development, the EPA also explained that the EPA did not identify information to suggest that the resin system changes have significantly altered the type of process units or HAP pollution control technologies used in the PCWP industry to date or have led to processes or practices that have not been accounted for in the promulgated PCWP NESHAP compliance options. The Petitioners dismissed as irrelevant the EPA's explanation that there are many types of resin systems used in the manufacture of the various PCWP and that the resin-system solution for one facility's product may not be applicable for another product produced at a different facility. The Petitioners also argued that it is irrelevant the EPA noted in 2020 plans for additional action for the PCWP NESHAP source category with respect to remanded PCWP process units in which the EPA would further consider the effects of resin system changes.

Given the Petitioners' objections, we rearticulated in the May 2023 proposal our conclusion from the 2020 RTR. Specifically, we retracted our characterization of low-HAP resins as a “development” under CAA section 112(d)(6) with respect to the standards established for the PCWP source category in 2004. As noted in 2020, the EPA did not identify information suggesting that the resin system changes have significantly altered the type of process units or HAP pollution control technologies used in the PCWP industry or have led to processes or practices that were not accounted for in the 2004 rule compliance options. Therefore, we agree with the Petitioners that it may have been inappropriate to describe resin changes as a “development” under CAA section 112(d)(6) that occurred after the PCWP NESHAP was promulgated in 2004. Moreover, we disagree with the Petitioners' claim that if resin changes were in fact such a “development,” the EPA would be required to establish MACT standards under CAA sections 112(d)(2) and (3) as a consequence of that development. CAA section 112(d)(6) does not require the EPA to reconduct MACT determinations, as the D.C. Circuit made clear in Natural Resources Defense Council (NRDC) v. EPA, 529 F.3d 1077 (D.C. Cir. 2008). Instead, CAA section 112(d)(6) provides the EPA with the ability to exercise its judgment to determine what revisions to preexisting standards are necessary, after considering such developments. The mere presence of a development does not alone compel the EPA to determine that revising a promulgated MACT standard is necessary. Rather, the EPA is required to review the standard and determine whether to revise the standard after taking into account the development. This preserves the EPA's ability to exercise judgment regarding whether a change to a promulgated standard is necessary. In any event, as discussed in section III.D of this preamble, we proposed work practice standards under CAA section 112(h) for RMH process units for which no emission standards were in place to respond to the 2007 partial remand and vacatur of the 2004 rule. These work practices were based on the use of non-HAP resins or resins with low vapor ( printed page 41430) pressure, which have a low potential for HAP emissions, including resin types that were available at the time of the 2004 rule.

b. What comments did we receive on our proposed revisions to address the issues and what were our responses and final decisions?

We received comments on the safety-related shutdown and pressurized refiner work practices. One commenter opposed these work practices while another commenter supported them. Upon review of the comments provided, the EPA has reconsidered the work practices for safety-related shutdown and pressurized refiner startup and shutdown events, and the Agency is retaining these work practice standards as promulgated in the 2020 RTR.^[79] The specific comments related to the work practices and our detailed response are in the RTC located in the docket.^[80]

We also received a comment concerning the EPA's proposed retraction of a finding published in the 2019 proposed technology review.^[81] The EPA stated in the 2019 review that the increased availability of low-HAP resins constituted a “development” that must be considered pursuant to CAA section 112(d)(6).^[82] Commenters asserted that the EPA's proposed retraction of this finding in the May 2023 proposal is arbitrary. The commenter noted that pursuant to CAA section 112(d)(6), the EPA must evaluate whether this development warrants strengthening the MACT standard. A different commenter indicated the EPA correctly determined that the option for facilities to reformulate resins was already contemplated during the development of the 2004 rule. The commenter stated that as an alternative to installing controls to reduce emissions, facilities can utilize the PBCO and meet HAP emission limits for each process unit. Upon review of the comments provided, we are reaffirming our conclusion from the 2020 RTR that no change to the preexisting PCWP NESHAP standards is warranted as a result of resin system changes. The specific comments and our detailed response are in the RTC located in the docket.

H. What are the effective and compliance dates of the standards?

As proposed, the final rule requires affected sources that commence construction or reconstruction on or before May 18, 2023, to comply with the new emission standards within three years after the effective date ( i.e., by July 6, 2029). For affected sources that commenced construction or reconstruction after May 18, 2023, owners and operators must comply with the new provisions by July 6, 2026 or upon startup, whichever is later. An affected source is the collection of process units at a PCWP facility. Examples of new affected sources are new greenfield PCWP or lumber facilities, existing facilities constructing new PCWP manufacturing process lines in addition to (or as a replacement for) existing process lines, and existing lumber facilities adding (or replacing) lumber kilns in projects that meet the definition of reconstruction.

Commenters offered differing opinions on our proposal to provide three years after the effective date of the new provisions for existing affected sources to comply. One commenter argued that three years was too long, while another commenter argued that the three-year compliance period was too short to implement all new requirements.

Amendments to the PCWP NESHAP finalized in this rulemaking for adoption under CAA section 112(d)(2) and (3) are subject to the compliance deadlines outlined in the CAA under CAA section 112(i). For existing sources, CAA section 112(i)(3) provides that there shall be compliance “as expeditiously as practicable, but in no event later than 3 years after the effective date of such standard” subject to certain exemptions further detailed in the statute. In determining what compliance period is as “expeditious as practicable,” we consider the amount of time needed to plan and construct projects and change operating procedures. As provided in CAA section 112(i), all new affected sources would comply with these provisions by the effective date of the final amendments to the PCWP NESHAP or upon startup, whichever is later.

The EPA projects that many existing sources will need to make changes ( e.g., review operations, assemble documentation, install add-on controls and monitoring equipment) to comply with the finalized limits for various process units in their facility. These sources will require time to develop plans, construct, conduct performance testing, and implement monitoring to comply with the revised provisions. Therefore, the final rule allows three years for existing sources to become compliant with the applicable emission standards finalized in this action.

IV. Summary of Cost, Environmental, and Economic Impacts and Additional Analyses Conducted

A. What are the affected sources?

There are currently 219 major source facilities subject to the PCWP NESHAP. We estimated that six new PCWP facilities will be constructed and become subject to the NESHAP in the five years following the May 2023 proposal. A memorandum documenting the revised changes to the facility list since the 2023 proposed rule can be found in the docket for this rulemaking.^[83]

B. What are the air quality impacts?

This final action is expected to reduce 721 tpy of directly-regulated HAPs compared to baseline emissions of 7,250 tpy.

Additionally, the final rule will result in a decrease of other air emissions that are not regulated by this rule. In comparison to baseline emissions of 58,036 tpy VOC, the EPA estimates VOC emission reductions of approximately 8,504 tpy.^[84] We also estimate that the final action would result in additional reductions of 202 tpy of PM, 144 tpy of PM <2.5 µm in diameter (PM_2.5), 132 tpy of NOx, 719 tpy of CO, 12 tpy of SO₂ .^[85]

C. What are the cost impacts?

The EPA estimates that this final action would cost approximately $121 million in total capital costs (distributed across multiple years) and $53 million per year (in 2024 dollars) in total annualized costs.^[86]

D. What are the economic impacts?

For the final rule, the EPA estimated the cost of compliance with the final emission limits. This includes the capital costs of installation, subsequent maintenance and operation of the ( printed page 41431) controls, and other one-time and annual costs. To assess the potential economic impacts, the EPA prepared a partial equilibrium analysis modeling impacts to prices, production, and imports and exports. The EPA additionally performed a screening analysis that compared the expected annualized cost of compliance to the total sales revenue for the ultimate owners of affected facilities.

For this final rule, the partial equilibrium analysis estimated an expected economic cost to both producers and consumers and accounting for changes to prices and quantities caused by the final amendments equal to $53 million. The expected annualized compliance cost from the screening analysis is $237,680 (on average) for each facility, including 219 existing and six projected new facilities, with an estimated nationwide annualized cost of $53,500,000. The 219 existing affected facilities are owned by 64 parent companies, and the compliance costs associated with the final amendments are expected to be on average about 0.27 percent of annual sales revenue per ultimate owner.

Information on our cost and economic impact estimates for the PCWP manufacturing source category is contained in Economic Impact Analysis for the Final National Emissions Standards for Hazardous Air Pollutants: Plywood and Composite Wood Products Amendments, available in the docket for this rulemaking.^[87]

E. What are the benefits?

The EPA is obligated to present the Agency's best scientific understanding and the implications of that science when developing policies and regulations. However, the EPA's analytical practices often provided the public with false precision and confidence regarding the monetized impacts of fine PM_2.5 and ozone due to changes in emissions of PM_2.5 as well as PM_2.5 and ozone precursors. In addition, the science regarding the exposure, health effects from exposure, and valuation of reduction in health effect are evolving with better data and methods, especially at low concentrations of PM and ozone. Some of the sources of uncertainties include the set of assumptions used in projecting the health impact of reducing PM. These projections are based on a series of models that take into account emissions changes, resulting distributions of changes in ambient air quality, the estimated reductions in health effects from changes in exposure, and the composition of the population that will benefit from the reduced exposure. Each component includes assumptions, each with varying degrees of uncertainty.

In addition, the EPA historically provided point estimates rather than just ranges or only quantifying emissions, which leads the public to believe the Agency has a better understanding of the monetized impacts of exposure to PM_2.5 and ozone than it does in reality. Therefore, to address these concerns, the EPA is no longer monetizing benefits from PM_2.5 and ozone but will continue to quantify the emissions until the Agency is confident enough in the modeling to properly monetize those impacts. Implementing the final amendments is expected to reduce emissions of HAP and non-HAP pollutants, such as VOC. We estimate that the final amendments would reduce HAP emissions from the source category by approximately 721 tpy. The amendments would regulate emissions of acetaldehyde, acrolein, formaldehyde, methanol, phenol, propionaldehyde, non-Hg HAP metals, Hg, HCl, PAH, D/F and MDI. Information regarding the health effects of these compounds can be found in Health Effects Notebook for Hazardous Air Pollutants  ^[88] and in the EPA Integrated Risk Information System database.^[89]

The final amendments would reduce emissions of VOC which, in conjunction with NOx and in the presence of sunlight, form ground-level ozone. There are health benefits of reducing VOC emissions in terms of the number and value of avoided ozone-attributable deaths and illnesses. The Integrated Science Assessment for Ozone^[90] found short-term (less than one month) exposures to ozone to be causally related to respiratory effects, a “likely to be causal” relationship with metabolic effects, and a “suggestive of, but not sufficient to infer, a causal relationship” for central nervous system effects, cardiovascular effects, and total mortality. The ISA reported that long-term exposures (one month or longer) to ozone are “likely to be causal” for respiratory effects including respiratory mortality, and a “suggestive of, but not sufficient to infer, a causal relationship” for cardiovascular effects, reproductive effects, central nervous system effects, metabolic effects, and total mortality.

The human health risk estimated for this source category for the 2020 RTR was determined to be acceptable, and the standards were determined to provide an ample margin of safety to protect public health. Specifically, the maximum individual cancer risk was 30-in-1 million for actual and allowable emissions and the noncancer hazard indices for chronic exposure were below 1 ( i.e., 0.8 for actual and allowable emissions). The maximum noncancer hazard quotient for acute exposure was 4. These health risk estimates were based on HAP emissions from the source category after addition of air pollution controls used to meet the MACT standards promulgated in 2004, as well as the baseline HAP emissions from process units for which standards are being promulgated in this action. While the 2020 RTR final amendments reduced emissions by an unquantified amount by removing the SSM exemption and adding repeat testing requirements, the changes to the PCWP NESHAP in this final action will reduce emissions by an additional 721 tons of HAP per year and will further improve human health exposures for populations in all demographic groups.

V. Statutory and Executive Order Reviews

Additional information about these statutes and Executive Orders can be found at https://www.epa.gov/​laws-regulations/​laws-and-executive-orders.

A. Executive Order 12866: Regulatory Planning and Review and Executive Order 13563: Improving Regulation and Regulatory Review

This action is not a significant regulatory action and was therefore not submitted to the Office of Management and Budget (OMB) for review.

B. Executive Order 14192: Unleashing Prosperity Through Deregulation

This action is not an Executive Order 14192 regulatory action because this action is not significant under Executive Order 12866.

C. Paperwork Reduction Act (PRA)

The information collection activities in this final rule have been submitted for approval to OMB under the PRA. The information collection request (ICR) document that the EPA prepared has been assigned EPA ICR number 1984.12. You can find a copy of the ICR in the ( printed page 41432) docket for this rule, and it is briefly summarized here.

The final changes to the reporting and recordkeeping requirements for the PCWP NESHAP incorporate the reporting and recordkeeping requirements associated with the MACT standards being added to the rule for multiple HAP from new and existing process units.

Respondents/affected entities: Owners or operators of PCWP or kiln-dried lumber manufacturing plants that are major sources, or that are located at, or are part of, major sources of HAP emissions.

Respondent's obligation to respond: Mandatory.^[91]

Estimated number of respondents: On average over the next three years, approximately 219 existing major sources would be subject to these standards. It is also estimated that six additional respondents would become subject to the emission standards over the three-year period.

Frequency of response: The frequency of responses varies depending on the burden item ( e.g., one-time, semiannual, annual, every five years).

Total estimated burden: The average annual burden to industry over the next three years from the final recordkeeping and reporting requirements is estimated to be 44,400 hours per year. Burden is defined at 5 CFR 1320.3(b).

Total estimated cost: The total annual recordkeeping and reporting cost for all facilities to comply with all the requirements in the NESHAP, including the requirements in this final rule, is estimated to be $10,290,000 per year including $3,870,000 in annualized capital and O&M costs.

An agency may not conduct or sponsor, and a person is not required to respond to, a collection of information unless it displays a currently valid OMB control number. The OMB control numbers for the EPA's regulations in 40 CFR are listed in 40 CFR part 9. When OMB approves this ICR, the Agency will announce that approval in the Federal Register and publish a technical amendment to 40 CFR part 9 to display the OMB control number for the approved information collection activities contained in this rule.

D. Regulatory Flexibility Act (RFA)

I certify that this action will not have a significant economic impact on a substantial number of small entities under the RFA. The small entities subject to the requirements of this action are small businesses as defined by the U.S. Small Business Administration (SBA). The EPA prepared a small business screening analysis to determine if any of the identified affected entities are small entities, as defined by the SBA. This analysis is available in the docket for this rulemaking (Docket ID No. EPA-HQ-OAR-2016-0243). The Agency has determined that 18 out of 64 small ultimate PCWP manufacturing parent companies may experience an impact ranging from approximately 0.03 percent to approximately 1.09 percent of annual sales, with three of the 18 ultimate parent companies experiencing an impact of more than one percent of annual sales. The 18 parent companies own 22 affected PCWP facilities. The EPA does not expect a substantial economic impact from these final amendments because only three out of 18 small business ultimate parent owners in the PCWP manufacturing source category face incremental total annualized compliance costs more than one percent but less than three percent of annual sales revenue.

Details of this analysis are presented in Economic Impact Analysis for the Final National Emissions Standards for Hazardous Air Pollutants: Plywood and Composite Wood Products Amendments, located in the docket for this action.^[92]

E. Unfunded Mandates Reform Act (UMRA)

This action does not contain an unfunded mandate of $100 million or more as described in UMRA, 2 U.S.C. 1531-1538, and does not significantly or uniquely affect small governments. While this action creates an enforceable duty on the private sector and one facility owned by a Tribal government, the cost does not exceed $100 million or more.

F. Executive Order 13132: Federalism

This action does not have federalism implications. It will not have substantial direct effects on the States, on the relationship between the national government and the States, or on the distribution of power and responsibilities among the various levels of government.

G. Executive Order 13175: Consultation and Coordination With Indian Tribal Governments

This action does not have Tribal implications as specified in Executive Order 13175. It will not have substantial direct effects on Tribal governments, on the relationship between the Federal Government and Indian Tribes, or on the distribution of power and responsibilities between the Federal Government and Indian Tribes, as specified in Executive Order 13175. There are facilities subject to this rule located on the lands of the Coeur D'Alene Tribe, the Confederated Tribes and Bands of the Yakima Nation, and the Choctaw Nation. Consistent with the EPA Policy on Consultation and Coordination with Indian Tribes, the EPA offered consultation opportunities for Tribal officials early in the process of developing this rule to permit them to have meaningful and timely input into its development. The Choctaw Nation requested and received a pre-proposal meeting, a summary of which is available in the docket for this rulemaking. The EPA also offered consultation opportunities to all federally recognized Tribes during the comment period from May 18, 2023, to July 18, 2023, but received no request for consultation.

H. Executive Order 13045: Protection of Children From Environmental Health Risks and Safety Risks

This action is not subject to Executive Order 13045 because the EPA does not believe the environmental health or safety risks addressed by this action present a disproportionate risk to children.

I. Executive Order 13211: Actions Concerning Regulations That Significantly Affect Energy Supply, Distribution, or Use

This action is not a “significant energy action” because it is not likely to have a significant adverse effect on the supply, distribution, or use of energy. In this final action, the EPA is setting emission standards for the PCWP source category. This does not impact energy supply, distribution, or use.

J. National Technology Transfer and Advancement Act (NTTAA) and 1 CFR Part 51

This action involves technical standards. Therefore, the EPA conducted searches for the PCWP NESHAP through the Enhanced National Standards Systems Network (NSSN) Database managed by the American National Standards Institute (ANSI). We also conducted a review of voluntary consensus standards (VCS) organizations and accessed and searched their databases. We conducted searches for EPA Methods 1, 1A, 2, 2A, 2C, 2D, 2F of appendix A-1 to part 60 of this chapter; EPA Test Methods 2G, 3, 3A, 3B of appendix A-2 to part 60 of this chapter; EPA Test Methods 4, 5 of appendix A-3 to part 60 of this chapter; ( printed page 41433) EPA Test Method 10 of appendix A-4 to part 60 of this chapter; EPA Test Method 18 of appendix A-6 to part 60 of this chapter; EPA Test Methods 23, 25A of appendix A-7 to part 60 of this chapter; EPA Test Methods 26A, 29 of appendix A-8 to part 60 of this chapter; EPA Test Methods 204, 204A, 204B, 204C, 204D, 204E, 204F, 205 of appendix M to part 51 of this chapter; EPA Test Methods 308, 316, 320, 326 of appendix A to part 63 of this chapter; and EPA Test Method 0011 (incorporated by reference at 40 CFR 260.11(c)(4)). During the EPA's VCS search, if the title or abstract (if provided) of the VCS described technical sampling and analytical procedures that are similar to the EPA's referenced method, the EPA ordered a copy of the standard and reviewed it as a potential equivalent method. We reviewed all potential standards to determine the practicality of the VCS for this rule. This review requires significant method validation data that meet the requirements of EPA Method 301 for accepting alternative methods or scientific, engineering, and policy equivalence to procedures in the EPA referenced methods. The EPA may reconsider determinations of impracticality when additional information is available for any particular VCS.

Detailed information on the VCS search and determination can be found in the memorandum, Voluntary Consensus Standard Results for NEHSAP: Plywood and Composite Wood Products, which is available in the docket for this action.^[93] Two VCS were identified as acceptable alternatives to the EPA test methods for this final rule.

The VCS ANSI/ASME PTC 19.10-1981 Part 10, “Flue and Exhaust Gas Analyses,” is an acceptable alternative to EPA Method 3B manual portions only and not the instrumental portion. This method determines quantitatively the gaseous constituents of exhausts resulting from stationary combustion sources. The manual procedures (but not instrumental procedures) of ASME/ANSI PTC 19.10-1981 Part 10 may be used as an alternative to EPA Method 3B for measuring the oxygen or carbon dioxide content of the exhaust gas. The gases covered in ASME/ANSI PTC 19.10-1981 are oxygen, carbon dioxide, carbon monoxide, nitrogen, sulfur dioxide, sulfur trioxide, nitric oxide, nitrogen dioxide, hydrogen sulfide, and hydrocarbons. However, the use in this rule is only applicable to oxygen and carbon dioxide. This VCS may be obtained from American Society of Mechanical Engineers (ASME), Three Park Avenue, New York, NY 10016-5990, telephone (800) 843-2763, https://www.asme.org. The EPA is finalizing our proposal to incorporate by reference (IBR) the VCS ANSI/ASME PTC 19.10-1981 Part 10, “Flue and Exhaust Gas Analyses,” as an acceptable alternative to EPA Method 3B manual portions only and not the instrumental portion.

The VCS ASTM D6348-12e1, “Determination of Gaseous Compounds by Extractive Direct Interface Fourier Transform (FTIR) Spectroscopy,” is an acceptable alternative to EPA Method 320 with certain conditions. The VCS ASTM D6348-12e1 employs an extractive sampling system to direct stationary source effluent to an FTIR spectrometer for the identification and quantification of gaseous compounds. Concentration results are provided. This test method is potentially applicable for the determination of compounds that (1) have sufficient vapor pressure to be transported to the FTIR spectrometer; and (2) absorb a sufficient amount of infrared radiation to be detected. The VCS ASTM D6348-12e1 may be obtained from https://www.astm.org or from the ASTM Headquarters at 100 Barr Harbor Drive, P.O. Box C700, West Conshohocken, Pennsylvania, 19428-2959. The EPA is finalizing our proposal to IBR the VCS ASTM D6348-12e1, “Determination of Gaseous Compounds by Extractive Direct Interface Fourier Transform (FTIR) Spectroscopy,” as an acceptable alternative to EPA Method 320 in place of ASTM D6348-03. ASTM D6348-03(2010) was determined to be equivalent to EPA Method 320 with caveats. ASTM D6348-12e1 is a revised version of ASTM D6348-03(2010) and includes a new section on accepting the results from the direct measurement of a certified spike gas cylinder but lacks the caveats placed on the ASTM D6348-03(2010) version. ASTM D6348-12e1 is an extractive FTIR field test method used to quantify gas phase concentrations of multiple analytes from stationary source effluent and is an acceptable alternative to EPA Method 320 at this time with caveats requiring inclusion of selected annexes to the standard as mandatory. When using ASTM D6348-12e1, the following conditions must be met:

• The test plan preparation and implementation in the Annexes to ASTM D6348-03, sections A1 through A8 are mandatory; and
• In ASTM D6348-03, Annex A5 (Analyte Spiking Technique), the percent (%) R must be determined for each target analyte.^[94]

In order for the test data to be acceptable for a compound, percent R must be 70 percent ≤ R ≤ 130 percent. If the percent R value does not meet this criterion for a target compound, the test data is not acceptable for that compound and the test must be repeated for that analyte ( i.e., the sampling and/or analytical procedure should be adjusted before a retest). The percent R value for each compound must be reported in the test report, and all field measurements must be corrected with the calculated percent R value for that compound by using the following equation: Reported Results = (Measured Concentration in Stack)/(percent R) × 100.

In addition to the VCS mentioned earlier in this section, we are finalizing our proposal to IBR ASTM D1835-05, “Standard Specification for Liquefied Petroleum (LP) Gases,” for use in the definition of natural gas in 40 CFR 63.2292. The VCS ASTM D-1835-05 covers those products commonly referred to as liquefied petroleum gases, consisting of propane, propene (propylene), butane, and mixtures of these materials. This specification is designed to properly define acceptable LP products for domestic, commercial, or industrial uses. This VCS may be obtained from https://www.astm.org or from the ASTM Headquarters at 100 Barr Harbor Drive, P.O. Box C700, West Conshohocken, Pennsylvania, 19428-2959.

K. Congressional Review Act (CRA)

This action is subject to the CRA, and the EPA will submit a rule report to each House of the Congress and to the Comptroller General of the United States. This action is not a “major rule” as defined by 5 U.S.C. 804(2).

For the reasons stated in the preamble, the Environmental Protection Agency amends part 63 of title 40, chapter I, of the Code of Federal Regulations as follows: