# National Emissions Standards for Hazardous Air Pollutants: Ferroalloys Production > Briefs, arguments, decisions, and more. URL: https://www.frixlaw.com/law-library/documents/fr%3A2015-15038 ## Record - **Collection:** Federal Register - **Document type:** Rule - **Published:** June 30, 2015 - **Citation:** 80 FR 37366 ## Text ENVIRONMENTAL PROTECTION AGENCY 40 CFR Part 63 [EPA-HQ-OAR-2010-0895; FRL-9928-66-OAR] RIN 2060-AQ11 National Emissions Standards for Hazardous Air Pollutants: Ferroalloys Production AGENCY: Environmental Protection Agency (EPA). ACTION: Final rule. SUMMARY: This action finalizes the residual risk and technology review (RTR) conducted for the Ferroalloys Production source category regulated under national emission standards for hazardous air pollutants (NESHAP). These final amendments include revisions to particulate matter (PM) standards for electric arc furnaces, metal oxygen refining processes, and crushing and screening operations, and expand and revise the requirements to control process fugitive emissions from furnace operations, tapping, casting, and other processes. We are also finalizing opacity limits, as proposed in 2014. However, regarding opacity monitoring, in lieu of Method 9, we are requiring monitoring with the digital camera opacity technique (DCOT). Furthermore, we are finalizing emissions standards for four previously unregulated hazardous air pollutants (HAP): Formaldehyde, hydrogen chloride (HCl), mercury (Hg) and polycyclic aromatic hydrocarbons (PAH). Other requirements related to testing, monitoring, notification, recordkeeping, and reporting are included. This rule is health protective due to the revised emissions limits for the stacks and the requirement of enhanced fugitive emissions controls that will achieve significant reductions of process fugitive emissions, especially manganese. DATES: This final action is effective on June 30, 2015. The incorporation by reference of certain publications listed in the rule is approved by the Director of the Federal Register as of June 30, 2015. ADDRESSES: The Environmental Protection Agency (EPA) has established a docket for this action under Docket ID No. EPA-HQ-OAR-2010-0895. All documents in the docket are listed on the www.regulations.gov Web site. Although listed in the index, some information is not publicly available, e.g. , confidential business information (CBI) or other information whose disclosure is restricted by statute. Certain other material, such as copyrighted material, is not placed on the Internet and will be publicly available only in hard copy form. Publicly available docket materials are available either electronically through http://www.regulations.gov , or in hard copy at the EPA Docket Center, EPA WJC West Building, Room Number 3334, 1301 Constitution Ave. NW., Washington, DC. The Public Reading Room hours of operation are 8:30 a.m. to 4:30 p.m. Eastern Standard Time (EST), Monday through Friday. The telephone number for the Public Reading Room is (202) 566-1744, and the telephone number for the Air Docket is (202) 566-1742. FOR FURTHER INFORMATION CONTACT: For questions about this final action, contact Phil Mulrine, Sector Policies and Programs Division (D243-02), Office of Air Quality Planning and Standards, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina, 27711; telephone number: (919) 541-5289; fax number: (919) 541-3207; and email address: mulrine.phil@epa.gov. For specific information regarding the risk modeling methodology, contact Darcie Smith, Health and Environmental Impacts Division (C539-02), Office of Air Quality Planning and Standards, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711; telephone number: (919) 541-2076; fax number: (919) 541-0840; and email address: smith.darcie@epa.gov . For information about the applicability of the NESHAP to a particular entity, contact Cary Secrest, Office of Enforcement and Compliance Assurance, U.S. Environmental Protection Agency, EPA WJC Building, 1200 Pennsylvania Ave. NW., Washington, DC 20460; telephone number: (202) 564-8661; and email address: secrest.cary@epa.gov. SUPPLEMENTARY INFORMATION: Preamble Acronyms and Abbreviation 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: ATSDR Agency for Toxic Substances and Disease Registry BLDS bag leak detection system BTF Beyond-the-Floor CAA Clean Air Act CBI Confidential Business Information CFR Code of Federal Regulations EJ environmental justice EPA Environmental Protection Agency ERPG Emergency Response Planning Guidelines ERT Electronic Reporting Tool FeMn Ferromanganese FR Federal Register HAP hazardous air pollutants HCl hydrochloric acid HI Hazard Index HQ Hazard Quotient ICR Information Collection Request IRIS Integrated Risk Information System km kilometer MACT maximum achievable control technology mg/dscm milligrams per dry standard cubic meter mg/m 3 milligrams per cubic meter MIR maximum individual risk MOR metal oxygen refining MRL Minimal Risk Level NAAQS National Ambient Air Quality Standards NAICS North American Industry Classification System NESHAP National Emissions Standards for Hazardous Air Pollutants NTTAA National Technology Transfer and Advancement Act OAQPS Office of Air Quality Planning and Standards OECA Office of Enforcement and Compliance Assurance OMB Office of Management and Budget PAH polycyclic aromatic hydrocarbons PB-HAP hazardous air pollutants known to be persistent and bio-accumulative in the environment PM particulate matter POM polycyclic organic matter REL reference exposure level RFA Regulatory Flexibility Act RfC reference concentration RTR residual risk and technology review SAB Science Advisory Board SBA Small Business Administration SiMn Silicomanganese SSM startup, shutdown, and malfunction TOSHI target organ-specific hazard index TPY tons per year TRIM.FaTE Total Risk Integrated Methodology.Fate, Transport, and Ecological Exposure model TTN Technology Transfer Network μg/dscm micrograms per dry standard cubic meter μg/m 3 micrograms per cubic meter UMRA Unfunded Mandates Reform Act UPL Upper Prediction Limit VCS voluntary consensus standards Background Information On November 23, 2011, and October 6, 2014, the EPA proposed revisions to the Ferroalloys Production NESHAP based on our RTR. In this action, we are finalizing decisions and revisions for the NESHAP. We summarize some of the more significant comments we timely received regarding the proposed rule and provide our responses in this preamble. A summary of all other public comments on the proposal and the EPA's responses to those comments are available in document titled: National Emission Standards for Hazardous Air Pollutant Emissions: Ferroalloys Production Summary of Public Comments and the EPA's Responses on Proposed Rule (76 FR 72508, November 23, 2011) and Supplemental Proposal (79 FR 60238, October 6, 2014) , Docket ID No. EPA-HQ-OAR-2010-0895, which is available in the docket. A “track changes” version of the regulatory language that incorporates the changes in this action is also available in the docket. Organization of this Document. The information in this preamble is organized as follows: I. General Information A. Does this action apply to me? B. Where can I get a copy of this document and other related information? C. Judicial Review and Administrative Reconsideration II. Background A. What is the statutory authority for this action? B. What is the Ferroalloys Production source category and how does the NESHAP regulate HAP emissions from the source category? C. What changes did we propose for the Ferroalloys Production source category in our November 23, 2011, proposal and our October 6, 2014, supplemental proposal? III. What is included in this final rule? A. What are the final rule amendments based on the risk review for the Ferroalloys Production source category? B. What are the final rule amendments based on the technology review for the Ferroalloys Production source category? C. What are the final rule amendments pursuant to CAA section 112(d)(2) & (3) for the Ferroalloys Production source category? D. What are requirements during periods of startup, shutdown, and malfunction? E. What other changes have been made to the NESHAP? F. What are the effective and compliance dates of the standards? G. What are the requirements for submission of performance test data to the EPA? IV. What is the rationale for our final decisions and amendments for the Ferroalloys Production source category? A. Residual Risk Review for the Ferroalloys Production Source Category B. Technology Review for the Ferroalloys Production Source Category C. CAA Section 112(d)(2) & (3) Revisions for the Ferroalloys Production Source Category D. What changes did we make to the Ferroalloys Production opacity monitoring requirement? V. 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? F. What analysis of environmental justice did we conduct? G. What analysis of children's environmental health did we conduct? VI. Statutory and Executive Order Reviews A. Executive Orders 12866: Regulatory Planning and Review and Executive Order 13563: Improving Regulation and Regulatory Review B. Paperwork Reduction Act (PRA) C. Regulatory Flexibility Act (RFA) D. Unfunded Mandates Reform Act (UMRA) E. Executive Order 13132: Federalism F. Executive Order 13175: Consultation and Coordination With Indian Tribal Governments G. Executive Order 13045: Protection of Children From Environmental Health Risks and Safety Risks H. Executive Order 13211: Actions Concerning Regulations That Significantly Affect Energy Supply, Distribution or Use I. National Technology Transfer and Advancement Act and 1 CFR part 51 J. Executive Order 12898: Federal Actions To Address Environmental Justice in Minority Populations and Low-Income Populations K. Congressional Review Act (CRA) I. General Information A. Does this action apply to me? Regulated Entities. Categories and entities potentially regulated by this action are shown in Table 1 of this preamble. Table 1—NESHAP and Industrial Source Categories Affected by This Final Action NESHAP and source category NAICS a Code Ferroalloys Production 331112 a North American Industry Classification System. Table 1 of this preamble is not intended to be exhaustive, but rather to provide a guide for readers regarding entities likely to be affected by the final action for the source category listed. To determine whether your facility is affected, you should examine the applicability criteria in 40 CFR part 63, subpart XXX (National Emission Standards for Hazardous Air Pollutants (NESHAP): Ferroalloys Production). 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. B. 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 final action will also be available on the Internet through the Technology Transfer Network (TTN) Web site, a forum for information and technology exchange in various areas of air pollution control. Following signature by the EPA Administrator, the EPA will post a copy of this final action at: http://www.epa.gov/ttn/atw/ferroa/ferropg.html. Following publication in the Federal Register , the EPA will post the Federal Register version and key technical documents at this same Web site. Additional information is available on the RTR Web site at http://www.epa.gov/ttn/atw/rrisk/rtrpg.html. This information includes an overview of the RTR program, links to project Web sites for the RTR source categories and detailed emissions and other data we used as inputs to the risk assessments. C. 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 by August 31, 2015. Under CAA section 307(b)(2), the requirements established by this final rule may not be challenged separately in any civil or criminal proceedings brought by the EPA to enforce the requirements. Section 307(d)(7)(B) of the Clean Air Act (CAA) further provides that “[o]nly an objection to a rule or procedure which was raised with reasonable specificity during the period for public comment (including any public hearing) may be raised during judicial review.” This section also provides a mechanism for the EPA to reconsider the rule “[i]f 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, EPA WJC 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. II. Background A. What is the statutory authority for this action? Section 112 of the CAA establishes a two-stage regulatory process to address emissions of HAP from stationary sources. In the first stage, we must identify categories of sources emitting one or more of the HAP listed in CAA section 112(b) and then promulgate technology-based NESHAP for those sources. “Major sources” are those that emit, or have the potential to emit, any single HAP at a rate of 10 tons per year (tpy) or more, or 25 tpy or more of any combination of HAP. For major sources, these standards are commonly referred to as maximum achievable control technology (MACT) standards and 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. For these MACT standards, the statute specifies certain minimum stringency requirements, which are referred to as MACT floor requirements, and which may not be based on cost considerations. See CAA section 112(d)(3). For new sources, the MACT floor cannot be less stringent than the emission control achieved in practice by the best-controlled similar source. For existing sources the MACT standards can be less stringent than the 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 developing MACT standards, we must also consider control options that are more stringent than the floor, under CAA section 112(d)(2). We 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. In the second stage of the regulatory process, the CAA requires the EPA to undertake two different analyses, which we refer to as the technology review and the residual risk review. Under the technology review, we must review the technology-based standards and revise them “as necessary (taking into account developments in practices, processes, and control technologies)” no less frequently than every 8 years, pursuant to CAA section 112(d)(6). Under the residual risk review, we must evaluate the risk to public health remaining after application of the technology-based standards and revise the standards, if necessary, to provide an ample margin of safety to protect public health or to prevent, taking into consideration costs, energy, safety, and other relevant factors, an adverse environmental effect. The residual risk review is required within 8 years after promulgation of the technology-based standards, pursuant to CAA section 112(f). In conducting the residual risk review, if the EPA determines that the current standards provide an ample margin of safety to protect public health, it is not necessary to revise the MACT standards pursuant to CAA section 112(f). 1 For more information on the statutory authority for this rule, see 79 FR 60238. 1 The U.S. Court of Appeals has affirmed this approach of implementing CAA section 112(f)(2)(A); NRDC v. EPA, 529 F.3d 1077, 1083 (D.C. Cir. 2008) (“If EPA determines that the existing technology-based standards provide an `ample margin of safety,' then the Agency is free to readopt those standards during the residual risk rulemaking.”). B. What is the Ferroalloys Production source category and how does the NESHAP regulate HAP emissions from the source category? The EPA promulgated the Ferroalloys Production NESHAP on May 20, 1999 (64 FR 27450). The standards are codified at 40 CFR part 63, subpart XXX. The ferroalloys production industry consists of facilities that produce ferromanganese (FeMn) or silicomanganese (SiMn). The source category covered by this MACT standard currently includes two facilities. The rule applies to ferroalloys production operations that are located at major sources of HAP emissions or are co-located at a major source of HAP emissions. The HAP emission sources at facilities subject to the Ferroalloys Production NESHAP are open, semi-sealed, or sealed submerged arc furnaces, tapping operations, casting operations, metal oxygen refining (MOR) process, crushing and screening operations, other processes, such as ladle treatment and slag raking, and outdoor fugitive dust sources. The 1999 NESHAP regulated these emissions sources through emission limits for PM, opacity limits, and work practices. C. What changes did we propose for the Ferroalloys Production source category in our November 23, 2011, proposal and our October 6, 2014, supplemental proposal? On November 23, 2011, the EPA published a proposed rule in the Federal Register (76 FR 72508) for the Ferroalloys Production NESHAP, 40 CFR part 63, subpart XXX that took into consideration the RTR analyses. In the 2011 proposed rule, we proposed: • Revisions to the numeric emission limits for PM from furnace stacks to reflect the current performance of control devices in place at ferroalloys production facilities to control furnace emissions (primary and tapping), crushing and screening operations, and the MOR operation at one plant; • Addition of Hg, HCl, PAH, and formaldehyde furnace stack emission standards that reflected the MACT determination for control of these pollutants; • Requirements to capture process fugitive emissions using full building enclosure with negative pressure building ventilation and duct the captured emissions to a control device; and • Revisions to the opacity standards to reflect effective capture and control of process fugitive emissions. On October 6, 2014, the EPA published a supplemental proposed rule in the Federal Register (79 FR 60238). For the supplemental proposal, we proposed: • Revisions to the proposed PM furnace stack emission standards based on additional test data submitted by the facilities; • Revisions to the proposed Hg, HCl, and PAH furnace stack emission standards based on additional test data submitted by the facilities; • Requirements to capture process fugitive emissions using effective, enhanced local capture, and duct the captured emissions to control devices; • Revisions to the opacity standards to reflect effective, enhanced capture, and control of process fugitive emissions; • To demonstrate compliance with the opacity limits, we proposed facilities would need to take opacity readings for an entire furnace cycle once per week per furnace using Method 9 or as an option they could take the readings using DCOT; and • Several minor clarifications and corrections. III. What is included in this final rule? This action finalizes the EPA's determinations pursuant to the RTR provisions of CAA section 112 for the Ferroalloys Production source category and amends the existing Ferroalloys Production NESHAP based on those determinations. Among the changes finalized in this action are: The promulgation of MACT-based limits for previously unregulated HAP; requirements to effectively capture and control process fugitive emissions; the removal of startup, shutdown, and malfunction (SSM) exemptions; and the addition of DCOT monitoring. This action also reflects several changes to the November 2011 and October 2014 proposals in consideration of comments received during the public comment periods as described in section IV of this preamble. A. What are the final rule amendments based on the risk review for the Ferroalloys Production source category? This section provides a summary of the final amendments to the Ferroalloys Production NESHAP being promulgated pursuant to CAA section 112(f). 1. Stack Emissions We are promulgating PM emission limits for stacks at the following levels: 4.0 milligrams per dry standard cubic meter (mg/dscm) for new or reconstructed electric arc furnaces; 25 mg/dscm for existing electric arc furnaces; and 4.0 mg/dscm for any new, reconstructed, or existing local ventilation control device. These emission limits are the same as the limits proposed in the 2014 supplemental proposal. In addition, we are promulgating a PM limit of 3.9 mg/dscm for any new, reconstructed, or existing MOR process and a PM limit of 13 mg/dscm for any new, reconstructed, or existing crushing and screening equipment, which are consistent with what we proposed in our November 23, 2011, proposal. 2. Process Fugitive Emissions Sources We are promulgating a requirement that facilities in this source category must achieve effective enhanced capture of process fugitive emissions using a system of primary hoods (that capture process fugitive emissions near the source) and/or secondary capture of fugitives (which would capture remaining fugitive emissions near the roof-line). Facilities must install, operate, and maintain a process fugitives capture system that is designed to capture 95 percent or more of the process fugitive emissions. We are also promulgating an opacity limit of 8-percent to ensure process fugitive emissions are effectively captured. This is what we proposed in the October 6, 2014, supplemental proposal. However, we have revised the rule based on public comment, to provide more flexibility on how facilities achieve 95-percent capture of process fugitive emissions. We also strengthened the monitoring provisions to ensure that the required reductions are achieved. B. What are the final rule amendments based on the technology review for the Ferroalloys Production source category? We determined that there are developments in practices, processes, and control technologies that warrant revisions to the MACT standards for this source category for both stack PM emissions and process fugitive emissions. Therefore, under the authority of CAA section 112(d)(6), we are promulgating the same PM stack emission limits and enhanced fugitive control requirements that we are promulgating under CAA section 112(f), as described in section A above. C. What are the final rule amendments pursuant to CAA section 112(d)(2) & (3) for the Ferroalloys Production source category? We are promulgating emission limits for formaldehyde, HCl, Hg, and PAH, which were previously unregulated HAP, pursuant to CAA section 112(d)(2) and 112(d)(3). We are promulgating a formaldehyde emission limit of 201 micrograms per dry standard cubic meter (μg/dscm) for any new, reconstructed, or existing electric arc furnace. This is the same limit that we proposed on November 23, 2011. We are promulgating an HCl emission limit of 180 μg/dscm for new or reconstructed electric arc furnaces and 1,100 μg/dscm for existing electric arc furnaces. This is the same limit that we proposed on October 6, 2014. For electric arc furnaces producing FeMn, we are promulgating Hg emission limits of 13 μg/dscm for new or reconstructed electric arc furnaces and 130 μg/dscm for existing electric arc furnaces. For electric arc furnaces producing SiMn, we are promulgating Hg emission limits of 4 μg/dscm for new or reconstructed electric arc furnaces and 12 μg/dscm for existing electric arc furnaces. The Hg limit for new SiMn furnaces is the same as in the October 6, 2014, supplemental proposal. The final Hg limits for new and existing FeMn and existing SiMn furnaces are generally consistent with the supplemental proposal; however, there were changes to these three limits due to the inclusion of new emission data we received shortly before or during the supplemental proposal comment period. For electric arc furnaces producing FeMn, we are promulgating a PAH emission limit of 12,000 μg/dscm for new or reconstructed and existing electric arc furnaces. The FeMn furnace PAH emission limits are significantly higher than what we proposed in the October 6, 2014, supplemental proposal due to the inclusion of new PAH emission data we received a few weeks before signature of the supplemental proposal and during the supplemental proposal comment period. We explained in the supplemental proposal preamble that we received data shortly before that notice and provided the data for comment (i.e., the data were available in the docket). The data received during the comment period were consistent with the data mentioned in the supplemental proposal. For electric arc furnaces producing SiMn, we are promulgating a PAH emission limit of 72 μg/dscm for new or reconstructed electric arc furnaces and 130 μg/dscm for existing electric arc furnaces. The SiMn furnace new PAH emission limit is the same as the limit in the October 6, 2014, supplemental proposal. There was a slight revision to the existing SiMn furnace PAH limit due to the inclusion of new emission data we received during the supplemental proposal comment period. D. What are the requirements during periods of startup, shutdown and malfunction? We are finalizing, as proposed in the supplemental proposal, changes to the Ferroalloys Production NESHAP to eliminate the SSM exemption. Consistent with Sierra Club v. EPA 551 F. 3d 1019 (D.C. Cir. 2008), the EPA is establishing standards in this rule that apply at all times. Table 1 to subpart XXX of part 63 (General Provisions applicability table) is being revised to change several references related to requirements that apply during periods of SSM. We also are eliminating or revising certain recordkeeping and reporting requirements related to the eliminated SSM exemption. The EPA also made changes to the rule to remove or modify inappropriate, unnecessary, or redundant language in the absence of the SSM exemption. We determined that facilities in this source category can meet the applicable emission standards in the Ferroalloys Production NESHAP at all times, including periods of startup and shutdown; therefore, the EPA determined that no separate standards are needed to address emissions during these periods. E. What other changes have been made to the NESHAP? This rule also finalizes revisions to several other Ferroalloys Production NESHAP requirements as proposed, or in some cases with some modification as described in this section. To increase the ease and efficiency of data submittal and data accessibility, we are finalizing, as proposed, a requirement that owners and operators of ferroalloys production facilities submit electronic copies of certain required performance test reports through an electronic performance test report tool called the Electronic Reporting Tool (ERT). This requirement to submit performance test data electronically to the EPA does not require any additional performance testing and applies only to those performance tests conducted using test methods that are supported by the ERT. We are finalizing the opacity standards, as proposed in the supplemental proposal. However, regarding compliance demonstration, we are requiring that facilities measure opacity using DCOT. In the supplemental proposal, we proposed facilities would need to monitor opacity with Method 9 or DCOT. However, after considering public comments, we decided to require DCOT rather than have it as optional. Regarding monitoring frequency, we proposed facilities would need to do opacity readings weekly per furnace building with no opportunity to reduce frequency overtime. After considering public comments, we have decided to require weekly readings initially, as proposed, but allow a facility an opportunity to decrease frequency of opacity readings to monthly per furnace building after 26 weeks of successful, compliant opacity readings. In addition, due to the large variation in PAH emissions from furnace stacks during FeMn production, we are requiring quarterly compliance tests for PAHs (i.e., four PAH compliance tests per year) for furnaces while producing FeMn, with an opportunity for facilities to request decreased frequency of such compliance testing from their permit authority after the first year and after four or more successful PAH compliance tests have been completed and submitted electronically. We are also finalizing other minor changes to the NESHAP in response to comments received during the public comment period for the proposal and supplemental proposal, as described in this preamble. F. What are the effective and compliance dates of the standards? The revisions to the MACT standards being promulgated in this action are effective on June 30, 2015. The compliance date for existing ferroalloys production sources for all the requirements promulgated in this final rule is June 30, 2017. Facilities must comply with the changes set out in this final rule (which are being promulgated under CAA sections 112(d)(2), 112(d)(3), 112(d)(6), and 112(f)(2) for all affected sources) no later than 2 years after the effective date of the final rule. CAA section 112(f)(4) generally provides that a standard promulgated pursuant to CAA section 112(f)(2) applies 90 days after the effective date, but further provides for a compliance period of up to 2 years when the Administrator determines that such time is necessary for the installation of controls and that steps will be taken during that period to assure protection to health from imminent endangerment. We conclude that 2 years are necessary to complete the installation of the enhanced local capture system and other controls. In the period between the effective date of this rule and the compliance date, existing sources will need to continue to comply with the requirements specified in 40 CFR 63.1650 through 40 CFR 63.1660. New sources must comply with the all of the standards immediately upon the effective date of the standard, June 30, 2015, or upon startup, whichever is later. G. What are the requirements for submission of performance test data to the EPA? As we proposed, the EPA is taking a step to increase the ease and efficiency of data submittal and data accessibility. Specifically, the EPA is finalizing the requirement for owners and operators of ferroalloys production facilities to submit electronic copies of certain required performance test reports. Data will be collected by direct computer-to-computer electronic transfer using EPA-provided software. This EPA-provided software is an electronic performance test report tool called the ERT. The ERT will generate an electronic report package which will be submitted to the Compliance and Emissions Data Reporting Interface (CEDRI) and then archived to the EPA's Central Data Exchange (CDX). A description and instructions for use of the ERT can be found at http://www.epa.gov/ttn/chief/ert/index.html and CEDRI can be accessed through the CDX Web site ( http://www.epa.gov/cdx ). The requirement to submit performance test data electronically to the EPA does not create any additional performance testing and will apply only to those performance tests conducted using test methods that are supported by the ERT. A listing of the pollutants and test methods supported by the ERT is available at the ERT Web site. The EPA believes, through this approach, industry will save time in the performance test submittal process. Additionally, this rulemaking benefits industry by reducing recordkeeping costs as the performance test reports that are submitted to the EPA using CEDRI are no longer required to be kept in hard copy. State, local, and tribal agencies will benefit from more streamlined and accurate review of performance test data that will become available through WebFIRE. The public will also benefit. Having these data publicly available enhances transparency and accountability. For a more thorough discussion of electronic reporting of performance tests using direct computer-to-computer electronic transfer and using EPA-provided software, see the discussion in the preamble of the proposal. In summary, in addition to supporting regulation development, control strategy development, and other air pollution control activities, having an electronic database populated with performance test data will save industry, state, local, tribal agencies, and the EPA significant time, money, and effort while improving the quality of emission inventories and air quality regulations and enhancing the public's access to this important information. IV. What is the rationale for our final decisions and amendments for the Ferroalloys Production source category? For each issue, this section provides a description of what we proposed and what we are finalizing for the issue, the EPA's rationale for the final decisions and amendments, and a summary of key comments and responses. For all comments not discussed in this preamble, comment summaries and the EPA's responses can be found in the comment summary and response document, which is available in the docket. A. Residual Risk Review for the Ferroalloys Production Source Category 1. What did we propose pursuant to CAA section 112(f) for the Ferroalloys Production source category? Pursuant to CAA section 112(f), we conducted a residual risk review and presented the results of this review, along with our proposed decisions regarding risk acceptability and ample margin of safety, in the October 6, 2014, supplemental proposal for the Ferroalloys Production NESHAP (79 FR 60238). The results of the risk assessment for the 2014 supplemental proposal are presented briefly below in Table 2 and in more detail in the residual risk document, Residual Risk Assessment for the Ferroalloys Source Category in Support of the September 2014 Supplemental Proposal , which is available in the docket for this rulemaking. Based on actual emissions estimates for the Ferroalloys Production source category supplemental proposal, the maximum individual risk (MIR) for cancer was estimated to be up to 20-in-1 million driven by emissions of chromium compounds, PAHs, and nickel compounds. The maximum chronic non-cancer target organ-specific hazard index (TOSHI) value was estimated to be up to 4 driven by fugitive emissions of manganese. The maximum off-site acute hazard quotient (HQ) value was estimated to be 1 for arsenic compounds, hydrogen fluoride (HF), and formaldehyde. The total estimated national cancer incidence from this source category, based on actual emission levels, was 0.002 excess cancer cases per year, or one case in every 500 years. Based on MACT-allowable emissions estimated for the Ferroalloys Production source category supplemental proposal, the MIR was estimated to be up to 100-in-1 million driven by emissions of arsenic and cadmium compounds from the MOR process baghouse outlet. The maximum chronic non-cancer TOSHI value was estimated to be up to 40 driven by emissions of manganese from the MOR process. The total estimated national cancer incidence from this source category, based on MACT-allowable emission levels, was 0.005 excess cancer cases per year, or one case in every 200 years. We also found there were emissions of four persistent and bioaccumulative HAP (PB-HAP) with an available RTR multipathway screening value, and the reported emissions of these four HAP (cadmium compounds, dioxins/furans, Hg compounds, and PAH) were greater than the Tier 1 multipathway screening values for these compounds for both facilities at the time of the supplemental proposal. We conducted a Tier 2 multipathway screen for both facilities, and conducted a refined multipathway assessment for one facility in the source category. Results of the refined multipathway assessment predict a potential lifetime cancer risk of 10-in-1 million to the maximum exposed individual due to exposure to dioxins and PAHs. The non-cancer HQ was predicted to be below 1 for cadmium compounds and 1 for Hg compounds. However, as explained in the Revised Development of the Risk and Technology Review (RTR) Emissions Dataset for the Ferroalloys Production Source Category for the 2014 Supplemental Proposal document, it is important to note that about 75 percent of the emissions test results for dioxins were below the detection limit. To be conservative, in our calculations of emissions estimates, we assumed all the test results that were recorded as below detection were one half the detection limit. Therefore, there are considerable uncertainties in estimated emissions for dioxins. Nevertheless, since we assumed emissions were at the level of one half the detection limit in all these cases where emissions were not even detected, we believe our emissions estimates are conservative ( i.e. , more likely to be overestimates rather than underestimates of the true emissions). Emissions of the four PB-HAP and two environmental HAP (HCl and HF) were reported by ferroalloys facilities. Tier 1 results for PB-HAP indicate that concentrations of cadmium compounds and dioxins are below the ecological benchmarks. Mercury compounds and PAHs concentrations were greater than the benchmark so a Tier 2 screen was conducted. For PAH and methylmercury, none of the individual modeled concentrations for any facility exceeded any of the ecological benchmarks. For mercuric chloride, the weighted average modeled concentrations for all soil parcels were well below the soil benchmarks. For HCl and HF, the average modeled concentrations around each facility did not exceed any ecological benchmarks. For the supplemental proposal, we weighed all health risk factors in our risk acceptability determination and we proposed that the residual risks from the Ferroalloys Production source category are unacceptable. Table 2—Ferroalloys Inhalation Risk Assessment Results in the October 2014 Supplemental Proposal Maximum individual cancer risk (in 1 million) a Actual emissions level MACT- allowable emissions level c Estimated population at increased risk levels of cancer Estimated annual cancer incidence (cases per year) Maximum chronic non-cancer TOSHI b Actual emissions level MACT- allowable emissions level Maximum screening acute non-cancer HQ d 20 100 >= 1-in-1 million: 31,000 >= 10-in-1 million: 400 >= 100-in-1 million: 0 0.002 4 40 HQ REL = 1 (arsenic compounds, formaldehyde, hydrofluoric acid). a Estimated maximum individual excess lifetime cancer risk due to HAP emissions from the source category. b Maximum TOSHI. The target organ with the highest TOSHI for the Ferroalloys Production source category for both actual and allowable emissions is the neurological system. The estimated population at increased levels of noncancer hazard is 1,500 based on actual emissions and 11,000 based on allowable emissions. c The development of allowable emission estimates can be found in the memorandum titled Revised Development of the RTR Emissions Dataset for the Ferroalloys Production Source Category for the 2014 Supplemental Proposal , which is available in the docket. d See section III.A.3 of the supplemental proposal or the risk assessment document supporting the supplemental proposal for explanation of acute dose-response values. Acute assessments are not performed on allowable emissions. As described above, to address the unacceptable risks in the supplemental proposal, we proposed tighter PM emission limits for the stacks, which significantly reduce risks due to allowable emissions. To reduce risks due to process fugitive emissions, we proposed facilities must achieve effective enhanced capture of process fugitive emissions using a system of primary hoods (that capture process fugitive emissions near the source) and/or secondary capture of fugitives (which would capture remaining fugitive emissions near the roof-line). As described in the supplemental proposal, we estimated that these controls would reduce the MIR cancer risk estimate to 10-in-1 million and that the chronic noncancer hazard index (HI) would be reduced to an HI of 1. Acute screening and multipathway results were also reduced. In the supplemental proposal, we concluded that these risks, after the implementation of proposed controls, were acceptable. We then considered whether the Ferroalloys Production NESHAP provides an ample margin of safety to protect public health and whether more stringent standards are necessary to prevent an adverse environmental effect, taking into consideration costs, energy, safety, and other relevant factors. In considering whether the standards should be tightened to provide an ample margin of safety to protect public health, we considered the same risk factors that we considered for our acceptability determination and also considered the costs, technological feasibility, and other relevant factors related to emissions control options that might reduce risks associated with emissions from the source category. Based on our ample margin of safety analysis for the supplemental proposal, we did not identify any additional cost-effective controls to further reduce risks beyond the requirements we proposed to achieve acceptable risks. Therefore, we proposed that additional HAP emissions controls are not necessary to provide an ample margin of safety. Based on the results of our screening analysis for risks to the environment, we also proposed that more stringent standards are not necessary to prevent an adverse environmental effect. 2. How did the risk review change for the Ferroalloys Production source category? Information received by the EPA shortly before and during the supplemental proposal comment period included additional PAH and Hg test data that were not included in the supplemental proposal risk assessment due to timing and the need to review the data. We described the data in the supplemental proposal and asked for comment on the use of these data. After completion of the data review, these data were included in the risk assessment for the final rule. Therefore, PAH and Hg emissions estimates were revised for the final rule assessment. Some revisions were also made for other HAP emissions. These changes are discussed further in section IV of this preamble. With the exception of the revised emissions described above, the risk assessment supporting the final rule was conducted in the same manner, using the same models and methods, as that conducted for the supplemental proposal. The documentation for the final rule risk assessment can be found in the document titled Residual Risk Assessment for the Ferroalloys Source Category in Support of the 2015 Risk and Technology Review Final Rule , which is available in the docket for this rulemaking. a. Inhalation Risk Assessment Results. Table 3 provides an overall summary of the results of the inhalation risk assessment supporting the final rule. Table 3—Ferroalloys Inhalation Risk Assessment Results in the 2015 Final Rule Maximum individual cancer risk (in 1 million) a Actual emissions level MACT- allowable emissions level c Estimated population at increased risk levels of cancer Estimated annual cancer incidence (cases per year) Maximum chronic non-cancer TOSHI b Actual emissions level MACT- allowable emissions level Maximum screening acute non-cancer HQ d 20 100 >= 1-in-1 million: 41,000 >= 10-in-1 million: 90 >= 100-in-1 million: 0 0.003 4 40 HQ REL = 1 (hydrofluoric acid, arsenic compounds). a Estimated maximum individual excess lifetime cancer risk due to HAP emissions from the source category. b Maximum TOSHI. The target organ with the highest TOSHI for the Ferroalloys Production source category for both actual and allowable emissions is the neurological system. The estimated population at increased levels of noncancer hazard is 1,300 based on actual emissions and 11,000 based on allowable emissions. c The development of allowable emission estimates can be found in the memorandum titled Revised Development of the RTR Emissions Dataset for the Ferroalloys Production Source Category for the 2014 Supplemental Proposal , which is available in the docket. d See section III.A.3 of the supplemental proposal or the risk assessment document supporting the supplemental proposal for explanation of acute dose-response values. Acute assessments are not performed on allowable emissions. The inhalation risk modeling performed to estimate risks based on actual and allowable emissions for the final rule relied primarily on updated emissions estimates based on data received through two Information Collection Requests (ICRs), additional data submitted by the companies voluntarily, and revised calculations as described further in the Revised Development of the Risk and Technology Review (RTR) Emissions Dataset for the Ferroalloys Production Source Category for the 2015 Final Rule , which is available in the docket for this action. The results of the chronic baseline inhalation cancer risk assessment indicate that, based on updated estimates of actual emissions, the cancer MIR posed by the Ferroalloys Production source category is 20-in-1 million, with chromium compounds, PAHs, and nickel compounds from tapping fugitives, furnace fugitives, and furnace stacks accounting for more than 70 percent of the MIR. The total estimated cancer incidence from ferroalloys production sources based on updated actual emission levels is 0.003 excess cancer cases per year, or one case every 333 years, with emissions of PAH, chromium compounds, and cadmium compounds contributing 49 percent, 15 percent, and 12 percent, respectively, to this cancer incidence. In addition, we note that approximately 90 people are estimated to have cancer risks greater than or equal to 10-in-1 million, and approximately 41,000 people are estimated to have risks greater than or equal to 1-in-1 million because of actual emissions from this source category. These results, based on updated actual emissions, are very similar to those presented in the supplemental proposal. When considering the updated MACT-allowable emissions, the maximum individual lifetime cancer risk is estimated to be up to 100-in-1 million, driven by emissions of arsenic and cadmium compounds from the MOR process baghouse outlet. The estimated cancer incidence is estimated to be 0.006 excess cancer cases per year or one excess case in every 167 years. Approximately 3,300 people are estimated to have cancer risks greater than or equal to 10-in-1 million and approximately 120,000 people are estimated to have cancer risks greater than or equal to 1-in-1 million considering updated allowable emissions from ferroalloys facilities. These results, based on updated MACT-allowable emissions, are very similar to those presented in the supplemental proposal. The maximum modeled chronic non-cancer HI (TOSHI) value for the source category based on updated actual emissions is estimated to be 4, with manganese emissions from tapping fugitives accounting for more than 50 percent of the HI. Approximately 1,300 people are estimated to have exposure to HI levels greater than 1 as a result of updated actual emissions from this source category. When considering updated MACT-allowable emissions, the maximum chronic non-cancer TOSHI is estimated to be 40, driven by manganese emissions from the MOR process baghouse outlet. Approximately 12,000 people are estimated to have potential exposure to TOSHI levels greater than 1 considering updated allowable emissions from these ferroalloys facilities. These results, for both updated actual and MACT-allowable emissions, are very similar to those presented in the supplemental proposal. b. Acute Risk Results. Based on the updated emissions described above, our screening analysis for worst-case acute impacts based on actual emissions indicates the potential for hydrofluoric acid and arsenic compounds to have HQ results of 1, based on their respective REL values. Both facilities have estimated acute HQs of 1 for these pollutants. Acute HQs for other pollutants ( e.g. , hydrochloric acid) are less than one. These acute results, based on updated emissions, are very similar to those presented in the supplemental proposal. All the HAP in this analysis have worst-case acute HQ values of 1 or less, indicating that they carry no potential to pose acute concerns. In characterizing the potential for acute non-cancer impacts of concern, it is important to remember the upward bias of these exposure estimates ( e.g. , worst-case meteorology coinciding with a person located at the point of maximum concentration during the hour) and to consider the results along with the conservative estimates used to develop peak hourly emissions as described earlier, as well as the screening methodology. More discussion of our acute screening methods can be found in the supplemental proposal or in the risk assessment document, Residual Risk Assessment for the Ferroalloys Production Source Category in Support of the 2015 Final Rule, which are available in the docket. c. Multipathway Risk Screening Results. Results of the worst-case Tier I screening analysis indicate that PB-HAP emissions (based on updated estimates of actual emissions) from one or both facilities in this source category exceed the screening emission rates for cadmium compounds, Hg compounds, dioxins, and PAHs. For the compounds and facilities that did not screen out at Tier I, we conducted a Tier II screen. Based on the Tier II screening analysis, no facility emits cadmium compounds above the Tier II screening levels. One facility emits Hg compounds above the Tier II screening levels and exceeds that level by a factor of 8. Both facilities emit chlorinated dibenzodioxins and furans (CDDF) as 2,3,7,8-tetrachlorodibenzo-p-dioxin toxicity equivalent (TEQ) above the Tier II screening levels and the facility with the highest emissions of dioxins exceeds its Tier II screening level by a factor of 10. Both facilities emit POM as benzo(a)pyrene TEQ above the Tier II screening levels and the facility with the highest emissions exceeds its screening level by a factor of 50. These multipathway screening results, based on updated emissions, are very similar to those presented in the supplemental proposal. More information about our multipathway screening approach can be found in the supplemental proposal or in the risk assessment document, Residual Risk Assessment for the Ferroalloys Production Source Category in Support of the 2015 Final Rule, which are available in the docket. d. Multipathway Refined Risk Results. A refined multipathway analysis was conducted for one of the two facilities in this source category using the TRIM.FaTE model and the updated emissions as described above. The facility, Eramet Marietta Incorporated, in Marietta, Ohio, was selected based upon its close proximity to nearby lakes, and farms as well as having the highest potential multipathway risks for three of the four PB-HAP based on the Tier II analysis. In addition, it was selected for a refined multipathway assessment in the supplemental proposal. These three PB-HAP were cadmium, Hg, and PAHs. Even though neither facility exceeded the Tier II screening levels for cadmium, Eramet had the higher value. Eramet also emits dioxins, but the other facility had a higher exceedance of its Tier II screening level. The refined analysis was conducted on all four PB-HAP using updated emissions as described above. The refined analysis for this facility showed that the Tier II screen for each pollutant over-predicted the potential risk when compared to the refined analysis results. Overall, the refined analysis predicts a potential lifetime cancer risk of 20-in-1 million to the maximum most exposed individual due to exposure to dioxins and PAHs. The non-cancer HQ is predicted to be below 1 for cadmium compounds and 1 for Hg compounds. These results, based on updated emissions, are very similar to those presented in the supplemental proposal. Further details on the refined multipathway analysis can be found in Appendix 10 of the Residual Risk Assessment for the Ferroalloys Production Source Category in Support of the 2015 Final Rule, which is available in the docket. e. Environmental Risk Screening Results. As described in section III.A of the supplemental proposal preamble (79 FR 60238), we conducted an environmental risk screening assessment for the Ferroalloys Production source category. In the Tier I screening analysis for PB-HAP (other than lead, which was evaluated differently as noted in section III.A of the supplemental proposal preamble, 79 FR 60238), the individual modeled Tier I concentrations for one facility in the source category exceeded some sediment, fish-avian piscivorus, and surface soil benchmarks for PAHs, methylmercury, and mercuric chloride. Therefore, we conducted a Tier II assessment. In the Tier II screening analysis for PAHs and methylmercury, none of the individual modeled concentrations for any facility in the source category exceeded any of the ecological benchmarks (either the lowest-observed-adverse-effect level or the no-observed-adverse-effect level). For mercuric chloride, soil benchmarks were exceeded for some individual modeled points that collectively accounted for 11 percent of the modeled area. However, the weighted average modeled concentration for all soil parcels was well below the soil benchmarks. For lead, we did not estimate any exceedances of the secondary lead National Ambient Air Quality Standards (NAAQS). For HCl, each individual concentration ( i.e. , each off-site data point in the modeling domain) was below the ecological benchmarks for all facilities. The average modeled HCl concentration around each facility ( i.e. , the average concentration of all off-site data points in the modeling domain) did not exceed any ecological benchmark. For HF, some individual modeled points exceeded the ecological benchmark but accounted for less than 0.02 percent of the modeled area. The average modeled HF concentration around each facility ( i.e. , the average concentration of all off-site data points in the modeling domain) did not exceed any ecological benchmarks. These results, based on updated emissions, are very similar to those presented in the supplemental proposal. f. Facility-Wide Risk Assessment Results. As in the supplemental proposal, for both facilities in this source category, there are no other HAP emissions sources present beyond those included in the source category. Therefore, we conclude that the facility-wide risk is the same as the source category risk and that no separate facility-wide analysis is necessary. g. Demographic Analysis Results. To examine the potential for any environmental justice (EJ) issues that might be associated with the source category, we updated the demographic analysis that was conducted for the supplemental proposal, using the risk results based on the updated emissions. A demographic analysis is an assessment of risks to individual demographic groups of the population close to the facilities. In this analysis, we evaluated the distribution of HAP-related cancer risks and noncancer hazards from the Ferroalloys Production source category across different social, demographic, and economic groups within the populations living near facilities identified as having the highest risks. The methodology and the results of the demographic analyses are included in a technical report, Risk and Technology Review—Analysis of Socio-Economic Factors for Populations Living Near Ferroalloys Facilities, which is available in the docket for this action. The results of the demographic analysis are summarized in Table 4 below. These results, for various demographic groups, are based on the estimated risks from actual emissions levels for the population living within 50 kilometers (km) of the facilities. Table 4—Ferroalloys Production Demographic Risk Analysis Results for 2015 Final Rule Nationwide Population with cancer risk at or above 1-in-1 million due to Ferroalloys Production Population with chronic hazard index above 1 due to Ferroalloys Production Total Population 312,861,265 40,748 1,348 Race by Percent White 72 97 99 All Other Races 28 3 1 Race by Percent White 72 97 99 African American 13 1 0 Native American 1 0 0 Other and Multiracial 14 2 1 Ethnicity by Percent Hispanic 17 1 1 Non-Hispanic 83 99 99 Income by Percent Below Poverty Level 14 15 6 Above Poverty Level 86 85 94 Education by Percent Over 25 and without High School Diploma 15 11 10 Over 25 and with a High School Diploma 85 89 90 Age by Percent Ages 0 to 17 24 21 22 Ages 18 to 64 63 61 59 Ages 65 and up 13 18 19 The results of the Ferroalloys Production source category demographic analysis indicate that emissions from the source category expose approximately 41,000 people to a cancer risk at or above 1-in-1 million and approximately 1,300 people to a chronic non-cancer TOSHI greater than 1 (we note that many of those in the first risk group are the same as those in the second). The percentages of the at-risk population in each demographic group (except for ages 65 and up) are similar to or lower than their respective nationwide percentages. These results are very similar to those presented in the supplemental proposal. 3. What key comments did we receive on the risk review, and what are our responses? Several comments were received regarding the risk assessment for the Ferroalloys Production source category. The following is a summary of some of the more significant comments and our responses to those comments. Other comments received and our responses to those comments can be found in the document titled National Emission Standards for Hazardous Air Pollutant Emissions: Ferroalloys Production Summary of Public Comments and the EPA's Responses on Proposed Rule (76 FR 72508, November 23, 2011) and Supplemental Proposal (79 FR 60238, October 6, 2014) , which is available in the docket for this action (EPA-HQ-OAR-2010-0895). Comment: Several comments were received on the reference value used in the risk assessment to evaluate chronic noncancer effects due to exposure to manganese. In the 2011 proposal, we used the Integrated Risk Information System (IRIS) reference concentration (RfC), and we received negative comments regarding that value not being the “best available science.” We evaluated the available values and, in accordance with our prioritized dose-response values and Scientific Advisory Board (SAB) comments, we used the Agency for Toxic Substances and Disease Registry (ATSDR) minimum risk level (MRL) for manganese in the risk assessment for the 2014 supplemental proposal. We received mixed comments in response to the supplemental proposal. Some comments were negative regarding our use of the ATSDR MRL, while others were generally supportive of our use of the MRL compared to the IRIS value, yet still thought the MRL was not the appropriate reference value to use in the assessment. Regarding use of the IRIS RfC for manganese in the 2011 proposal risk assessment, commenters stated that the manganese RfC was outdated, did not constitute the best available science (including use of benchmark dose statistical analyses or physiologically-based pharmacokinetic models), and substantial research has been conducted since the 1993 IRIS RfC was last updated. The commenters refer to their own calculations and studies and developed their own reference value for manganese and state that the EPA should use that value. Regarding use of the ATSDR MRL for manganese in the 2014 supplemental proposal risk assessment, the same commenters stated that the manganese MRL was an improvement over the IRIS RfC, but was still not the best available science because, in their review, ATSDR did not apply physiologically-based pharmacokinetic models. The commenters again refer to their own calculations and studies developing a reference value for manganese and state that EPA should use that value. Another commenter disagrees with the use of the ATSDR MRL because the EPA has not provided sufficient rationale for using a less-protective value. Instead, this commenter recommended that we continue to use the IRIS RfC value. Response: We agree that there were newer information and assessments available at the time of the 2011 proposal and also for the 2014 supplemental proposal, some of which may use the currently preferred approach for developing dose-response values (i.e., the benchmark dose approach). However, we only use reference values which meet certain criteria in regards to how they are derived (using EPA guidelines or similar), derived by credible sources with health-protective goals similar to those of the EPA, using peer-review procedures also similar to the level applied to the EPA values, and with an open public comment process. We have a tiered priority list for sources of chronic dose-response information, which meet these criteria (as described in the supplemental proposal, 79 FR 60238). The tiered prioritized list has been through a SAB review and was favorably received. In the risk assessment for the 2011 proposal, we used the IRIS RfC for chronic exposure to manganese and received numerous comments regarding use of that value. In response to those comments, we considered the existing peer-reviewed health effect reference values for chronic inhalation exposure to manganese from other federal, state, and international agencies and organizations. We developed a reference value array document 2 providing additional details for the available values. We noted that the ATSDR MRL value available for the 2011 proposal was a draft value. The ATSDR MRL was subsequently finalized in 2012. 2 U.S. EPA. Mn and BTEX Reference Value Arrays (Final Reports). U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-12/047F, 2013. In our consideration of available reference values, we did not include some values specifically noted in public comments. The level of peer review for non-governmental scientific publications is qualitatively different than the governmental processes used to derive the values described in our tiered prioritized list, and some of the values in the manganese reference value array document. The information provided by these additional references from the commenter(s) may prove useful in an IRIS reassessment for manganese, and we agree that the physiologically-based models, along with all other relevant available peer-reviewed literature, will be considered in any IRIS reassessment of manganese. Yet, a direct application of any of these values instead of an established value in our tiered list of prioritized dose-response values would be inconsistent with the EPA policy as implemented in the RTR Program, and with recommendations from the SAB. After considering the values in our tiered list of prioritized dose-response values, and consistent with Agency policy supported by SAB, we decided to rely on the 2012 ATSDR MRL value for the 2014 supplemental proposal. Both the 1993 IRIS RfC and the 2012 ATSDR MRL were based on the same study (Roels et al., 1993). In developing their assessment, ATSDR used updated dose-response modeling methodology (benchmark dose approach) and considered recent pharmacokinetic findings to support their selection of uncertainty values in the MRL derivation. 4. What is the rationale for our final approach and final decisions for the risk review? As noted in section II.A.1 of this preamble, the EPA sets standards under CAA section 112(f)(2) using “a two-step standard-setting approach, with an analytical first step to determine an `acceptable risk' that considers all health information, including risk estimation uncertainty and includes a presumptive limit on maximum individual lifetime risk (MIR) of approximately 1 in 10 thousand.” 3 (54 FR 38045, September 14, 1989). 3 1-in-10 thousand is equivalent to 100-in-1 million. The EPA currently describes cancer risks as `n-in-1 million.' a. Acceptability Determination. As in the supplemental proposal, the EPA concludes that the risks are unacceptable for the following reasons. First, the EPA considered the fact that the noncancer hazard HQ ranges from 4 based on actual emissions to 40 based on allowable emissions. The EPA has not established under section 112 of the CAA a numerical range for risk acceptability for noncancer effects as it has with carcinogens, nor has it determined that there is a bright line above which acceptability is denied. However, the Agency has established that, as exposure increases above a reference level (as indicated by a HQ or TOSHI greater than 1), confidence that the public will not experience adverse health effects decreases and the likelihood that an effect will occur increases. For the Ferroalloys Production source category, the potential for members of the public to be exposed to manganese at concentrations up to 40 times the MRL reduces the Agency's confidence that the public is protected from adverse health effects and diminished the Agency's ability to determine that such exposures are acceptable. Second, the EPA considered the fact that the cancer risk estimate for actual emissions is 20-in-1 million and up to 100-in-1 million for allowable emissions. While 20-in-1 million is well within the acceptable range, risks from allowable emissions are at the upper end of the range of acceptability. This fact, combined with the fact that the noncancer hazard is up to 40 times the MRL and the refined multipathway HQ for Hg is at the RfD, leads the Agency to conclude that the risk from this source category is unacceptable. b. What is EPA requiring in the final rule to address the unacceptable risks? As mentioned above, to address the unacceptable risks, we are promulgating tighter PM emission limits for the stacks, which significantly reduces risks due to allowable emissions. Furthermore, to reduce risks due to process fugitive emissions, we are promulgating a requirement that facilities must achieve effective enhanced capture of process fugitive emissions using a system of primary hoods (that capture process fugitive emissions near the source) and/or secondary capture of fugitives (which would capture remaining fugitive emissions near the roof-line). Facilities must install, operate, and maintain a process fugitives capture system that is designed to capture and control 95 percent or more of the process fugitive emissions. We are also promulgating an opacity limit of 8 percent to ensure process fugitive emissions are effectively captured and controlled. Facilities will need to meet an average opacity of 8 percent for the entire furnace cycle (about 90-120 minutes) with a maximum opacity of no more than 20-percent opacity for any 12-minute period. Moreover, facilities will need to monitor various control parameters (such as fan speed, amperage, pressure drops, and/or damper positioning) to ensure the process fugitive capture systems and controls are working properly. c. Remaining Risks After Implementation of the Requirements to Address Unacceptable Risks. To determine the remaining risks after implementation of the lower stack PM emissions limits and requirements to effectively control process fugitives (described above), we conducted a post control risk assessment, which is described in detail in the document titled Residual Risk Assessment for the Ferroalloys Source Category in Support of the 2015 Final Rule, which is available in the docket for this rulemaking. Based on this post control risk assessment, we conclude that after the requirements described above to address unacceptable risks are implemented, the risks to public health will be substantially reduced. For example, the results of the post-control chronic inhalation cancer risk assessment indicate that the maximum individual lifetime cancer risk posed by these two facilities, after the implementation of the promulgated controls, will be no higher than 10-in-1 million, with an estimated reduction in cancer incidence to 0.002 cases per year. In addition, the number of people estimated to have a cancer risk greater than or equal to 1-in-1 million would be 26,000. The results of the post-control risk assessment also indicate that the maximum chronic noncancer inhalation TOSHI value would be reduced to 1. The number of people estimated to have a TOSHI greater than 1 would be reduced to 0. We also estimate that after the implementation of controls, the maximum worst-case acute HQ value would be less than 1 (based on REL values). Considering post-control emissions of multipathway HAP, Hg emissions would be reduced by approximately 3 pounds per year (lbs/yr), lead would be reduced by about 1,600 lbs/yr, polycyclic organic matter (POM) emissions would be reduced by approximately 3,600 lbs/yr, cadmium would be reduced by about 150 lbs/yr, and dioxins and furans would be reduced by about 0.002 lbs/yr from the baseline emission rates. d. Ample Margin of Safety Analysis. Under the ample margin of safety analysis, we again considered all of the health factors evaluated in the acceptability determination and evaluated the cost and feasibility of available control technologies and other measures (including the controls, measures, and costs reviewed under the technology review) that could be applied in this source category to further reduce the risks due to emissions of HAP identified in our risk assessment. As described above, we estimate that the actions finalized under CAA section 112(f)(2) to address unacceptable risks will reduce the MIR to 10-in-1 million. The cancer incidence will be reduced to 0.002 cases per year and the number of people estimated to have cancer risks greater than 1-in-1 million will be reduced to 26,000 people. The chronic noncancer inhalation TOSHI will be reduced to 1 and the number of people exposed to a TOSHI level greater than 1 will be reduced to 0. In addition, the potential multipathway impacts will be reduced. Based on all of the above information, we conclude that the risks will be acceptable after implementation of the lower stack limits for PM and the control requirements to reduce process fugitive emissions, as we concluded in the supplemental proposal. Based on our research and analysis, we did not identify any cost-effective controls beyond those described above that would achieve further reduction in risk. While in theory, the 2011 proposed approach of total enclosure with negative pressure would provide some additional risk reduction, the additional risk reduction is minimal and, similar to our assessment and conclusions described in the supplemental proposal, we continue to believe the total enclosure approach would not be economically feasible and may not be technically feasible for these facilities. No other technology advances were identified during the comment period. Therefore, we are not promulgating any additional requirements under the ample margin of safety analysis beyond the requirements being finalized to address unacceptable risks (as described above). We conclude that the controls to achieve acceptable risks will also provide an ample margin of safety to protect public health. B. Technology Review for the Ferroalloys Production Source Category 1. What did we propose pursuant to CAA section 112(d)(6) for the Ferroalloys Production source category? Pursuant to CAA section 112(d)(6), we conducted a technology review, which focused on identifying and evaluating developments in practices, processes, and control technologies for the emission sources in the Ferroalloys Production source category. For the 2011 proposal (76 FR 72508), we identified developments in practices, processes or control technologies for PM emissions from stacks (as a surrogate for metal HAP) and for process fugitive metal HAP emissions. Based on the comments received from the public and information received through a 2012 ICR, we revised both the technology review and risk assessment for the Ferroalloys Production source category, which were described in detail in the 2014 supplemental proposal (79 FR 60238). a. PM Emission Limits From Stacks. For PM stack emissions limits, we determined for the 2011 proposal that the test data received from the two facilities indicate that all five furnaces that are in operation have PM emission levels that are well below their respective emission limits in the 1999 MACT rule, which were based on size and product being produced. The test data received from the facilities also indicate that the PM emission levels for MOR and crushing and sizing are well below their respective emission limits in the 1999 MACT rule. These findings demonstrate that add-on particulate control technologies (Venturi scrubber, positive pressure fabric filter, negative pressure fabric filter) used to control emissions from the sources are effective in reducing PM (used as a surrogate for metal HAP). Based on these findings, in 2011 we proposed a PM limit of 24 mg/dscm corrected to 2 percent carbon dioxide (CO 2 ) for existing furnaces. We received additional test data after the 2011 proposal and re-evaluated the PM limit using available PM emissions test data and consideration of variability across these data. Based on this analysis, we determined that it was appropriate to propose a revised PM limit of 25 mg/dscm for existing furnaces. No additional add-on control is expected to be required by the facilities to meet this revised existing source limit. To demonstrate compliance, we proposed these sources would be required to conduct periodic performance testing and develop and operate according to a baghouse operating plan or continuously monitor Venturi scrubber operating parameters. We also proposed that furnace baghouses would be required to be equipped with bag leak detection systems (BLDS). For the 2011 proposal, the proposed new source PM standard was determined by evaluating the available data from the best performing furnace (which was determined to be furnace #2 at Felman). The proposed new source limit was determined to be 9.3 mg/dscm. We received additional test data after the 2011 proposal and re-evaluated the new source limit using the available test data. The revised new source PM standard for furnaces for the 2014 supplemental proposal was determined by evaluating the available data from the best performing furnace (which was again determined to be furnace #2 at Felman). The new source MACT limit was determined to be 4.0 mg/dscm based on data from furnace #2 and was proposed as the MACT emissions limit for PM from new and reconstructed source furnace stacks in the 2014 supplemental proposal. The PM emission limit for the local ventilation control device outlet was also re-evaluated using compliance test data and test data from the 2012 ICR. A local ventilation control system is used to capture tapping, casting, or ladle treatment emissions and direct them to a control device other than one associated with the furnace. The 2011 proposal included a proposed PM limit for the local ventilation control device that was based on PM data from the furnaces. After the 2011 proposal, we received test data from three different emissions tests (for a total of nine test runs) specifically for this local ventilation source. We determined these data were more appropriate for the development of a limit for this source than the furnace data we had used for the 2011 proposal. There is currently only one local ventilation control device outlet emissions source in this source category. Using the new data for the one existing local ventilation source, we calculated a revised emissions limit of 4.0 mg/dscm and determined that this was an appropriate emissions limit for this source. Therefore, we proposed an emissions limit of 4.0 mg/dscm for existing, new, and reconstructed local ventilation control device emissions sources in the supplemental proposal. For crushing and screening operations, we proposed an emission limit of 13 mg/dscm for new and existing crushing and sizing operations in the 2011 proposal. We did not receive any additional data for this emission source and, therefore, made no revisions to this proposed limit in the 2014 supplemental proposal. The MOR operation is a unique process that is operated by only one facility (Eramet). We calculated a proposed emission limit of 3.9 mg/dscm in the 2011 proposal that would apply to both new and existing MOR operation sources. We did not receive any additional data for this emission source and, therefore, made no revisions to this proposed limit in the 2014 supplemental proposal. b. Emission Standards for Process Fugitives. For process fugitive metal HAP emissions, we identified two potential developments in practices and control techniques. One option would require facilities to install and operate enhanced capture of process fugitive emissions using a combination of primary hoods and ductwork in close proximity to the emission sources, such as tapping or casting and/or secondary hoods located near the roofline. Another option would be to require full enclosure of the furnace building(s) with negative pressure and evacuate the process fugitive emissions to a control device(s). In the 2011 proposal, we proposed that the full furnace building enclosure option represented an advance in emission control measures since the Ferroalloys Production NESHAP was originally promulgated in 1999. For day-to-day continuous monitoring to demonstrate compliance with the proposed full building enclosure requirements, the 2011 proposal relied mainly on requiring monitoring differential pressure to ensure facilities maintained a negative pressure of at least 0.007 inches of water and that emissions within the facilities would need to be vented to PM control devices. This was to be supplemented by operation and work practice standards that required preparation of a process fugitive emissions ventilation plan for each shop building. In the 2011 proposal, we also proposed a requirement that emissions exiting from a shop building may not exceed more than 10-percent opacity for more than one 6-minute period, to be demonstrated every 5 years as part of the periodic required performance tests. We received significant comments in response to the 2011 proposal. Commenters claimed that we had significantly underestimated the costs for full building enclosure and that it would not be feasible for these facilities. After reviewing and considering the comments along with other information, we decided to re-evaluate the proposed requirement for negative pressure ventilation and consider other options. Based on our re-evaluation, for the 2014 supplemental proposal, we concluded that the full-building enclosure option may not be feasible and would have significant economic impacts on the facilities. However, we concluded that an option based on enhanced local capture and control of process fugitive emissions using a combination of primary and secondary hoods is a feasible and cost-effective approach to achieve significant reductions in process fugitive HAP emissions. Therefore, in the 2014 supplemental proposal, we proposed that facilities would need to install and operate a local capture system using a combination of primary and/or secondary hoods that is designed to achieve at least 95-percent capture and control of process fugitive emissions. With the move to the proposed enhanced local capture alternative in the 2014 supplemental proposal, we no longer had a day-to-day continuous requirement of monitoring negative pressure. Instead, in the 2014 supplemental proposal, continuous compliance demonstration would be based mainly on meeting an opacity limit, monitoring ventilation parameters (such as fan speed, amperage, and/or damper positioning), and documenting the design of the system to achieve 95-percent capture. Since opacity monitoring would be a primary method to demonstrate continuous compliance, we proposed that facilities would need to meet an average opacity of 8 percent for an entire furnace cycle (about 90-120 minutes) with a maximum opacity of no more than 20 percent opacity for any 12-minute period. Furthermore, we proposed facilities would need to monitor opacity for a full furnace cycle (about 90-120 minutes) at least once per week per furnace building. We also proposed that, if the average opacity reading from the shop building is greater than 8-percent opacity during an observed furnace process cycle, an additional two more furnace process cycles must be observed such that the average opacity during the entire observation period is less than 7-percent opacity. A furnace process cycle means the period in which the furnace is tapped to the time in which the furnace is tapped again and includes periods of charging, smelting, tapping, casting, and ladle raking. Regarding the design requirements, in the supplemental proposal, we proposed that the facilities in this source category must install, operate, and maintain a process fugitives capture system that is designed to collect 95 percent or more of the process fugitive emissions from furnace operations, casting MOR process, ladle raking, and slag skimming and crushing and screening operations and convey the collected emissions to a control device that meets specified emission limits and the proposed opacity limits. We proposed that this plan be submitted to the permitting authority, incorporated into the source's operating permit and updated every 5 years or when there is a significant change in variables that affect process fugitive emissions ventilation design. We proposed that this list of design criteria, coupled with the requirement for frequent opacity observations and operating parameter monitoring, would ensure process fugitive emissions are effectively controlled and would result in enforceable requirements. More information concerning our proposed technology review can be found in the memoranda titled, Revised Technology Review for the Ferroalloys Production Source Category, and Cost Impacts of Control Options Considered for the Ferroalloys Production NESHAP to Address Fugitive HAP Emissions, which are available in the docket, and in the preamble to the 2014 supplemental proposed rule, 79 FR at 60271 to 60273. 2. How did the technology review change for the Ferroalloys Production source category? For the October 6, 2014, supplemental proposal, we solicited comment regarding the use of new technologies to provide continuous or near continuous long term approaches to monitoring emissions from industrial sources for the Ferroalloy Production source category. After considering comments received and after evaluating the technologies further, we are replacing the weekly Method 9 opacity requirement with a weekly requirement to measure opacity using ASTM D7520-13 and DCOT to demonstrate compliance with the process fugitives standards. The final rule amendments require facilities to use the DCOT to measure opacity at least once per week for each of the furnace and MOR buildings to demonstrate compliance with the opacity limits. However, as mentioned above, facilities will have the opportunity to reduce the frequency of opacity readings to monthly after 26 consecutive weeks of compliant weekly readings. The facilities would still be required to meet an average opacity standard of 8-percent opacity for the furnace cycle (90-120 minutes) and at no time during operation may any two consecutive 6-minute block opacity readings be greater than 20-percent opacity. The cost of implementing the DCOT system is estimated to be approximately $200,000 per year for the source category with weekly readings. However, these costs decrease to about $90,000 per year for the source category if they do monthly readings per furnace building. All other requirements we proposed under CAA section 112(d)(6) in the supplemental proposal have not changed. 3. What key comments did we receive on the technology review, and what are our responses? Several comments were received regarding the technology review for the Ferroalloys Production source category. The following is a summary of the more significant comments and our responses to those comments. Other comments received and our responses to those comments can be found in the document titled National Emission Standards for Hazardous Air Pollutant Emissions: Ferroalloys Production Summary of Public Comments and the EPA's Responses on Proposed Rule (76 FR 72508, November 23, 2011) and Supplemental Proposal (79 FR 60238, October 6, 2014), which is available in the docket for this action (EPA-HQ-OAR-2010-0895). Comment: One commenter supported the EPA's decision to re-evaluate the feasibility and cost-effectiveness of the controls that the Agency proposed in its 2011 proposal. However, the commenter objects to the EPA's conclusion that an alternative system involving both primary and secondary capture is available and represents an “advancement in technology” pursuant to CAA section 112(d)(6). The commenter states that this type of system does not currently exist in practice at any ferroalloy operation. They explain that, in theory, such a system appears likely to provide some degree of additional reductions. However, the commenter notes some of the specific potential control methods mentioned by the EPA have already been proven not to work. As an example, the commenter states that curtains have previously been installed in an attempt to contain additional furnace emissions, but the curtains burned up due to the extreme heat in only a few weeks. The commenter, therefore, objects both to the characterization of these additional controls as a currently available “advancement in technology,” and to the EPA's conclusion that the cost of almost $100,000 per ton of HAP reductions for these additional controls is cost effective. Response: In their supplemental comments on the 2011 proposed rule, industry representatives provided suggested alternative designs to address fugitive emissions from the furnace buildings. The designs suggested by the industry representatives included improving the existing primary hooding and capture systems close to the emissions sources and/or adding secondary capture to ensure effective capture and control of process fugitive emissions. The use of a primary hooding and exhaust system in conjunction with general secondary hooding and exhaust system was estimated to provide a total capture of 95 percent of process fugitive emissions, including emissions from the tapping, casting, crushing/screening, and skimming/slag raking processes. We reviewed these designs and discussed the designs with ventilation experts. The ventilation experts agreed that the suggested primary system along with secondary capture could achieve 95 percent reduction of process fugitive emissions from the buildings. They noted that many of the designs and improvements were based on the elements of good ventilation systems that are used in other industries to capture and control fugitive emissions. Because these designs have been only partially deployed in this industry, they constitute a relevant development in technology beyond what is required by the current rule. We view the successful deployment of these technologies in other industries and the expert judgement of industrial ventilation experts as establishing that the technologies are technically available for transfer to the Ferroalloy Production source category. As part of our technology review, we evaluated the costs and effectiveness of a regulatory option that is based on the general emission control scenario suggested by the industry representatives which would include a system of primary and/or secondary hooding designed to capture 95 percent of process fugitive emissions. The process fugitive emissions would be captured by the primary and/or secondary hoods and routed to PM control devices. This option for the control of process fugitive emissions under CAA section 112(d)(6) is exactly the same option that we are promulgating under CAA section 112(f)(2) to capture and control fugitives (described in section IV.A of this preamble). We estimate that the total capital cost including monitoring would be about $40.3 million, the total annualized costs would be about $7.7 million per year, and that it would achieve 77 tpy reduction of HAP, mostly manganese and other HAP metals (e.g., cadmium compounds, chromium compounds, nickel compounds) and also achieve about 229 tpy reduction of PM. Based on our evaluation, we conclude that installing and operating such a system is a feasible and cost-effective approach to achieve significant reductions in process fugitive HAP emissions and will achieve almost as much reductions as the full building enclosure option (229 vs. 252 tons PM reductions). In light of the technical feasibility and cost effectiveness of this enhanced fugitive capture option (that includes a combination of primary capture and/or secondary capture designed to capture and control 95 percent of process fugitive), we are promulgating this option under the authority of section 112(d)(6) of the CAA. The control requirements and compliance requirements under this CAA section 112(d)(6) option are the exact same requirements we are promulgating under CAA section 112(f)(2) to address unacceptable risks for process fugitive emissions (described in section IV.A of this preamble). As described in that section, facilities must install, operate, and maintain a process fugitives capture system that is designed to capture 95 percent or more of the process fugitive emissions. Facilities will also need to meet an average opacity of 8 percent for each furnace cycle (about 90-120 minutes) with a maximum opacity of no more than 20 percent opacity for any two consecutive 6-minute block opacity readings (12-minute period). To demonstrate compliance, facilities will need to initially monitor opacity for a full furnace cycle (about 90-120 minutes) at least once per week per furnace building using the DCOT. Moreover, facilities will need to monitor various control parameters (such as fan speed, amperage, pressure drops, and/or damper positioning) to ensure the fugitive capture system and controls are working properly. Comment: One commenter states that the only notable development that occurred in ferroalloys emission practices, processes, and control technologies since the 1999 NESHAP took effect is the installation of scrubbers and baghouses. Since scrubbers and baghouses have demonstrably different performance in controlling particulate emissions, the commenter claims that developments since 1999 warrant separate particulate emission limits based on the type of control device involved. The commenter states that the EPA did not acknowledge this development and proposed a single stack particulate limit for all furnaces. The commenter provided proposed PM limits of 27 mg/dscm for wet particulate scrubbers and 6.2 mg/dscm for baghouses, and notes that these limits would actually reduce the total allowable particulate emissions from their facility in comparison to the EPA's proposed single limit of 25 mg/dscm. Response: Section 112 of the CAA grants the EPA discretion to establish “categories and subcategories” of sources to be regulated under CAA section 112, and further allows the EPA to “distinguish among classes, types and sizes of sources within a category or subcategory” when establishing MACT standards. However, we believe it is not appropriate to establish subcategories based on type of control technology used by these emission sources. In the case of the PM emissions from the ferroalloy furnaces, we believe if it was appropriate, we could subcategorize based on the size of the furnace or the product being produced in that furnace. However, we determined that there was no statistical difference in PM emissions based on the size of the individual furnaces or by the product being produced in those furnaces. Therefore, we decided it was not appropriate to subcategorize for PM emissions and instead established a single PM limit for all of the furnaces, regardless of size or product being produced. Comment: One commenter believes that the EPA's proposed requirements to reduce process fugitive emissions under CAA section 112(d)(6) are not based on control practices in use in the ferroalloys industry, but rather simply reflect a decision by the EPA that the sources at Eramet and Felman should be subject to additional requirements. By putting the enhanced fugitive control requirements under CAA section 112(d)(6), the commenter believes that the EPA dispenses with any attempt to justify the requirements as cost effective, as would be required to impose for “beyond the MACT floor” standards under CAA section 112(d)(2), and the EPA dispenses with any attempt to present a risk-based justification for the requirements, as would be required under CAA section 112(f)(2). Response: As an initial matter, we note the process fugitive control requirements are justified as risk-based requirements under CAA section 112(f)(2). See section IV.A of this preamble. Therefore, the premise of this comment is factually incorrect. That said, the requirements of this rule also are justified under CAA section 112(d)(6). Under CAA section 112(d)(6), we are required to review emission standards no less frequently than every 8 years and revise them “as necessary (taking into account developments in practices, processes, and control technologies).” The ferroalloys industry already includes some of the controls envisioned under this control scenario. For example, all 5 furnaces in the source category in the U.S. already have some type of primary hooding to capture some process fugitive emissions from tapping and/or casting operations. In fact, one of the five furnaces in the U.S. already achieves good capture of tapping emissions with their current configuration. Furthermore, effective primary and secondary capture systems are currently used in other metals industries (e.g., steel production, secondary lead production) to effectively capture and control process fugitives. Moreover, as described above, representatives from the ferroalloys companies have provided suggestions as to how such a system could be designed, installed and operated to achieve 95-percent capture of fugitives. Therefore, we conclude such a system is technically feasible. Furthermore, as we described above, we conclude these controls would be cost effective ($91,000 per ton of HAP metal reduced). Therefore, we conclude it is appropriate to promulgate this control option under section 112(d)(6) of the CAA. 4. What is the rationale for our final approach for the technology review? a. PM Emissions Limits from Stacks. The available test data from the five furnaces located at the two facilities indicate that all of these furnaces have PM emission levels that are well below their respective emission limits in the 1999 MACT rule. These findings demonstrate that the add-on emission control technologies (Venturi scrubber, positive pressure fabric filter, negative pressure fabric filter) used to control emissions from the furnaces are effective in reducing particulate matter (used as a surrogate for metal HAP). The PM emissions, used as a surrogate for metal HAP, that were reported by the industry in response to the 2010 ICR, were far below the level specified in the current NESHAP, indicating improvements in the control of PM emissions since promulgation of the current NESHAP. We re-evaluated the data received in 2010, along with additional data received in 2012 and 2013, to determine whether it is appropriate to promulgate revised emissions limits for PM from the furnace process vents. More details regarding the available PM data and this re-evaluation are provided in the Revised Technology Review for the Ferroalloys Production Source Category for the Supplemental Proposal, which is available in the docket. Unlike PAH and Hg stack data, we did not see significant differences in emissions based on product produced ( e.g., FeMn or SiMn). Therefore, we are not promulgating separate PM stack limits based on product type. Based on this analysis, we determined it is appropriate to finalize the revised existing source furnace stack PM emissions limit of 25 mg/dscm, which is the same limit we proposed in the supplemental proposal. No additional add-on controls are expected to be required by the facilities to meet the revised existing source limit of 25 mg/dscm. However, this revised limit will result in significantly lower “allowable” PM emissions from the source category compared to the level of emissions allowed by the 1999 MACT rule and would help prevent any emissions increases. To demonstrate compliance, these sources will be required to conduct periodic performance testing and develop and operate according to a baghouse operating plan or continuously monitor Venturi scrubber operating parameters. Also furnace baghouses will be required to be equipped with BLDS. The final PM standard for new and reconstructed furnaces is 4.0 mg/dscm and was determined by evaluating the available data from the best performing furnace (which was determined to be furnace #2 at Felman). As described above, the PM emission limit for the local ventilation control device outlet was re-evaluated for the supplemental proposal using compliance test data and test data from the 2012 ICR. We did not receive any additional data since the supplemental proposal for this source. Using all the available data for the one existing local ventilation source, we calculated an emissions limit of 4.0 mg/dscm, which is the exact same limit we proposed in the supplemental proposal. We conclude that this is still an appropriate emissions limit for this source. Therefore, we are promulgating this emissions limit of 4.0 mg/dscm for existing, new, and reconstructed local ventilation control device emissions sources. In addition, we are promulgating a PM limit of 3.9 mg/dscm for any new, reconstructed, or existing MOR process, and a PM limit of 13 mg/dscm for any new, reconstructed, or existing crushing and screening equipment, which are consistent with what we proposed in our November 23, 2011, proposal. Furthermore, as mentioned in section III of this preamble, we are promulgating a PM limit of 3.9 mg/dscm for any new, reconstructed, or existing MOR process, and a PM limit of 13 mg/dscm for any new, reconstructed, or existing crushing and screening equipment. 2. Standards for Process Fugitive Metal HAP Emissions In the 2011 proposal, we proposed a requirement for sources to enclose the furnace building, collect fugitive emissions such that the furnace building is maintained under negative pressure, and duct those emissions to control devices. As described above, commenters on the 2011 proposal disagreed with our assessment. Commenters also raised concerns about worker safety and comfort in designing and operating full enclosure systems. We believe that such issues can be overcome with proper ventilation design and installation of air conditioning systems and other steps to ensure these issues are not a problem. However, after further review and evaluation, we conclude that it would be quite costly for these facilities to become fully enclosed with negative pressure and achieve the appropriate ventilation and conditioning of indoor air. We re-evaluated the costs and operational feasibility associated with the full building enclosure with negative pressure. We consulted with ventilation experts who have worked with hot process fugitives similar to those found in the ferroalloys industry ( e.g., electric arc furnace steel mini-mills and secondary lead smelters). We determined that substantially more air flow, air exchanges, ductwork, fans and control devices and supporting structural improvements would be needed (compared to what we had estimated in the 2011 proposal) to achieve negative pressure and also ensure adequate ventilation and air quality in these large furnace buildings. Therefore, as explained in the supplemental proposal, we determined that the proposed negative pressure approach presented in the 2011 proposal would be much more expensive than what we had estimated in 2011 and may not be feasible for these facilities. As mentioned above, for the supplemental proposal, we also evaluated another option based on enhanced capture of the process fugitive emissions using a combination of effective local capture with primary hooding close to the emissions sources and/or secondary capture of remaining fugitives with roof-line capture hoods and control devices. These buildings are currently designed such that fugitive emissions that are not captured by the primary hoods flow upward with a natural draft to the open roof vents and are vented to the atmosphere uncontrolled. Under our enhanced control scenario, the primary capture close to the emissions sources would be significantly improved with effective local hooding and ventilation and the remaining fugitive emissions (that are not captured by the primary hoods) would be drawn up to the roof-line and captured with secondary hooding and vented to control devices. In cases where additional collection of fugitives from the roof areas is needed to comply with the rule, fume collection areas may be isolated via baffles (so the area above the furnace where fumes collect may be kept separated from “empty” spaces in large buildings) and roof openings over fume collection areas can be sealed and fumes directed to control devices. The fugitive emission capture system should achieve inflow at the building floor, but outflow toward the roof where most of the remaining fugitives would be captured by the secondary hooding. We concluded that a rigorous, systematic examination of the ventilation requirements throughout the building is the key to developing a fugitive emission capture system (consisting of primary hoods, secondary hoods, enclosures, and/or building ventilation ducted to PM control devices) that can be designed and operated to achieve very low levels of fugitive emissions. Such an evaluation considers worker health, safety, and comfort and it is designed to optimize existing ventilation options (fan capacity and hood design). Thus, we concluded that an enhanced capture system based on these design principles does represent an advancement in technology. We estimate that this type of control system could capture 95 percent of the process fugitive emissions and vent those emissions to PM control devices. This enhanced local capture option is described in more detail in the Revised Technology Review for the Ferroalloys Production Source Category and in the Cost Impacts of Control Options to Address Fugitive HAP Emissions for the Ferroalloys Production NESHAP Supplemental Proposal documents, which are available in the docket. Under this control option, the cost elements vary by plant and furnace and include the following: • Curtains or doors surrounding furnace tops to contain fugitive emissions; • Improvements to hoods collecting tapping emissions; • Upgrade fans to improve the airflow of fabric filters controlling fugitive emissions; • Addition of “secondary capture” or additional hoods to capture emissions from tapping platforms or crucibles; • Addition of fugitives capture for casting operations; • Improvement of existing control devices or addition of fabric filters; and • Addition of rooftop ventilation, in which fugitive emissions escaping local capture are collected in the roof canopy over process areas through addition of partitions, hoods, and then directed through ducts to control devices. We estimate the total capital costs of installing the required ductwork, fans and control devices under the enhanced capture option (which is described above and in more detail in the Cost Impacts of Control Options to Address Fugitive HAP Emissions for the Ferroalloys Production NESHAP Supplemental Proposal document) to be $40.3 million and the total annualized cost to be $7.7 million for the two plants. The total estimated HAP reduction for the enhanced capture option is 77 tpy at a cost per ton of $103,000 ($52 per pound). We also estimate that this option would achieve PM emission reductions of 229 tpy, resulting in cost per ton of PM removed of $34,600 per ton and achieve particulate matter 2.5 microns and less (PM 2.5 ) emission reductions of 48 tons per year, resulting in a cost per ton of PM 2.5 removal of $165,000 per ton. We believe these controls for process fugitive HAP emissions (described above), which are based on enhanced capture (with primary and secondary hooding) are feasible for the Ferroalloys Production source category from a technical standpoint and are cost effective. These cost effectivenesses are in the range of cost effectiveness for PM and HAP metals from other previous rules. However, it is important to note that there is no bright line for determining acceptable cost effectiveness for HAP metals. Each rulemaking is different and various factors must be considered. Some of the other factors we consider when making decisions whether to establish standards beyond-the-floor (BTF) under CAA section 112(d)(2) or under CAA section 112(d)(6) include, but are not limited to, the following: which of the HAP metals are being reduced and by how much; total capital costs; annual costs; and costs compared to total revenues ( e.g. , costs to revenue ratios). As described in the supplemental proposal, we also re-evaluated the option based on full building enclosure with negative pressure. Based on those analyses, we concluded in the supplemental proposal and conclude again in this action that the full-building enclosure option with negative pressure may not be feasible and would have significant economic impacts on the facilities (including potential closure for one or more facilities). Therefore, we are not promulgating an option based on full building enclosure with negative pressure. However, consistent with the supplemental proposal, we conclude that the enhanced local capture option is a feasible and cost-effective approach to achieve significant reductions in fugitive HAP emissions and will achieve almost as much reductions as the full-building enclosure option (229 vs. 252 tons PM reductions) and, thus, achieving most of the emission reductions at significantly lower costs. In light of the technical feasibility and cost effectiveness of the enhanced capture option, we are promulgating the enhanced capture option under the authority of section 112(d)(6) of the CAA. Regarding monitoring requirements, as described above, in the 2011 proposal, we proposed that facilities would need to conduct day-to-day continuous monitoring of differential pressure to comply with the proposed full building enclosure with negative pressure requirements. With the move to the enhanced local capture alternative option, there is no longer any requirement to monitor negative pressure. Under this option, the main ongoing compliance requirements will be based on opacity readings and parametric monitoring. Therefore, since opacity is a main method of monitoring compliance for process fugitive emissions controls, we believe that frequent opacity monitoring is necessary, as reflected in the supplemental proposal. Furthermore, as we explained in the supplemental proposal, we believe an average opacity limit of 8 percent is appropriate to ensure effective capture and control of process fugitive emissions over the entire furnace cycles and that a maximum opacity of 20 percent for any 2 consecutive 6-minute periods is appropriate to prevent spikes in fugitive emissions. Therefore, we are promulgating an average opacity limit of 8 percent and a maximum opacity limit of 20 percent for any 2 consecutive 6-minute periods. Regarding opacity monitoring, we are promulgating a requirement that facilities conduct opacity observations at least once per week for a full furnace cycle for each operating furnace and each MOR operation using the DCOT instead of Method 9. We believe the DCOT is appropriate for the final rule because it provides more objective and better substantiated opacity readings. However, as described above, we are allowing an opportunity for facilities to decrease frequency of opacity monitoring to monthly after 26 compliant weekly readings. Similar to the supplemental proposal, we are also finalizing the requirement that, if the average opacity reading from the shop building is greater than 8-percent opacity during an observed furnace process cycle, an additional two more furnace process cycles must be observed such that the average opacity during the entire observation period is less than 7-percent opacity. A furnace process cycle means the period in which the furnace is tapped to the time in which the furnace is tapped again and includes periods of charging, smelting, tapping, casting, and ladle raking. As mentioned above, we are also promulgating the requirement that at no time during operation may any two consecutive 6-minute block opacity readings be greater than 20-percent opacity. We believe that the source should demonstrate that the overall design of the ventilation system is adequate to achieve the final standards. Therefore, we are promulgating the requirement that facilities in this source category must install, operate, and maintain a process fugitives capture system that is designed to collect 95 percent or more of the process fugitive emissions from furnace operations, casting MOR process, ladle raking and slag skimming and crushing, and screening operations, and convey the collected emissions to a control device that meets specified emission limits and the opacity limits. We are also requiring continuous monitoring of key ventilation operating system parameters and periodic inspections of the ventilation systems to ensure that the ventilation systems are operating as designed. We believe that if the facilities design the capture and control systems according to the most recent (at the time of construction) ventilation design principles recommended by the American Conference of Governmental Industrial Hygienists (ACGIH), including detailed schematics of the ventilation system design, addressing variables that affect capture efficiency such as cross drafts and describes protocol or design characteristics to minimize such events and identifies monitoring and maintenance steps, the plan will be capable of ensuring the system is properly designed and continues to operate as designed. Therefore, we are promulgating the requirement that facilities develop such a plan and submit this plan to the permitting authority. The plan must also be incorporated into the source's operating permit and updated every 5 years or when there is a significant change in variables that affect process fugitive emissions ventilation design. This design plan, coupled with the requirement for frequent opacity observations and operating parameter monitoring, will ensure fugitive emissions are effectively controlled and will result in enforceable requirements. We recognize that other design requirements and/or more frequent opacity observations may yield more compliance certainty, but incur greater costs and not result in measurable decreases in emissions. We believe the additional PM data we received justifies the revised PM stack emission limits we are promulgating under the authority of section 112(d)(6) of the CAA. We also believe the enhanced capture and control is a development in technology that is feasible and cost effective, so we are promulgating the enhanced local capture and control option under the authority of section 112(d)(6) of the CAA. Furthermore, we believe it is appropriate to promulgate the DCOT to ensure adequate furnace capture and control. C. CAA Section 112(d)(2) & (3) Revisions for the Ferroalloys Production Source Category 1. What did we propose pursuant to CAA section 112(d)(2) & (3) for the Ferroalloys Production source category? In the November 23, 2011, proposal, we proposed a formaldehyde emission limit of 201 μg/dscm for any new, reconstructed, or existing electric arc furnace. In the October 6, 2014, supplemental proposal, we proposed the following: • HCL emission limit of 180 μg/dscm for new or reconstructed electric arc furnaces and 1,100 μg/dscm for existing electric arc furnaces; • Hg emission limit of 17 μg/dscm for new or reconstructed electric arc furnaces producing FeMn, and 170 μg/dscm for existing electric arc furnaces producing FeMn; • Hg emission limit of 4 μg/dscm for new or reconstructed electric arc furnaces producing SiMn and 12 μg/dscm for existing electric arc furnaces producing SiMn; • PAH emission limit of 880 mu;g/dscm for new or reconstructed electric arc furnaces producing FeMn and 1,400 μg/dscm for existing electric arc furnaces producing FeMn; and • PAH emission limit of 72 μg/dscm for new or reconstructed electric arc furnaces producing SiMn and 120 μg/dscm for existing electric arc furnaces producing SiMn. 2. How did the CAA section 112(d)(2) & (3) revisions change for the Ferroalloys Production source category? In mid-August 2014, a few weeks prior to the signature of the supplemental proposal, we received a test report with Hg and PAH data, which we were unable to incorporate into the proposed limits in the supplemental proposal, in part because of the timing and in part because we had not completed our review and technical analysis of the data. We noted receipt of the data and invited comment on it in the supplemental proposal, and made the data available for review. We committed to considering these data in the final rule based on public comment and our technical analysis. In addition to the pre-supplemental proposal data, another Hg and PAH test report was received during the comment period. The new test data for FeMn production received in August 2014 and during the comment period had much higher PAH concentrations than the data that were previously provided. The new PAH test data for SiMn production were only slightly higher than previous data received from the facilities. The new Hg data for both FeMn and SiMn production were comparable to the test data that we used to develop the proposed limits for the supplemental proposal. For this action, we re-evaluated the PAH and Hg emission limits to include the new test data. The 99-percent upper prediction limit (UPL) calculation using all the available reliable data for PAH emissions results in an emissions limit of 12,000 μg/dscm for existing furnaces producing FeMn and 130 μg/dscm for existing furnaces producing SiMn. With regard to new source limits, as mentioned previously, there are only two furnaces in the source category that produce FeMn, and both furnaces are located at Eramet. The units are similar in design and process the same types of raw materials, and we, therefore, expect little or no difference in the performance of these units. The available emissions data, which show that the two units mean emissions are only 2-percent different, support this hypothesis. We conclude, based on the similarities in the units and the available data, that these two furnaces achieve the same degree of control of PAH emissions with their current control devices. Accordingly, we consider these two units to be equal performers with regard to PAH emissions and therefore, we used all the data from both units to calculate the new source emissions limit. Using the 99-percent UPL calculation, we derive an emissions limit of 11,500 μg/dscm for new furnaces producing FeMn. For SiMn, there were no changes to the best performing source and the PAH limit of 72 μg/dscm proposed in the supplemental proposal is the same limit selected for the final rule for new furnaces producing SiMn. The 99-percent UPL for PAHs for FeMn production is about 8 times higher than the proposed PAH limit for FeMn in the supplemental proposal, whereas the 99-percent UPL for PAHs for SiMn production is comparable to the proposed limit in the supplemental proposal. The new data show there is substantial variability in PAH emissions from the furnaces, especially during FeMn production. As mentioned in section III.E of this preamble, due to the large variation in PAH emissions from furnace stacks during FeMn production, we are requiring quarterly compliance tests for PAHs (i.e., four PAH compliance tests per year) for furnaces while producing FeMn, with an opportunity for facilities to apply for decreased frequency of such compliance testing from their permit authority after the first year and after four or more successful PAH compliance tests have been completed and submitted to the permit authority. We expect that any application submitted by an affected source to request reduced frequent compliance testing for PAHs should include information regarding the four or more compliant test results and what factors or conditions are contributing to the quantity and variation of PAH emissions. For example, the application could include, among other things, information about the amounts and types of input materials, types of electrodes used, electrode consumption rates, furnace temperature and other furnace, process or product information that may be affecting the PAH emissions. The re-evaluation of the Hg test data, which includes the new test data, produced a 99-percent UPL of 130 μg/dscm for existing furnaces producing FeMn and 12 μg/dscm for existing furnaces producing SiMn. For new sources, the new test data did not affect the 99-percent UPL of 4 μg/dscm for new furnaces producing SiMn. With regard to the new source limit in the supplemental proposal for Hg for furn [Text truncated at 120,000 characters. The full text is on the page linked above.] --- Source: Frix Law Library, https://www.frixlaw.com/law-library/documents/fr%3A2015-15038. Public record. Not legal advice.