
FROM:	Jeff Coburn  -  RTI International
TO:	Phil Mulrine, EPA/OAQPS
FOR:	EPA Docket No. EPA-HQ-OAR-2019-0373
DATE:	August 7, 2019
SUBJECT:	Area Source Technology Review for the Iron and Steel Foundries NESHAP
1.	Purpose
      This memorandum documents the technical support and analyses conducted for the EPA's technology review of the national emission standards for hazardous air pollutants (NESHAP) for area source iron and steel foundries in 40 CFR part 63, subpart ZZZZZ. 
2.	Background
      Section 112(d)(5) of the Clean Air Act (CAA) directs the EPA to develop generally available control technology (GACT) standards to control HAP emissions from area sources. The term "area source" means any stationary source of hazardous air pollutants that is not a major source (i.e., a facility that emits or has the potential to emit considering controls, in the aggregate, 10 tons per year or more of any hazardous air pollutant or 25 tons per year or more of any combination of hazardous air pollutants). On January 2, 2008, the EPA published final standards for iron and steel foundries that are area sources of HAP emissions (40 CFR part 63, subpart ZZZZZ)
      The EPA is then required, under CAA section 112(d)(6), to review these technology-based standards and to revise them "as necessary (taking into account developments in practices, processes and control technologies)" no less frequently than every 8 years. The NESHAP for area source iron and steel foundries were promulgated over 8 years ago and are now being reviewed. 
3.	Introduction to Iron and Steel Foundries
3.1	Iron and Steel Foundry Processes
      There are numerous operations conducted at a typical iron and steel foundry that are potential sources of HAP emissions as illustrated in Exhibit 1. Foundry operations start with two different paths: one path includes the metal input (e.g., scrap, ingot or other form of iron or steel) and metal melting and the other path includes sand input and mold and core making. The two paths merge and continue the production with pouring of the molten metal into the mold, followed by cooling of the casting and separation of the solid casting from the mold (commonly referred to as "shakeout" or "knockout"). 

Exhibit 1. Simplified schematic of operations at a typical iron and steel foundry.
      For sand mold foundries (the most common type of foundry), sand is typically recovered from the shakeout operations, reconditioned, and reused in the mold and core making operations. The cast metal recovered from the shakeout operations goes to the cutting, grinding, finishing, and cleaning processes to make final products. Discarded or off-spec materials from the cutting, grinding, and finishing processes can be recycled and reused in the melting operations. Additional description of foundry processes and their emission points is provided in the foundry background information document (BID) (U.S. EPA, 2002). In the following sections, we will discuss each of the primary emissions sources, the current emission limits, and our review of developments in practices, processes and control technologies.
3.2 	Emission Limitations in the Iron and Steel Foundry NESHAP
      During the development of the area source NESHAP, there were about 420 area source iron and steel foundries in the United States and its territories. This number was down from over 500 area source foundries initially identified from the EPA's 1998 detailed information collection request of all iron and steel foundries (EPA, 1998). Based on the expected continuation of this trend, we estimate that there are currently about 300 area source iron and steel foundries. The area source NESHAP for iron and steel foundries contains a mixture of numeric emission limits and work practice standards. The area source NESHAP defines the affected facility as the entire iron and steel foundry or that portion of the facility associated with foundry operations. The area source NESHAP for iron and steel foundries has separate standards for "large foundries" and "small foundries" A "large [area source] foundry" is an existing foundry with annual metal melt production of greater than 20,000 tons or a new foundry with annual metal melt capacity of greater than 10,000 tons. A "small foundry" is an existing foundry with annual metal melt production of 20,000 tons or less or a new foundry with annual metal melt capacity of 10,000 tons or less. The area source NESHAP has different emission limits for existing versus new iron and steel foundries. Exhibit 2 summarizes the emission limits in the NESHAP for area source iron and steel foundries (40 CFR part 63, subpart ZZZZZ). A more detailed summary of the emission limits and other rule requirements in Subpart ZZZZZ has also been provided previously (Pierce, 2016).
      The emission limits in that area source NESHAP are specific to metal HAP. Foundries may elect to comply with either the particulate matter (PM) emission limit (used as a surrogate for metal HAP) or the metal HAP emission limit. Based on the PM/metal HAP emission limits in the area source rule, a variety of PM control technologies may be used including fabric filters (baghouses), cartridge filters, wet scrubbers, electrostatic precipitators (ESPs), and cyclone separators. For electric induction furnaces, which have a lower potential to emit than cupolas or electric arc furnaces, it is often possible to meet the emission limits for existing sources with no control or only a suppression control (i.e., use of a lid to cover the furnace during portions of the melting cycle)    
      The area source NESHAP for iron and steel foundries includes work practice standards to reduce HAP emissions from mold and core making and metal melting operations. These work practice requirements are the same for large foundries and small foundries and apply equally to new and existing iron and steel foundries. These work practices are summarized below:
 Operate using a scrap acquisition plan to limit mercury, lead, chlorinated plastic parts, and organic liquids in the scrap purchased for use in metal melting furnaces (and scrap preheaters).
 For furan (furfuryl alcohol) warm box for mold or core making, use binder formulation that does not include methanol as an ingredient in the catalyst portion of the binder system.
                                        

Exhibit 3. NESHAP emission limits applicable to area source iron and steel foundries.
                        Source / Pollutant / Format[1]
                            40 CFR 63 subpart ZZZZZ
                                       
                                Large Existing
                                   Large New
                                Small Existing
                                   Small New
Metal Melting Furnaces / Metal HAP (meet one of the following)[2]
PM, lb/ton
                                      0.8
                                      0.1
                                      N/A
                                      N/A
Metal HAP, lb/ton
                                     0.06
                                     0.008
                                      N/A
                                      N/A
Other / Metal HAP
Building Opacity
                                    20%[3]
                                    20%[3]
                                      N/A
                                      N/A
   [1]Format abbreviation: lb/ton = pound per ton metal melted.
   [2].Emissions averaging is allowed for metal melting furnaces so these emission limits may apply to each individual metal melting furnace or to the group of metal melting furnaces, as elected by the facility owner or operator.
   [3] Except for one 6-minute average per hour that does not exceed 30 percent opacity.

4.	Technology Review
      For the purposes of this technology review, a "development" is considered to be a(n): 

 Add-on control technology or other equipment that was not identified and considered during the development of the current NESHAP for the source category; 
 Improvement to an existing add-on control technology or other equipment that could result in significant additional HAP emissions reductions; 
 Work practices or operational procedures that were not identified or considered during development of the current NESHAP for the source category; 
 Applicable process changes or pollution prevention alternatives that were not identified and considered during the development of the current NESHAP for the source category; or
 Any significant changes in the cost (including cost effectiveness) of applying controls (including controls the EPA considered during the development of the original MACT standards). 
      
      We investigated developments in practices, processes, and control technologies through a review of the RACT/BACT/LAER Clearinghouse (RBLC) and a review of international best practices. The results of these analyses are presented in the following sections.
4.1	RBLC Search
      Under EPA's New Source Review (NSR) program, if a company is planning to build a new plant or make a major modification to an existing plant such that criteria air pollution emissions will increase by a certain amount, then the company must obtain an NSR permit. The NSR permit is a construction permit, which generally requires the company to minimize air pollution emissions by changing the process to prevent air pollution and/or installing air pollution control equipment. The terms "BACT", "LAER", and "RACT" are acronyms for different program requirements relevant to the NSR program. Best Available Control Technology, or BACT, is required on new or modified major sources in areas meeting the national ambient air quality standards (i.e., attainment areas). Lowest Achievable Emission Rate, or LAER, is required on new or modified major sources in non-attainment areas. Reasonably Available Control Technology, or RACT, is required on existing major sources in non-attainment areas. BACT and LAER (and sometimes RACT) are determined on a case-by-case basis, usually by state or local permitting agencies. 

      The EPA established the RBLC to provide a central database of air pollution control technology information (including past BACT and LAER decisions contained in NSR permits) to promote the sharing of information among permitting agencies and to aid in future case-by-case determinations. The RBLC contains over 5,000 air pollution control permit determinations that were submitted by all 50 states and several U.S. territories on over 200 different air pollutants and 1,000 industrial processes. It was designed to help permit applicants and reviewers identify appropriate technologies and pollution prevention concepts to mitigate air pollutant emission from stationary air pollution sources. 

      The RBLC provides several options for searching the permit database on-line to locate applicable control technologies. Searches on the RBLC database were conducted using the default 10-year time frame (January 1, 2008 to October 23, 2018), which is effectively the time since EPA promulgated a NESHAP for iron and steel foundries. The search focused on process types listed in the RBLC for iron or steel foundries as shown in Exhibit 3. 
Exhibit 3. Process types listed in the RBLC search function for iron and steel foundries.
                                       
                                       

      Search results for each process type were reviewed. The primary controls identified were the use of fabric filters to control PM emissions from melting furnaces, mold and core making, shakeout, and sand handling operations. The PM emission limits were consistent with the MACT limits (either at or between the MACT limits for new and existing sources within the major source rule). A few foundries had VOC limits, but these limits were expected to be met without the use of a control device. No specific statements were made about mold and core binder re-formulations required to meet the VOC limits. It appears that these limits were based on their normal binder formulations. The results of the RBLC search did not identify new developments in practices, processes, or control technologies for the iron foundries and steel foundries source categories under section 112(d)(6).
4.2	International Best Practices Review
      An Internet search for international best practices related to air emissions from iron and steel foundries was conducted. The following reports were identified and reviewed. 
 Council Decision (EU) 2016/768 of 21 April 2016 on the acceptance of Amendments to the 1998 Protocol to the 1979 Convention on Long-Range Transboundary Air Pollution on Heavy Metals.  https://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=CELEX:32016D0768&from=EN 
 Guidance document on best available techniques for controlling emissions of heavy metals and their compounds from the source categories listed in annex II to the Protocol on Heavy Metals. ECE/EB.AIR/116. United Nations, Economic and Social Council, Economic Commission for Europe. 24 July 2013. http://undocs.org/en/ECE/EB.AIR/116 
 Draft proposal for a guidance document on best available techniques for controlling emissions of heavy metals and their compounds from the source categories listed in annex II. Working Group Strategies and Review, 49[th] Session. Informal document No. 16. 12-16 September 2011. https://www.unece.org/fileadmin/DAM/env/documents/2011/eb/wg5/WGSR49/Informal%20docs/16_AnnexIIIversion_trackchanges.doc 
 Final Draft BAT Guidance Note on Best Available Techniques for Ferrous Metal Foundries. Environmental Protection Agency, Ireland. September 2012. https://www.epa.ie/pubs/advice/bat/BAT%20Note%20-%20Ferrous%20Metal%20Foundries-%20Final%20Draft%20-%20August%202012%20-%20SH.pdf 
 Environmental, Health, and Safety Guidelines for Foundries. World Bank Group, International Finance Corporation. April 30, 2007. http://documents.worldbank.org/curated/en/741011490086417947/pdf/113620-WP-ENGLISH-Foundries-PUBLIC.pdf  
 Integrated Pollution Prevention and Control: Reference Document on Best Available Techniques in the Smitheries and Foundry Industry. May 2005. European Commission. http://eippcb.jrc.ec.europa.eu/reference/BREF/sf_bref_0505.pdf 
      The first document listed above is regarding European Union (EU) requirements for heavy metal emissions from specific sources. The second and third document apply to countries that are parties to Convention on Long-range Transboundary Air Pollution (LRTAP), Protocol on Heavy Metals. The 2011 draft proposal for a guidance document on best available techniques included PM emission limits for foundry emission sources of 5 mg/Nm[3], which is equal to the new source standard for major source foundries in 40 CFR part 63, subpart EEEEE. The final guidance document as available online ends at page 33 and does not include the section for iron and steel foundries. Nonetheless, the final amendments to the 1998 Protocol to the 1979 Convention on Long-Range Transboundary Air Pollution on Heavy Metals contain emission limits of 20 mg/Nm[3], which equates to 0.008 gr/dscf, which is higher than the emission limits for existing sources in CFR part 63, subpart EEEEE, but well below the emission limits in that area source NESHAP. The draft guidance also suggests an emission limit for induction furnaces of 0.2 kg/tonne, which is 0.4 lb/ton. This limit is a factor of two lower than the emission limits for existing sources at a large (area source) foundry in 40 CFR part 63, subpart ZZZZZ, but 4 times higher than the limit for new sources at large (area source) foundries. During the development of the area source standards, the EPA specifically evaluated requiring area source foundries to meet more stringent metal HAP emissions (Chin, 2007). Based on the similarities of the emission limits in these recent updates to the EU standards, the LRTAP guidance documents, and the US EPA rules, no developments in practices, processes, and control technologies were identified from the review of these the first three documents. We also identified no significant changes in the costs of the PM control systems used at iron and steel foundries. Therefore, the information available suggests that there would be no significant change in the cost analysis conducted previously beyond a mere escalation of the previous costs to more current year (2018) dollars. 
       Ireland's Final Draft BAT Guidance Note on Best Available Techniques for Ferrous Metal Foundries (2012) primarily discusses best available techniques (BAT) for induction melting furnaces. Recommendations include use of clean scrap and use of lid or hood extraction systems to capture emissions across the full "working" (melting) cycle. Recommended dust emission limits were 5-20 mg/Nm[3], consistent with the emission limits for major source foundries in 40 CFR part 63, subpart EEEEE, and the EU guidance for heavy metals from iron and steel foundries. As noted previously, application of lower metal HAP limits was considered during the development of the area source standards; no additional developments in practices, processes, and control technologies were identified from the review of this document. We did analyze the costs for developing more stringent requirements to capture other metal HAP emission sources at major source foundries, such as alloy addition and ladle transfers (Coburn, 2019b). Application of these controls at smaller foundries would be less cost-effective than at major source foundries and would likely cause adverse impacts to several small businesses. 
      World Bank's Environmental, Health, and Safety Guidelines for Foundries includes PM emission limits of 20 mg/Nm[3] for dust containing heavy metals and 50 mg/Nm[3] for dust that does not contain heavy metals (presumably dust from sand handling systems). This document also contains some emission limits for specific metals, such as 1 mg/Nm[3] for lead and cadmium and 5 mg/Nm[3] for nickel and chromium. No emission limit was provided from mercury. We did not identify any developments in practices, processes, and control technologies from the review of this document.
      Europe's integrated pollution prevention and control (IPPC) Reference Document on Best Available Techniques in the Smitheries and Foundry Industry is the most detailed review of best available techniques (BAT) for reducing emissions from iron and steel foundry operations. It included consideration of a wide variety of emission reduction techniques, including proper scrap management, operating at optimal blast rates (for cupola), and capture and controlling emissions from melting furnaces. Recommended dust emission limits were 5-20 mg/Nm[3], consistent with the major source MACT emission limits and the values used in more recent EU guidance for heavy metals from iron and steel foundries. This document had a chapter specifically devoted to emerging techniques for foundries. Most of these techniques involved energy efficiency improvements and methods to reduce solid waste generation. One technique, the use of inorganic binder systems, lowers air emissions. The US EPA did consider different "green" binder systems and formulations when developing the NESHAP for iron and steel foundries but had difficulty identifying times when the alternative system could be mandated. The new source emission limit for volatile organic HAP from automated pouring, cooling, and shakeout lines is expected to promote green or low-emitting binder systems, including inorganic binder systems. We did not identify any developments in practices, processes, and control technologies, including the use of inorganic or other green binder systems, that were not already considered in the development of the NESHAP based on the review of this document. We did conduct an analysis of additional organic HAP emissions control options, including the use of low-emitting binder systems, for major source iron and steel foundries (Coburn, 2019a). Application of these controls at smaller foundries would be less cost-effective than at major source foundries and would likely cause adverse impacts to several small businesses.
4.3	Mercury Switch Removal
      Based on our understanding of the types of scrap and raw materials processed, we conclude that the predominant contributor to potential mercury emissions at iron and steel foundries are probably motor vehicle switches that contain mercury (i.e., mercury switches) that are found in vehicles built before 2004 and end up in the metal scrap. The area source iron and steel foundry NESHAP has scrap management requirements to remove mercury switches and lead components from automobile scrap in the foundry input material. The EPA along with industry, environmental groups and other stakeholders developed a national voluntary mercury switch removal program known as the National Vehicle Mercury Switch Recovery Program (NVMSRP). The NVMSRP is now managed by the End of Life Vehicle Solutions (ELVS). The NVMSRP is a cooperative effort established in 2006 among vehicle manufacturers, steel manufacturers, vehicle dismantlers, scrap shredders, the EPA, and other stakeholders, to support the removal of mercury switches from end-of-life vehicles. The NVMSRP involves more than 10,000 steel recyclers. The initial Memorandum of Understanding (MOU) between the NVMSRP parties was signed in 2006. The area source NESHAP has streamlined scrap management requirements for the foundries if they use a supplier that is participating in the NVMSRP. 
      The 2006 MOU was written to expire at the end of 2017. In December 2017, the NVMSRP parties signed a renewed MOU that extends the program through 2021. Given its success, the EPA continues to support the NVMSRP that already has removed and safely recycled more than 6.8 million mercury switches containing a total of more than 7.6 tons of mercury. The MOU and renewed MOU are in the docket for this rule. The renewed MOU and other information regarding the NVMSRP are available at: https://www.epa.gov/smartsectors/mercury-switch-recovery-program.  
      With the phase-out of mercury in convenience switches and anti-lock braking systems by auto manufacturers in the 2004 model year, there is a limited time horizon for the need to remove mercury switches from automobile scrap. As fewer cars each year will have mercury switches that can be removed, it appears that eventually maintaining this requirement past in future years may impose unnecessary burden on the foundry (and scrap suppliers) to certify that the mercury switches have been removed from automotive scrap when only a very limited percentage of automotive scrap would still contain mercury switches. Thus, at some point in the future, this could be considered an important development in practices with respect to scrap management requirements. We conclude it is premature to make such a change in the rule at this time because there are still plenty of pre-2004 automobiles on the road that will be recycled as scrap metal in the coming years. Nevertheless, based on this development, at some future date (such as maybe the next 8-year technology review), it may be appropriate for the EPA to consider phasing out the mercury switch removal requirement in the scrap management plan. 
5.	Summary
      Based on this technology review, the only potential "developments in practices, processes, and control technologies" that were identified for area source iron and steel foundries are changes to the prevalence of mercury in automotive scrap and changes to the EPA's mercury switch removal program. However, it may be premature to make any changes to the NESHAP at this time due to these potential developments. Nevertheless, based on these changes, the EPA may want to consider modifying and/or phasing out the scrap management requirements specific to mercury switch removal sometime in the future once the agency can be confident that scrap will not contain mercury switches, even without the scrap management requirements. No other developments in practices, processes, and control technologies were identified beyond those considered in the development of the original area source 2008 NESHAP for iron and steel foundries.  
6.	References
Chin, C. 2007. Memorandum from Conrad Chin, U.S. EPA, to EPA Docket No. EPA-HQ-OAR-2006-0359. "Impact Estimates for Area Source Iron and Steel Foundries." September 4. Docket Item No. EPA-HQ-OAR-2006-0359-0006. 
Coburn, J. 2019a. Memorandum from Jeff Coburn, RTI International, to Phil Mulrine, U.S. EPA. "Control Cost Estimates for Organic HAP Emissions from Iron and Steel Foundries." July 2. 
Coburn, J. 2019b. Memorandum from Jeff Coburn, RTI International, to Phil Mulrine, U.S. EPA. "Control Cost Estimates for Metal HAP Emissions from Iron and Steel Foundries." July 3. 
European Commission. 2005. Integrated Pollution Prevention and Control: Reference Document on Best Available Techniques in the Smitheries and Foundry Industry. May. http://eippcb.jrc.ec.europa.eu/reference/BREF/sf_bref_0505.pdf 
European Commission. 2016. "Council Decision (EU) 2016/768 of 21 April 2016 on the acceptance of Amendments to the 1998 Protocol to the 1979 Convention on Long-Range Transboundary Air Pollution on Heavy Metals." Official Journal of the European Union. Document L 127/8. May 18.  https://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=CELEX:32016D0768&from=EN
Ireland Environmental Protection Agency. 2012. Final Draft BAT Guidance Note on Best Available Techniques for Ferrous Metal Foundries. Environmental Protection Agency, Ireland. September. https://www.epa.ie/pubs/advice/bat/BAT%20Note%20-%20Ferrous%20Metal%20Foundries-%20Final%20Draft%20-%20August%202012%20-%20SH.pdf
Pierce, S. 2016. Memorandum from Sandra Pierce, RTI International, to Phil Mulrine, U.S. EPA. "Summary of Requirements in Area Source Foundries NESHAP." August 11. 
United Nations. 2013. Guidance document on best available techniques for controlling emissions of heavy metals and their compounds from the source categories listed in annex II to the Protocol on Heavy Metals. ECE/EB.AIR/116. United Nations, Economic and Social Council, Economic Commission for Europe. July 24. http://undocs.org/en/ECE/EB.AIR/116 
U.S. Environmental Protection Agency. 1998. Compilation of Information from Information Collection Request Forms Submitted by Iron and Steel Foundries to the U.S. EPA Office of Air Quality Planning and Standards, Research Triangle Park, NC.
Working Group Strategies and Review. 2011. Draft proposal for a guidance document on best available techniques for controlling emissions of heavy metals and their compounds from the source categories listed in annex II. Informal document No. 16, reviewed at the 49[th] Session, Geneva. September 12-16. https://www.unece.org/fileadmin/DAM/env/documents/2011/eb/wg5/WGSR49/Informal%20docs/16_AnnexIIIversion_trackchanges.doc 
World Bank. 2007. Environmental, Health, and Safety Guidelines for Foundries. World Bank Group, International Finance Corporation. April 30. http://documents.worldbank.org/curated/en/741011490086417947/pdf/113620-WP-ENGLISH-Foundries-PUBLIC.pdf  


