Document ID: EPA-HQ-OAR-2002-0049-0142
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2023-08-25T04:00Z

MEMORANDUM

DATE:	May 1, 2023

FROM:	Donna Lee Jones, U.S. Environmental Protection Agency; Gabrielle Raymond, RTI International

TO:	Electric Arc Furnace NSPS Technology Review Project File

SUBJECT:	Cost Analyses to Determine BSER for PM Emissions and Opacity from EAF Facilities 
--------------------------------------------------------------------------------

INTRODUCTION

      This memorandum summarizes the cost estimates used in the development of a new standard for particulate matter (PM) emissions and melt shop opacity for electric arc furnace (EAF) steel manufacturing facilities as part of the technology review of new source performance standards (NSPS) for EAF constructed after October 21, 1974, and on or before August 17, 1983 (40 CFR part 60, subpart AA); and the NSPS for EAF and argon oxygen decarburization (AOD) constructed after August 17, 1983 (40 CFR part 60, subpart AAa). Under Clean Air Act (CAA), section 111(b)(1)(B), the technology review of the NSPS must occur at least every 8 years. The intended effect of the NSPS standards is to require all new, modified, and reconstructed EAF and AOD vessels at steel plants to control emissions to the level achievable through use of the best demonstrated system of continuous emission reduction (BSER), considering costs, nonair quality health and environmental impacts, and energy requirements. (See CAA section 111(a)(1)). Entities potentially regulated by this action include steel manufacturing facilities that operate EAF and AOD. There are approximately 90 EAF currently in the United States of America (U.S.), with approximately nine new facilities estimated over the next ten years (0.9 new facilities per year). 
      
EAF BACKGROUND: PROCESS AND EMISSIONS 

      An EAF is a metallurgical furnace used to produce carbon and alloy steels in the steel industry. The input material to an EAF is typically 100 percent scrap steel. Cylindrical, refractory-lined EAF are equipped with carbon electrodes that are raised or lowered through the furnace roof. With electrodes retracted, the furnace roof can be rotated to permit the charge of scrap steel by overhead crane. Electric current is passed between the electrodes and through the scrap, generating arcing and the generation of enough heat to melt the scrap steel charge. Alloying agents and fluxing materials usually are added through doors on the side of the furnace. After the melting and refining periods, impurities (in the form of a slag) and the refined steel are poured from the furnace. If an AOD is present, it follows the EAF in the production sequence and is used to oxidize carbon, silicon, and impurities, such as sulfur, and reduce alloy additions compared to an EAF alone. Use of AODs reduces EAF heat times, improves quality control, and increases daily steel production. AODs are primarily used in stainless steel making.

      The production of steel in an EAF is a batch process. Cycles, or heats, range from about 1.5 to 5 hours to produce carbon steel and from 5 to 10 hours to produce alloy steel. Scrap steel is charged to begin a cycle, and alloying agents and slag forming materials are added for refining. Stages of each cycle normally are charging, melting, refining (which usually includes oxygen blowing), and tapping. All those operations generate PM emissions. Air emission control techniques typically involve an air emission capture system and a gas cleaning system. Air emission capture systems used in the EAF industry include direct shell evacuation control (DEC) systems, side draft hoods, combination hoods, canopy hoods, scavenger ducts, and furnace enclosures. The DEC system consists of ductwork attached to a separate opening, or "fourth hole", at the top (roof) of the furnace, which draws emissions to a gas cleaner and which works only when the furnace is upright and the top (roof) is in place. Side draft hoods collect furnace off gases from around the electrode holes and work doors after the gases leave the furnace. A combination hood incorporates elements from the side draft and DEC systems. Canopy hoods and scavenger ducts are used to address charging and tapping emissions. Baghouses are typically used as gas cleaning systems, i.e., control devices. Particulate matter emissions from the furnace via side draft or DEC systems are called "primary" emissions, and emissions from charging and tapping are called "secondary" emissions.
      
      Particulate matter and opacity test data were obtained from baghouses (also known as fabric filters) at EAF facilities by the EPA under CAA section 114 authority in 2010 (and 2016). The 2010 CAA section 114 request included a request for new testing in 2010 for PM and opacity (and mercury), and any previous test reports for PM and opacity (and mercury) over the previous 5 years (2005 to 2009). The EPA Test Method 5 was followed for PM tests and EPA Method 9 for opacity. In 2010, a total of 165 reports were obtained from 31 EAF facilities. In 2016, EPA requested new testing under CAA section 114 authority. A total of 10 reports were obtained from three EAF facilities that had previously submitted test reports in 2010 and included test reports from new testing in 2016 and 2017. In addition, two PM and opacity test reports were obtained from EPA Region V for two EAF facilities. These reports and their data from 33 facilities comprise the EPA's EAF test data for PM and opacity that were used in the technology review of the EAF NSPS and are discussed in detail in the memorandum titled "Particulate Matter Emissions from Electric Arc Furnace Facilities for NSPS Review," Hereafter referred to as the "Emissions Memorandum." The EAF data discussed here and in the cited memorandum are referred to as the "EAF data." Copies of the PM test reports can be found in the docket for this rule (EPA-OAR-HQ-2002-0049).
      
 3.0	FORMAT OF THE PM STANDARD FOR NEW EAF AND THEIR CONTROL DEVICES 
      
      In the years since 1984 when the last technology review for the EAF NSPS was done, the control equipment and operation of EAFs have again improved. Fabric filter and baghouse technology have matured and improved as a result of improvements to filter bags, such as the invention of Goretex[(R)] and its use in filter bags; improved baghouse design and cleaning mechanisms; the addition of computerized controllers for furnace and baghouse operations; improved design in capture systems; and the widespread use of baghouse technology to meet Federal, state, and local PM regulations and requirements to meet the National Ambient Air Quality Standards. The technology improvements and widespread use in the pollution control market have resulted in lower equipment and operating costs, and better operation of EAF, capture systems, and baghouses that have lowered PM emissions from baghouses, improved capture, and, consequently, lowered the opacity of the exhaust leaving EAF melt shops.

      Work was done to develop a lower PM limit for EAF/AOD control devices to reflect the improvements in PM control and lower melt shop opacity. The new limit was developed as facility-wide total PM emissions in terms of the mass of PM per mass of steel produced (pounds PM per ton steel produced (lb/ton) or milligrams PM per kilogram steel produced (mg/kg)). The lower PM limits on a mass basis also would be lower if developed in units of air flow. A production-based standard is considered a better metric than one based on air flow, because the latter format allows dilution air to artificially lower the measured PM concentration effect so that the test results are not a reflection of the true PM emissions from the EAF. In addition, facility-wide total control device PM emissions would alleviate the potential disparity in control device emissions between low-and high-loading control devices, such as that for control devices for primary vs. secondary emissions, as well as for well-operated vs. inefficiently-operated control devices. Also, by dividing up the emissions into separate baghouses, each falling under the same NSPS PM limit, there is no accounting for the total PM emissions from the facility. Most metal production industries have production-based air pollution limits.

 4.0	DATA USED TO DETERMINE BSER FOR OPACITY AND PM

      The EAF test data described above was used along with other EAF operating and cost data to determine BSER for opacity and PM as part of the technology review. For facilities with EAF that are subject to the 1975 (40 CFR part 60, subpart AA) and 1984 NSPS (40 CFR part 60, subpart AAa), the melt shop opacity must be less than 6 percent, except for 40 CFR part 60, subpart AA (only), where melt shop opacity during charging periods and tapping periods have limits of 20 percent and 40 percent opacity, respectively. In both of the current EAF NSPS (40 CFR part 60, subparts AA and AAa), the exhaust from control devices must be less than 3 percent opacity and for dust handling operations, opacity must be less than a 10 percent. 
      
      Opacity data for over 30 facilities in test reports period from 2005 through 2011 in the EAF data revealed that all facilities operated at the limit for opacity from control device exhaust and for dust handling. However, lower levels of opacity were achieved for melt shops for many of the EAF facilities. Out of 31 EAF facilities with melt shop opacity data, 15 facilities achieved melt shop opacity of 0 percent during melting and refining, typically in more than one test report. As part of the technology review for the EAF NSPS, the costs to achieve 0 percent opacity were examined to determine if all new facilities could meet a lower melt shop opacity limit as BSER for EAF. 
      
      It was important to use only data from EAF facilities with 0 percent melt shop opacity to determine BSER for control device PM emissions because facilities that control their melt shop opacity to 0 percent opacity during melting and refining are collecting more PM (specifically, from the melt shop) than facilities that have a nonzero melt shop opacity during melting and refining and therefore, also are sending more PM to their control devices. Consequently, EAF facilities with 0 percent melt shop opacity are expected to have higher control device PM emission rates on average compared to EAF facilities with greater than 0 percent melt shop opacity. As a corollary, at EAF facilities with 6 percent melt shop opacity (the current NSPS limit), some of the PM generated by the EAF is not captured, avoids the control device, and exits through the melt shop roof, which raises the melt shop opacity above zero. In turn, facilities with 6 percent melt shop opacity collect less PM and, therefore, less PM is sent to control device, which results in lower PM emissions in the control device exhaust. Overall, much less PM is emitted to the environment with 0 percent opacity during melting and refining than with 6 percent opacity at all times, despite the higher level of control device emissions. This effect is shown quantitatively using the EAF data, as discussed below.
      
      The total facility PM emissions for EAF facilities achieving 0 percent melt shop opacity during melting and refining were compiled in the units of mass of PM emitted per mass of steel produced to evaluate a new facility-wide PM limit and its associated costs. Of the 15 EAF facilities in the EPA data with 0 percent melt shop opacity, control device PM emissions data and steel production values needed to develop an emission standard in mass of PM per mass of steel production were available for 13 of the15 facilities and included 51 individual tests from 23 baghouses and 21 EAF. These 13 EAF facilities and their PM emissions were used to demonstrate that 0 percent melt shop opacity is BSER and to develop a facility-wide total PM control device emission standard that is BSER for new EAF. Table 1 shows the 13 EAF facilities with 0 percent melt shop opacity during melting and refining and their total baghouse EAF PM emissions in lb/ton and gr/dscf.
                Table 1.  Total EAF Baghouse PM Emissions Data
     For EAF with 0 Percent Melt Shop Opacity During Melting and Refining
                                    lb/ton
                                     Rank
                                 Facility Name
                                     No. 
                                    EAF/AOD
                            Combined Total Baghouse
                               Melt Shop Opacity

                                       
                                 PM Emissions

                                       
                                    lb/ton
                                    gr/dscf

                                       1
Timken-Faircrest-OH
                                       1
                                    1.3E-02
                                    1.8E-04
                                     000%
                                       2
CMC-Mesa-AZ
                                       1
                                    1.3E-02
                                    2.3E-04
                                     000%
                                       3
Nucor-Crawfordsville-IN
                                       2
                                    1.6E-02
                                    1.8E-03
                                     000%
                                       4
Gerdau-Charlotte-NC
                                       1
                                    2.3E-02
                                    9.3E-04
                                     000%
                                       5
AK Steel-Butler-PA
                                       3
                                    3.1E-02
                                    3.0E-04
                                     000%
                                       6
Timken-Harrison-OH
                                       2
                                    3.6E-02
                                    1.3E-04
                                     000%
                                       7
Nucor-Huger-SC
                                       2
                                    5.2E-02
                                    6.9E-03
                                     000%
                                       8
Gerdau-Jackson-MI
                                       2
                                    5.4E-02
                                    5.3E-04
                                     000%
                                       9
CMC-Birmingham-AL
                                       1
                                    5.5E-02
                                    3.3E-03
                                     000%
                                      10
CMC-Cayce-SC
                                       1
                                    6.4E-02
                                    9.0E-03
                                     000%
                                      11
Nucor-Jewett-TX
                                       1
                                    1.2E-01
                                    6.6E-03
                                     000%
                                      12
AK Steel-Mansfield-OH
                                       2
                                    1.4E-01
                                    3.4E-03
                                     000%
                                      13
North American Stainless-Ghent-KY
                                       2
                                    1.6E-01
                                    1.6E-03
                                     000%

emissions expressed both on a mass basis (lb/ton) as well as in the air flow format of the current rule, in grains per dry standard cubic feet (gr/dscf). Details of the opacity and PM emissions from all EAF facilities in the EAF data are discussed in the Emissions Memorandum.[1]

 5.0	COST ANALYSIS FOR BSER FOR OPACITY

      To determine if 0 percent opacity during melting and refining and 6 percent during charging and tapping (hereafter referred to as 0/6 percent opacity) is BSER for the EAF melt shop, an estimate of the PM emissions reductions with the lower opacity during melting and refining as compared to the baseline of 6 percent opacity at all times was estimated as well as the costs to achieve the additional PM control and opacity reduction. Emissions data from the EAF data were used along with emission factors and EAF control information in the literature to determine the PM emission reductions. It was assumed that facilities achieving 0 percent melt shop opacity during melting and refining have better fugitive collection than facilities with higher melt shop opacities. Therefore, for the BSER calculations, we assessed the cost of adding a partial roof canopy (segmented canopy hood, closed roof over furnace, open roof monitor elsewhere) to collect PM emissions that might escape through the melt shop roof vents and achieve complete control of melt shop fugitives. The procedures used to determine whether 0 percent opacity using a new canopy hooding is BSER are described below. 
      
 5.1	PM Emission Reductions with 0/6 Percent Opacity 
      To improve the estimates, two approaches were used to estimate potential PM emission reductions with the addition of a partial roof canopy to reduce melt shop opacity from 6 percent to 0 percent. The resulting average, calculated from the two PM estimates, was used in the overall BSER cost-effectiveness calculation. The methodology in each of the two approaches is described below. Figure 1 illustrates the details of calculations in the two estimating methods.

Figure 1.  Details of estimates for PM reduced from melt shop at 6 percent opacity vs. 0 percent.
Figure 1.  (continued). 

      The first method to estimate PM reductions with 0 percent melt shop opacity vs. 6 percent opacity used PM data from the EAF background information document prepared in 1983 (1983 BID) for the EAF 1984 NSPS.  The data from the 1983 BID are shown in Figure 1 under Method 1, Parts (A) and (B). The average uncontrolled EAF PM emissions of 15 g/kg [29 lb/ton] from the 1983 BID and the average capture efficiency of 90 percent, for a "segmented canopy hood, closed roof over furnace, open roof monitor elsewhere," also from the 1983 BID, were used along with the estimated steel production of an average EAF facility, at 542,500 tons per year (tpy), to produce an estimate of the roof vent PM emission rate for an average EAF of 795 tpy, as illustrated in Figure 1. This PM emission rate was assumed to be the melt shop PM fugitive emission rate from the roof vent of a melt shop for an average EAF with 6 percent melt shop opacity, the current NSPS standard.
      
      The second method used to estimate PM emission reductions with 0 percent melt shop opacity vs. 6 percent opacity used PM emission data obtained from the EAF data for facilities with 0 and 6 percent melt shop opacity.[1] Opacity and PM emission data were available for 9 EAF facilities, 12 EAF/AODs, 13 baghouses, and 33 individual tests where 6 percent melt shop opacity was achieved; and 13 facilities 21 EAF/AODs, 23 baghouses and 51 individual tests where 0 percent melt shop opacity was achieved. The annual baghouse stack emissions for facilities with less than 6 percent melt shop opacity was estimated at 12 tpy PM based on an average emission rate of 4.42e-02 lb/ton for nine facilities and an average steel production of 542,500 tpy steel,[5] as above. Total PM emissions generated by the EAF are estimated as the PM emissions sent to the baghouse plus any uncaptured emissions emanating from the melt shop as opacity (if not controlled to 0 percent opacity). The captured PM emissions routed to the baghouse can be calculated from the PM emitted from the baghouse 12 tpy and an assumption of baghouse control efficiency of 99.8 percent, to produce an estimate of 6,000 tpy PM routed to the baghouse at an average facility where 6 percent melt shop opacity was achieved. 
      
      Further in the second approach to calculate total PM emissions generated (uncontrolled) by the EAF, the value of 6.000 tpy captured PM routed to the baghouse estimated above is added to an estimate of uncaptured PM emitted from the melt shop, where there is less than 6 percent melt shop opacity. Using the estimate of 90 percent captured PM at a melt shop with 6 percent opacity,[4] the total PM emissions generated by the EAF is calculated as 6,667 tpy PM (6,000 tpy/0.9). The difference between the PM generated and the PM captured, at 667 tpy (6,667-6,000 tpy), is the second estimate of the amount of PM that is controlled with 0 percent melt shop opacity compared to a melt shop at 6 percent opacity, because all PM is captured at a 0 percent melt shop opacity facility). Refer to Figure 1 for details of the calculations. As a check on the estimate of 6,667 tpy total uncontrolled PM from the EAF, an emission factor in the format of PM emitted per ton steel was calculated using to total PM and the average steel production 542,500 tpy used in the calculations. The result, at 25 lb/ton PM emitted per ton steel, is in the expected range in 1983 BID cited above in the first method, between 17 to 42 lb/ton.[3] This result also confirms that the baghouse efficiency value of 99.8 percent used in the calculation is appropriate. The average of the two methods (795 tpy from method 1 and 667 tpy from method 2), at 731 tpy is used in the BSER analysis as the additional PM controlled between a melt shop at 0 percent opacity vs. 6 percent. For BSER where 6 percent is permitted during charging and tapping, the reductions are slightly lower, at 684 tpy for the additional PM controlled between a melt shop at 0 percent opacity vs. 0/6 percent opacity, where 6 percent opacity is permitted during charging and tapping. 
      
 5.2	Costs for Installing and Operating a Partition Roof Canopy 
      Canopy hoods are a common method of controlling fugitive EAF emissions.[2] To estimate the costs for EAF facilities to reduce their PM emissions and melt shop opacity from 6 percent to 0/6 percent opacity, the costs for addition of a partition roof canopy (above the crane rails) were estimated using the procedure and information from the National Emission Standards for Hazardous Air Pollutants (NESHAP) for Ferroalloys, where EAF also are used and shop fugitives also are a concern.  Detailed cost information was not available to the EPA to support cost estimates for the canopy at steel-making EAF facilities; whereas, the ferroalloy cost estimates included detailed cost input parameters from the ferroalloy industry where EAFs are also used. Therefore, without source-category specific information, the ferroalloy cost estimates were used for this EAF NSPS rule.
      
      To adapt the ferroalloy cost-estimating procedure to steel-making EAF, equipment costs and other parameters were scaled by the ratio (0.51) of the ferroalloys EAF baghouse flowrate at 200[o]F, 330,000 actual cubic feet per minute (ACFM), to the average steel EAF flowrate in the EAF data at 200[o]F, 641,000 ACFM, which corresponds to 530,000 standard cubic feet per minute (SCFM) for a medium-sized or average EAF facility. Using the ferroalloy cost estimates with the average steel-making EAF flowrate and other parameters from the EAF data, capital costs for the partial canopy hood at a medium-sized steel-making EAF were estimated at $$7,613,440, operating and maintenance costs at $388,334, and total annualized costs at $1,135,153 in $2022. Details of the cost estimating procedure for addition of a partition roof canopy (above the crane rails) for a medium-sized EAF are shown in Figure 2.
      
      Similar cost analyses were done for a small and large EAF facilities using flowrates from the EAF data. Table 2 shows the cost values for small, medium, and large EAF baghouses and melt shops to achieve 0/6 percent melt shop opacity with a partial roof canopy hood above the crane rails. Appendix A shows the details of the cost estimating procedure for addition of a partition roof canopy (above the crane rails) for a small and large EAF. A small percent of the costs (approximately 8 percent) is due to electricity needed to power the fans that draw air into the canopy hood and into the control device, at $5,484, $77,733, and $313,933 in annual costs for small, medium, and large facilities, respectively, in $2022.
      
 5.3	Overall Cost Effectiveness to Achieve 0/6 Percent Melt Shop Opacity for Medium-sized facility 
      The cost-effectiveness of a partition roof canopy (above the crane rails) used for a steel-making EAF was estimated using the annual costs of the canopy, at $1,135,153 per year from Section 5.2 above, and the PM reduction of  684 tpy for achieving 0/6 percent melt shop opacity from 6 percent opacity, described in Section 5.1, above, resulting in $1,700 per ton PM removed in $2022 (rounded to two significant figures). The same analyses performed for small and large EAF baghouses and melt shops produced similar cost-effectiveness values, at $1,800 per ton and $1,700 per ton for small and large EAF baghouses, respectively (rounded to two significant figures), as shown in Table 2. The values of $1,800 per ton and lower are considered cost-effective and, therefore, the use of additional canopy hoods above the crane rails is considered BSER for melt shop opacity for new EAF/AOD using this approach.
      
         Figure 2. EAF canopy costs for a medium-size facility.
                                       
      Figure 2. (continued).
                                       

  Table 2.  Costs and Parameters for Achieving 0/6 Percent Melt Shop Opacity 
             with a Partial Roof Canopy Hood Above the Crane Rails
                                Cost Parameter
                             Facility Size[1][,2]

                                     Small
                                    Medium
                                     Large
Flow, acfm
                                    45,229
                                    641,126
                                   3,207,589
Capital Costs
                                   $537,096
                                  $7,613,440
                                  $38,090,470
Operating and Maintenance Costs
                                    $33,031
                                   $388,334
                                  $1,918,585
Total Annualized Costs 
                                    $85,716
                                  $1,135,153
                                  $5,654,963
PM Removed 6% opacity to 0% opacity, tpy
                                      56
                                      731
                                     3,977
PM Removed 6% opacity to 0%&6% opacity, tpy[3]
                                      48
                                      684
                                     3,421
Cost-effectiveness, $/ton (6% to 0%)
                                    $1,528
                                    $1,428
                                    $1,422
Cost-effectiveness, $/ton (6% to 0%&6%)[3]
                                    $1,777
                                    $1,660
                                    $1,653
1 For small and large facilities, PM is calculated by ratio of flowrates in the EAF data to medium-sized facility's flowrate and emissions, using smallest and largest facility sizes in the EAF data. 
[2] Numbers have been rounded and, therefore, may not calculate exactly
[3] Reflects PM removed with 0% opacity during melting and refining and 6% opacity during charging and tapping. See the Emissions Memorandum[1] for explanation of how these estimates were derived.

 6.0	COST ANALYSIS FOR MASS-BASED FACILITY-WIDE PM LIMIT

6.1	Costs Analysis Using II&S Air-to-Cloth Ratios
      
      The emissions data from the EAF data from 13 EAF facilities with 0 percent opacity during melting and refining are shown in Table 1 along with estimated costs of control were used to determine BSER for a mass-based facility-wide PM limit for EAF/AOD facilities. As discussed above, it was important to use data from EAF facilities with 0 percent melt shop opacity during melting and refining to determine BSER for control device PM emissions because facilities that control their melt shop opacity to 0 percent opacity are collecting more PM (specifically, from the melt shop) than facilities that have a nonzero melt shop opacity and, therefore, also are sending more PM to their control devices. Consequently, EAF facilities with 0 percent melt shop opacity are expected to have higher control device PM emission rates on average compared to EAF facilities with greater than 0 percent melt shop opacity.
      
      The number of PM test reports used per facility in the BSER analysis for the facility-wide PM limit ranged from one (3-run) test to 10 tests, with a median of 3 tests. The EAF facility total baghouse PM emissions per mass of steel produced from 13 facilities in the EAF data with 0 percent melt shop opacity during melting and refining ranged from a low of 1.3E-02 lb/ton to a high of 1.6E-01 lb/ton with a median of 5.2E-02 lb/ton. A graph of the total facility baghouse PM emission rates in mass units (lb/ton) for the 13 facilities with 0 percent melt shop opacity is shown in in Figure 3 with an exponential line of best fit.
      
      The control costs for a range of baghouse performance levels were estimated based on baghouse air-to-cloth (A/C) ratio, in units of length (L) per unit of time (T), as derived from volumetric air flow (L[3]/T) per unit bag area or "cloth", L[2]. The A/C ratio is generally accepted as the most important design parameter between 
                                       
      Figure 3. Total facility PM lb/ton ranked for 13 EAF facilities with 0 percent opacity during melting and refining.

baghouses of different performance levels, where a low A/C ratio is considered to be the best level of control (less air and more baghouse filter cloth) and a high A/C ratio is considered a low or poor level control (high air volume and low baghouse filter area).[7] Because no data for A/C ratio were available in the EAF PM test reports, values for baghouse A/C ratio were taken from CAA section 114 responses submitted to EPA in 2011 by the integrated iron and steel industry (II&S) industry for the risk and technology review of the NESHAP in 40 CFR
part 63, subpart FFFFF. The A/C ratio data were taken from 70 II&S blast furnace baghouses at 14 facilities. The baghouses used to control emissions from furnaces in the II&S industry are expected to be operated similar   to baghouses used at EAFs/AODs. The A/C ratio in the II&S data ranged from a low of 1.3 ft/min to a high of 7.2 ft/min. Figure 4 shows the A/C ratios from the II&S data.
      
      In order to explore what level of PM emissions in the data would be BSER, considering costs, five points across the range in the ranked PM data and five points across the range in ranked A/C ratios were matched to represent five model facilities of increasingly controlled levels of total facility baghouse PM emissions, with the lowest (best controlled) PM emissions matched to the lowest (best) A/C ratio and labelled Model Plant A, and the highest (worst controlled) PM emissions matched the highest (worst) A/C ratio labelled Model Plant E, with the intermediary facilities similarly matched so that there were five distinct operating levels for each of five model plants. The five values for both PM emission rate and A/C ratio used for model plants are indicated on Figures 3 and 4, respectively. Two PM emission rate values (0.080 and 0.10 lb/ton) are taken from the exponential curve on Figure 3 to better represent typical the EAF emission data. 
      

Figure 4.  Air-to-cloth ratios from II&S facility data with endpoints and quartiles marked.

          Table 3.  Model Plant Parameters Used in the Cost Analysis
                        For a Facility-wide Baghouse PM Limit
                               Using II&S A/C Data
                                 Model Plants
                               PM Emission Rate
                                   A/C Ratio
      
      lb/ton
                                    ft/min
                                       A
      0.013
      1.3
                                       B
      0.034
      2.9
                                       C
      0.080
      4.0
                                       D
      0.10
      4.9
                                       E
      0.16
      7.2
      
      
      To determine what PM limit should be set as BSER, the first cost analysis started at the highest emitting facility in terms of PM lb/ton (Model Plant E) using three sizes of EAF facilities: small, "average" or median, and large. Steel production for each facility size was taken from industry capacity data[5] and corresponded to 50,000, 775,000, and 3,450,000 tpy for small, medium, and large facilities, respectively, where medium was determined from the median of industry data, and small and large were the smallest and largest facilities. Estimates of baghouse flowrate were taken from the EAF data, at 45,229 acfm, 641,126 acfm, and 3,207,589 acfm for small, medium, and large facility-level baghouses, respectively. The five A/C ratios discussed above were used in the cost procedures for the model plants (A through E) at small, medium, and large facilities. Table 3 shows the model plants PM emissions and A/C ratios for each facility size used in the analysis for a  facility-wide baghouse PM lb/ton limit.
      
      Capital, annual operating and maintenance (O&M), and annualized costs were estimated for new baghouses for each the five model plants for all three facility sizes following the procedures in the EPA Cost Manual.[7] Capital costs reflect the cost of bags needed for each A/C ratio for the model plants. The O&M costs reflect periodic replacement of bags, along with other typical baghouse O&M costs. The results are shown in Table 4 for each model plant and each facility size (small, medium, large). Capital costs for new baghouses at a medium-sized facility ranged from $4,800,000 to $24,000,000 for model plants (A through E) in $2022. Annual O&M costs for the medium facility ranged from $1,600,000 to $2,750,000 for the model plants in $2022. Annualized costs for the medium-sized model plants ranged from $2,000,000 to $5,000,000 for the model plants in $2022. The cost-effectiveness of control for the medium-sized model plants in terms of the additional cost of control (annual costs) between Model Plants A through D per ton of additional PM removed ranged from $12,200 per ton to $52,000 per ton medium-sized model plants in $2022. 
      
      A candidate BSER for PM control in a new lb/ton PM standard was determined by starting with the least stringent level of control at Model Plant E, and then comparing these costs to the next higher-controlled model plant, sequentially, in terms of lower emissions, lower A/C ratio, additional PM control, and higher costs. The analysis shows that only the highest emitting Model Plant (E) in the data, at 0.16 lb/ton, was considered BSER compared to the next lowest, Model Plant D, where the cost-effectiveness was $12,400/ton in $2022 for a medium-size facility in $2022. 
      
      The incremental cost-effectiveness of control was also calculated comparing each model to the next more stringent model in terms of the additional cost of control (annual costs) in $2022. The incremental costs of control from Model Plant E to Model Plant D is $12,200 per ton for the medium-sized model plant shown in last column of Table 4 in $2022. The incremental cost-effectiveness of Model Plant E compared to model plant D ranged from approximately $12,400 to $13,700 per ton PM removed for all sizes of facilities, small, medium, and large in $2022. The cost-effectiveness for Model Plants D through A were not considered cost-effective for all three size of facilities. 
      
      Figure 5 shows the cost calculations for Model Plant E, as BSER, for a medium-sized EAF facility in $2022. Appendix B shows the cost calculations for a small and large EAF facility for Model Plant E in $2022. Cost calculations for all models and sizes are in Appendix C in attached Excel(TM) files in $2022. 
      
    
          Table 4.  BSER Cost Analyses with II&S A/C Data ($2022)
                                  Model Plant
                       Total Controlled EAF PM Emissions
                        EAF Facility Average Production
                         EAF Facility PM Emission Rate
                                   A/C Ratio
                             Cost for New Baghouse
              Additional PM Controlled (tpy) from Baseline Level
                              Cost-Effectiveness
     Incremental Cost-Effectiveness from Next Higher-emitting Model Plant

                                    Capital
                                Annual O&M
                                 Annual Costs
                                 Annual Costs 
                     Delta from Next Highest Model Plant 

                                       
                                       

                                    lb/ton
                                      tpy
                                      tpy

                                       $
                                     $/yr
                                     $/yr
                                     $/yr

                                    delta$/
                                    ton PM
                                    delta$/
                                    ton PM
                                SMALL FACILITY
                                       
                                       A
                                     0.013
                                    50,000
                                      0.3
                                     1.34
                                                                     $2,123,152
                                                                       $346,912
                                                                       $546,722
                                                                       $204,741
                                     3.6 
                                   $56,851 
                                      --
                                       B
                                     0.034
                                    50,000
                                      0.8
                                     2.87
                                                                     $1,255,021
                                                                       $289,352
                                                                       $408,511
                                                                        $66,530
                                     3.1 
                                   $21,544 
                                   $269,312 
                                       C
                                     0.080
                                    50,000
                                      2.0
                                     4.00
                                                                     $1,040,210
                                                                       $276,458
                                                                       $375,662
                                                                        $33,681
                                     1.9 
                                   $17,476 
                                   $28,296 
                                       D
                                     0.10
                                    50,000
                                      2.5
                                     4.90
                                                                       $940,020
                                                                       $271,125
                                                                       $361,021
                                                                        $19,039
                                     1.4 
                                   $13,340 
                                   $29,282 
                                       E
                                     0.16
                                    50,000
                                      3.9
                                     7.22
                                                                       $796,912
                                                                       $265,380
                                                                       $341,981
                                                                             $0
                                       0
                                      --
                                    $13,340
                                MEDIUM FACILITY
                                       
                                       A
                                     0.013
                                    775,000
                                      5.1
                                     1.34
                                                                    $23,578,469
                                                                     $2,754,577
                                                                    $4,947,617 
                                                                     $2,902,173
                                     55.8 
                                   $51,991 
                                      --
                                       B
                                     0.034
                                    775,000
                                     13.0
                                     2.87
                                                                    $11,272,482
                                                                     $1,938,625
                                                                    $2,988,420 
                                                                       $942,977
                                     47.9 
                                   $19,700 
                                   $246,297 
                                       C
                                     0.080
                                    775,000
                                     31.0
                                     4.00
                                                                     $8,227,752
                                                                     $1,755,951
                                                                    $2,522,887 
                                                                       $477,444
                                     29.9 
                                   $15,983 
                                   $25,872 
                                       D
                                     0.10
                                    775,000
                                     38.8
                                     4.90
                                                                     $6,807,382
                                                                     $1,680,295
                                                                    $2,315,277 
                                                                       $269,834
                                     22.1 
                                   $12,197 
                                   $26,788 
                                       E
                                     0.16
                                    775,000
                                     60.9
                                     7.22
                                                                     $4,778,920
                                                                     $1,598,907
                                                                    $2,045,443 
                                                                             $0
                                       0
                                      --
                                   $12,197 
                                LARGE FACILITY
                                       
                                       A
                                     0.013
                                   3,450,000
                                     22.5
                                     1.34
                                                                   $115,984,136
                                                                   $12,340,664 
                                                                    $23,118,320
                                                                    $14,519,707
                                    248.5 
                                   $58,431 
                                      --
                                       B
                                     0.034
                                   3,450,000
                                     57.9
                                     2.87
                                                                    $54,416,582
                                                                    $8,258,404 
                                                                    $13,316,348
                                                                     $4,717,735
                                    213.1 
                                   $22,140 
                                   $276,807 
                                       C
                                     0.080
                                   3,450,000
                                     138.0
                                     4.00
                                                                    $39,183,640
                                                                    $7,344,483 
                                                                    $10,987,265
                                                                     $2,388,652
                                    133.0 
                                   $17,962 
                                   $29,076 
                                       D
                                     0.10
                                   3,450,000
                                     172.5
                                     4.90
                                                                    $32,077,522
                                                                    $6,966,000 
                                                                     $9,948,613
                                                                     $1,350,000
                                     98.5 
                                   $13,708 
                                   $30,106 
                                       E
                                     0.16
                                   3,450,000
                                     271.0
                                     7.22
                                                                    $21,929,003
                                                                    $6,558,810 
                                  $8,598,613
                                                                            $0 
                                       0
                                      --
                                   $13,708 

Notes: A/C = air-to cloth ratio (ft/min). lb/ton = pound per ton. tpy = tons per year. Discrepancies in calculations made with table data may occur due to rounding.

    
    
Figure 5.  BSER Cost Calculations  -  lb/ton  -  Medium Facility.
                                       
  Figure 5.  (continued).
Figure 5. (continued).

6.2	PM lb/ton Costs Analysis Using 2005 EAF Air-to-Cloth Ratios
      
      In addition to the EAF test data from 2010 CAA section 114 request responses, the EPA analyzed data obtained via the 2005 CAA section 114 request that was used to support the EAF area source National Emission Standards for Hazardous Air Pollutants (NESHAP) in 40 CFR part 63, subpart YYYYY, which was promulgated on 12/28/2007. (Docket Number EPA-HQ-OAR-2004-0083). The primary purpose of obtaining the 2005 EAF data was to verify whether the cost analysis based on air-to-cloth (A/C) ratios taken from 2010 data for II&S facilities used in the EAF NSPS proposal were valid by comparing to the BSER analysis results using A/C ratios from 2005 EAF data from EAF facilities obtained for the EAF NESHAP. Only 7 of the 13 zero opacity facilities from 2010 CAA section 114 request used in the PM lb/ton proposal analysis had A/C analysis data in the 2005 EAF CAA section 114 request. Table 5 shows the matchup of 2005 EAF facilities by location (city, state) and, in most cases, name to the 2010 CAA section 114 request zero opacity facilities. One additional facility on the list of 13 2010 CAA section 114 request zero opacity facilities, NAS Ghent-KY, provided A/C data in 2010 for all their baghouses as part of their request for exemption for testing for similar 
          Table 5.  2005 EAF A/C Data Matched to 2010 EAF Facilities
                                     Count
                           2010 Facility-City-State
                                     2010 
                                    lb-ton
                        Matching 2005 EAF Facility Name
                               2005 EAF Facility
                                  City, State
                     2005 Facility A/C (weighted average)
                                       1
Gerdau-Charlotte-NC
                                   2.30E-02
Charlotte Steel Mill
Charlotte
NC
                                      2.2
                                       2
Nucor-Huger-SC
                                   5.20E-02
Nucor Steel  -  Berkeley
Huger
SC
                                      2.6
                                       3
Timken-Harrison-OH
                                   3.60E-02
Harrison Steel Plant
Canton
OH
                                      2.6
                                       4
Nucor-Crawfordsville-IN
                                   1.60E-02
Nucor  -  Crawfordsville
Crawfordsville
IN
                                      3.2
                                       5
CMC-Cayce-SC
                                   6.40E-02
SMI Steel  -  SC
Cayce
SC
                                      3.3
                                       6
Timken-Faircrest-OH
                                   1.30E-02
Faircrest Steel Plant
Canton
OH
                                      3.4
                                       7
CMC-Birmingham-AL
                                   5.50E-02
SMI Steel  -  Alabama
Birmingham
AL
                                      3.7
                                       8
NAS-Ghent-KY*
                                   1.60E-01
 
 
 
                                       *
* Reported A/C in 2010 was an overall average for the facility baghouses at 4.5 ft/min.

      
      
sources. A comparison of the A/C ratios from 2010 II&S data to the 2005 EAF data is shown in Figure 6. Appendix D contains the data used for the match up of 2005 EAF facilities to 2010 EAF facilities for purposes of using the 2005 EAF A/C ratios with 2010 CAA section 114 request lb/ton data instead of II&S A/C data.

      To provide a more robust analysis for a lb/ton BSER standard, total facility PM emissions in lb/ton using the 2005 EAF data were added to the BSER lb/ton dataset in the EAF BSER cost analysis for PM lb/ton  if sufficient data were available to develop a lb/ton emission ratio and A/C ratios also were available. Because in most cases the A/C ratios for secondary baghouses were not provided in the 2005 CAA section 114 request dataset, only facilities in the 2010 CAA section 114 request dataset with combined primary and secondary (P/S) baghouses were used if lb/ton PM factors could be developed and A/C ratios were available. There were 10 EAF facilities in the 2005 EAF CAA section 114 request data that had sufficient data to calculate total facility lb/ton and where A/C ratio were available for all baghouses. The eight 2010 section 114 request zero opacity facilities along with matched EAF A/C ratios from the 2005 CAA section 114 request and the 10 facilities from the 2005 EAF section 114 request and their total facility PM emissions in lb/ton and their A/C data are shown in Table 6 along with their total facility PM lb/ton emissions levels. See the Emissions Memorandum[1] for more information about the 2005 EAF CAA section 114 request facility-wide lb/ton emissions and their development. Appendix D also contains the data used for developing lb/ton values from the 2005 EAF facility data.
      
      In order to develop another set of model plants that span the range of A/C ratios at EAF baghouse, the 18 datapoints described above (10 lb/ton PM emission factors from 2005 CAA section 114 request and 8 from 2010 CAA section 114 request, all with 2005 EAF A/C ratios) were plotted. A line of best fit to the data in Table 6 was used to develop a second set of model plants for a BSER cost analysis. Figure 7 shows the combined 18 datapoints and the line of best fit shown as a dotted line in the range of the model plants. Table 7
 
                                       
 Figure 6. Comparison of A/C ratios from 2010 II&S data and 2005 EAF data.
      
      
               Table 6.  Combined 2005 and 2010 lb/ton Datasets 
                           with 2005 EAF A/C Ratios
                                     Count
                         2010 Zero Opacity Facilities
                                     2010 
                                    lb-ton
                               2005 Facility A/C
                              (weighted average)*
                                       1
Timken-Faircrest-OH
                                    1.3E-02
                                      3.4
                                       2
Nucor-Crawfordsville-IN
                                    1.6E-02
                                      3.2
                                       3
Gerdau-Charlotte-NC
                                    2.3E-02
                                      2.2
                                       4
Timken-Harrison-OH
                                    3.6E-02
                                      2.6
                                       5
Nucor-Huger-SC
                                    5.2E-02
                                      2.6
                                       6
CMC-Birmingham-AL
                                    5.5E-02
                                      3.7
                                       7
CMC-Cayce-SC
                                    6.4E-02
                                      3.3
                                       8
NAS-Ghent-KY
                                    1.6E-01
                                     4.5*
                                     Count
                      2005 Facilities with P/S Baghouses
                                  2005 lb/ton
                               2005 Facility A/C
                               (weighted average
                                       1
Nucor-Norfolk-NE
                                    8.7E-03
                                      2.8
                                       2
Nucor-Cofield-NC
                                    1.3E-02
                                      3.0
                                       3
Nucor-Blytheville-AR
                                    1.4E-02
                                      3.0
                                       4
Nucor Bar Mill-Plymouth-UT
                                    1.8E-02
                                      2.1
                                       5
North Star Steel-St. Paul-MN
                                    1.9E-02
                                      2.0
                                       6
Nucor Berkeley-Huger-SC
                                    2.2E-02
                                      2.6
                                       7
IPSCO Steel-Axis-AL
                                    3.2E-02
                                      2.6
                                       8
SMI Steel-Cayce-SC
                                    5.8E-02
                                      3.3
                                       9
CMC/Struct Metals/SMI-Sequin-TX
                                    8.5E-02
                                      6.0
                                      10
IPSCO Steel-Muscantine-IA
                                    8.7E-02
                                      5.1
      
                                          
      Figure 7. Combined 2005&2010 dataset (18 data points) and line of best fit.
      
      
      Table 7.  Model Plant Parameters Based on Line of Best Fit*
                                  Model Plant
                                    EAF A/C
                                     Ratio
                                      PM
                                    lb/ton
                                       A
                                       2
                                      013
                                       B
                                       3
                                     0.38
                                       C
                                       4
                                      063
                                       D
                                       6
                                     0.11
                                       E
                                       7
                                     0.14
                                       F
                                       8
                                     0.16
*Equation of line of best fit is as follows:
y  == 0.251x  -  0.0377
      
      
      
      
      
      
      
show the model plant parameters generated from the line of best fit (r[2] = 0.488) across the range of potential A/C ratios; a plot of these data is shown in Figure 8. 
      
      
                                          
           Figure 8. Line of best fit for combined 2005&2010 dataset (18 data points).
      

      The cost analysis for a small, medium, and large facilities based on model plants generated with 2005 EAF A/C ratios and PM lb/ton emissions data from the 18 facilities from the combined 2005 and 2010 CAA section 114 requests are shown in Table 8. The analysis shown in Table 8 with 2005 EAF A/C data is similar to what is shown in Table 4 for EAF total facility lb/ton data using II&S A/C data. The incremental cost-effectiveness of Model Plant F (2005 A/C ratio data) compared to Model Plant E, the next highest model plant, ranged from approximately $7,300 to $7,900 per ton PM removed for all sizes of facilities, small, medium, and large in Table 8. The incremental cost-effectiveness for Model Plants A through E were not considered cost-effective for all three size of facilities. Figure 9 shows the cost calculations for Model Plant F, as BSER, for a medium-sized EAF facility (2005 A/C data). Appendix E shows the cost calculations for a small and large EAF facility for Model Plant E (2005 A/C data). Cost calculations for all models and sizes are in Appendix F in the attached Excel(TM) files.
    
    Table 9 compares the BSER model plant for small, medium, and large EAF facilities using the two datasets: 2005 EAF A/C and 2005&2010 lb/ton EAF data, and 2010 II&S A/C ratios and 2010 lb/ton EAF data. The values in Table 9 for capital costs, O&M costs, and annual costs for the three sizes facilities for the highest model plant (Model Plant F) with 2005 EAF A/C ratio data were similar to the highest model plant in the analysis with II&S data (Model Plant E). In both cases, the incremental cost-effectiveness of the BSER model plant to next level was higher than acceptable, at $7,000/ton and $13,500/ton for 2005 EAF A/C ratios vs. 2010 II&S A/C ratios, respectively.
    
          Table 8.  BSER Cost Analyses with 2005 EAF A/C Data ($2022)
                                  Model Plant
                       Total Controlled EAF PM Emissions
                        EAF Facility Average Production
                         EAF Facility PM Emission Rate
                                   A/C Ratio
                             Cost for New Baghouse
              Additional PM Controlled (tpy) from Baseline Level
                            Cost-Effectiveness (CE)
             Incremental CE from Next Higher-emitting Model Plant

                                    Capital
                                Annual O&M
                                 Annual Costs
                                 Annual Costs 
                     Delta from Next Highest Model Plant 

                                       
                                       

                                    lb/ton
                                      tpy
                                      tpy

                                       $
                                     $/yr
                                     $/yr
                                     $/yr

                                    delta$/
                                    ton PM
                                    delta$/
                                    ton PM
                                SMALL FACILITY
                                       
                                       A
                                     0.011
                                    50,000
                                      0.3
                                      2.0
                                                                     $1,585,754
                                                                       $310,761
                                                                       $460,646
                                                                       $122,036
                                      3.8
                                   $32,115 
                                      --
                                       B
                                     0.036
                                    50,000
                                      0.9
                                      3.0
                                                                     $1,222,058
                                                                       $287,290
                                                                       $403,388
                                                                        $64,778
                                      3.2
                                   $20,307 
                                    $93,865
                                       C
                                     0.060
                                    50,000
                                      1.5
                                      4.0
                                                                     $1,040,210
                                                                       $276,458
                                                                       $375,662
                                                                        $37,052
                                      2.6
                                   $14,361 
                                    $45,453
                                       D
                                     0.11
                                    50,000
                                      2.8
                                      6.0
                                                                       $858,363
                                                                       $267,437
                                                                       $349,747
                                                                        $11,137
                                      1.3
                                    $8,874 
                                    $19,558
                                       E
                                     0.14
                                    50,000
                                      3.5
                                      7.0
                                                                       $806,414
                                                                       $265,642
                                                                       $343,126
                                                                         $4,516
                                      0.6
                                    $7,196 
                                    $10,552
                                       F
                                     0.16
                                    50,000
                                      4.1
                                      8.0
                                                                       $767,439
                                                                       $264,747
                                                                       $338,610
                                       -
                                       0
                                       -
                                    $7,196 
                                MEDIUM FACILITY
                                       
                                       A
                                     0.011
                                    775,000
                                      4.3
                                      2.0
                                                                    $15,960,808
                                                                     $2,242,156
                                                                     $3,727,505
                                                                     $1,729,804
                                     58.9 
                                   $29,368 
                                      --
                                       B
                                     0.036
                                    775,000
                                      14
                                      3.0
                                                                    $10,805,447
                                                                     $1,909,496
                                                                     $2,915,903
                                                                       $918,202
                                     49.4 
                                   $18,570 
                                   $85,838 
                                       C
                                     0.060
                                    775,000
                                      23
                                      4.0
                                                                     $8,227,752
                                                                     $1,755,951
                                                                     $2,522,887
                                                                       $525,186
                                     40.0 
                                   $13,133 
                                   $41,567 
                                       D
                                     0.11
                                    775,000
                                      44
                                      6.0
                                                                     $5,650,057
                                                                     $1,628,089
                                                                     $2,155,554
                                                                       $157,853
                                     19.5 
                                    $8,115 
                                   $17,886 
                                       E
                                     0.14
                                    775,000
                                      53
                                      7.0
                                                                     $4,913,565
                                                                     $1,602,603
                                                                     $2,061,648
                                                                        $63,947
                                     9.7 
                                    $6,575 
                                    $9,655 
                                       F
                                     0.16
                                    775,000
                                      63
                                      8.0
                                                                     $4,361,224
                                                                     $1,589,971
                                                                     $1,997,701
                                       - 
                                      0 
                                       -
                                    $6,575 
                                LARGE FACILITY
                                       
                                       A
                                     0.011
                                   3,450,000
                                      19
                                      2.0
                                                                    $77,872,613
                                                                     $9,777,019
                                                                    $17,014,061
                                                                     $8,654,343
                                     262.2
                                    $33,007
                                      --
                                       B
                                     0.036
                                   3,450,000
                                      61
                                      3.0
                                                                    $52,079,984
                                                                     $8,112,672
                                                                    $12,953,541
                                                                     $4,593,823
                                     220.1
                                    $20,871
                                    $96,472
                                       C
                                     0.060
                                   3,450,000
                                      103
                                      4.0
                                                                    $39,183,640
                                                                     $7,344,483
                                                                    $10,987,265
                                                                     $2,627,547
                                     178.0
                                    $14,760
                                    $46,716
                                       D
                                     0.11
                                   3,450,000
                                      195
                                      6.0
                                                                    $26,287,326
                                                                     $6,704,797
                                                                     $9,149,494
                                                                       $789,776
                                     86.6
                                    $9,120
                                    $20,101
                                       E
                                     0.14
                                   3,450,000
                                      238
                                      7.0
                                                                    $22,602,668
                                                                     $6,577,314
                                                                     $8,679,700
                                                                       $319,982
                                     43.3
                                    $7,390
                                    $10,850
                                       F
                                     0.16
                                   3,450,000
                                      281
                                      8.0
                                                                    $19,839,154
                                                                     $6,514,065
                                                                     $8,359,718
                                       -
                                       0
                                       
                                    $7,390
Notes: A/C=air-to-cloth ratio (ft/min).lb/ton=pound per ton tpy=tons per year. Discrepancies in calculations made with table data may occur due to rounding.

      
  Figure 9.  BSER Cost Calculations lb/ton Medium Facility  -  2005.
                                                                               
Figure 9.  (continued). Figure 9.  (continued).
                                       
      
                                       
Table 9.  Comparison of BSER Model Plants for Small, Medium, and Large EAF Facilities Using Two Datasets: 2005 EAF A/C Ratios and 2010 II&S A/C Ratios, Both with 2010 EAF lb/ton Data
                                  Model Plant
                       Total Controlled EAF PM Emissions
                        EAF Facility Average Production
                         EAF Facility PM Emission Rate
                                   A/C Ratio
                             Cost for New Baghouse
             Incremental CE from Next Higher-emitting Model Plant

                                       
                                    Capital
                                Annual O&M
                                 Annual Costs
                                       

                                    lb/ton
                                      tpy
                                      tpy
Value
                                     Basis
                                       $
                                     $/yr
                                     $/yr
                                    delta$/
                                    ton PM
                                SMALL FACILITY
                                       E
                                     0.16
                                    50,000
                                      3.9
                                      7.2
                                 2011 II&S
                                   $796,912
                                   $265,380
                                   $341,981
                                    $13,340
                                       F
                                     0.16
                                    50,000
                                      4.1
                                      8.0
                                   2005 EAF
                                   $767,439
                                   $264,747
                                   $338,610
                                    $7,196 
                                MEDIUM FACILITY
                                       E
                                     0.16
                                    775,000
                                      61
                                      7.2
                                 2011 II&S
                                  $4,778,920
                                  $1,598,907
                                  $2,045,443
                                   $12,197 
                                       F
                                     0.16
                                    775,000
                                      63
                                      8.0
                                   2005 EAF
                                  $4,361,224
                                  $1,589,971
                                  $1,997,701
                                    $6,575 
                                LARGE FACILITY
                                       E
                                     0.16
                                   3,450,000
                                      271
                                      7.2
                                 2011 II&S
                                  $21,929,003
                                  $6,558,810
                                  $8,598,613
                                   $13,708 
                                       F
                                     0.16
                                   3,450,000
                                      281
                                      8.0
                                   2005 EAF
                                  $19,839,154
                                  $6,514,065
                                  $8,359,718
                                    $7,390
    
6.4	Conclusions for EAF NSPS Final Rule
    
      With two approaches to the cost analysis for BSER for the EAF lb/ton PM standard using both EAF 2005 EAF A/C data and 2010 II&S A/C data and the same conclusion for BSER reached for both, there is no change in the facility-wide PM standard for PM at 0.16 lb/ton.

 7.0	OVERALL REDUCTION IN EMISSIONS WITH FACILITY-WIDE PM LIMIT AND 0/6 PERCENT MELT SHOP OPACITY STANDARD
 
      As discussed above, EAF facility control devices collect and emit slightly more PM when the melt shop has 0 percent opacity as compared to melt shops with 6 percent opacity, the current standard. However, the overall PM emissions are greatly reduced with 0 percent melt shop opacity compared to 6 percent, and to a slightly lesser extent with 0 percent during melting and refining and 6 percent during charging and tapping. This can be shown quantitatively, as follows, using a medium-sized facility as an example. 
      
The baghouses at EAF facilities with 0 percent melt shop opacity would emit 0.16 lb/ton BSER limit which translates to 43 tpy PM emissions for an average facility producing 542,500 tpy steel. Whereas in the example above in Figure 1 (method 2), the emissions from a baghouse where there is 6 percent melt shop opacity is 0.044 lb/ton, which is 12 tpy PM emissions for the average facility. This results in an additional 31 tpy (43 tpy minus 12 tpy) emitted from the baghouse at a 0 percent melt shop opacity facility. However, the PM emissions theoretically saved from being emitted with 0 percent melt shop opacity is 731 tpy, so despite the additional net 31 tpy baghouse emissions, the net savings of PM emissions overall at the facility is 700 tpy (731 tpy minus 13 tpy), presenting a clear case of prevention of PM from being emitted. For facilities achieving 0 percent during melting and refining and 6 percent during charging and tapping (i.e., 0/6 percent), the reductions are slightly lower, at 602 tpy net savings of PM emissions overall at the facility. See the Emissions Memorandum[1] for more details on these estimates.

However, because most EAF facilities likely are already achieving at or close to 0 percent melt shop opacity, the actual emission reductions with a 0 percent opacity limit are much lower. The EAF data for 30 facilities in test reports obtained in 2010 showed that the average actual melt shop opacity was 0.14 percent. Actual PM emission estimates for small, medium, and large facilities achieving 0.14 percent melt shop opacity are estimated at 5.7, 16.3, and 37.3 tpy PM, respectively, which then are equal to the emission reductions when facilities lower their emissions to 0 percent opacity. For facilities achieving 0.14 percent melt shop opacity, when these facilities lower their emissions to 0/6 percent opacity, PM emission reductions are 4.9, 14, and 32 tpy PM. See the Emissions Memorandum[1] for more details on these estimates.

 8.0	OVERALL INDUSTRY COST IMPACTS OF BSER

      The overall industry cost impacts of BSER under the EAF NSPS presented in this section include the costs for a canopy hood (if needed) to achieve 0 percent opacity during melting and refining, and 6 percent during charging and tapping; costs for PM testing with EPA Method 5 every 5 years at all the baghouses at the facility; and increased opacity costs for additional testing during charging and tapping. An estimate of the number of future new, modified, or reconstructed EAF facilities also are included in the costs estimate for the new EAF NSPS. These cost items are discussed below along with overall estimated cost impacts of the rule 10 years after proposal. 
      
      Because the lb/ton PM standard under the NSPS 40 CFR part 60, subpart AAb for new EAF was based on the highest-emitting facility in the EPA dataset, it is expected that any new facility would be able to meet the new PM standard of 0.16 lb/ton without incurring additional costs for PM control. In addition, based on information from 2010 through 2017 obtained by the EPA for 31 EAF facilities, the EPA found the average melt shop opacity to be 0.14 percent, with about half of the units in the dataset achieving 0 percent opacity. Because opacity in the baseline is already low, the EPA expects any new, modified or reconstructed facility would be able to meet the 0 percent opacity limit during melting and refining without any additional control devices beyond those that might already be required by a New Source Review program or state requirement, or with minor process changes to improve capture of exhaust flows or other process parameters, if needed. However, to evaluate BSER for melt shop roof vents, the EPA developed an upper bound estimate of potential compliance costs based upon the assumption that affected units would install a partial roof canopy above the crane rails to achieve 0 percent melt shop opacity during melting and refining. This level of opacity is compared to a baseline hypothetical facility meeting 6 percent melt shop opacity, the current standard for NSPS 40 CFR part 60, subparts AA and AAa during melting and refining, and the requirement for all phases of operation for NSPS 40 CFR part 60, subpart AAa. Therefore, the overall industry costs of the new NSPS presented in this section should be understood to be an upper bound estimate of potential compliance costs. 
      
 8.1	PM Testing Costs
      
      Under the General Provisions to 40 CFR part 60, subpart A (§60.8) and as reflected in the current two EAF NSPS (40 CFR part 60, subparts AA and AAa), facilities are required to perform a PM compliance test upon start-up of their PM control devices (baghouses) with no additional testing after initial startup unless the EAF is shut down and re-started. The one-time PM compliance test requirement was not changed for the two current EAF NSPS as part of the EAF NSPS technology review. However, for the new EAF NSPS (40 CFR part 60, subpart AAb), a PM compliance testing frequency of once every five years was added to the new NSPS rule, which is expected to coincide with testing required in a typical 5-year permit cycle. Because testing is required upon the initial startup under the general provisions of 40 CFR part 60 (§ 60.8 Performance tests). 
      
      The cost impacts per facility with a requirement for PM performance testing every 5 years reflect an estimated $26,211 per EPA Method 5 test ($2022) including recordkeeping and reporting. Amortizing over 5 years, the annual costs of this testing is $6,478 per test. Assuming 1.64 baghouses per facility, on average, based on EAF data from the existing industry, the annualized testing costs are $10,625 per facility. These EPA Method 5 costs are shown in Table 10. 
      
8.2	Increased Melt Shop Roof Vent Opacity Testing Costs

      Under new 40 CFR part 60, subpart AAb, no increased opacity compliance testing is required on baghouse exhaust, the dust handling systems, or for the melt shop roof vent during melting and refining because this opacity testing is already required to be performed daily under 40 CFR part 60, subparts AA and AAa. However, with the new requirements under 40 CFR part 60, subpart AAb for melt shop roof vent opacity 
      
     Table 10.  Costs and Parameters for New Facilities under Subpart AAb.
                                Cost Parameter
                                 Facility Size

                                     Small
                                    Medium
                                     Large
Annual costs for canopy hood[1]
                                    $85,716
                                  $1,135,153
                                  $5,654,963
Cost per EPA Method 5 Test[2]
                                   $26,211 
                                   $26,211 
                                   $26,211 
Annualized baghouse testing cost over 5 years[3]
                                   $10,625 
                                   $10,625 
                                    $4,514 
Costs for Increased Opacity Testing[2,4]
                                   $95,104 
                                   $95,104 
                                   $95,104 
Total facility costs for canopy and testing[2]
                                   $191,445 
                                  $1,240,882 
                                  $5,754,581 
[1] See Table 2 for details of the annualized canopy hood costs.
[2] Testing costs include recordkeeping and reporting.
[3] Amortized over 5 years and using an estimate of 1.64 baghouses per facility, on average, and using a capital recovery factor of 0.24716, based on an annual interest rate of 7.5 percent (from Federal Reserve Economic Data (FRED). Bank Prime Loan Rate Changes: Historical Dates of Changes and Rates. Available at:  https://fred.stlouisfed.org/series/PRIME. Accessed 01/2023.
[4] Increased opacity testing during charging and tapping in addition to melting&refining. Estimated 2 hours additional per day, 35 days per year. Labor rate of $130/hour from Bureau of Labor Statistics. Occupational Employment and Wages, September 2022. Table 2. Employer Costs for Employee Compensation for Civilian Workers by Occupational and Industry Group. Professional and Related. Accessed 01/27/23.  https://www.bls.gov/news.release/ecec.t02.htm Increased by 110 percent by BLS to account for the benefit packages available to those employed by private industry.

at 0 percent opacity during melting and refining (one phase of operation) and 6 percent opacity during charging and tapping (two phases of operation), an increase in opacity testing would be needed to test during charging and during tapping. 

      The daily opacity testing during melting and refining is expected to take 2 to 3 hours for the melt shop roof vent including recordkeeping and reporting. The additional time to test during charging and tapping is estimated to take 4 hours total including recordkeeping and reporting, with some time efficiency due to performing the opacity tests in the sequence of melting&refining, tapping, and charging; or tapping, charging, and melting&refining, so that the minimum amount of time is spent waiting for the next operational sequence to occur. Therefore, an additional two hours of opacity testing per day are assumed for the opacity testing required by 40 CFR part 60, subpart AAb for melt shop roof vent opacity at 0 percent opacity during melting and refining, and 6 percent opacity during charging and tapping (including recordkeeping and reporting). Using a cost of $130.28 per hour per worker from Bureau of Labor Statistics, this translates to an additional $260.56 per day for the two additional hours to test during charging and tapping for one facility and $95,104 per year, assuming 365 days per year. These costs also are shown in Table 10.

 8.3	Capture Equipment Costs for New, Modified, or Reconstructed facilities
      
	The annualized costs for adding a partial roof canopy above the crane rails to ensure 0/6 percent melt shop opacity were found to be $86,000, $1,100,000, and $5,700,000 per year per facility (rounded) for small, medium, and large sized facilities, respectively ($2022), as described above in Section 5.3 and shown in Table 10.

 8.4	Estimate of New Facilities After Proposal

      An overall total of nine new facilities are estimated to start up in the 10 years after proposal (2022 - 2032). This translates to 0.9 facilities per year, with the following distribution per year starting in the first full year after proposal (2023), given publication of the proposal in 2022: 0.3 small facilities per year; 0.4 medium facilities per year; 0.2 large facilities per year, for a total of 3 small, 4 medium, and 2 large facilities at the end of 10 years (2033). This distribution of new facilities are shown in Table 11, Sections A&B, where Section A shows the annul new facilities and Section B shows the cumulative facilities. 

 8.5	Overall Industry Costs under BSER
      
      The upper bound estimate of the total industry costs due to BSER reflected by the new EAF NSPS at 40 CFR part 60, subpart AAb, over the 10 years after proposal also are shown in Table 11. These costs include the cost for PM testing of baghouses for compliance tests (Section C) starting in the sixth year after proposal (2028), where PM testing costs are amortized over 5 years for an annualized cost of $10,625 per facility per year $2022, assuming 1.64 baghouses per facility, on average. Using the rate of new facilities described above, at 0.9 total facilities per year, the total annual EPA Method 5 testing costs are $9,562 per year for all three sizes of facilities, and $47,811 total cumulative costs ($2022) at the end of 10 years after proposal (2032), where PM testing costs do not start to be incurred until 2028.
      
      Also including in Table 11 (Section C) are the annual costs for the additional opacity testing during charging and tapping starting in the first year after proposal. Annual costs are $85,594 using the rate of new facilities described above, at 0.9 total facilities per year for all three sizes of facilities with $855,940 total cumulative costs ($2022) at the end of 10 years after proposal (2032) due to increased opacity testing. The total of both tests, PM and opacity, 10 years after proposal (2032) is $903,751. Annual costs vary due to the offset of testing for PM but stabilize at $105,729 per year at 5 years after proposal.
      
      The cumulative annualized cost impacts per year due to installation of capture equipment (canopy hood) to achieve 0/6 percent melt shop opacity in the 10 years after proposal of new subpart 40 CFR part 60, subpart AAb based on the estimated nine new facilities also are shown in Table 11, Section D. Annualized costs per year are $1,789,743 based on the distribution of 0.9 new facilities per year and total costs after 10 years is $16,107,687.
      
      Total cumulative industry costs in the 10 years after proposal (2032) are $17,011,437 for PM and opacity testing, and canopy costs the new 40 CFR part 60, subpart AAb, based on an estimate of 9 new facilities by 2032, as shown in Table 11, Section E. As previously mentioned, these costs, which include adding canopy hoods at a cumulative cost after 10 years of $16,107,687, should be viewed as an upper bound of the potential compliance cost impacts of achieving 0/6 percent opacity from melt shop roof vents at the projected new, modified and reconstructed facilities because many facilities will be able to achieve 0 percent opacity without adding a canopy hood, as was seen in the EAF test data from 2010 and earlier. Appendix G shows all the calculations used to determine the overall industry costs under BSER over 10 years in the attached Excel file.

Table 11.  Estimated Industry Costs for New EAF NSPS in 10 Years After Proposal (40 CFR Part 60, Subpart AAb).
                              Year After Proposal
                                     2023
                                     2024
                                     2025
                                     2026
                                     2027
                                     2028
                                     2029
                                     2030
                                     2031
                                     2032
A. Assumed New Facilities in a Given Year After Proposal[1]
                                     Small
                                                                           0.30
                                                                           0.30
                                                                           0.30
                                                                           0.30
                                                                           0.30
                                                                           0.30
                                                                           0.30
                                                                           0.30
                                                                           0.30
                                                                           0.30
                                    Medium
                                                                           0.40
                                                                           0.40
                                                                           0.40
                                                                           0.40
                                                                           0.40
                                                                           0.40
                                                                           0.40
                                                                           0.40
                                                                           0.40
                                                                           0.40
                                     Large
                                                                           0.20
                                                                           0.20
                                                                           0.20
                                                                           0.20
                                                                           0.20
                                                                           0.20
                                                                           0.20
                                                                           0.20
                                                                           0.20
                                                                           0.20
                                     Total
                                                                           0.90
                                                                           0.90
                                                                           0.90
                                                                           0.90
                                                                           0.90
                                                                           0.90
                                                                           0.90
                                                                           0.90
                                                                           0.90
                                                                           0.90
B. Cumulative Assumed New Facilities in a Given Year After Proposal[1]
                                     Small
                                                                           0.30
                                                                           0.60
                                                                           0.90
                                                                           1.20
                                                                           1.50
                                                                           1.80
                                                                           2.10
                                                                           2.40
                                                                           2.70
                                                                           3.00
                                    Medium
                                                                           0.40
                                                                           0.80
                                                                           1.20
                                                                           1.60
                                                                           2.00
                                                                           2.40
                                                                           2.80
                                                                           3.20
                                                                           3.60
                                                                           4.00
                                     Large
                                                                           0.20
                                                                           0.40
                                                                           0.60
                                                                           0.80
                                                                           1.00
                                                                           1.20
                                                                           1.40
                                                                           1.60
                                                                           1.80
                                                                           2.00
                                     Total
                                                                           0.90
                                                                           1.80
                                                                           2.70
                                                                           3.60
                                                                           4.50
                                                                           5.40
                                                                           6.30
                                                                           7.20
                                                                           8.10
                                                                           9.00
C. Cumulative Testing Costs for Assumed New Facilities per Year where Testing Starts for Opacity in Year 1 and PM Testing Starts in Year 6 (2028)[2] 
                                     Small
                                    $28,531
                                    $57,063
                                    $85,594
                                   $114,125
                                   $142,657
                                   $174,375
                                   $206,094
                                   $237,813
                                   $269,532
                                   $301,250
                                    Medium
                                    $38,042
                                    $76,084
                                   $114,125
                                   $152,167
                                   $190,209
                                   $232,500
                                   $274,792
                                   $317,084
                                   $359,375
                                   $401,667
                                     Large
                                    $19,021
                                    $38,042
                                    $57,063
                                    $76,084
                                    $95,104
                                   $116,250
                                   $137,396
                                   $158,542
                                   $179,688
                                   $200,834
                                     Total
                                    $85,594
                                   $171,188
                                   $256,782
                                   $342,376
                                   $427,970
                                   $523,126
                                   $618,282
                                   $713,438
                                   $808,595
                                   $903,751
       D. Cumulative Canopy Costs for Assumed New Facilities per Year[3]
                                     Small
                                                                        $25,715
                                                                        $51,430
                                                                        $77,145
                                                                       $102,859
                                                                       $128,574
                                                                       $154,289
                                                                       $180,004
                                                                       $205,719
                                                                       $231,434
                                                                       $257,148
                                    Medium
                                                                       $454,061
                                                                       $908,123
                                                                     $1,362,184
                                                                     $1,816,245
                                                                     $2,270,307
                                                                     $2,724,368
                                                                     $3,178,429
                                                                     $3,632,490
                                                                     $4,086,552
                                                                     $4,540,613
                                     Large
                                                                     $1,130,993
                                                                     $2,261,985
                                                                     $3,392,978
                                                                     $4,523,970
                                                                     $5,654,963
                                                                     $6,785,955
                                                                     $7,916,948
                                                                     $9,047,940
                                                                    $10,178,933
                                                                    $11,309,925
                                     Total
                                                                     $1,610,769
                                                                     $3,221,537
                                                                     $4,832,306
                                                                     $6,443,075
                                                                     $8,053,843
                                                                     $9,664,612
                                                                    $11,275,381
                                                                    $12,886,149
                                                                    $14,496,918
                                                                    $16,107,687
E. Total Cumulative Testing and Canopy Hood Costs per Year for Assumed New Facilities
                                     Small
                                                                        $54,246
                                                                       $108,492
                                                                       $162,738
                                                                       $216,985
                                                                       $271,231
                                                                       $328,664
                                                                       $386,098
                                                                       $443,532
                                                                       $500,965
                                                                       $558,399
                                    Medium
                                                                       $492,103
                                                                       $984,206
                                                                     $1,476,309
                                                                     $1,968,412
                                                                     $2,460,515
                                                                     $2,956,868
                                                                     $3,453,221
                                                                     $3,949,574
                                                                     $4,445,927
                                                                     $4,942,280
                                     Large
                                                                     $1,150,013
                                                                     $2,300,027
                                                                     $3,450,040
                                                                     $4,600,054
                                                                     $5,750,067
                                                                     $6,902,205
                                                                     $8,054,344
                                                                     $9,206,482
                                                                    $10,358,620
                                                                    $11,510,759
Overall Total
                                  $1,696,363
                                  $3,392,725
                                  $5,089,088
                                  $6,785,450
                                  $8,481,813
                                  $10,187,738
                                  $11,893,663
                                  $13,599,588
                                  $15,305,513
                                  $17,011,437
[1] An overall total of nine new facilities are estimated to start up in the 10 years after proposal (2022 - 2032). This translates to 0.9 facilities per year, for a total of 3 small, 4 medium, and 2 large facilities at the end of 10 years.
[2] Under the General Provisions to 40 CFR part 60, subpart A (§60.8), facilities are required to perform a PM compliance test upon start-up of the facility. For the new EAF NSPS (40 CFR part 60, subpart AAb), a compliance testing frequency of once every five years is proposed. Therefore, the costs due to PM testing under 40 CFR part 60, subpart AAb would not begin until 5 years after proposal, at the earliest.
[3] These costs should be viewed as an upper bound estimate because most facilities are expected to be able to achieve 0 percent opacity during melting and refining without a canopy hood, as shown in the EAF test data from 2010. In addition, no control costs were estimated to achieve the lb/ton PM total facility control device limit because the facilities in the EAF data already were achieving this level in 2010.

                                     APPENDIX A
                                       
   Cost Details for Small and Large Facilities for Addition of a Canopy Hood
                         and Excel Files for All sizes
                                       
                     [2 Pgs pdf plus Excel files for ALL]
                             Pg 2 of 2 Appendix A
                                       
                                       
                                     APPENDIX B
                                       
         Baghouse Cost Details for Small and Large New EAF Facilities 
                   for Determining lb/ton Vales for Model E
                            Using II&S A/C Data
                                       
                        [pdfs only -3 pages each size] 
 
                                       
                                   APPENDIX C
                                       
     Baghouse Cost Details for Determining Facility PM BSER lb/ton Values 
             for Models A- E Using II&S A/C Data  -  All Sizes
                                       
                              [Excel files only] 
                                       
                                     APPENDIX D
      
            Matching of 2005 EAF Facility Data To 2010 EAF Facility Data
                    For Purposes of Using The 2005 EAF A/C Ratios
                                          
                                  [excel file only]
                                    APPENDIX E
                                         
         Baghouse Cost Details for Small and Large New EAF Facilities 
           for Determining Facility PM BSER lb/ton Vales for Model E
                              Using EAF A/C Data
                                       
                        [pdfs only -3 pages each size] 
                                         
                                         
    
    
                                     APPENDIX F
                                         
     Baghouse Cost Details for Determining Facility PM BSER lb/ton Values 
                               for Models A- F 
                       Using EAF A/C Data  -  All sizes
                                       
                               [Excel(TM) file only].
                                     APPENDIX G
                                          
      Calculations to Determine Overall Industry Costs Under BSER Over 10 Years
                                          
                             [attached Excel file only]