Appendix 1 Emissions Inventory Support Memoranda

# E C 

# / R Incorporated Providing Environmental Technical Support Since 1989

MEMORANDUM

DATE: October 1 4

, 201 1

SUBJECT: Modeling Emission Estimation Methodologies for Ferroalloy Facilities

FROM: Bradley Nelson, EC/R, Inc.

TO: Conrad Chin , EPA OAQPS/SPPD/ MMG

1.0 PURPOSE

The purpose of this memorandum is to present a summary of the test data and to document the methodologies used to estimate pollutant emissions from processes at two ferroalloy facilities. The emission estimates developed in this task were used to create a database that will be used to model risks as part of the “risk and technology” (RTR) review for the Ferroalloy Production
source category.

2.0 BACKGROUND

Under the "technology revi ew" provision of CAA section 112, EPA is required to review maximum achievable control technology (MACT) standards and to revise them "as necessary (taking into account developments in practices, processes and control technologies)" no less frequently than every 8 years. Under the "residual risk" provision of the CAA section 112, EPA must evaluate the MACT standards within 8 years after promulgation and promulgate standards if required to provide an ample margin of safety to protect public health or preven t an adverse
environmental effect. EPA has combined the two review activities into the RTR reviews for the Ferroalloys Production source category.

The National Emission Standards for Hazardous Air Pollutants ( NESHAP ) for Ferromanganese
and Silicomanganese Production applies to new and existing ferroalloy production facilities that manufacture ferromanganese and /or silicomanganese and are major sources of HAP emissions or

are co

- located at major sources of HAP emissions. The NESHAP establish ed emissions
standards for the following HAP emission sources at a ferroalloy production facility :

Submerged arc furnaces Metal oxygen refining (MOR) process2

Crushing and screening operations Fugitive dust sources.

The current rule contains emission stan dards that limit particulate matter emissions from existing
and new or reconstructed emission sources. The limits for the submerged arc furnaces depend on
the product produced and furnace design. The rule also sets limits for the air pollution control
de vices associated w ith the MOR process and crushing and screening operations. Currently, there are two facilities in the U.S. that are affected by this rule; Eramet Marietta, Inc. and Felman
Production Inc. A summary of the HAP emission sources for each facility is provided in Section
3.0.

To estimate the facility HAP emissions, a n Information Collection Request (ICR) under Section 114 of the Clean Air Act (CAA) was sent to each of the ferroalloy production facilities to gather source testing in formation from the electric arc furnace (EAF) process (which includes emissions that occur during charging, melting, and tapping ) and the product crushing process.
The HAP source test data that w ere collected from the control device outlet for each furna ce include: metal HAP (arsenic, chromium, lead, manganese, mercury, and nickel ) , hydrochloric
acid

, hydrofluoric acid, hexavalent chrom ium , formaldehyde, polycyclic aromatic hydrocarbons (PAH), p olychlorinated b iphenyls (PCB), and c hlorodibenzodioxin s and chlorodibenzofurans (CDD/CDF) . In addition, non

- HAP emissions were measured from the EAF control device
outlet for: carbon monoxide (CO) and particulate matter (PM)

. Total p hosphorus was also measured for the ICR using EPA Method 29, however this method does not distinguish between white phosphorus (which is a non

- HAP) and red phosphorus (which is a HAP). Due to the uncertainty of the percentage of red phosphorus in the total phosphorus test results, it was concluded that phosphorus would not be incorpor ated in the emissions used for modeling. The source test data collected for the crushing and sizing operations include: particulate matter (PM), metal HAP (arsenic, chromium, lead, manganese, mercury, and nickel), and phosphorus. Again, total phosphorus was measured using Method 29 and therefore not included in the emissions us3ed for modeling. In addition to the source tests , a sample of coal was analyzed for sulfur, proximate analysis, and ultimate analysis.

3.0 FERROALLOY FACILITY SUMMARY

The follo wing section describes the HAP emission sources for the Eramet Marietta, Inc. and Felman Production Inc. ferroalloy production facilities.

Eramet Marietta Inc.

The Eramet facility is located in Marietta, Ohio and produces ferromanganese (FeMn) and silicomanganese (SiMn) using two electric arc furnaces (EAF) identified as EAF 1 and EAF 12. The EAF 1 furnace is a submerged arc furnace rated at 30 megawatts (MW) and is equipped with3

a negative pressure fabric filter to control particulate emissions. The fabric filter controls emissions from the furnace and was installed in 2011 to replace a wet scrubber system. A separate fabric filter system is used to control charging, melting, and tapping emissions from this
furnace. The EAF 12 furnace is a subme rged arc furnace rated at 22 MW and is equipped with two wet scrubbers to control primary and secondary emissions from the furnace and tapping. The scrubbers operate simultaneously and exhaust through a single stack. The facility has a third furnace, EAF 18, which is permitted, but is considered to be inoperable until extensive repair can be made to the furnace. Therefore, EAF 18 was not considered an emission source and was not included in the emission inventory for Eramet. Other HAP emission sources i nclude: a MOR process controlled by a positive

- pressure baghouse

, and a crushing a nd sizing system (C2P) that is controlled by three negative pressure baghouse s . There are also fugitive emissions that are emitted from each of these emissions sources, in a ddition to the fugitive emissions from the casting operations for EAF 1, EAF 12, and the MOR process.

The emission sources used for modeling emissions from the Eramet facility were created from the plant configuration discussed above. For the EAFs and t he MOR process, emission points were created for the control device outlet emissions, as well as fugitive emissions from the two
EAF s and the one MOR process . For the crushing system, emission points were created for each of the three baghouse outlets and one emission point for fugitive emissions from the crushing operation. Emission points were also created for casting fugitive emissions from each of the two
EAFs and the one MOR process.

Felman Production Inc.

The Felman facility is located in New Haven, West Virginia and produces SiMn using three electric arc furnaces identified as Furnace 2, Furnace 5, and Furnace 7. Furnaces 2, 5, and 7 are open EAFs rated at 32, 20, and 20 MW respectively. Each of these furnaces is e quipped with a positive

- pressure baghouse to limit emissions of PM and metal HAP from the furnace. The facility has a crushing and sizing system controlled using a negative pressure baghouse. There are also fugitive emissions that are emitted from each o f these emissions sources, in addition to the fugitive emissions from the casting operations for Furnace 2, Furnace 5, and Furnace 7.

The Felman facility emission points used for modeling emissions were created from the plant configuration discussed above. Emission points were created for the control device outlet
emissions for each of the three EAFs, as well as a fugitive emission point for each of the three EAFs. For the crushing system s , emission points were created for the crusher baghouse outlet and fugitive emissions from the crushing units . Emission points were also created for casting fugitive emissions from each of the three EAFs.4

4 .0 POLLUTANT E MISSION DATA

The following section describes the test data that was collected from each of the ferroalloy
facilities. This section will describe the test methods that were used to measure emissions for each pollutant from the processes that we re tested. A summary of the type of pollutant data collected in the ICR is presented in Table 4

- 1.

Particulate Matter

Test data for PM w ere received from each of the ferroalloy facilities for one of the electric arc furnaces (EAF) and from one of the product crushing operation s

. Eramet provided PM results
from the scrubber outlet for EAF 12 and from Baghouse #1 for the crushing and sizing operation using EPA Method 5 . Felman provided PM test results from the Furnace 2 baghouse and the baghouse contro lling emissions from the crushing and sizing operation using EPA Method 5D and EPA method 5 respectively.

Metal HAP and Phosphorus

Test data for metal HAP ( arsenic, chromium, lead, manganese, mercury, and nickel ) and phosphorus were collected from the scrubber outlet for EAF 12 and from Baghouse #1 for the product crushing operation for Eramet . The metal HAP data for Felman were obtained from the Furnace 2 baghouse and the baghouse controlling emissions from the crushing and sizing operation

. The furnace and product crushing test data were collected using EPA Method 29.

Hexavalent Chromium

Hexavalent chromium data were collected from EAF 12 and Furnace 2 for the Felman and
Eramet facilities respectively, using EPA Method 316. No hexavalent chrom ium data were requested for the product crushing operations.

HCl/HF

Test data for hydrochloric acid (HCl) and hydrofluoric acid (HF) were collected from the
scrubber outlet of EAF 12 at Eramet and the baghouse outlet of Furnace 2 at Felman using EPA Method 26A. The product crushing processes were not tested for HCl or HF.

Formald e hyde

Testing for formaldehyde was performed on scrubber outlet of EAF 12 at Eramet and the baghouse outlet of Furnace 2 at Felman using EPA Method 316. Formald ehyde testing was not performed on any of the product crushing processes.5 Table 4

- 1. Summary of Pollutant Data Collected in the ICR

Facility Process Particulate Matter Metal HAP & Phosphorus Cr+6 HC l / HF Formaldehyde PAH, PCB, CDD/CDF

Method 5D Method 5 Method 29 Method 316 Method 26A Method 316 Method 23 FF Dust

Felman EAF      

Crusher  

Eramet EAF      

Crusher  6

PAH/PCB/

CDD/CDF

Data for, polychlorinated biphenyls (PCB), c hlorinated dibenzo

- p

- dioxins (CDD), and
chlorinated dibenzo

- p

- furans (CDF) were collected and analyzed using EPA Method 23 from the scrubber outlet of EAF 12 at the Eramet facility. The PAH emissions from the scrubber outlet of EAF 12 were measured using Method 0010. The PAH, PCB, and CDD/CDF data for Furnace 2 at Felman facility were obtained from the fabric filter dust using SW 846 Method 3500C/3600, and analyzed using SW

- 846 Method 8270D for PAH and PCBs and SW 846

- 8280B for CDD/CDF. The analysis results were presented for each individual congener for each of the CDD/CDF, PCB, and PCB groups. No PAH, PCB, or CDD/CDF emissions data were collected for the product crushing units.

Other Data

In addition to the pollutant data described above, analyses of the coal/coke and furnace exhaust
concentrations of oxygen (O 2 ), carbon dioxide (CO 2 ), and carbon monoxide (CO) were
measured. The O 2 and CO 2 concentrations were measured using EPA Method 3A, and the CO concentration was measured using EPA Method 10. For coal/coke, the samples were analyzed using ASTM D31 77

- 02 for sulfur, D3172

- 07 for proximate analysis, and D3176

- 09 for ultimate analysis.

5 .0 METHODOLOGY FOR DEVELOPING EMISSION ESTIMATES

The test data provided in the ICR was used to develop a modeling emissions database for determining if there are risk s associated with the HAP emissions from the ferroalloy facilities. The analytical results provided in the ICR were used to calculate emissions for each of the pollutants. For analytical results reported below the detection limit, one half of the method
detection limit was used to estimate the results from that test run. This section describes the methodology used to estimate annual emissions from all of the sources at each of the ferroalloy
facilities.

EAF Emissions

The EAF annual emissions for all pollutants were estimated using the information provided in the facility’s ICR submittal. The annual emissions for the tested EAF units were calculated using the pounds per hour test data provided in the facility test repo rt and converting to annual emissions assuming 8760 hours of operation per year. For the EAF units that were not tested, the annual emissions were estimated using PM test data from previous test data submittals and using a pollutant

- to

- PM ratio to calcula te the other pollutants. A more detailed description for7

each facility is provided in the paragraphs below. A table of the PM ratios used for estimating emissions from EAFs that were not tested is provided in Table 5

- 1.

The Eramet facility provided ICR test data for EAF 12 which w ere used to calculate pollutant
emissions from the scrubber outlet for all of the pollutants . Eramet also provided a supplemental test report for the newly installed fabric filter for EAF 1 for the pollutants: PM, manganese, HC l, and HF. To estimate the emissions of the pollutants not tested in the supplemental test report , the PM emission rate was multiplied by a n EAF 12 pollutant

- to

- PM ratio for the specified pollutant. For an example, the arsenic emission rate was estimated using the following equation:

where;

Arsenic EAF 1 = Estimated arsenic emissions from EAF 12 in tons per year,

PM EAF 1 = PM test results in supplemental test report in tons per year,

Arsenic EAF 12 = Arsenic test results from ICR submittal in tons per year, and

PM EAF 12 = PM test results from ICR submittal in tons per year.

This same equation was used for the other pollutants that were not tested in the supplemental test report, substi tuting the pollutant to be estimated for arsenic in the equation. A summary of the pollutant emissions for each of the EAFs is presented in Table 5

- 2.8

Table 5

- 1. Summary of PM Ratios Used to Estimate Emissions from EAFs

Facility EAF Unit PM Emissions (Tons/yr) PM Ratio Test Date(s)

Eramet EAF 12 24.7

--- 8/17

- 18/2010

EAF 1 49.1 1.99 5/19/2009

Felman Furnace 2 20.4

--- 7/9

- 10/2010

Furnace 5 15.5 0.763 11/18 /200 9

Furnace 7 24.5 1.20 11/17/2009

The Felman facility submitted ICR test data for Furnace 2 which were used to calculate the pollutant emissions from this EAF. The PM, metals, phosphorus, HCl, and HF annual emissions were calculated using the emissions data from the ICR. The individual species PAH , PCB, and CDD/CDF emissions were estimated using the fabric filter dust analysis. This was done by estimating the uncontrolled fabric filter dust concentration and multiplying that by the uncontrolled PM emissions. The resulting value was then multiplied by the PAH , PCB, and CDD/CDF control efficiency to estimate the emission from the fabric filter. The equation below
shows the calculation.

where;

PAH, PCB, CDD, CDF Emissions = Estimated PAH, PCB, CDD, or CDF emissions in tons per

year,

Conc = Concentration of PAH, PCB, CDD, CDF species in the fabric filter dust in ng /Kg,

CE PAH,CDD,CDF = Estimated removal efficiency of PAH, PCB, CDD, or CDF using a fabric filter (assumed to be 50%),

PM tons/yr = Calculated PM emissions from Furnace 2 in tons per year, and

CE P M = Estimated removal efficiency of PM using a fabric filter (assumed to be 99%).9

The other values in the equation are constants to convert the emissions to tons per year. A summary of the assumed fabric filter control efficiencies for these pollutants is presented in
Table 5

- 3. This equation was used to estimate e missions for each of the congeners for PAH, PCB, CDD, and CDF.

The emissions from Felman Furnaces 5 and 7 were calculated using the pollutant

- to

- PM ratio from Furnace 2 using the same methodology that was used above for Eramet. Compliance test data rep orted in November 2009 were used for the PM emissions for Furnaces 5 and 7. A summary of the pollutant emissions for each of the EAFs is presented in Table 5

- 2

.

EAF Fugitive Emissions

The EAF fugitive emissions were estimated by calculating the uncontrolled pollutant emissions rate from the furnace and estimating the percentage of the uncontrolled pollutant emissions that is captured from the EAF. The difference between the uncontrolled pollutant emission rate and the estimated captured pollutan t emissions were assumed to be the EAF fugitive emissions. The uncontrolled pollutant emissions rate was calculated using the EAF annual emissions for each pollutant and the assumed control efficiency for that pollutant. A summary of the assumed fabric
f ilter and scrubber control efficiencies for the pollutants is presented in Table 5

- 3 . It was assumed that 92 percent of the uncontrolled emissions were generated from the EAF and 8 percent of the uncontrolled emissions occur during tapping of the EAF. Th e capture system from the EAF was assumed to capture 95 percent of the uncontrolled pollutant emissions generated by the furnace and 85 percent of the EAF tapping emissions.10 Table 5

- 2 . Summary of Facility Process Annual Emissions for the F erroalloy Industry

Note:
The red shaded areas indicate annual emissions based on some runs that were measured below the detection limit.
The blue shaded areas indicate annual emissions based on all runs measured below the detection limit. The grey shaded areas indicate annual emissions were not estimated for these pollutants. The PAH, CDD/CDF, and PCB emissions are the sum of the mas s of all of the individual congeners.11

An example of the fugitive emission calculation is presented below for arsenic.

where,

Aresenic fugitive = Estimated fugitive emissions from the EAF in tons per year,

As EAF = Arsenic emissions for the EAF in tons per year,

CE = Control efficiency of the furnace control device,

0.92 = Percentage of uncontrolled emissions from the EAF,

Capt EAF = Assumed capture efficiency for the furnace emissions, and

0.08 = Percentage of uncontrolled emissions from tapping of the EAF.

This approach was used to calculate the individual pollutant fugitive emissions from each of the EAFs for the Eramet and Felman facilities. A summary of the annual fugitive emissions fr om each of the EAFs is presented in Table 5

- 2

.12

Table 5

- 3 . Control Efficiencies used to Estimate EAF Exhaust and Fugitive Emissions

Pollutant(s) Scrubber Control Efficiency (%) Fabric Filter

Control Efficiency (%)

Particulate Matter 95 99

Metal HAP 95 99

Hexavalent Chromium 95 99

Mercury 15 15

Hydrochloric Acid/Hydrofluoric Acid 90 0

Formaldehyde 90 0

PAH, PCB, CDD/CDF 50 50

Casting Fugitive Emissions

Particulate matter emissions from casting were calculated using a PM emission factor of 2.4 pounds of fugitive PM emissions per ton of ferroalloy cast. 1 Th is emission factor w as used to estimate the fugitive particulate matter emissions from casting operations. The casting emissions for the metal pollutants were estimated by developing a pollutant

- to

- PM profile for each of the EAF pollutants and multiplying that profile by the estimated casting fugitive PM emission rate.

where;

Arsenic Cast = Estimated arsenic emissions from casting in tons per year,

PM Cast = Estimated PM emissions from casting in tons per year,

Arsenic EAF = Arsenic emissions from the associated EAF in tons per year, and

PM EAF = PM emissions from the associated EA F in tons per year.

A summary of the casting emissions are shown in Table 5

- 2

.

1 Ohio Environmental Protection Agency, Reasonably Available Control Measures for Fugitive Dust Sources

, Section 2.14 Ferroalloys Production, September 1980

.13

Product Crushing Operations Emissions

The product crushing emissions were calculated using the test data provided in the ICR for both
facilities . The hourly emission rate ca lculated in the test report was multiplied by 8760 hours per year to estimate the annual emission from the product crusher. For crushers that were not tested,
the annual emission rate s were assumed to be the same as the crusher that was tested. A summary of the annual product crusher emissions is presented in Table 5

- 2

.

Product Crushing Operations Fugitive Emissions

The annual fugitive emission s from the product crushing operations were estimated by calculating the uncontrolled pollutant emission rate s using the pollutant control efficiencies and assuming only 98 percent of these emissions are captured. The un

- captured pollutant emissions were assumed to be fugitive. A summary of the annual fugitive emissions from the product crushing operations is
sh own in Table 5

- 2

.

Control Efficiency Sensitivity

The control efficiencies in Table 5

- 3 used to estimate fugitive emissions are based on the expected emission reduction from the control technology. Historical performance shows that PM and metal
HAP emissi ons are reduced by 99 percent when routed to a fabric filter control device. However, the fabric filter control effectiveness can vary slightly from facility to facility. The effect of this variation has a large effect on the calculation of the fugitive emissions, because of the material balance approach used to estimate fugitive emissions. Therefore, a sensitivity analysis was performed to determine the effect of the fabric filter control efficiency has on the particulate emissions. The sensitivity ana lysis was performed using 99, 98, and 97 percent control efficiency for the fabric filter using PM as the pollutant. A summary of the PM results for each of the ferroalloy facilities is presented in Table 5

- 4

. As the table shows, the average difference f or fugitive emis sion was 28.4 percent when going from 99 to 98 percent control efficiency. The average difference between the fugitive emissions for the 99 to 97 percent control efficiency was
37.9 percent. The percent difference between the fugitive PM emissions ranged from 1 3 .3 percent
for the 99 to 98 control effectiveness to 58.0 percent for the 99 to 97 percent con trol effectiveness.14

Table 5

- 4 Summary of Sensitivity Analysis for Estimating Fugitive Emissions

6.0 MODELING DATABASE

The modeling database was assembled using the annual pollutant emissions calculated for each process at the ferroalloy facilit ies . As shown in Table 5

- 1 , some of the pollutant emissions were based on one or more analytical results that were reported below the detection limit. For these analytical results, one half of the detection limit was used to estimate the pollutant concentration. The run results were then averaged and the average concentration was used to calculate the pollutant emission s. After the d atabase was assembled, a peer review of the pollutant emissions was conducted to determine if the emissions were representative of the ferroalloy facilities. The
review raised questions regarding the determination of pollutant emissions from analytical results that were reported below the detection limit , and the calculation of emission rates from baghouse
dust data

.

Modeling Emissions QA/QC

A review of the emissions showed that most of the metal HAP emissions were calculated from test
data that w ere measured above the detection limit . The exceptions were lead and chromium from the Eramet facility, and mercury from both the Eramet and Felman facilities. In the case of lead at the Eramet facility, only the back half samples (impinger content s and rin se) reported results below
the detection limit. The majority of the total measured concentrations for lead were found in the front half sample s (filter and probe rinse) for each of the test s

. Therefore, the results of the test data
for lead were consider ed valid and were modeled for EAF emission points. The chromium concentration results for the crusher outlet were also reported below the detection limit for one of the back half samples. Again the majority of the chromium concentrations were reported fr om the front half samples, and were determined to be valid test results.

Mercury emissions from the ferroalloy process will include particle

- bound mercury, elemental mercury, and oxidized mercury. Particle

- bound mercury is the mercury that has condensed onto particulate matter. Elemental mercury (Hg 0 ) and oxidized mercury (Hg 2 2+ , Hg 2+ ) comprise the

vapor

- phase mercury. Particle

- bound, elemental, and oxidized mercury combined make up total15

mercury emissions. Particle

- bound mercury emissions from EAFs make up a small percentage of the total mercury emissions , because much of the particulate has been captured in the particulate
control device

. The mercury emissions for Eramet and Felman were calculated from analytical
results that were a mixture of det ected and non

- detected fractions, which is fairly common in Hg results from Method 29. The test method divides the sample into five fractions which include: Fraction 1B (rinse of front half glassware), Fraction 2B (rinse of back half acidic peroxide impin gers), Fraction 3A (rinse of empty impinger), and fractions 3B and 3C (contents of acidic permanganate impingers). The Method 29 sampling is designed to measure total mercury by capturing particulate mercury in Fraction 1B, and vapor phase mercury in Frac tions 2B, 3A, 3B and 3C. Mercury was reported above the detection limit in all of the Fraction 3C samples, and all but one of the Fraction 2B samples from the test data submitted by the facilities, which indicate the presence of oxidized and elemental mer cury in the gas stream. Therefore, the mercury results were determined to be significant and included in the modeling database.

A review of the HCl and HF emissions data found that 50 percent of the analytical data for the HCl
test runs were measured bel ow the detection limit, and 100 percent of the analytical data for the HF
test runs were measured below the detection limit. The modeling emissions for HCl and HF were calculated by using the analytical results for test runs reported above the detection l imit and one half of the detection limit for the test runs that were reported below the detection limit. [Note that after the modeling was concluded, a decision was made to exclude the HF test and modeling results from regulatory action because of the unc ertainty of the HF test results.]

The CDD/CDF, PCB, and PAH concentrations for the two facilities were measured using different test methods. Eramet used Method 23 to measure the CDD/CDF and PCB concentrations, and
Method 0010 to measure the PAH concentr ations from the outlet of the control device. The outlet
emissions from Eramet were calculated by multiplying the exhaust gas concentration and the exhaust gas flow rate. The Felman CDD/CDF, PCB, and PAH concentrations were obtained from
the fabric filte r dust using SW 846 Method 3500C/3600, and analyzed using SW

- 846 Method
8270D for PAH and PCBs and SW 846

- 8280B for CDD/CDF. The analysis results were presented for each individual congener for each of the CDD/CDF, PCB, and PCB groups. The outlet
emissio ns from Felman were calculated using a material balance methodology that assumes the control efficiency of the fabric filter to estimate the emissions. Because these concentrations were
measured using different test methods , an analysis of the CDD/CDF, PCB and PAH test results w as conducted to determine the effect of the analytical results reported below the detection limit on the
emissions.

Tables 6

- 1, 6

- 2, and 6

- 3 present a summary of the CDD/CDF, P CB , and P AH test results respectively and the mas s percentages of these values th a t were reported below the detection limit. As the tables show, the percentage of annual emissions that are based on analytical results reported
below the detection limit for Eramet was 100 percent for the CDD/CDF emissions

, 50.7 percent for16

the PCB emissions, and 0 percent for the PAH emissions. For Felman, the estimated CDD/CDF emissions are based on 5.1 percent non

- detects, 18.7 percent non

- detects for PCB emissions, and 32.8 percent non

- detects for PAH emissions. The t est results from the Eramet tests are considered to be more representative of the actual emissions from the emission sources, because they were measured from the exhaust gas stream. The CDD/CDF and PCB modeling data from Eramet are based on 51 percent non

- detects for the mass emissions. Based on these results, it was determined that the CDD/CDF and PCB emissions should not be modeled because of the uncertainty of the emissions of these pollutants. The PAH modeling data is based on test results above the detection limit, and is believed to be representative of the actual emissions from the EAF emissions source. Therefore, the PAH emissions data were included in the data used for modeling.

Table 6

- 1. Summary of the CDD/CDF Analytical Results

Table 6

- 2 . Summary of the PCB Analytical Results17 Table 6

- 3 . Summary of the PAH Analytical Results

The PAH emissions were divided into four separate “ risk PAH groups” and the groups were modeled as individual pollutants. The groups were establi shed by assigning individual PAH pollutants with similar inhalation risks based on the unit risk estimate. The group emissions were calculated by summing the individual PAH emissions in each group. Table 6

- 4 provides a summary of the individual PAH pollu tants that were provided in the ICR test reports and the group for which they were assigned. In addition, naphthalene emissions from the facilities were modeled separately as an organic HAP and not as a PAH, based on EPA assessment guidelines, which state
that naphthalene is inventoried as a separate HAP and is not included nor summarized in any PAH

group

.18 Table 6

- 4 List of PAH Groups and their Individual PAH Pollutants

Group Code Group Name Group URE (1/(μg/m 3 )) PAH Pollutant

72002 Group 2 8.8E

- 5 Acenaphthene Acenaphthylene

Anthracene Benzo[e]pyrene Benzo[g,h,i]perylene

Benzofluoranthenes

Fluoranthene

Fluorene Perylene

Phenanthrene Pyrene

75002 Group 5 1.6E

- 3 Benzo[a]pyrene(7

- PAH) Dibenzo[a,h]anthracene

76002 Group 6 1.6E

- 4 Benz[a]anthracene Benzo[b]fluoranthene Benzo[b+k]fluoranthene Indeno[1,2,3

- c,d]pyrene

77002 Group 7 1.6E

- 5 Chrysene

The total mercury and chromium emissions that were used for modeling were speciated into chromium III and chromium VI, and mercuric chloride and elemental mercury. The speciation of the mercury samples for these facilities was done using mercury speciation factors developed for the ferroalloys industry. 2 The speciation factor divides t he total mercury emissions into 10 percent particulate mercury, 10 percent gaseous mercury, and 80 percent elemental mercury. Using these speciation factors, the mercuric chloride was calculated as 20 percent of the total mercury emissions
and elemental m ercury was calculated to be 80 percent of the total mercury emissions. The speciation of total chromium was done by subtracting the chromium VI emissions from the total
chromium emissions to obtain the chromium III emissions.

2 Environmental Protection Agency, Emissions Modeling Clearinghouse Speciation, April 2010. http://www.epa.gov/ttnchie1/emch/spec iation/19

Emission Process Groups

T he emission sources from the test data were divided into emission process groups using the Standard Classification Codes (SCC) supplied by the facility in the ICR. The emission groups for the Ferroalloys category were; open EAF, fugitive dust sources, raw material crushing and screening operations, casting, and other. Table 6

- 5 presents a summary of the SCC and the assigned emission process group.

Latitude/Longitude QA/QC

The latitude and longitude coordinates provided by the facilities were reviewed t o ensure that the coordinates matched the location of the emission points. This was done by plotting each emission point on a map of the facility using Google Earth. The plotted emission points were then evaluated to determine if the emission point match ed the expected location of the emission point. If it was determined that the emission point did not match the expected location on the facility map, the point was moved to the expected location and new latitude and longitude coordinates were
determined. The map and the emission point coordinates were sent to the facilities for confirmation
of the locations.

Stack and Fugitive Parameters QA/QC

The stack and fugitive emission parameters provided by the facility in the ICR were verified to ensure they were correct. The volumetric flow rates for the point sources were checked by
calculat ing the volumetric flow rate u sing the velocity and duct dimensions . The calculated flow

rates were co mpared with the volumetric flow rates provided in the test reports. If the flow rate
difference exceeded 30 percent, e ngineering judgments were made to revise the velocity or duct dimension data. Fugitive parameters were inputted using the Google Earth m ap for each of the facilities and estimating the length, width, and angle of the fugitive emissions.20 Table 6

- 5. Summary of Assigned Emission Process Groups for the Ferroalloys SCC21

7.0 MACT ALLOWABLES

The modeling emissions calculated from the ICR test data represent s an estimate of the mass emissions actually emitted during the specified annual time period. These “actual” emission levels are often lower than the emission levels that a facility might be al lowed to emit and still comply
with the MACT standards. The emissions level allowed to be emitted by the MACT standards is
referred to as the “MACT

- allowable” emissions level. This represents the highest emissions level that could be emitted by the facil ity without violating the MACT standards. The assessment of
these risks at the MACT

- allowable level r eflects the maximum level sources could emit and still comply with national emission standards.

To estimate emissions at the MACT

- allowable level, a rati o of MACT

- allowable to actual emissions for each source type (i.e., the individual stack emissions) were developed for each of the
facilit ies in the source category. This ratio is based on the emission limits required by the MACT standards compared to the reported actual emissions. T hese ratios for each emission point type at
the facilit ies in this source category were applied to the maximum chronic risk estimates from the
inhalation risk assessment to obtain maximum risk estimates based on MACT

- allowable emissions.
A table of the MACT

- allowable ratios is presented in Table 7

- 1.22 Table 7

- 1. Summary of MACT

- Allowable Ratios for Eramet and Felman1

EC/R 10 /0 6 /2011 DRAFT: DO NOT CITE OR QUOTE MEMORANDUM

TO: Conrad Chin , USEPA / OAQPS /MMG

FROM: Jeff Harris, EC/R Inc.

DATE: October 6 , 2011

SUBJECT: Methodology for Estimation of Maximum Hourly Emissions for Ferroalloys Sources

Section 112(f)(2) of the Clean Air Act (CAA) directs EPA to assess the risk remaining (residual
risk) after the application of maximum achievable control technology (MACT) standards under
section 112(d). EPA is to promulgate mor e stringent standards for a category or subcategory of
sources subject to MACT standards under section 112(d) if promulgation of such standards is
necessary to protect public health with an ample margin of safety or to prevent (taking into

consideration va rious factors) adverse environmental effects.

In an effort to streamline the process of making residual risk decisions, EPA plans to address
residual risk and perform a technology review simultaneously for multiple source categories.
For this source categ ory, t he first part of this approach is to compile and review facility

- specific
data collected by EPA, and to conduct preliminary risk assessments.

The risk assessment will include both chronic and acute inhalation risks. The chronic risks are

based on lo ng

- term, annual average emissions, while the acute risks are based on short

- term
hourly emissions and account for the maximum potential short term emission rates for the
industry. Because of differences in control effects for groups of pollutants

, we determined that it

is necessary to use different methodologies to calculate the estimated maximum hourly emission

rate for emissions of total particulate matter ( PM ) (also representing other HAP metals)

, formaldehyde, and a cid g ases ( hydrochloric acid

, HC l & hydrofluoric acid

, HF) from ferroalloys
industry sources. M aximum hourly emission s for PM and formaldehyde are derived from annual

emissions rates estimated from available emission test results 1

, while the estimated emissions for

1 For additional detail on calculation of annual emission rates, see Modeling Emission Estimation Methodologies for Ferroalloy Facilities

, October 4, 2011, available in the Ferroalloys source category docket.2

EC/R 10 /0 6 /2011 DRAFT: DO NOT CITE OR QUOTE HC l and HF are calculated assuming an average emission rate due to the consistent

chlorine /fluorine content in the co ke burned at the facilities

.

Total PM & Formaldehyde

A large portion of the total emissions from ferroalloys facilities are a result of e lectric a rc

f urnaces (EAF), which operate continuously and are only shut down for product changes or
major maintenance, both of which are uncommon. Other operations, such as tapping of the
molten metal product from the furnaces, and casting of the molten metal into i ngots, occur on a
regular but intermittent basis. ( e.g., Tapping and casting occur about every two hours, and last

around 30 minutes each .) Similarly, sizing operations (performed to crush the large ingots of
product into smaller sized nuggets or powders ) are intermittent, depending on production levels.

Because the furnaces operate continuously, it is reasonable to consider them as steady

- state
operations, and then look at the maximum emissions from the remaining processes (tapping,
casting, and sizing) as they are the operations that might conceivably result in an emi ssions
spike.

Estimated yearly emissions from steady

- state emissions points are divided by 8760 to calculate
estimated hourly emissions. Intermittent emission points are assumed to operate 25 percent of
the time (30 minutes out of each two hour period.) This is a conservative estimate, because it is
very unlikely that all furnaces would ever be tapped simultaneously , and it is impossible for
tapping a nd casting from a given furnace to occur simultaneously since casting of the molten
metal must occur after it is tapped. This methodology is also likely to overestimate the operating
frequency of product sizing operations. Following this reasoning, estima ted yearly emissions
from intermittent emissions points are divided by 2190 (or 8760/4) to calculate estimated hourly

emissions. We calculate the maximum hourly emissions as the sum of the hourly steady

- state
emissions and the hourly intermittent emission s and have created a separate acute emissions
modeling file based on these data (See Tables 1

- 4 at the end of this memo )

.

Although we have modeled emissions of formaldehyde and acid gases from some intermittent
processes, they may not actually be emitted. Because emissions from tapping and casting

processes were not tested , modeled emissions from tapping and casting were based on the3

EC/R 10 /0 6 /2011 DRAFT: DO NOT CITE OR QUOTE emissions profile of the furnace stack 2 . Removing f orm aldehyde and acid gases from the
emissions profiles used for these emissions points might be appropriate for future modeling
efforts, but we believe that retaining them is a more conservative approach for this analysis

.

Acid Gases ( HC l and HF )

HC l and HF emissions are primarily influenced by the c hlorine and fluorine c ontent of the
reducing agent (typically coal or coke) used in the EAF. Because the ferromanganese facilities
subject to the rule both use coke as a reducing agent , the variability in impurit y levels ( i.e. , the

chlorine and fluorine that result in HCl and HF emissions) is very low . B ecause of this, and
because HF and HCl are emitted by processes that operate continuously (as described above), we

believe that there should be no difference betw een estimated maximum hourly emissions and
average hourly emissions o f acid gases

.

2 I bid

.4

EC/R 10 /0 6 /2011 DRAFT: DO NOT CITE OR QUOTE5

EC/R 10 /0 6 /2011 DRAFT: DO NOT CITE OR QUOTE