# National Emission Standards for Hazardous Air

Pollutant Emissions: Ferroalloys Production

Summary of Public Comments and Responses on Proposed Rule (7 6 FR 72508 , November 2 3 , 201 1 ) and Supplemental Proposal

(79 FR 60238, October 6, 2014)

U.S. Environmental Protection Agency Office of Air Quality Planning and Standards Sector Policies and Programs Division Research Triangle Park, NC 27711ii 

## (This page is intentionally left blank)iii 

### Table of Contents

1.0 EMISSION ESTIMATES USED IN RISK MODELING

................................ .................. 9

1.1 Methodology to Estimate Baseline and Control Scenario Emissions

.............................. 9

1.2 Method to Estimate Fugitive Emissions is Flawed

................................ ........................ 13

1.3 Stack Testing Data Used in Estimating Emissions

................................ ........................ 16

1.3.1 Nickel Speciation of Emissions

................................ ................................ .............. 18

1.3.2 Treatment of Non

- detects

................................ ................................ ....................... 19

1.4 Use of Allowable vs. Actual Emissions

................................ ................................ ......... 20

2.0 EPA RISK ASSESSMENT

................................ ................................ ............................... 23

2.1 Dose

- Response Values

................................ ................................ ................................ ... 23

2.1.1 Chronic Dose

- Response Values

................................ ................................ .............. 23

2.1.2 Acute Dose

- response Values

................................ ................................ .................. 42

2.2 Chronic Risk Assessment Issues

................................ ................................ .................... 45

2.2.1 Census Block Centroid s

................................ ................................ .......................... 45

2.2.2 Activity Patterns and Exposure

................................ ................................ ............... 47

2.2.3 Respirable Emissions

................................ ................................ .............................. 52

2.2.4 Cumulative Risk

................................ ................................ ................................ ...... 53

2.2.5 Chronic risk assessment results

................................ ................................ .............. 58

2.3 Acute Risk Assessment Issues

................................ ................................ ....................... 58

2.4 Facility

- wide Risk Assessment

................................ ................................ ...................... 60

2.5 Multipathway and Environmental Effects

................................ ................................ ...... 62

2.5.1 Multipathway

................................ ................................ ................................ .......... 62

2.5.2 Environmental Effects

................................ ................................ ............................ 70

2.6 Environmental Justice Assessment Issues

................................ ................................ ...... 71iv

2.7 Other Modeling Methodology Issues

................................ ................................ ............. 75

2.8 Community H ealth Impacts and Concerns

................................ ................................ ..... 80

2.8.1 Community Issues

................................ ................................ ................................ ... 80

2.8.2 Local Resident Concerns Regarding Health and Air Quality

................................ . 85

3.0 D ECISION

................................ ................................ ................................ ......................... 88

3.1 Finding of Unacceptable Risk is Justified

................................ ................................ ...... 88

3.2 Finding of Unacceptable Risk is Not Justified

................................ ............................... 90

3.3 Finding of Acceptable Post

- Control Risk is Deficient

................................ ................... 92

3.4 The Rule Does Not Provide an Ample Margin of Safety

................................ .............. 98

4.0 PREVIOUSLY UNREGULATED POLLUTANTS AND EMISSION POINTS AND TECHNOLOGY REVIEW

................................ ................................ ................................ ......... 100

4.1 Regulating Previously Unregulated Pollutants and Emission Points

........................... 100

4.2 Technology Review

................................ ................................ ................................ ...... 102

4.3 Stack Emission Limits

................................ ................................ ................................ .. 109

4.4 Object to UPL Methodology

................................ ................................ ........................ 112

4.5 Emission Averaging Across Multiple Furnaces

................................ ........................... 11 5

4.6 F ugitive Emissions Capture

................................ ................................ ......................... 116

4.6.1 Total Negative Pressure Enclosure

................................ ................................ ....... 116

4.6.2 Enhanced Local Capture Option

................................ ................................ ........... 120

4.7 Ambient Air Monitoring Option

................................ ................................ .................. 124

4.7.1 Activated Car

bon Injection

................................ ................................ .......................... 127

4.7.2 Mercury Control

................................ ................................ ................................ .... 128

4.7.3 Formaldehyde Control

................................ ................................ .......................... 128

4.8 Opacity Standards

................................ ................................ ................................ ........ 129

4.9 Fugitive Dust

................................ ................................ ................................ ................ 135v

4.10 Fo rmat of the Regulation

................................ ................................ .............................. 136

4.10.1 Need to Retain Subcategories

................................ ................................ ............... 136

4.10.2 Concentration Format is Not Appropriate

................................ ............................ 136

4.10.3 PM Cannot be Used as a Surrogate

................................ ................................ ....... 138

4.11 Complian ce Testing Requirements

................................ ................................ .............. 140

4.12 Monitoring, Reporting and Recordkeeping Requirements

................................ .......... 142

4.13 Compliance Date

................................ ................................ ................................ .......... 147

5.0 ECONOMIC IMPACTS OF PROPOSED RULE

................................ ........................... 151

5.1 Impacts on Economy and National Interests

................................ ................................ ... 151

5.2 Benefits Analysis

................................ ................................ ................................ .......... 156

5.2.1 Regulatory Comm ents

................................ ................................ .......................... 156

5.2.2 Methodology Comments

................................ ................................ ....................... 158

5.2.3 Uncertainties in the Benefits Analysis

................................ ................................ .. 160

5.2.4 Limits of Statistical Analysis

................................ ................................ ................ 162

6.0 STARTUP, SHUT DOWN AND MALFUNCTION (SSM) PERIODS AND AFFIRMATIVE DEFENSE

................................ ................................ ................................ ....... 164

6.1 SSM

................................ ................................ ................................ .............................. 164

6.2 Affirmative Defense

................................ ................................ ................................ ..... 172

7.0 OTHER COMMENTS

................................ ................................ ................................ ..... 179

7.1 Overall Support

................................ ................................ ................................ ............ 179

7.2 Request for Extension/Additional Review

................................ ................................ ... 179

7.3 Object to Additional Testing or Data Gathering

................................ .......................... 181

7.4 Citizen Involvement in the Rulemaking Process

................................ ......................... 181

7. 5 Other

................................ ................................ ................................ ............................. 1826

Purpose and Background

The EPA proposed amendments to the National Emissions Standards for Hazardous Air Pollutants (NESHAP) for ferroalloys production facilities to address the results of a residual risk and technology review on November 23, 2011

. Fifty

- five public comments (from 41

comm e nters) were received during the comment period

. In addition, both companies that would be affected by the final rule submitted supplemental comments in July 2012 as well as additional supporting information

, such as new test data

, in the summer and fall of 2012. Other commenters met with us in person or via teleconference to reiterate their earlier comments. On October 6, 2014, the EPA published a supplemental proposal that addressed many of the key issues brought up by commenters on the 2011 proposed rule. Twenty

- seven comments (from 20 commenters) were received during the comment period for the 2014 supplemental proposal. The purpose of this document is to su mmarize the comments received on the 2011 proposed rule and 2014 supplemental proposal that were not addressed in the promulgation preamble.

Commenters

Commenter Name Document Id a EPA

- HQ

- OAR

2010

- 0895

- XXXX Date

American Chemistry Council (ACC) 0076 2/1/12 American Iron and Steel Institute (AISI) 0271, 0275 12/24/14 Anonymous (Afscmewv@aol.com) 0086 2/1/12 Anonymous (SSkal@aol.com) 0081 2/1/12 Anonymous Public Comment 0257 0258 0261 0268 11/28/14 12/4/14 12/17/14 12/20/14 Karin Arnold 0102 2/1/12 Albert Arnone 0260 12/17/14 Caroline Beidler 0089 2/1/12 Sherri Biegeleisen 0103 2/1/12 Ellyn Burnes 0077 2/1/12 CC Metals and Alloys, LLC (CCMA) 0069 1/31/12 Coalition for Responsible Waste Incineration (CRWI) 0071 2/1/12 Kathleen Davies 0104 2/1/12 Earthjustice (on behalf of Neighbors for Clean Air, Ohio Citizen Action and Sierra Club) 0107 through 0114 0276 0277 0278 2/1/12 12/24/14 12/29/14 1/15/15

Attachments /supporting materials to comment letter 0301 0373 0042 2/18/15

2/12/15 1/21/15 Eramet Marietta Inc. (EMI) 0051, 0052 0059 12/12/11 12/28/117

Commenter Name Document Id a EPA

- HQ

- OAR

2010

- 0895

- XXXX Date

0106 0122 0251 0253 0256 0272, 0273 2/1/12

8/28/12 10/28/14 11/4/14 11/28/14 12/24/14

Felman Production Inc. (Felman) 0053 0073 0123 0252 0269 0274 (copy of 0269) 12/15/11

2/1/12 8/28/12 10/29/14 12/20/14 12/24/14 Brian Gath 0093 2/1/12 Sharon Growick 009 6 2/1/12 Roger Hall 0101 2/1/12 Emily Haynes 0087 2/1/12 J. Harris 0084 2/1/12 Industrial Energy Consumers of America (IECA) 0263 0267 12/19/14 12/20/14 Julia E. Johnson 0082 2/1/12 Brian Kuru 0095 2/1/12 Manganese Interest Group (MIG) 0055 0067, 0070 0266 12/19/11 1/31/12 12/20/14 Kenneth Marantz 0088 2/1/12 Terry Martin 0079 2/1/12 National Association of Clean Air Agencies (NACAA) 0065 1/25/12 North American Metals Council (NAMC) 0072 2/1/12 David Neubauer 0092 2/1/12 Nickel Producers Environmental Research Association, Inc. (NiPERA) 0066 0264 1/31/12 12/19/14 Melissa Ochal 0083 2/1/12 Ohio Citizen Action (OCA) 0068 0105 0270 1/25/12

2/1/12 12/24/14 Ohio Environmental Protection Agency (Ohio EPA) 0265 12/19/14 The Residual Risk Coalition (R2C) 0075 2/1/12 June Robb 0078 2/1/12 Barbara Stewart 0098 2/1/12 Patrick Stewart 0090 2/1/12 Scott Strickler 0099 2/1/12 SSM Coalition 0074 2/1/12 James Thiel 0094 2/1/128

Commenter Name Document Id a EPA

- HQ

- OAR

2010

- 0895

- XXXX Date

RoseMarie E. Thomas 0097 2/1/12 University of Cincinnati, College of Medicine 0085 2/1/12 Virtual Technology, LLC 0262 0279 12/19/14

2/5/15 Washington County 0247 10/14/14 West Virginia Department of Environmental Protection (WV DEP) 0255 11/20/14 Dawn Wittberg 0091 2/1/12 Richard A. Wittberg 0100 2/1/12 Kim and Dan Wolford 0080 2/1/129

Issues Raised by Commenters

1.0 EMISSION ESTIMAT E S USED IN RISK M ODELING

1.1 Methodology to Estimate Baseline and Control Scenario Emissions
Comment: In response to the 2011 proposal, t wo commenters (0122, 0123) recommend ed changes to the methodology used to estimate emissions from each of the plants. One commenter (0122) suggest ed that stack emissions from control devices be based on all recent performance tests, not just the 2010 tests conducted for the EPA prior to proposal. The commenter (0122) also suggest ed that the furnace 1 control device emissions be based upon the baghouse that is currently in operation, not the scrubber that was previously in place. Additionally, the commenter (0122) point ed out that furnace 1 tapping baghouse emissions were excluded from the baseline file included in the proposal docket.

The commenters ( 0122, 0123) recommend ed replacing the mass balance approach described by the EPA at proposal to estimate emissions from tapping and crushing/screening with the use of applicable emission factors. The commenters (0122, 0123) also suggest ed replacing the cas ting emission factor used by the EPA at proposal with a different emission factor. The commenters (0122, 0123) suggest ed estimating tapping fugitive emission using an uncontrolled PM emissions factor of 0.29 lb/ton, based on AP

- 42, Table 12.5

- 1 for “BOF Ta pping, a t building monitor” with maximum process rate information provided by the plants. The commenters (0122, 0123) suggest ed estimating casting emissions using an uncontrolled PM emissions factor of 0.056 lb/ton, based on AP

- 42, Table 12.5

- 1 for “Hot me tal transfer, a t building monitor” with maximum process rate information provided by the plants. The commenters (0122, 0123) also recommend ed estimating uncontrolled emissions from their crushing and screening operations using PM 10 emission factors for metallic minerals processing as presented in AP

- 42, Table 11.24

- 2 with maximum process rates.
In their comments on the supplemental proposal, commenter 0272 note d that the EPA used AP

42 emission factors developed for basic oxygen fur naces (BOF) to estimate fugitive emissions from ferroalloy operations. This section included “at the source” and “at the monitor” emission factors to estimate ferroalloy production process fugitive emissions, and the EPA chose to use the “at the source” em ission factors, which produce d estimated emission rates about three times higher than “at the monitor” factors. The commenter (0272) believes that the “correct” choice of emission factors are the ones that produce predicted emissions closest to real air da ta. The availability of real world data means that it is possible in this rulemaking for EPA to use each set of factors in its model and determine objectively which set produces results that better match reality. The commenter (0272) state d that using the BOF “at the monitor” emission factors overestimates actual air concentrations, but less than the “at the source” emissions factors and that even with this correction, the EPA’s model remains very conservative. The commenter (0272) therefore recommend ed tha t the EPA adjust its modeling assumptions to use the BOF “at the monitor” emission factors.10

One commenter (0122) state d that the EPA’s characterization of the removal of material from the MOR process is incorrect because it equates that operation to tappi ng of an active furnace. Therefore, according to the commenter (0122), it is more correct to characterize these emissions using the hot metal transfer emission factors. The commenter (0122) add ed that the emissions should be calculated when the ladle from the furnace process is poured into the MOR and again when the treated material (post

- MOR processing) is cast.
In supplemental comments to their original comment s , two commenters (0122, 0123) provided revised estimates of manganese emissions for both a base line scenario and an “enhanced control” scenario. These estimates and the associated emission estimation methodology are located in the project docket. As described by the commenters (0122, 0123), the manganese emissions are based on each plant ' s estimate of a “worst

- case” ratio of PM to manganese emissions (41 percent at EMI and 23 percent at Felman for most operations except for 52.9 percent for crushing/screening operations)

. Based on their calculations, both commenters (0122, 0123) concluded that their proposed “enhanced local capture” scenarios would collectively reduce emissions from the affected source s by 95 percent.
Based on the commenters’ (0122, 0123) engineering studies of baseline capture efficiencies, they also recommend ed changes to some of th e capture efficiency assumptions made in the proposal analysis conducted by the EPA. In most cases, the commenters (0122, 0123) suggested efficiencies that are less than the efficiencies estimated by the EPA.
The commenter (0272) acknowledge d that mathemat ical modeling is necessary to fill gaps when actual data is unavailable. However, the commenter (0272) state d that the EPA should not ignore

nor allow modeling to trump real world data when it is available , as the commenter contends occurred here in develo ping the 2014 proposal.

Response: We agree that certain changes should be made to the emission estimation methodology based on these comments. First, we have developed a new baseline scenario that included modeling emissions from the current furnace 1 bagh ouse at EMI instead of the previously used scrubber. We also believe that it is appropriate to use a broader range of PM and HAP stack test data to estimate control device stack emissions to reflect potential operational variability.
Regarding the use of emission factors, we recognize that emission factors are commonly used by plants to estimate emissions from their processes and that they can have a higher degree of precision and accuracy than a mass balance approach. We reviewed the factors suggested by the commenters and agree that the use of the BOF tapping and hot metal transfer as surrogates for ferroalloys tapping and casting is appropriate, given the absence of AP

- 42 factors specific to ferroalloys. However, we disagree with the use of the “at the m onitor” factors suggested by the

commenters.11

First, we note that these emission factors were not based on emissions collected at the roof monitor, but instead collected in hoods or ductwork located above the actual emission source and estimates of assumed capture efficiency were made to estimate the “uncontrolled” portion. This differs from a measurement of actual emissions at the roof monitor. Second, the respective BOF tapping and hot metal transfer tables each show a second emission factor associated wi th each operation (“at the source”)

. For tapping the factor is 0.291 lb/ton and for hot metal transfer the factor is 0.19 lb/ton. These factors are also based on tests that sampled the air inside a hood or duct (albeit one that was probably closer to the s ource of the emissions than the so

- called “at the monitor” collection sites) with assumptions made about capture efficiency to determine uncontrolled emissions. We decid ed to use the higher emission factors (EFs) in our calculations because we believe they more accurately reflect actual emissions from these sources. Furthermore, given that there are some uncertainties regarding these emissions, we believe it is appropriate to use the more conservative estimates to err or on the side of public health protecti on. Further explanation of the EFs and our rationale for choosing these EFs are provided in the document titled R evised Development of the Risk and Technology Review (RTR) Emissions Dataset for the Ferroalloys Production Source Category for the 2014 Supplemental Proposal , which is provided in the docket for this action.
In their proposed emission estimation procedures, the commenters assumed that use of the tapping emission factor suffices to estimate all fugitive emissions from the furnaces, which implies that there are no fugitive emissions from the main furnace hood (e .g., primary emissions). During a subsequent conversation, the commenters stated that they believe the main furnace hoods capture 100 percent of furnace emissions except during upset events (malfunctions). However, we believe that an assumption of 100 perc ent capture is too high and have retained the assumption that there are some primary furnace fugitive emission s although we did assume a slightly higher capture efficiency (and thus lower emissions) of the main furnace hood (up from 95 to 98 percent) since the 2011 proposal

. We note that the EPA’s estimates of casting emission at proposal were based on an emissions factor contained in a previous RACM determination from the state of Ohio. However, upon closer examination, we were unable to sufficiently docum ent this emission factor and decided that the use of the BOF factor is more defensible.
For crushing and screening emissions, we determined that use of more recently updated emission factors from the crushed stone AP

- 42 (give table) should be considered as well. We identified candidate emission factors and consulted with the plants regarding their application to specific equipment operated at each plant. Based on this process, the plants submitted revised estimates of crushing and screening emissions that w e included in our final modeling files.
We agree that the commenter’s (EMI2) description of the MOR process better characterizes the nature of emissions from that source, and we have revised the emission estimation procedures accordingly.12

Regarding the iss ue of the ratio of PM to manganese emissions, we believe that the use of stack test data is a better methodology to estimate the actual emissions from the plants. For example, we have stack test data from the furnaces that show the PM, manganese and other HAP emissions from the control device stacks. We think that furnace emissions are a better surrogate for estimating the ratios of PM to manganese for tapping fugitive emissions (where we lack tapping baghouse data) and casting fugitive emissions than a gen eric “worst

- case” value. Similarly, we have stack data from the MOR baghouse and crushing and screening operations that we think are a better surrogate for MOR fugitives and crushing and screening fugitives, respectively.
With regard to capture efficiencie s, for the 2014 supplemental proposal and the final rule, we developed estimates of capture efficiency for each of the processes based on site visits, observations, and engineering judgement provided by several EPA engineers. The capture efficiency assumpt ions, and explanation of how they were developed, are described in more detail in the document titled R evised Development of the Risk and Technology Review (RTR) Emissions Dataset for the Ferroalloys Production Source Category for the 2014 Supplemental Pro posal , which is provided in the docket for this action.

Comment: Commenter 0073 disagrees with the EPA’s proposal to regulate all furnace types and products as part of the same category, noting significant differences in feedstocks, processes, operations and emissions. Specifically, the commenter (0073) notes that emissions from ferromanganese operations contain a different HAP profile than those from silicomanganese operations and the 2010 stack testing did not include the only ferromanganese furnace in operation in the U.S. (at EMI). The commenter (0073) disagrees with the EPA’s assumption that that the HAP

- to

- PM ratio from ferromanganese manufacturing would be the same as that from silicomanganese manufacturing. The commenter (0073) states that ferroman ganese production generates a fraction of the PM that silicomanganese generates, with a very different HAP profile. The commenter (0073) states that the MACT floor the EPA calculated based on these data does not represent what well

- controlled ferromanganes e operations “achieve” in practice. T he commenter (0073) requests that the EPA continue the specific subcategories that were established as part of the original rule, evaluate all available reliable emissions data for each subcategory and calculate the 99% UPL based on these data. The commenter (0073) also asserts that the EPA should first subcategorize among the different types of ferroalloy operations, re

evaluate the risk data to identify the residual risks associated with each individual subcategory,

an d then identify category

- specific controls as necessary to address those risks.

Response: Furnace #12 at EMI was tested in August 2010 while producing ferromanganese. In response to comments, we have compared the emission profile (PM to Mn emissions) for the two product types. The results are in the project docket. The analysis confirms the commenter’s contention that silicomanganese production has higher relative PM content and a lower relative Mn content. However, given that the majority of ferroalloys p roduction occurs with fabric filters, which are constant PM outlet devices, we believe that outlet emissions are not a function of PM13

loading and/or product type. We also reviewed historical data of PM emissions and found that the sole scrubber (typically considered an efficiency device vs. constant outlet device) emitted higher PM but still within the range supported by the UPL analysis. Therefore, we do not believe that subcategorizing the standards for PM emissions is needed.
While we did not subcategor ize, we did revise some emissions estimates. The data for Felman, which was modeled using information from the ICR test and was based on silicomanganese production, was not changed. However, in the case of EMI, we did revise emission estimates of
manganese and mercury emissions, using a revised silicomanganese emission factor for furnace # 1, which was producing silicomanganese during the ICR test program. This revision was needed to correct the original data file assumption, which based the manganese and m ercury emissions profile on the furnace #12 data, derived from a test during ferromanganese production.

1.2 Method to Estimate Fugitive Emissions is Flawed
Comment: In comments on the supplemental proposal, two commenters (0270, 0276) disagree with the EPA’s use of emission factors to estimate fugitive emissions from furnace and tapping operations. Both commenters (0270, 0276) state that such factors were compiled decades ago, were poorly documented and are of questionable reliability. One commenter (0276) ref erences an EPA evaluation report of emissions factor development in support of these concerns. 1 The commenter (0276) is concerned that use of these factors introduces significant uncertainties into the EPA 's assessment and likely leads to underestimation o f fugitive emissions and risk. The commenter (0276) states that the uncertainty in the fugitive emissions supports the need for the EPA to find risk unacceptable and assure a stronger margin of safety to protect public health.

Commenter 0270 and 0276 state that to reduce the uncertainty in the fugitive emissions estimates , the EPA should have used the methodology it used in other instances, where fugitive emissions are based on measured stack emissions, estimated control device efficiency and estimated capt ure efficiency. While this methodology depends upon two uncertain estimates, the commenters (0270, 0276) believe it provides a better estimate than the emission factors the EPA used . The commenter (0270) states that based on the emissions test data provide d to the EPA, control efficiencies can be determined for Felman and estimated for Eramet, which are greater than the AP

- 42 default estimates for control device efficiencies, and the commenter suggests the EPA collect the full test reports from Eramet to de termine the correct control efficiency for all the pollutants measured. According to the commenter (0270), with this information, only the

1 See, e.g., U.S. Environmental Protection Agency, Evaluation Report: EPA Can Improve Emissions Factors Development and Management , 2006

- P

- 00017, Office of Inspector General, U.S. Environmental Protection Agency, Washington, DC, Mar. 22, 2006. Available at http://www.epa.gov/oig/reports/2006/20060322

- 2006

- P

00017.pdf (accessed November 2011); Emissions Factor Uncertainty Assessment

– Review Draft Feb. 2007, http://www.epa.gov/ttn/chief/efpac/documents/ef_uncertaint y_assess_draft0207s.pdf.14

capture efficiency would be estimated in determining the fugitive emissions of particulate matter, metals and PAH emi ssions.

Commenter 0276 states that the EPA has not shown that the emission factors it used represent real

- world impacts, and the EPA should have used the measured concentrations of metals at nearby schools in the EPA’s receptor models to assess of the ver acity of the emission factors. T he commenter (0276) also states that the EPA should have evaluated the EPA

- collected data on manganese in Marietta, Ohio (Warren Elementary School).

Response: The commenter points out the uncertainty in using emissions facto rs to estimate fugitive emissions but fails to consider that uncertainty in emissions factors is a two

- tailed factor, the uncertainty may either over estimate or underestimate emissions . The commenter is assuming the factor underestimates fugitive emission s when, in fact, that specificity is unknown to EPA. Using ambient measurement data collected at Warren Elementary School to back calculate fugitive emissions from a source would result in an estimate with greater uncertainty than the emissions factors tha t EPA used.

Comment: In comments on the supplemental proposal, commenter 0276 states that the EPA has not adequately supported its assumptions about the capture efficiency of several of the ventilation systems considered. The commenter (0276) states that u nless the EPA can show that the partial capture method works to remove unacceptable risk, it must require total enclosure to remove unacceptable risk and assure the requisite “ample margin of safety to protect public health.”

Two commenters (0270, 0276) di sagree with the EPA’s “unsupported” assumption that a ventilation system designed to meet the guidelines of the ACGIH Ventilation Manual can achieve 95% capture. According to the commenters (0270, 0276), this assumption is speculative

, and it is unlikely that the EPA can obtain verification of this level of capture from the authors of the manual.

Both commenters (0270, 0276) state that the EPA can use an alternative approach to evaluate capture efficiency by varying the capture efficien cy and using the estimated measured captured particulate emissions to arrive at estimated capture efficiencies. They provided the results of this analysis and conclude that it shows resulting capture efficiencies that yield roughly comparable uncontrolled melting and tapping emissions. According to commenters (0270, 0276), the existing capture would be approximately 80% for combined melting and tapping at furnace 12, a capture efficiency of 80% for melting emissions for furnace 1 and a 20% capture of Furnac e 1 tapping emissions. The commenters (0270, 0276) add that this analysis assume s that the ratio of PAH to particulate matter is consistent between the outlet and inlet, which is uncertain.
The commenters (0270, 0276) also state that the resulting estimate s of fugitive emissions that are based upon measured data from the facilities are orders of magnitude greater that the EPA’s fugitive emission estimates. One commenter (0276) adds that if the EPA were to estimate15

fugitives based on these data, risk could b e as high as 2,000 in 1 million, which is much higher than the EPA found in its analysis. Both commenters (0270, 0276) state that the EPA should improve the fugitive emissions estimates and require alternative measurement of the building roof monitors usin g a revised Method 14 (for use at facilities other than aluminum smelters) and require the installation of safe access and means for sampling emissions from roof monitors. The commenters (0270, 0276) also recommend that the EPA require a Professional Engin eer certification that the desired capture efficiency is achieved.

Response: We have discussed various approaches for reducing fugitive emissions, and hence unacceptable risk

, with ventilation experts and determined that a ventilation system designed using American Conference of Governmental Industrial Hygienists ( ACGIH ) principles can achieve 95% capture of these emissions. We would characterize our view of ventilation and capture performance as based on our technical judgment informed by expert opinion ra ther than mere speculation. B ased on information from ventilation experts and the proposed ventilation plans submitted by the facilities, we believe that 95% of the overall fugitive emissions emitted from the various processes can be captured and controll ed.
We reviewed various methodologies to estimate fugitive emissions from the various processes, including the methodology provided by the commenters, and determined that the emission factor approach provided the best estimate for these emissions. We deter mined that using a mass balance approach does not account for particles that are not emitted from the building, therefore overestimating fugitive emissions for the purposes of modeling, and hence overestimating the risk associated with these fugitive emiss ions. The mass balance approach also relies on other assumptions regarding the precise control efficiencies of each of the control devices.
We have also reviewed the installation of roof monitoring equipment to measure fugitive emissions from the building and determined that the cost of installing this equipment was cost prohibitive. The buildings that house the furnaces are old and would require much infrastructure to install a monitoring system. In addition, there were a number of safety issues associated with the installation of a roof monitoring system. For these reasons, we determined that the installation of a DOCS system and weekly opacity monitoring (and/or eventually monthly monitoring), along with parametric monitoring and the requirement to develo p a capture and control design plan, will provide the assurance that the overall 95% capture of fugitive emissions i s met.

Comment: Two commenters (0270, 0276) describe issues associated with relying o n an estimate of capture efficiency based on visual obs ervation of the plume. The commenters (0270, 0276) describe the limits of observation below 5 to 10 percent opacity and note that the lack of visible emissions does not indicate that there are no emissions. One commenter (0270) states that particulate matter can be over 40 mg/m 3 and not produce a visible plume. One commenter (0276) adds that past studies have shown that at opacities of about 5 percent , trained observers would likely assign a value of zero.16

The commenters (0270, 0276) also note that the visibility of emissions under ideal conditions is highly dependent on the particulate size and other characteristics , such as lighting conditions

. They concluded that the only reliable basis of determining capture efficiency is to measure the emissions cap tured by the ventilation system and the emissions which have escaped capture

, as is done in the Primary Aluminum Production rule.

Response: The EPA does not require opacity monitoring as a means of complying with a PM

e missions limit, and we recognize that there are unique and substantial differences between percent opacity and PM emissions concentration in any given plume. The EPA does recognize opacity as a visible means to ensure that emissions controls are being operated appropriat ely to control emissio ns and when such controls are not being operated appropriately an opacity measurement will demonstrate that fact in a manner that is quicker, less expensive, and nearly as reliable as an emissions test. We conclude that the opacity limits being promulgated in this rule, along with the other requirements in the rule, will ensure that the process fugitives are effectively captured and controlled.

1.3 Stack Testing Data Used in Estimating Emissions
Comment: In comments o n the supplemental proposal, two commenters (0270, 0276) describe concerns about the overall quality of the test reports and the lack of recognition by the EPA of particular deficiencies. The commenters (0270, 0276) state that the EPA had sufficient time to identify deficiencies, require their correction (or repeat tests), explain how the EPA would reconcile the deficiencies and explain how the EPA would use the data in spite of the deficiencies, but the record is silent o n this. The commenters provide examp les where there was apparently inadequate QA for testing of PAH and mercury compounds. They believe that the EPA did not establish clear primary and secondary Data Quality Objectives

, otherwise several ICR tests would have been returned to the industry for correction or retesting. They provide several files that include their comments on source test reports that were in the docket.

To assure data quality for information the EPA uses in this rulemaking, the commenters (0270, 0276) state that the EPA should (1) require the submission of the documentation for all tests; (2) review the documentation for compliance with the published test methods; and (3) use only the test data which includes the complete documentation for the target pollutants and meets specifi ed data quality criteria. If necessary, the commenters (0270, 0276) state that the EPA should require industry to retest or resubmit data

, without delay, to correct their errors and ensure the EPA has sufficient data to perform its regulatory duties in this rulemaking.

The commenters (0270, 0276) add that these quality issues are the basis for their recommendation that performance tests to demonstrate compliance with any emission limit the EPA establishes must be performed by a crew with a field crew lead that is a Qualified Individual according to the ASTM D7036

- 04 and that this individual be employed by a company which is accredited by an authoritative body per these same ASTM criteria. They believe that the17

errors shown here illustrate that having a facility implement these tests without the appropriate qualified supervision will not produce data EPA or the public can rely on.

Response: The test data provided by the facilities used to calculate emission s used for risk modeling and for determining emission limits have gone through an extensive review and have met the QA/QC requirements for this RTR. We believe that the current data set pro vides a solid basis for estimating emissions for risk modeling and for calculating emission limits. The majority of the comments on the test reports submitted by the commenter w ere already noted and addressed in the test data database before the data were used in the development of the emissions estimates used for modeling or for the emission limit calculation s. The data sets we used for our analyses include multiple valid test runs from the furnaces for the HAP pollutants and account for changes in product ion and seasonal variations.

Comment: Two commenters (0270, 0276) describe data quality concerns with test run averaging. They said that it is difficult to determine if any data were excluded from averaging, which data

were average d and how the EPA average d the data to arrive at the emissions used for the residual risk assessment and the enhanced capture and control estimates. The c ommenters (0270, 0276) state that it appears the data are averaged on a test run basis, but the EPA has not shown that averagin g in this manner is appropriate or scientifically valid. They suggest that the EPA consider a more representative methodology based on averaging the test runs for each test series and then averaging the test series. According to the commenters (0270, 0276)

, with this methodology, the within

- source variation of emissions receive equal weighting so that a test series that includes a higher number of test runs is not over

- represented and a single test run test is not under

- represented.

The commenters (0270, 0 276) believe that variations in the emissions are due primarily to process variations

, which have not been fully documented in the test reports

, and may not be documented in other records available to the company. For example, the commenters (0270, 0276) suggest that the high variations in the measured PAH emissions may be the result of variations in the coal tar pitch in the Soderberg paste, the destructive distillation of the coal added to the molten metal and the mass of Soderberg paste used for the specific metal being produced. They state that excluding a single run test or averaging on a run

- by

- run basis would cause this normal process variat ion to be under

- represented in the residual risk assessment. They conclude that the potential causes of the variation must be investigated and those variables which the company can control and which result in higher emissions should be excluded from use in establish ing emission limits.

Response: The emissions estimates used for modeling for each of the facilities were calculated using the average of each test for the specific pollutant. Therefore, if we had 4 tests for a specific pollutant with each test co nsisting of 3 runs, the average of the 4 tests were used to determine the emissions and not the average of all of the individual runs. If one or more of the test run s were18

determined to not meet the QA/QC requirements of this RTR, the test point(s) were re moved and the test average would be calculated using the valid runs.

For calculating the emissions limits, the UPL uses the individual test run data to determine the variability within the data set to determine an emission limit that can statistically be a chieved 99% of the time. For purposes of calculating this UPL value, we only used test data that consisted of 2, 3 or 4 runs. The approach to calculate MACT limits and the data sets used to calculate the UPL are describ ed in more detail in the MACT Floor m emorandum which is available in the docket.

1.3.1 Nickel Speciation of Emissions
Comment: In their comments on the 2011 proposal, c ommenter 0073 states that the EPA assumed that 100 percent of the nickel was the most cancerous form (nickel subsulfide). The

comme nter (0073) reports that, based on a laboratory analysis , they determined that their dust contain s virtually no nickel subsulfide, with most nickel in the form of nickel oxide

– which presents a significantly lower cancer risk than nickel subsulfide

. The commenter (0073) asserts that changing this assumption will lower Felman’s risk results to within acceptable levels.

Commenter 0066 adds that that t here is no basis to expect that nickel subsulfide is more than a minor component of total nickel emissions f rom Ferroalloys Production facilities, if it is present at all. The c ommenter (0066) references examples from oil

- fired steam generating units and from Texas CEQ.
In their comments on the supplemental proposal, commenter 0269 supports EPA’s decision to

rev erse its 2011 decision to treat all nickel compounds as having equal toxicity and/or carcinogenic potential. The commenter states that n ickel emissions from ferromanganese operations involve mixtures of nickel compounds. The commenter (0269) further states that, a s the Agency has noted, current science recognizes these different nickel compounds have different potential toxicity and carcinogenic hazards, and that a mixture of different nickel compounds poses significantly lower health risks than nickel subs ulfide.

Response : The commenter is incorrect in saying that the EPA assumed that 100 percent of the nickel emissions from the ferroalloys facilities were nickel subsulfide

. What the EPA does assume, as described in more detail in the risk assessment report for the supplemental proposal available in the docket and in our response below (see the Nickel URE section), is that all nickel compounds have the potential to be carcinogenic

. Therefore, without additional information, we make health protective assumpti ons, and for the 2011 proposal, we applied the current IRIS cancer unit risk estimate (URE) for nickel subsulfide to all nickel compounds in this data set.

The commenter did provide additional information during the 2011 proposal comment period, in the for m of a laboratory test report. We have reviewed the i nformation and we agree that it is unlikely that 100 percent of the nickel from the commenter’s furnace is in the form of nickel19

subsulfide. The commenter provided the results of Energy dispersive X

- Ray Spectroscopy (EDS) that was used to determine the species of nickel in the baghouse dust sample. EDS is a form of X

- ray Fluorescence Spectroscopy. The assumption in the report is that the proximity of nickel to sulfur elements would indicate nickel sulfur species, the absence of sulfur near the nickel would indicate a different form of nickel was present in the sample. This is an indirect way to determine if nickel

- sulfur compounds are present in the particle samples. The report seems also to show there is not enough sulfur in the sample to combine with the nickel so nickel

- sulfur compounds could not predominate. This is another indirect way of making the point about the form of nickel in the samples. We also believe that the most likely reaction occurring i n the furnace would be oxidation, leading the formation of compounds such as nickel oxide and sulfur dioxide rather than nickel subsulfide. Taken together, we recognize that it is likely that the majority of emissions are probably nickel oxide and not nick el subsulfide. Given the new information, and our current knowledge of the carcinogenic potential of all nickel compounds, and the potential differences in carcinogenic potential across nickel compounds, we consider it reasonable to use a value that is 50 percent of the IRIS URE for nickel subsulfide for providing an estimate of the cancer potency for different mixtures of nickel compounds in the revised dataset for the 2014 supplemental proposal and 2015 final rule . Please see section 2.1.1 for further dis cussion regarding the nickel cancer dose

- response value used in the risk modeling.

1.3.2 Treatment of Non

- detects
Comment: Commenters 0073 and 0269 note that the EPA assumes HAPs not detected in stack tests are actually present and have a concentration of one

- half of the test method’s detection limit. Commenter 0269 adds that the acute risk is driven by hydrogen fluoride, a c ompound never actually detected in the emission tests. The commenter further states that this policy assumption could have a significant impact on the cumulative estimated MIR lifetime excess cancer risk.

Response: For the purposes of estimating emissio ns from the ferroalloy process emission sources, we used the guidelines 2 for addressing analytical test results that are measured below the detection limit (BDL) to determine emissions from the test data. These procedures specify that for BDL tests results , one half of the method detection limit (MDL) be used to estimate the emission value. The MDL is the smallest amount of a substance that an analytical method can reliably distinguish from zero, at a specified confidence level, from the instrument signal
p roduced by a blank sample. This means that even though a test results is reported as BDL, it does not mean that the compound is not present, but means that it is unable to be measured by the method and analytical equipment. Therefore, the EPA uses one half of the MDL to estimate the compound emissions that may be present in the test sample.

2 Recommended Procedures for Development of Emissions Factors and Use of the WebFIRE Database, August 2013 (EPA

- 453/D

- 13

- 001)20

We explained our approach to use non

- detect dat a in our analyses at proposal. Our approach is consistent with the EPA’s policy on handling such data. As a point of clari fication, acute risks do not contribute to the cumulative estimated MIR lifetime excess cancer risk. Cancer risk is estimated for carcinogens and only for chronic exposures. Acute risks, which may also be estimated for carcinogens i f they have both a URE a nd an acute dose

- response value, are estimated using acute non

- cancer dose

- response values, for an hour exposure duration, and is not aggregated with cancer risks.

1.4 Use of Allowable vs. Actual Emissions
Comment: T hree commenters (0075, 0106 , 0271 ) assert th at the EPA cannot lawfully use MACT allowable emissions in the proposed risk assessments and residual risk determinations because the Agency has failed to provide an explanation for why risk assessments based on actual emissions estimates are inadequate. O ne commenter (0075) asserts that lack of an explanation as to why this approach is justified or any record evidence supporting the use of MACT allowable emissions renders th e proposal insupportable under the law. C ommenter s (0075 and 0271 ) note that sectio n 112(f)(1)(B) requires the EPA also to report on “the actual health effects with respect to persons living in the vicinity of” affected sources, and that the Agency’s risk assessment methodology already reflects numerous conservative assumptions. They bel ieve that these requirements clearly provide for the reporting of real risk based on reliable actual emissions data, not hypothetical risk based on less reliable data. C ommenters (0075, 0106) state that the EPA has provided no data demonstrating that affec ted sources actually emit at levels significantly higher than the actual data show for any significant period of time.

One commenter (0106) states that Section 112(f)(2) only provides for risk based standards " if promulgation of such standards is required in order to provide an ample margin of safety.... " (emphasis added) and notes that in Natural Resources Defense Council v. EPA , 824 F.2d 1146, 1164

- 65 (D.C. Cir. 1987), the court noted that “safe” does not mean “risk

- free” and the Act should be interpret ed and applied in a reasonable manner, reflecting the fact that risks are an accepted part of life and that the Act does not seek to proscribe risk levels that are otherwise “acceptable in the world in which we live.” The commenter (0106) asserts that cons idering all of the conservative assumptions the EPA independently builds into its risk assessment methodology, simply assuming that a facility will emit far more than it actually does (possibly more than it ever has) without some reasoned explanation is un reasonable.
Commenter 0107 states that the agency ' s analysis of risk using only the “allowable” emissions number is incomplete because facilities may violate that standard and emit HAPs at a level beyond what is “ allowable” under the rule. The commenter (0107) states that ignoring the potential for non

- compliance is equivalent to treating additional health risk caused by exceedances as zero when the EPA knows that there is additional risk from malfunctions and viol ations. The commenter (0107) adds that the EPA must consult data regarding the use of the21

malfunction (or “SSM”) exemption and enforcement actions in the past and other information it has regarding the history or likelihood of malfunctions or other violati ons. The commenter (0107) states that the factor approach that the EPA has used to address acute health risk shows that the EPA can create a more appropriate factor that would account for the potential for malfunctions and violations of the standard. It sh ould do so and then assess health risk accordingly for acute, cancer and non

- cancer risk when emissions spike above the “allowable” level under the existing standard.

Commenter 0065 recommends the EPA consider potential or allowable emissions, rather than actual emissions, as much as possible in evaluating residual risk, especially in conducting the post

- control risk assessment and in assessing acute health risks. Since facility emissions could increase over time for a variety of reasons, and with them the associated impacts, the use of potential or allowable emissions is more appropriate. The commenter (0065) adds that the major source HAP thresholds are based on maximum potential to

- emit, as opposed to actual emissions, and air agencies issue permits based on potential emissions. The commenter (0065) contends that limiting the scope of a risk evaluation to actual emissions would be inconsistent with the applicability section of Part 63 rules.
In their comments on the supplemental proposal, commenter 0272 a sserts that the EPA has no authority to base risk acceptability decisions on a hypothetical worst

- case emission scenario that simply assumes without a factual basis that EMI is capable of emitting every HAP at its maximum permitted rate continuously for a sustained basis, including 30 to 70 years in the case of cancer risk assessments. The commenter (0272) believes that the EPA incorporated even greater unreasonableness into its “allowable” scenario by ignoring the technology

- based standards it has proposed under Section 112(d), which the EPA intends to impose regardless of the results of the risk assessment.
The commenter (0272) believes that these scenarios allow an assessment of the impact of EPA’s unreasonable assumption that future worst

- case emissions could be at the rates allowed by the 1999 NESHAP rather than the 2014 NESHAP, along with its use of emission factors that produce modeled emission estimates six times higher than measured results (e.g., EPA’s fugitive emissions factors). The scenarios also remove the hypothetical emissions from EMI’s inoperable Furnace 18. In addition, the scenarios assessed the impact of EPA’s failure to account for respirable particulates and its use of implausible exposure assumptions.

The commenter (0272) also provided alternative enhanced capture scenario emissions by applying their “corrected actual” emissions scenario, even though the commenter believes that the EPA has no basis for requiring additional particulate controls.

Response: Consistent with previous risk ass essments, the EPA considers both allowable and actual emissions in assessing chronic exposure and risk under section 112(f)(2) for the ferroalloys source category (see e.g., the National Emission Standards for Coke Oven Batteries22

(70 FR 19998

- 19999, April 15, 2005) and in the proposed and final National Emission Standard for Organic Hazardous Air Pollutants from the Synthetic Organic Chemical Manufacturing Industry, or HON (71 FR 34428, June 14, 2006, and 71 FR 76603, December 21, 2006)). In those previous actions, we noted that modeling the allowable levels of emissions (i.e., the highest emission levels that could be emitted while still complying with the NESHAP requirements) is inherently reasonable since they reflect the maximum level sources could emit and still comply with national emission standards. This is in accord with the statutory requirement that the EPA evaluate “standards promulgated pursuant to subsection (d)” and if those standards “do not reduce lifetime excess cancer risk to the individual most exposed” the EPA must promulgate standards under section 112(f). This language most naturally refers to allowable emissions, since those are what the standards allow. Quite simply, in determining whether unacceptable residual risk remains after promu lgation of section 112(d) technology

- based standards, it is reasonable to consider the emissions allowed by those standards. In addition, the Benzene NESHAP looked to allowable emissions in assessing residual risk, and section 112(f) specifically preserves the Benzene NESHAP decision framework. But we also explained that it is reasonable to consider actual emissions, where such data are available, in both steps of the risk analysis, in accordance with the Benzene NESHAP. Sources could be emitting lower than MACT allowable levels and, if so, overall risk incidence is probably less than the maximum estimated levels. Failure to consider available data on actual emissions in risk estimates could unrealistically inflate risk levels. (See National Emission Standar ds for Coke Oven Batteries, 70 FR 19992, 19998, April 15, 2005.)
We disagree with the commenter that emissions that exceed standards should be part of the risk analysis. We further disagree with the commenter that we have ignored the risk associated with malfunctions. The final rule is designed to require sources to comply during all periods of operation. As explained in the preamble to the proposed rule, it is not possible to model malfunctions in the risk assessment, because by nature they are infrequent and unpredictable. The main purpose of the risk review is to evaluate whether the emission standard s should be made more stringent to reduce the risk posed after compliance with the underlying MACT standard. To the extent that a source is violating the un derlying MACT standard, no tightening of the emission standard under the residual risk rule will avoid or mi t i gate such violations. In other words, a source that is violating the MACT emissions standard promulgated under section 112(d) would not be any mor e likely to be able to avoid such violations and comply with a different presumably more stringent standard promulgated under section 112(f). Such events are violations and subject to enforcement by the EPA, the States, or citizens, and an action for injun ctive relief is the most effective means to address violations whether or not they are caused by malfunctions if an emissions event poses a significant health or environmental risk.

Comment: In their comments on the supplemental proposal, commenter 0272 st ates that the EPA has assumed in its allowable emissions scenario that EMI’s idle Furnace 18 will be used in the future and included the estimated emissions from that source when estimating the risk associated23

with “allowable” emissions. This appears to be based on the fact that Furnace 18 is still covered by EMI’s current operating permit and on statements from EMI that it is conceivable Furnace 18 might operate again sometime in the future. However, Furnace 18 is idle due to extensive damage that occurred to the unit in 2010 due to a furnace blow and EMI has no provision for reactivating the furnace in its current five

- year operational plan. Extensive repairs would be necessary before any future use would be possible. The commenter (0272) notes that the EP A addressed an analogous scenario in the Benzene NESHAP and deleted from its assessment coke batteries on cold

- idle that would require substantial construction or a pad

- up rebuild before they could be restarted. The commenter (0272) believes that Furnace 1 8 fits this characterization and should be treated consistently in this rulemaking.

Response: We disagree with the commenter and believe that the inclusion of potential emissions from Furnace 18 is appropriate. The furnace is currently permitted to operate and is therefore an allowable emission source. With respect to including Furnace 18 emissions in the allowable scenario, it is still covered by EMI’s operating permit and could operate in the future, so to be consistent with estimating “allowable” emissio ns, we included Furnace 18 in the allowable scenario. However, since it is damaged and would need extensive repairs, to calculate allowable emissions for this source, we assumed it would be subject to the standards in the 1999 NESHAP for new or major recon structed sources if it was repaired and operating again. With respect to the scenario described in the Benzene NESHAP, the text before the referenced comment response states that commenters supplied specific information regarding permanent plant or battery closure and changes in plant processes. EMI has not provided such information.

2.0 EPA RISK ASSESSMENT

2.1 Dose

- Response Values

2.1.1 Chronic Dose

- Response Values
Comment: Commenter 0107 states that the EPA must account for the increased susceptibility of children and pregnant women to HAP emissions from this source category in the risk assessment based on findings of the NAS review and CalEPA studies. The commenter (0107) is concerned that the EPA ’ s failure to include an adequate evaluation of increased early life sus ceptibility to HAP emissions systematically underestimates risk from the Ferroalloys source category for several HAP (POM, formaldehyde, arsenic, manganese, hexavalent chromium) and provides additional information supporting the need for these pollutant

- sp ecific analyses and information on the guidelines and other materials that the EPA should use to conduct such analyses. To satisfy its duty to protect children, the EPA must follow the best available science, at minimum, the EPA must adopt the following:

1. OEHHA Cancer Guidelines (Age

- Dependent Adjustment Factors) for all carcinogens and include pre

- natal susceptibility, and24

2. Child

- Specific Reference Doses (for Non

- Cancer Impacts), and

3. Children ’ s Default Safety Factor of At Least Ten (for Non

- Cance r Chronic & Acute Impacts), where specific information on children ’ s vulnerability is unavailable.
Commenter (0276) adds that the EPA ignore s the scientific recommendations to account for early life exposure and lead exposure from its own Children’s Health Advisory Committee.

Response: We disagree with the comment er ’s claim that the risk assessment for this source category does not consider the groups that may be most at

- risk (e.g., children and pregnant women). When the EPA derives exposure reference concentrations and unit risk estimates for hazardous air pollutants, including metal HAP, it also considers the most sensitive populations identified in the available literature, and importantly, the se are the values used in our risk

assessments. 3 The EPA has an approach for selecting appropriate health benchmark values and in general, this approach places greater weight on the EPA derived health benchmarks than those from other agencies. 4 Additionall y , th e approach of favoring EPA benchmarks (when they exist) has been endorsed by the SAB and ensures the use of values most consistent with well

established and scientifically

- based EPA science policy. T he EPA is currently evaluating the most appropriate use for the Cal OEHHA child

- specific reference doses . W e note that there are currently no such values for HAP inhalation, therefore their current utility would be limited to persistent and bioaccumulative HAP, which may be associated with non

- negligible ingestion exposures. Th e evaluation of the appropriateness of these values in the context of the RTR Program and EPA science policy is necessary prior to using these child

- specific reference doses (RfDs)
With respect to exposure, we use a health

- protectiv e assumption of a 70

- year exposure duration, in which populations are conservatively presumed to be exposed to airborne concentrations at their residence continuously, 24 hours per day for a full lifetime, including childhood.
With respect to cancer, the EPA uses the age

- dependent adjustment factor approach referred to by the commenter, but limits the use of those factors only to carcinogenic pollutants that are known to act via mutagenic mode of action, in contrast to the OEHHA approach, which uses them a cross the board for all carcinogens regardless of mode of action (MOA). In lieu of chemical

- specific data on which age or life

- stage specific risk estimates or potencies can be determined, default age dependent adjustment factors can be applied when assess ing cancer risk for early

- life exposures to chemicals which cause cancer through a mutagenic MOA. With regard to other carcinogenic pollutants for which early

- life susceptibility data are lacking, it is the Agency’s long

- standing science policy position th at use of the linear low

- dose extrapolation

3 US EPA. (2002). A review of the reference dose and reference concentration processes. EPA/630/P

- 02/002 F. Risk Assessment Forum, Washington, DC. Available online at http://www.epa.gov/raf/publications/pdfs/rfd

- final.pdf

4 http://www.epa.gov/ttn/atw/nata1999/99pdfs/healtheffectsinfo.pdf25

approach (without further adjustment) provides adequate public health conservatism in the absence of chemical

- specific data indicating differential early

- life susceptibility or when the mode of action is not muta genicity. 5 The basis for this methodology is provided in the 2005 Supplemental Guidance. 6

The EPA also disagrees with the commenter that a children’s default safety factor of 10 or more should be added to EPA’s reference values in response to the 10X fact or enacted by Congress in the Food Quality Protection Act (1996)

. 7 In response to the EPA non

- cancer reference value derivation, the Agency evaluated the methods for considering children’s risk in the development of reference values. As part of the respons e, the U.S. EPA (i.e. the Science Policy Council and Risk Assessment Forum) established the RfD/RfC Technical Panel to develop a strategy for implementing the Food Quality Protection Act (FQPA) and examine the issues relative to protecting children’s healt h and application of the 10X safety factor. One of the outcomes of the Technical Panel’s efforts was an in depth review of a number of issues related to the RfD/RfC process (U.S. EPA 2002). The most critical aspect in the derivation of a reference value
pe rtaining to the FQPA has to do with variation between individual humans and is accounted for by a default uncertainty factor (UF

- H) when no chemical

- specific data are available. EPA reviewed the default UF for inter

- human variability and found the EPA’s de fault value of 10 adequate for all susceptible populations, including children and infants. The EPA also recommended the use of chemical

- specific data in preference to default uncertainty factors when available (US EPA, 1994, 2011) 8 , and is developing Agen cy guidance to facilitate consistency in the development and use of data

- derived extrapolation factors for R fCs and RfDs (U.S EPA, 2011). 9 Additionally, the EPA also applies a database uncertainty factor (UF

- D) which is intended to account for the potenti al for deriving an under protective RfD/RfC as a result of an incomplete characterization of the chemical’s toxicity. In addition to the identification of toxicity information that is lacking, review of existing data may also suggest that a lower reference value might result if additional data were available.

5 U.S. EPA. A Review of the Reference Dose and Reference Concentration P rocesses. U.S. Environmental Protection Agency, Risk Assessment Forum, Washington, DC, EPA/630/P

- 02/002F, 2002

6 U.S. EPA. (2005), Supplemental Guidance for Assessing Susceptibility from Early

- Life Exposure to Carcinogens. EPA/630/R

- 03/003F. Washington, DC . Available online at: http://www.epa.gov/cancerguidelines/guidelines

carcinogen

- supplement.htm.

7 US Envi ronmental Protection Agency, Pesti cide: Regulating Pesti cides. The Food Quality Protection Act (FQPA). 1996. Available at http://www.epa.gov/pestici des/regulating/laws/fqpa/backgrnd.htm.

8 U.S. EPA (1994). Methods for derivation of inhalation reference concentrations and application of inhalation dosimetry. (EPA/600/8

- 90/066F). Research Triangle Park, NC. http://cfpub.epa.gov/ncea/cfm/recordisplay.cfm ?deid=71993

9 U.S. EPA (2011) External Review Draft of Guidance for Applying Quantitative Data to Develop Data

- Derived Extrapolation Factors for Interspecies and Intraspecies Extrapolation http://www.epa.gov/raf/DDEF/index.htm26

In conclusion, t he estimated risks must also be considered in the context of the full set of assumptions used for this risk assessment. Our unit risk estimates for HAP are considered a plausible upper

- bound estimate with an appropriate age dependent adjustment factor ; actual potency is likely to be lower and some of which could be as low as zero. Our chronic noncancer reference values have been derived considering the potential susceptibility of differe nt subgroups, with specific consideration of children. In addition, an extra 10X uncertainty factor is not needed in the RfC/RfD methodology because the currently available factors are considered sufficient to account for uncertainties in the database fro m which the reference values are derived. After considering these and other factors, we continue to consider the risks from emissions after application of the revisions to the NESHAP for this source category to provide an ample margin of safety (consisten t with the Benzene NESHAP framework).

Comment: Commenter 0107 notes that for the Ferroalloys source category, it is unclear whether there are HAPs missing from the EPA ’ s risk assessment and that the EPA should confirm that it has assessed the health risk for all emitted HAPs. The commenter (0107) adds that it is not clear from the record whether the EPA ’ s health risk assessment includes the currently uncontrolled emission points for which the EPA prop oses to set standards. The commenter (0107) states that the EPA must assess health risk from all pollutants, even where it has no current reference value, or must use an uncertainty factor to make up for the lack of a reference value. The commenter (0107) states that in the absence of an available reference dose, the EPA must, at minimum, add an uncertainty factor to account for the additional risk that a HAP likely causes, until such time

as the EPA does have a reference value to use.

Furthermore

, the c omm enter ( 0107 ) notes that the EPA ’ s risk assessment acknowledges other HAP emission s for which it has no reference values, but states that the EPA has failed to assess risk at all for these pollutants. The commenter (0107) adds that the EPA states that it pe rformed

no risk assessment for some hazardous air pollutants emitted by this source. The commenter (0107) is concerned that the EPA appears to have failed to account in any way for the acute health risks posed by manganese because of the lack of a reference value. The commenter states (0107) that this is irrational and unlawful. The commenter (0107) states that the EPA did not

even carry out a qualitative assessment of these HAPs, in effect assuming that risk from the HAPs is zero, which is not justified. The commenter (0107) notes that the EPA recognizes that its approach creates a potential understatement of health risk, but the E PA has not adequately explained how it has attempted to remove that understatement.

Response: This issue was addressed by the EPA’s Science Advisory Board (SAB) in their May 10, 2010, (EPA

- SAB

- 10

- 007) response to the EPA Administrator. 10 In that response, t he SAB

10 The SAB peer review of RTR Risk Assessment Methodologies is available at: http://yosemite.epa.gov/sab/sabproduct.nsf/4AB3966E263D943A8525771F00668381/$File/EPA

- SAB

- 10

- 007

- unsigned.pdf.27

Panel recommended that, for HAP that do not have dose

- response values from the EPA’s list, the EPA should consider and utilize, as appropriate, additional sources for such values that have undergone adequate and rigorous scientific peer review. The SAB panel further recommended that the inclusion of additional sources of dose

- response values into the EPA’s list should be adequately documented in a transparent manner in any residual risk assessment case study. We agree with this approach and have cons idered other sources of dose

- response data when conducting our risk determinations under RTR. However, in some instances no sources of information beyond those included in the EPA’s list are available.
The EPA agrees that we should ultimately develop toxi city values for all HAP utilizing all credible and relevant toxicity information. The need to update assessments with newly available data as well as the need to complete toxicological assessments for all HAP lacking dose

- response assessments further incre ases the importance of Agency activities to streamline and fully utilize the EPA’s already overloaded IRIS program. To that end, the EPA has always prioritized for future IRIS assessments those HAP without dose

- response values but with the greatest potenti al for public exposure. As a result of this prioritization, while not all HAP have scientifically accepted dose

- response values that can be used in residual risk assessments, it is clear that the vast majority of HAP which carry the potential to significan tly impact the results of residual risk assessments do, in fact, have credible dose

- response values. Thus, while we are not yet at the point where all HAP have dose

- response values, we are capable of deriving reasonable risk estimates for those HAP which d ominate the risks from any one source category. In the course of each residual risk assessment, should we encounter HAP without dose

- response values which carry the potential to create significant risks, we shall clearly point those out as uncertainties an d target them for future IRIS assessments. Moreover, as additional dose

- response values become available, the EPA will incorporate these dose

- response values into future risk assessments.
The EPA notes that we did state which HAP currently have no referenc e value. In the risk assessment document, Table 3.1

- 1 lists all the HAP emitted by the source category, and indicates whether there is an available cancer, chronic noncancer, and/or acute dose

- response value.
We disagree with the commenter ’s claim that it is not clear from the record whether the EPA’s health risk assessment includes the currently uncontrolled emission points for which the EPA proposes to set standards. Appendix 1 to the health risk assessment contains a full discussion of the testing condu cted for the ICR, how emissions estimates were developed from those test results, and how the modeling file (which is the basis for the risk assessment) was populated with the emissions estimates.

Comment: Commenter 0107 notes that an IRIS review is curren tly in process to update the EPA’s toxicity information for formaldehyde, hexavalent chromium, naphthalene, and PAH, which are pollutants emitted by this source category. The commenter (0107) adds that for these and any other pollutants currently under IRI S reassessment, the EPA must use the best available scientific information from the IRIS review during the current rulemaking. The commenter28

(0107) concludes that if the EPA determines that it must wait until these reassessments are complete to use the new ly available scientific information, then the EPA must take a more protective approach due to the outdated health risk reference information that it is using. The commenter (0107) adds that, to account for the delay and lack of reference values for some
po llutants, and the fact that it is still updating the toxicity information for other pollutants, the EPA must set a regulatory deadline no later than 8 years from the finalization of these rules, to review the current residual risk analysis and again perfor m a residual risk rulemaking once additional data on reference values become available.
Commenter 0075 asserts that the EPA’s data evaluation scheme which prioritizes the use of IRIS data as the highest ranking information is not reasonable or justifiable given the systemic failures identified by NAS.

Response: The EPA has a tiered prioritized list of appropriate health benchmark values and in general this hierarchy places greater weight on the EPA derived health benchmarks than those from other agencies. 11 We have a prioritization process aimed at incorporating into our assessments the best available science with respect to dose

- response information. This information is obtained from various sources and prioritized according to 1) conceptual consistency wit h the EPA risk assessment guidelines and 2) level of peer review received. Where we are lacking dose

- response information with higher priority (e.g., IRIS), we use other information sources, such as CalEPA. Notably, this priority list favoring the EPA benc hmarks (when they exist) over all others has been endorsed by the SAB. 12 “The Panel found the EPA’s approach to selecting dose

- response chronic toxicity values to be generally sound... The Panel supports the use of the Integrated Risk Information System (IRIS) as the preferred database for chronic dose

- response data. The Panel a lso strongly recommends that the EPA develop toxicity values for all HAP insofar as the data permit, and that it updates IRIS in a timelier manner.” “The preferred database for chronic dose

- response data is and should be the IRIS database. (p.17)”

The can cer dose

- response values that were used in th e 2014 supplemental proposal risk assessment for formaldehyde and hexavalent chromium are the current peer reviewed IRIS values, while naphthalene and PAH dose

- response values are from Cal EPA. The chronic

nonca ncer dose

- response values that were used in the 2014 supplemental proposal risk assessment for hexavalent chromium and naphthalene are the current peer reviewed IRIS values, while the formaldehyde value is from ATSDR. The sources for all values used in the risk assessment are presented in tables in Section 2.6.1 of the risk assessment document. At the time this analysis was performed these values were deemed to represent the best science. Revised

11 http://www.epa.gov/ttn/atw/nata1999/99pdfs/healtheffectsinfo.pdf

12 http://yosemite.epa.gov/sab/sabproduct.nsf/4AB3966E263D943A8525771F00668381/$File/EPA

- SAB

- 10

- 007

- unsigned.pdf29

IRIS values for these or other pollutants were not available at the time the analysis was performed. We cannot pick and choose newly available values that have not gone through the IRIS (or other similarly accepted) review process. We cannot delay rules for new IRIS values that may be developed in the future, howeve r we can re

- examine rules as new health information becomes available. Also, the commenter falsely assumes that all new IRIS dose

- response values will be more stringent than the existing values. The new IRIS dose

- response values could be less or more strin gent, or equal to the existing values depending on what the scientific data support.

2.1.1.1 Manganese RfC Comment: In their comments on the 2011 proposal, several commenters (0070, 0072, 0073, 0075, 0106) state that the EPA’s residual risk assessment significantl y overstates the risks associated with manganese by relying on an RfC that overstates risk. The commenters state that the EPA should re

- evaluate its risk assessment using a manganese inhalation reference supported by the full body of available data. These commenters state that the EPA used an outdated RfC for manganese, and the use of the current IRIS RfC of 0.05 μg/m3 for manganese does not constitute the best available science. Commenter 0075 notes that since this RfC was last updated in 1993, substantial research has been done to characterize the potential risk of inhaled manganese, including a 2009 publication by Bailey et al. which proposed an alternative RfC for manganese of 0.002 mg/m3 (based on 12 more

- recent occupational studies), which is over two orders of magnitude lower than the EPA’s RfC. The commenter (0075) states that the manganese HI value and the number of people exposed to high HI values would be much lower if this RfC was used. Commenter 0106 notes that the manganese RfC is based on parti cle inhalation, so the emissions and the concentration should only represent the toxicologically relevant fraction (i.e., PM2.5). The commenter (0106) also notes that the EPA established the current manganese RfC incorporating an “uncertainty factor” of 10 00 to provide conservative layers of safety based on gaps in the science that existed in 1993 and states that the more recent peer

- reviewed studies (Bailey et al.) have addressed and eliminated the data gaps that necessitated this conservative1000

- fold unc ertainty factor. The commenter (0106) asserts that the EPA’s explanation in the preamble to the proposed rule for use of the 1993 RfC does not address the large body of relevant peer

- reviewed science that has eliminated the justification for a 1000

- fold “u ncertainty factor.”

Also in comments on the 2011 proposal, two commenters (0070, 0073) note the EPA has previously acknowledged that the manganese RfC is based on incomplete data and of questionable reliability. In particular, the commenters (0070, 0073) note the failure to employ the preferred benchmark dose (BMD) statistical analysis in the development of the 1993 RfC. Three commenters (0070, 0073, 0106) state that the EPA’s reliance on an outdated manganese RfC without the requisite assessment of the be st available data does not meet the EPA’s obligations under the Agency’s information quality (IQ) guidelines. These commenters (0070, 0073, 0106), along with commenter 0072 state that the EPA should defer the final rule pending a comprehensive reassessment of the IRIS manganese RfC, correct the information related to the30

IRIS manganese RfC to make it conform to the IQ guidelines in this rule, or decline to rely on the outdated manganese RfC and use available information to develop the risk assessment. One

c ommenter (0073) also states that if a new RfC isn’t used, they want an explanation as to why and a chance to comment on that explanation.

In contrast, commenter (0107) cites several studies that are attached to the main comment letter that document neurolo gical, developmental, and reproductive health threats associated with manganese exposure, including neurotoxicity and impaired motor function. They also state that there is no known safe level of children’s exposure to manganese and the EPA must address th e potential increased vulnerability to children from manganese exposure. The commenter (0107) concludes that the EPA should consider all of this information as part of this rulemaking.

In their comments on the supplemental proposal, three commenters (0266, 0269, 0271) state that they further support the EPA’s decision to use the ATSDR for manganese instead of the existing IRIS RfC. One commenter (0269) noted that in their comments to the original proposal the existing IRIS RfC is more than twenty years out of date and significantly overstates the risks associated with manganese exposure. They believe the manganese ATSDR incorporates more recent scientific information and updated scientific analysis. However, they note that the ATSDR value still does not repr esent the best available science. The commenter (0269) supports the comments of the Manganese Interest Group (0266) and recommends that EPA follow MIG’s recommendations in the final rule.

One commenter (0266) believes that the ATSDR took into account the e xistence of physiologically

- based pharmacokinetic (PBPK) models in its manganese risk assessment, but ATSDR did not formally apply the models, nor did ATSDR consider application of the PBPK models by a variety of researchers who published important scienti fic papers after ATSDR’s assessment of the available science effectively ended. The commenter (0266) believes that application of the new science would result in an RfC or MRL for manganese no lower than 1.3 μg/m3 or potentially an order of magnitude highe r. Commenter 0272 believes the ATSDR MRL is overly conservative by a factor of 10 because the EPA did not take into account that the manganese emissions from ferroalloys production consist predominately of manganese oxides. Another commenter (0271) believe s that the data clearly indicate that the risk value that should be used for manganese is no lower than 1.3 μg Mn/m3 and believes that the EPA should use the 1.3 μg Mn/m3 value in its risk analysis. Commenter 0266 requests that the EPA correct its residual risk assessment for the ferroalloy NESHAP by deferring issuance of a final rule pending a reassessment of the ATSDR manganese MRL based on the best available science. The commenter (0266) provided a study (see Attachment B) entitled, “Physiologically Base d Pharmacokinetic Modeling for Comparative Exposure Assessment of Essential Elements: An Example of Manganese.” The study concluded that continuous exposure to manganese concentrations ranging from 50 μg/m3 to greater than 200 μg Mn/m3 would be needed to e xceed the NOAEL concentration, and potentially cause adverse effects, for the brain.31

In contrast, commenter 0276 disagrees with the EPA’s use of the ATSDR MRL and states that the EPA has not provided sufficient rationale to justify use of this less protec tive value. The commenter (0276) states that there is significant new information suggesting that the value should be more protective, not less. The commenter (0276) describes several recent studies, which show that the 1993 study that was the basis for th e original IRIS value likely underestimates the neurological harm caused by manganese exposure, particularly to children. The commenter (0276) adds that it is inconsistent with the EPA’s own child

- protection focused policies to use the ATSDR number instead of the more protective IRIS number.
The commenter (0276) states that waiting for “future” reviews to assess the implications of these 2014 studies ignores the harm to health risks now that are being addressed by the ferroalloys risk assessment. The comme nter (0276) adds that at a minimum, the EPA should apply an additional factor to account for the risk not addressed in the current analysis. The commenter notes that the most current research also provides further support the EPA’s finding of unacceptabili ty and the need for strong health risk

- based standards that assure an “ample margin of safety to protect the public health.”

Response : In response to the comments pertaining to use of the IRIS RfC in the 2011 proposal, we agree that there is newer informat ion available since the development of the RfC for manganese, and the preferred approach for developing reference values (i.e., the benchmark dose approach) has since been widely adopted in the IRIS Program. However, we would note that statistical modelin g, as was done in 1993, is consistent with the benchmark dose approach. We also agree that use of another value could change the risk results and presumably the acceptability decision. The ensuing paragraphs explain the approach taken by EPA in choosing reference values for use in the RTR Program.

The EPA has developed a tiered list of reference values; IRIS as is our preferred source for reference values. The remainder of reference values on the preferred list give priority to values from sources that ar e conceptually consistent with the EPA’s risk assessment guidelines and have undergone rigorous peer review. This prioritization scheme has been through a Scientific Advisory Board (SAB) review and was favorably received.

In response to public comments o n the 2011 proposal, the EPA considered the existing peer

reviewed health effect reference values for chronic inhalation exposure to manganese from other federal, state and international agencies and organizations, and notes the following details on the de rivation of each: 13

13 U.S. EPA. Mn and BTEX Reference Value Arrays (Final Reports). U.S. Environmental Protection Agency, Washington, DC, EPA/600.R

- 12/047F, 2013.32

• The current IRIS RfC (U.S. EPA, 1993) of 0.05 μg/m 3 was based on the lowest observed adverse effect level (LOAEL) from the study by Roels et al. (1992) on neurobehavioral effects in exposed workers. The LOAEL was used as the point of d eparture (POD) and then adjusted for dosimetry (ventilation rate from occupational to ambient, assuming systemic effects) and to account for duration of exposure (from occupational to continuous) ; and applying a total uncertainty factor (UF) of 1000 to

acc ount for these extrapolations

.

• In 2012, the Agency for Toxic Substances and Disease Registry (ATSDR) developed a chronic Minimal Risk Level (MRL) of 0.3 μg/m 3 based on neurobehavioral effects in exposed workers reported by Roels et al. (1992). The MRL used a BMCL 10 (a higher benchmark response level than used for the two values below ) as the POD . It was adjusted for duration of exposure (from occupational to co ntinuous) and a total UF of 100 was used (ATSDR, 2010). This value is six ti mes the existing IRIS value.

• The Office of Environmental Health Hazard Assessment (OEHHA) for the State of California (OEHHA, 2008) developed a chronic Reference Exposure Level (C A

REL) for Mn, based on neurobehavioral effects in exposed workers reported by Roels et al. (1992). The CAL

- REL was calculated using a BMCL 05 as the POD , which was adjusted for duration of exposure (from occupational to continuous)

, and application of a total UF of 300. The resulting value is 0.09 μg/m 3 , which is about a factor of 2 greater than the current IRIS RfC.

• Health Canada (2010) developed an RfC for Mn based on a study conducted by Lucchini et al. (1999) on neurobehavioral effects in exposed workers. The value was derived using a benchmark concentration analysis (BMCL 05 ) as the POD , which was adjusted for duration of exposure (from occupational to continuous) and application of a total uncertainty factor (UF) of 100. The res ulting value is the same as the current IRIS RfC of 0.05 μg/m 3 (U.S. EPA, 1993).

• The World Health Organization (WHO, 2000) developed a Health Guideline value for exposure to Mn based on a study of Roels et al. (1992). The value was derived using a BMCL 05 as the POD with adjustments to account for duration, and a total UF of 50. The resulting value is 0.15 μg/m 3 , which is a factor of 3 higher than the current IRIS RfC.

The current IRIS RfC for manganese is within a factor of three of the chronic inhalation reference values above, including those which use the benchmark analysis

.
We note that the size of the manganese

- containing particle has a bearing on the toxicity and some of the organizations listed above and others (especially those for occupational ex posures)33

have developed reference values based on different size fractions. 14 T he range of size fractions on which reference values have been developed include PM 2.5 , PM 3.5 , PM 5 , PM 10 , and TSP. The current and historical monitoring information is limited t o measurements of PM 2.5 or PM 10 , leaving these two fractions as the only ones available for any exposure analysis. The American Conference of Governmental Industrial Hygienists (ACGIH), the International Standards Organization (ISO), and the European Stand ardization Committee have all adopted 4 μm as the 50 percent cut point and indicator of respirable particles ; 15 in essence, this means 50 percent of respirable particles will be captured with a 4 μm impact separator and the other 50 percent will be larger p articles with increasingly smaller proportions being captured as the size goes up. Adoption of a PM 2.5 cut point would therefore ignore a large portion of the mass which is defined as respirable by a number of authoritative bodies, and making the choice of PM 10 as being the most appropriate for RTR regulatory decisions. All of the preferred reference values previously discussed are based on the same 1992 study by Roels et al., who also used 4 μm as the 50 percent cut point. Given all of these considerations , in addition to the EPA policy to be health protective in the face of uncertainty , PM 10 has been and will continue to be used to characterize these exposures to manganese.
In our consideration of available reference values, the EPA did not include some values specifically noted in public comments. The level of peer review and publication purpose for non

governmental scientific publications (e.g., Bailey et al 2009) is qualit atively different than the processes used to derive the reference values described in detail above. The EPA did not include the Ontario Ministry of the Environment (MOE) standard on manganese

- containing particles because it is a regulatory limit, similar t o a National Ambient Air Quality Standard (NAAQS), rather than a value developed for risk assessment purposes. The information provided by these additional references, however, may prove useful in the I RIS reassessment for manganese. A direct application of any of these values instead of an established reference value in our tiered list of prioritized dose

- response values would be inconsistent with the EPA policy as implemented in the RTR Program, and with recommendations from the SAB.

In 1994, the EPA co nducted an analysis in the context of evaluating the risks of exposure to
manganese in the fuel additive methylcyclopentadienyl manganese tricarbonyl (MMT); this was not intended to be a replacement for the 1993 IRIS RfC and did not follow the established review procedures for an IRIS assessment. The publication explicitly stated that “the RfC estimates developed for the purpose of this risk assessment do not represent a revision of the current verified RfC for manganese (EPA, 1994, pg. 10).” As a result o f the EPA’s MMT evaluation,

14 U.S. EPA. Mn and BTEX Reference Value Arrays (Final Reports). U.S. Environmental Protection Agency, Washington, DC, EPA/600.R

- 12/047F, 2013.

15 U.S. EPA, 2009. Integrated science assessment for particulate matter. EPA/600/R

- 08/139F. Research Triangle P ark, NC. http://cfpub.epa.gov/ncea/cfm/recordisplay.cfm?deid=216546.34

the EPA required the former Ethyl Corporation (now Afton Chemical) to conduct several studies under a test rule agreement

. 16 These studies produced a body of data used to develop physiologically based pharmacokinetic (PBPK) mode ls for laboratory animals and humans, which several commenters suggest the EPA consider in its RfC. The EPA agrees that the PBPK models, along with all other relevant available peer

- reviewed literature, will be considered in an IRIS reassessment for mangan ese, and EPA notes the use of these PBPK models to inform the derivation of other reference values (e.g., the MRL developed by ATSDR).

The EPA is aware that new scientific data have become available since the 1993 IRIS assessment for manganese was complet ed, including both experimental studies and epidemiological evaluations of exposed human populations. However, it is premature to estimate what, if any, revisions to the IRIS assessment for manganese may be needed until a comprehensive evaluation is conduc ted and such an evaluation cannot be completed by the court

- ordered deadline for this final rule. The EPA IRIS Program has placed manganese on its agenda for a revised assessment, which will begin with a scientific literature search and problem formulation meeting, where the public will be invited to participate and submit additional scientific information. Following problem formulation, a draft toxicological review is developed and subjected to internal Agency review, science consultation and discussion wi th other Federal Agencies and White House offices; a public review and comment period; and an independent external peer review. More detailed information on the IRIS assessment development process is available on the IRIS website. 17

After consideration of reference values in our tie red list of prioritized dose

- response values, and consistent with Agency policy which was supported by the SAB, we chose to rely on the 2012 ATSDR MRL for manganese in the supplemental proposal and final rule risk assessments. B oth the 1993 IRIS RfC and the 2012 ATSDR MRL were based on the same study (Roels et al., 1992). In developing their assessment, ATSDR used updated dose

- response modeling methods (benchmark dose approach) and considered recent pharmacokinetic findings to s upport their selection of an uncertainty factor in the derivation of the MRL.
With respect to the use of the ATSDR MRL in the 2014 supplemental proposal, we disagree with the comment that the ATSDR value is “less protective.” Although there are other val ues which arrive at a lower final value for manganese, the ATSDR used analytical approaches such as the benchmark dose implementing technical guidelines most consistent with EPA practices. Further,

16 More information on the MMT health effects testing can be found at: http://www.epa.gov/otaq/regs/fuels/additive/mmt_cmts.htm. Final test reports can be found at www.regulations.gov, doc ket number EPA

- HQ

- OAR

- 2004

- 0074.

17 Further explanation of the IRIS Assessment Development Process can be found at: http://www.epa.gov/iris/process.htm35

the actual issue is which derivation procedure best afford s accuracy

– what value best characterizes the ambient exposures under consideration? ATSDR used the most up

- to

- date information on the kinetics (absorption, distribution, metabolism and excretion) of manganese to ensure the derived MRL value did not appro ach exposure levels which would lead to toxicity. 18 EPA intends to explore application of the PBPK model in its revisions to the IRIS assessment.

We also disagree that an uncertainty factor should be removed due to the speciation of manganese emissions. Th e available reference values were designed to be applicable to manganese and manganese compounds; reference values for individual manganese species are not available. Exploration of the PBPK model applied to specific species of manganese may be possible pr ovided the exposures are characterized with respect to particle size and distribution.

2.1.1.2 Nickel URE
Comment: In their comments on the 2011 proposal, c ommenters ( 0066
, 0072 , 0106) assert that treating all nickel compounds as having the same carcinogenic po tency (URE) value as the URE the EPA assigned to nickel subsulfide in 1986 is deeply flawed and demonstrably illogical , and they urge the EPA to correct the cancer risk estimate for nickel

- containing emissions. The

commenter s ( 0066
, 0072 , 0106 ) add the EPA has not classified nickel species other than nickel subsulfide and nickel refinery dust as known human carcinogens and that even if the EPA decides to treat all nickel species as human carcinogens, there would be no basis to apply the URE for nicke l subsulfide to total nickel emissions , as the EPA recognizes that different nickel species have different carcinogenic potential

. Commenter 0066 also states that studies have shown elevated respiratory cancer risks only in certain types of nickel refineri es but not in those where nickel is present in oxide form

. Commenter (0066) further states that if the EPA chooses to assume that all nickel compounds are carcinogenic and that a single URE can be applied to “nickel compounds” as a group, it would be illog ical to use the URE for nickel subsulfide because the IRIS URE for nickel subsulfide is an artificial value that was calculated by doubling a calculated URE for nickel refinery dust, based on the assumption that nickel subsulfide constituted 50% of the nic kel species to which the refinery workers were exposed but was responsible for 100% of the cancer risk. Further, the commenter notes there is very little nickel subsulfide in emissions from ferroalloys facilities. The commenter (0066) asserts that epidemio logical and animal studies indicate that nickel

- related carcinogenicity has an actual or practical threshold that makes application of any linearized URE value to predict c ancer risks at low ambient levels of exposure problematic and highly conservative.

18 Manganese is an essential mineral nutrient, espec ially for fetal and neonate neurological development. There are homeostatic mechanisms within the body to help regulate the level of manganese in cells to ensure proper levels are maintained (not too much or too little); only after these homeostatic mechan isms are overwhelmed does manganese exert its toxic effects.36

C ommenter s 0066 and 0264 state that the EPA should use the TCEQ

- developed URE of 1.7 x 10

- 4 per μg/m 3 for nickel compounds. The commenter s (0066 and 0264) note that TCEQ has corrected certain methodology/calculation errors that the EPA had made, performed m ore refined modeling, and used additional data that were not available to the EPA in 1986 and asserts that this is the best currently available value for the EPA to use in estimating lung cancer risks associated with emissions of nickel

- containing particul ate from Ferroalloys Production facilities. Commenter (0264) notes that the TCEQ URE value would not change the EPA’s determination that residual risks in ferroalloys production is unacceptable, however they believe that this URE provides a sound scientific foundation and used in future rulemakings

. Response: As discussed above, in Section 1.2.1.1, the EPA has a tiered prioritization list of appropriate health benchmark values and in general this list places greater weight on the EPA

derived health benchmarks than those from other agencies. 19 We have a prioritization process aimed at incorporating into our risk assessments the best available science with respect to dose

response information. This information is obtained from various sources and prioritized according to 1) conceptual consistency with t he EPA risk assessment guidelines and 2) level of peer review received.
In the inhalation risk assessment for the 2011 proposal, to take a conservative approach, we considered all nickel compounds to have the same carcinogenic potential as nickel subsulfid e and used the IRIS URE for nickel subsulfide to estimate risks due to all nickel emissions from the source category. In the public comments provided in response to the proposal and available data in the docket, one facility provided additional data in the form of a laboratory test report that indicated it would be unlikely that 100 percent of the nickel from the furnace would be in the form of nickel subsulfide.

Based on consistent views of major scientific bodies ( e.g., IARC, NTP, WHO) that consider all nickel compounds to have carcinogenic potential, we currently consider all nickel compounds to have the potential of being carcinogenic to humans. Although the precise nickel compound (or compounds) responsible for carcinogenic effects in humans is not always clear, studies indicate that nickel sulfate and the combinations of nickel sulfides and oxides encountered in the nickel refining industries cause cancer in humans. The major scientific bodies mentioned above has also recognized that there are differences in toxicity and/or carcinogenic potential across the different nickel compounds. There are two additional URE values 20 derived for exposures to mixtures of nickel compounds, as a group, that are 2

- 3 fold lower than the IRIS URE for nic kel subsulfide for providing an estimate of the lower end of the plausible range of cancer potency values for

19 http://www.epa.gov/ttn/atw/nata1999/99pdfs/healtheffectsinfo.pdf

20 Two UREs (other than the current IRIS value) have been derived for nickel compounds as a group: one developed by the Californi a Department of Health Services (http://www.arb.ca.gov/toxics/id/summary/nickel_tech_b.pdf) and the other by the Texas Commission on Environmental Quality (http://www.epa.gov/ttn/atw/nata1999/99pdfs/healtheffectsinfo.pdf).37

different mixtures of nickel compounds. Given our current knowledge of the carcinogenic potential of all nickel compounds and the potential differ ences in carcinogenic potential across nickel compounds, we consider it reasonable to use a value that is 50 percent of the IRIs URE for nickel subsulfide for providing an estimate of the cancer potency for different mixtures of nickel compounds in the rev ised dataset for the 2014 supplemental proposal and 2015 final rule. Fifty percent of the IRIS URE for nickel subsulfide is the same numeric value as the IRIS URE for nickel refinery dust, but we did not use “nickel refinery dust” to classify nickel emissi ons from this source category.

2.1.1.3 Arsenic Risk URE
Comment: Commenter 0106 asserts that although the estimated arsenic cancer risk (20 in a million) is already well below the MIR target of 100 in a million (1 x 10

- 4), the EPA's cancer risk assessment is stil l overestimated . The commenter asserts that : arsenic URE has not been updated since 1984, and the use of this value ignores recent scientific studies which showed that a more scientifically supported arsenic URE (based on revisions to the exposure assessme nt in the original smelter cohort used by US EPA in 1984) is about 3

- fold lower than the current arsenic URE.

Commenter 0107 states that the EPA must account for early exposure to this pollutant and that California has listed this pollutant as being known to cause developmental toxicity

. Therefore, the assessment of risks due to arsenic exposure must be adjusted to account for increased early life susceptibility to non

- mutagenic carcinogens.

Response : The use of IRIS values has been discussed above ( in Sec tion 2.1.1 ). The explanation of how the EPA accounts for early childhood exposure has also been discussed above (in Section 2.1.1 ).

2.1.1.4 Form a ldehyde URE
Comment: Commenter 0076 states that the EPA’s reliance on an outdated formaldehyde inhalation exposure risk without the requisite assessment of the best available data does not meet the EPA’s obligations under the Agency’s information quality (IQ) guidelines. The commenter (0076) describes the IQ guidelines and explains why t he formaldehyde dose

- response value is not in compliance. The commenter (0076) cites the history of the formaldehyde dose

- response value and concludes that the 2011 NAS report should be used in determining what constitutes the best available science. The c ommenter (0076) asserts that the deference given to the 1991 IRIS Assessment is directly at odds with the EPA’s mandate to consider all credible and relevant information in a rulemaking proceeding. The commenter (0076) asserts that the proposed rule should be based on the best available science at the time of the rulemaking, and follow the EPA’s mandate to “consider all credible and relevant information” in the rulemaking. The commenter (0076) states that the EPA should reject the 1991 IRIS model and its co rresponding dose

response value and employ the CIIT biologically

- based dose

- response (BBDR) model, as38

recommended by the National Academy of Sciences in their 2011 Review of the Environmental Protection Agency's Draft IRIS Assessment of Formaldehyde

. Respo nse: In 2004, the EPA determined that the Chemical Industry Institute of Toxicology (CIIT) cancer dose

- response value for formaldehyde (5.5 x 10

- 9 per ug/m 3 ) was based on better science than the IRIS dose

- response value (1.2 x 10

- 5 per ug/m 3 ), and we switc hed from using the IRIS value to the CIIT value in risk assessments supporting regulatory actions

. Subsequent research published by the EPA suggested that the CIIT model was not appropriate and, in 2010, the EPA returned to using the 1991 IRIS value

. The E PA has been working on revising the formaldehyde IRIS assessment and The National Academy of Sciences (NAS) completed its review of the EPA’s draft assessment in April of 2011 ( http://www.nap.e du/catalog/php?record_id=13142 )

. The EPA will follow the NAS Report recommendations and will present results obtained by implementing the biologically based dose response (BBDR) model for formaldehyde

. The EPA will compare these estimates with those

curren tly presented in the External Review draft of the assessment and will discuss their strengths and weaknesses

. As recommended by the NAS committee, appropriate sensitivity and uncertainty analyses will be an integral component of implementing the BBDR model

. In the interim, we will present findings using the 1991 IRIS value as a primary estimate and the EPA may also consider other information as the science evolves

. The EPA notes that formaldehyde was not a driver of the risks attributable to the emissions f rom this source category

.
Comment : Commenter 0107 states that studies have found increased sensitivity of children to respiratory toxicity of formaldehyde and as a result “CalEPA has prioritized it as a toxic air contaminant of particular concern for children.” The EPA’s “residual risk assessment should h ave adjusted the dose

- response values for both the cancer and non

- cancer effects of formaldehyde exposure” to account for this increased early life susceptibility.

Response : The use of IRIS values has been discussed above ( in Section 2.1.1). The explanatio n of how the EPA accounts for early childhood exposure has also been discussed above (in Section 2.1.1).

2.1.1.5 Chromium RfC
Comment: Commenter 0075 states that the EPA relies on an outdated scientific assessment for chromium, one of the chemicals indicated as a driver for the unacceptable cancer risks. The

commenter (0075) notes that this c onclusion relies on data from a 13

- year

- old chromium IRIS RfC value for which the EPA noted it had low confidence. The commenter (0075) states that it is crucial to ensure that the residual risk assessment conclusions are based on the current scientific knowledge, and adds that newer scientific information is available, as evidenced by a 2003 publication by Crump et al. which evaluated the dose

- response relationship for inhalation exposure to hexavalent chromium and provided estimates of the carcinogenic potency. The

commenter (0075) asserts that failure to consider this study renders the EPA’s proposed risk conclusions arbitrary.39

Commenter 0107 refers to the EPA and CalEPA toxicological reviews 21
, 22 of hexavalent chromium which indicate that hexavalent chromium has a mutagenic mode of action. The commenter states that the EPA’s risk assessment should therefore include an early life exposure

a djustment.

Response: The use of IRIS values has been discussed above (in Section 2.1.1). The explanation of how the EPA accounts for early exposure has also been discussed above (in Section 2.1.1).

2.1.1.6 Lead Dose

- Response Values
Comment: Commenter 0107 is conce rned with EPA ’s reliance on the 2008 National Ambient Air Quality Standards (NAAQS) for Lead in assessing noncancer hazards for lead . The commenter (0107) states that this is relevant information but does not address all that is needed for a section 112(f) (2) assessment of health risk from lead. The commenter (0107) goes on to claim that the NAAQS was created to protect the average exposed member of the population from an IQ point loss above 2 points, and states that the NAAQS is not to protect the “most exposed” and most vulnerable member of that population implying that is necessary under section 112(f)(2) . The commenter (0107) also states that the NAAQS was also designed to address only a single pollutant (elemental lead), while section 112(f)(2) requir es the EPA to assess and address health risk from the combined effect of a source category on the most exposed
person.
According to the commenter (0107), there is new information since 2008 that EPA must consider in assessing the risks of lead under secti on 112(f)(2) . In comments on the supplemental proposal, commenter 0276 cites several recent studies as show ing that harm to children can occur at levels below the lead NAAQS. Commenter s 0107 and 0276 also state that lead can cause greater harm when in the presence of arsenic and manganese than lead exposure alone.
Commenter 0276 states that the EPA must address and incorporate the best available information on children’s exposure, including the EPA’s Children’s Health Protection Advisory Committee (CHPAC) recommendation of protecting children from an ambient concentration of lead of 0.02μg/m 3 rather than assuming that the 2008 NAAQS level of 0.15 μg/m 3 is protective enough.

Finally, the commenters (0107, 0276) note that section 112(f)(2) requires the EPA t o create an “ample margin of safety to protect public health, ” while the NAAQS only must satisfy the test to provide an “adequate margin of safety.” Commenter (0276) adds that the residual risk standards are designed to do more than just replicate other st atutory protections, such as those provided by the NAAQS. If Congress had intended the EPA simply to replicate the NAAQS , or some other different Clean Air Act requirement, commenter 0276 states that the section 7412(f)(2)

21 EPA 2010. Toxicological Review of Hexavalent Chromium (CAS No. 18540

- 29

- 9): In Support of Summary Information on the Integrated Risk Information System (IRIS) at 238.

22 Cal. EPA, OEHHA 2010. Draft Public Health Goal for Hexavalent Chromium in Drinking Wat er.40

requirement would become redunda nt for any HAP that also has any relationship to any other regulated pollutant. According to the commenter (0276), if there were any ambiguity on this question, statutory construction requires a reading of section 7412(f)(2) that preserves its independent value and meaning.
Commenter 0107 concludes that rather than only relying on the NAAQS to assess health risk from lead, the EPA should use all of the best available, most current information, including California’s lead health benchmark.

Response: While r ecognizing that lead has been demonstrated to exert “a broad array of deleterious effects on multiple organ systems,” the lead NAAQS targets the effects associated with relatively lower exposures and associated blood lead levels, specifically nervous syste m effects in children including cognitive and neurobehavioral effects (73 FR 66976). The 2008 decision on the lead NAAQS was informed by an evidence

- based framework for neurocognitive effects in young children. I n applying the evidence

- based framework, w e focused on a subpopulation of U.S. children, those living near air sources and more likely to be exposed at the level of the standard; to the same effect see 73 FR 67000/3

-- “The framework in effect focuses on the sensitive subpopulation that is the group of children living near sources and more likely to be exposed at the level of the standard. The evidence

- based framework estimates a mean air

- related IQ loss for this subpopulation of children; it does not estimate a mean for all U.S. children”; 73 FR 670 05/1

-- “the air

- related IQ loss framework provides estimates for the mean air

- related IQ loss of a subset of the population of U.S. children, and there are uncertainties associated with those estimates. It provides estimates for that subset of children like ly to be exposed to the level of the standard, which is generally expected to be the subpopulation of children living near sources who are likely to be most highly exposed.” In addition, in reviewing and sustaining the lead primary NAAQS, we note that the D.C. Circuit specifically noted that the rule was targeted to protect children living near lead sources: “EPA explained that the scientific evidence showing the impact of lead exposure in young children in the United States led it ‘to give greater promine nce to children as the sensitive subpopulation in this review’ and to focus its revision of the lead NAAQS on the ‘sensitive subpopulation that is the group of children living near [lead emission] sources and more likely to be exposed at the level of the s tandard.’ Given the scientific evidence on which it relied, the EPA’s decision to base the revised lead NAAQS on protecting the subset of children likely to be exposed to airborne lead at the level of the standard was not arbitrary or capricious.” Coali tion of Battery Recyclers, 604 F. 3d at 618.

A s noted in the risk assessment document, there is no RfD or other comparable chronic health benchmark value for lead compounds. I n 1988, the EPA’s IRIS program reviewed the health effects data regarding lead an d its inorganic compounds and determined that it would be inappropriate to develop an RfD for these compounds, s tating

,

“ A great deal of information on the health effects of lead has been obtained through decades of medical observation and scientific research. This information has been41

assessed in the development of air and water quality criteria by the A gency’s Office of He alth and Environmental Assessment (OHEA) in support of regulatory decision

- making by the Office of Air Quality Planning and Standards (OAQPS) and by the Office of Drinking Water (ODW). By comparison to most other environmental toxicants, the degree of unce rtainty about the health effects of lead is quite low. It appears that some of these effects, particularly changes in the levels of certain blood enzymes and in aspects of children’s neurobehavioral development may occur at blood lead levels so low that a threshold has yet to be determined . The A gency’s RfD Work Group discussed inorganic lead (and lead compounds) at two meetings (07/08/1985 and 07/22/1985) and considered it inappropriate to develop an RfD for inorganic lead. ”

The EPA’s IRIS assessment for L ead and compounds (inorganic) (CASRN 7439

- 92

- 1) can be found here: http://www.epa.gov/iris/subst/0277.htm

. With regard to the information identified by the commenters, much of this information was similar to information available at the time of the 2008 NAAQS decision. For example, in 2005, the CDC recognized the evidence of adverse health effects in children with blood lead levels below 10 μg/dL, and that there is no safe level of blood lead in young children (CDC, 2005). The commenter also cites a benchmark analysis by California OEHHA that was completed during the time of the last review (Carlisle and Dowli ng, 2007). The quantitative relationship from this analysis of a correlation of 1 IQ point change with a 1.0 μg /dL change in blood lead is actually a substantially smaller change in IQ per μg /dL blood lead than the slope of 1.75 IQ points per μg /dL blo od lead used in the evidence

- based framework that the Administrator relied upon in his 2008 decision on a revised level for the lead NAAQS in 2008 (73 FR 66964). Regarding the CHPAC recommendation on level and averaging time referenced by the commenter, t his was made to EPA in January of this year (2015) in the context of the current NAAQS review and the same comment was made and considered in the 2008 review, that concluded with the current lead NAAQS.
In response to the comment that the EPA is required t o assess the combined effect of multiple pollutants from a source category on the most exposed person, we agree and consider our analysis to have done this. The approach used to calculate chronic non

- cancer risks, developing the target

- organ specific hazar d index, specifically considers the combined effect of multiple pollutants on the same target organ. For this particular source category, lead and manganese were both considered to have an effect on the neurological system (lead is also considered to have a developmental effect). Any new scientific information concerning lead will be reviewed in accordance with the NAAQS review process.
The commenter also makes the legal argument that EPA cannot simply replicate the primary NAAQS in its proposed residual r isk rule because The Clean Air Act sets different tests for these rules to meet and EPA cannot substitute one for the other. We do not accept the commenter’s argument. The EPA consider ed the primary NAAQS for lead

-- which incorporates an adequate42

margin o f safety

-- in determining whether lead risks (taken together with cancer and other non

cancer health risks) from air

- borne lead from ferroalloys facilities are acceptable or unacceptable. Thus, to the extent the commenter’s argument rests on the differenc e between ‘adequate’ and ‘ample’ margin of safety, the argument is misplaced. 23 Margin

- of

- safety determinations for this rule are conducted separately, in accord with the two

- step framework set forth in the Benzene NESHAP and the en banc opinion in Vinyl Ch loride. See not only Vinyl Chloride , 824 F. 2d at 1165, 1166 but NRDC v. EPA , 902 F. 2d 962, 973

- 74 (D.C. Cir. 1990) (distinguishing the NAAQS process, whereby the margin of safety analysis is incorporated as part of the standard without a two

- step analys is, from residual risk determinations). 24 Using that framework, with its consideration of costs, cost

- effectiveness, technological feasibility, and other factors set out in the Benzene NESHAP, at proposal we did not identify any additional controls beyond t hose that would need to be implemented to ensure an acceptable level of risk with an ample margin of safety. The EPA thus disagrees with the commenter that section 112 (f)(2) standards would become redundant for any hazardous air pollutant that also has a relationship to any other regulated pollutant

.

2.1.2 Acute Dose

- response Values
Comment: Commenter 0065 states that the use of AEGLs or ERPGs does not include adequate safety and uncertainty factors and cannot be relied upon to protect the public from the advers e effects of exposure to toxic air pollutants. The commenter (0065) describes that these limits were developed for accident release emergency planning and are not appropriate for assessing daily human exposure scenarios. The commenter (0065) notes that in the December 2002 EPA document, "A Review of the Reference Dose and Reference Concentration Processes," The EPA stated that the primary purpose of the AEGL program is to develop guidelines for once

- in

- a

lifetime short

- term exposures to airborne concentrati ons of acutely toxic chemicals. The

commenter (0065) states that they are not meant to evaluate the acute impacts from routine emissions that occur over the life of a facility. Unlike the reference concentrations (RfCs) for chronic exposures, the AEGLs and ERPGs do not include adequate safety and uncertainty factors and cannot be relied upon to protect the public from the adverse effects of exposure to toxic air pollutants. The commenter (0065) states that their use is not appropriate in risk assessments and
urge s the EPA to increase its reliance on the California Reference Exposure Levels (RELs) to address acute exposures in the residual risk assessments.

Response: The EPA does not rely exclusively upon AEGL values for assessment of acute exposures. Rathe r, the EPA’s approach is to consider various acute health effect reference values

23 Indeed, the EPA’s utilization of a standard which also incorporates an adequate margin of safety to evaluate acceptability of risk is an added conservative (i.e. protective) element in its approach here.

24 The court was referring to the predecessor provision to the current section 112 (f), but its analysis is equally applicable to the revised provision.43

(see 76 FR 52772), including the California REL, in assessing the potential for risks from acute exposures. To better characterize the potential health risks associated with estimated acute exposures to HAP, and in response to a key recommendation from the SAB’s peer review of the EPA’s RTR risk assessment methodologies, 25 we generally examine a wider range of available acute health metrics (e.g., RELs, AEGLs) than we do for ou r chronic risk assessments. This is in response to the SAB’s acknowledgement that there are generally more data gaps and inconsistencies in acute reference values than there are in chronic reference values. In some cases, when Reference Value Arrays 26 for H AP have been developed, we consider additional acute values (i.e., occupational and international values) to provide a more complete risk characterization. As discussed in the preamble to the proposed rule, the exposure guidelines EPA considers depends on which exposure guidelines are available for the various HAP emitted. The EPA uses AEGL and ERPG values (when available) in conjunction with REL values (again, when available) to characterize potential acute health risks. However, it is often the case that HAP do not have all of these acute reference benchmark values. In these instances, the EPA can only describe the potential acute health risk in relation to the acute health values that are available. Importantly, when interpreting the results, we are caref ul to identify the benchmark being used and the health implications associated with any specific benchmark being exceeded.

2.1.2.1 Nickel

Comment: In response to the 2011 proposal, c ommenter 0106 states that the acute reference exposure level (REL) for nickel is based on the toxicity of nickel sulfate, which is more toxic than nickel oxide, the primary nickel species expected in the EMI emissions, and resultantly the acute inhalation risk from nickel emissions near the EMI facility is likely overestimated. The

com menter (0106) asserts that there is evidence that nickel oxide could be 10

- fold less toxic than nickel sulfate, suggesting the nickel screening HQ could be closer to 1 (or no risk).

Response: Although the commenter states that there is evidence that nickel oxide is 10

- fold less toxic than nickel sulfat e, the commenter does not provide quantitative evidence characterizing the 10

- fold differential toxic potential between nickel oxide and nickel sulfate (the latter being the form of nickel used to derive the a cute REL value from Cal EPA). Because there are great uncertainties associated with various aspects of the assessments of risks from acute exposures to HAP (uncertainties related to the acute health effects assessments, characterization of exposure

concent rations, etc.) and given the fact that these analyses represent worst

- case scenarios, the

25 The SAB peer review of RTR Risk Assessment Methodologies is available at: http://yosemite.epa.gov/sab/sabproduct.nsf/4AB3966E263D943A8525771F00668 381/$File/EPA

- SAB

- 10

- 007

- unsigned.pdf.

26 U.S. EPA. (2009) Chapter 2.9 Chemical Specific Reference Values for Formaldehyde in Graphical Arrays of Chemical

- Specific Health Effect Reference Values for Inhalation Exposures (Final Report). U.S. Environmental
Pr otection Agency, Washington, DC, EPA/600/R

– 09/061, and available on

- line at http://cfpub.epa.gov/ncea/cfm/recordisplay.cfm?deid=211003.44

estimated health acute impacts of nickel did not weigh heavily in the regulatory decision. Before the supplemental proposal, we evaluated the Cal EPA REL value for ni ckel and determined that it was not appropriate to use in this instance. Therefore, for the supplemental proposal and final rule we did not use the Cal EPA REL value to assess acute exposures to nickel (discussed further below).

Comment: In comments on th e supplemental proposal, commenter 0276 states a concern that the EPA is not u s ing the California REL (Cal. REL) for nickel. The commenter (0276) notes that the EPA states that it is not using the more protective Cal. REL for a 1

- hour period of exposure partly because it is the same as the ATSDR intermediate MRL, which supposedly provid es protection for 364 days. The commenter (0276) states that the REL could therefore be 364*24 (8736) times more protective, and such a difference in magnitude of protection should cast doubt on the protective nature of the MRL, not the REL. The commenter (0276) also states that the EPA’s justification for not using the Cal. REL is that it “departs” from its guidelines , and this justification is insufficient

. The commenter (0276) also dispute s the EPA’s rationale that California does not apply an inhalation dosimetric adjustment factor without explaining why this difference undermines the REL. In addition, the commenter states that the EPA should address potential harm to the immune system in addition to inhalation risk, and the REL is based on research show ing harm to the immune system.

Response: As described in the Risk Assessment document (section 2.6.2), we have concluded that the California EPA 1

- hour acute REL value is not appropriate to use to support EPA’s risk and technology review rules. This concl usion, based on details provided in the risk assessment document, takes into account: the effect on which the acute REL is based; aspects of the methodology used in its derivation; and how this assessment stands in comparison to the ATSDR toxicological ass essment, which considered the broader nickel health effects database.

The broad nickel noncancer health effects database strongly suggests that the respiratory tract is the primary target of nickel toxicity following inhalation exposure. The available data base on acute noncancer respiratory effects is limited and was considered unsuitable for quantitative analysis of nickel toxicity by both California EPA 27 and ATSDR. 28 The California EPA’s acute (1

- hour) REL is based on an alternative endpoint, immunotoxicit y in mice, specifically depressed antibody response measured in an antibody plaque assay.

In addition, the California acute (1

- hour) REL for nickel includes the application of methods that are different from those described in EPA guidelines. Specificall y, the (1

- hour) REL applies uncertainty factors that depart from the defaults in EPA guidelines and does not apply an inhalation dosimetric adjustment factor.

27 http://oehha.ca.gov/air/allrels.html

28 http://www.atsdr.cdc.gov/substances/toxsubstance.asp?toxid=4445

Further, the ATSDR’s intermediate MRL (relevant to nickel exposures for a time frame between 14 and 364 days), was established at the same concentration as the California EPA (1

- hour) REL, indicating that exposure to this concentration “is likely to be without appreciable risk of adverse noncancer effects” (MRL definition 29 ) for up to 364 days. We ha ve high confidence in the nickel ATSDR intermediate MRL. Our analysis of the broad toxicity database for nickel indicates that this value is based on the most biologically

- relevant endpoint. That is, the intermediate MRL is based on a scientifically sound study of acute respiratory toxicity. Furthermore, this value is supported by a robust subchronic nickel toxicity database and was derived following guidelines that are consistent with EPA guidelines. 30 Finally, there are no AEGL

- 1/ERPG

- 1 or AEGL

- 2/ERPG

- 2 va lues available for nickel. Thus, for all the above mentioned reasons, we will not include nickel in our acute analysis for this source category or in future assessments unless and until an appropriate value becomes available.

2.1.2.2 Arsenic
Comment: In their comm ents on the 2011 proposal, c ommenter 0106 notes that the acute REL for arsenic of 0.2 μg/m 3 was developed by the California Office of Environmental Health Hazard Assessment, using assumptions inconsistent with standard US EPA risk assessment methodology (e.g., interpretation of the significance of a small decrease in fetal body weight). The comm enter (0106) suggests that use of more appropriate methodology would yield a more scientifically valid value of 2 μg/m 3 , and would eliminate the screening exceedance for acute exposures to arsenic.

Response: We acknowledge the comment, however it is not relevant to the final rule. Due to emissions estimate changes between the 2011 proposal and the 2014 supplemental proposal (and 2015 final rule), there are no longer exceedances of the acute REL for arsenic. In other words, for the supplemental proposal and for the final rule, the acute hazard quotient for arsenic was 1.

2.2 Chronic Risk Assessment Issues

2.2.1 Census Block Centroids
Comment: Commenter 0107 states that the EPA did not assess chronic or cancer risk at the closest or maximum point of exposure, even in those instances where local residents live nearer to a facility than the geographic centroid of the census block. The commenter (0107) explains that this approach underestimates exposure and could easily be re medied because HEM

AERMOD allows the system to make such an adjustment. The commenter (0107) notes that this conflicts with the recommendation of the SAB, which has urged the EPA to consider “specific

29 Agency for Toxic Substances and Disease Registry (ATSDR), Toxic Substances Portal, Minimal Risk Levels (MRLs) http://www.atsdr.cdc.gov/mrls/index.asp

30 US EPA 2002. Review of the reference dose and reference concentration processes (EPA/630/P

- 02/002F) Dec ember 2002, http://www.epa.gov/raf/publications/pdfs/rfd

- final.pdf46

locations of residences.” The commenter (0107) adds tha t the EPA has regularly received comments on this issue from state air pollution control agencies in past rulemakings. The commenter (0107) recommends that in this and future rulemakings, the EPA should follow the advice of these state regulators and start assessing risk at the edge or fence

- line of the facility

– i.e. , the point of maximum exposure

– not just at the centroid of a census block. The commenter (0107) concludes that failing to do so would be unlawful, arbitrary and capricious, as this approach fails to assess risk for the person “most exposed” to the source category‘s emissions.

Commenter 0065 made a similar comment that use of the most highly exposed census block dilutes the effect of sources’ emissions by estimating the impact at the centroi d of the census block instead of at the property line or wherever the maximum exposed individual is. The commenter (0065) states that census blocks are not homogeneous and even if the area near the property line is not developed, over time homes and busine sses could locate closer to the facility. The commenter (0065) states that by using HEM

- 3, the EPA can identify the maximum individual risk at any point in a census block that is within a 50

- kilometer radius from the center of the modeled facility.

Respon se: I n a national

- scale assessment of lifetime inhalation exposures and health risks from facilities in a source category, it is appropriate to identify exposure locations where it may be reasonably expected that an individual will spend a majority of his or her lifetime. I n determining chronic risks, it is appropriate to use census block information on where people actually reside

, rather than points at the property line, to locate the estimation of exposures and risks to individuals living near such facil ities.

Census blocks are the finest resolution available as part of the nationwide population data (as developed by the U.S. Census Bureau); on average, a census block is comprised of approximately 50 people or about 20 households. In the EPA risk assessm ents, the geographic centroid of each census block containing at least one person is used to represent the location where all the people in that census block live. The census block centroid with the highest estimated exposure then becomes the location of m aximum exposure, and the entire population of that census block is assumed to experience the maximum individual risk. In some cases, because actual residence locations may be closer to or farther from facility emission points, this may result in an overest imate or underestimate of the actual annual concentrations (although there is no systematic bias for average levels). Given the relatively small dimensions of census blocks in densely

- populated areas, there is little uncertainty introduced by using the cen sus block centroids in lieu of actual residence locations. There is the potential for more uncertainty when census blocks are larger, although there is still no systematic bias. The EPA concludes that the most appropriate locations at which to estimate chr onic exposures and risks are the census block centroids because: 1) census blocks are the finest resolution available in the national census data, 2) facility fence lines do not typically represent locations where chronic exposures are likely (i.e., people do not typically live at the fence line of facilities) and 3) there is no bias introduced into the estimate of the MIR by using census block centroid locations. In it s peer review of the47

methodologies used to estimate risks as part of the RTR rulemaking efforts, the EPA’s Science Advisory Board (SAB) endorsed this approach. 31

In addition to the approach described above, the EPA recognizes that where a census block centroid is located on industrial property or is large and the centroid is less likely to be representative of the block’s residential locations, the block centroid may not be the appropriate surrogate. For this source category, as described in the risk assessment document available in the docket (and in more detail in Appendix 8 of that document) , in cases where a census block centroid was within 300 meters of any emission source (and therefore possibly on facility property), we viewed aerial images of the facility to determine whether the block centroid was likely located on facility property. Li kewise, we examined aerial images of all large census blocks within one kilometer of any emission source. If the block centroid did not represent the residential locations within that block, we relocated it to better represent them and/or we added addition al receptors for residences nearer to the facility than the centroid. For this source category, we relocated three census blocks that appeared to be on facility property (ferroalloys or other industry) or were otherwise not representative of the surroundin g population. In addition, we added six user receptors to represent the surrounding population. Appendix 8 of the risk assessment, titled Residual Risk Assessment for the Ferroalloys Source Category in Support of the September Supplemental Proposal (Septem ber 2014) provides additional information about these changes.

2.2.2 Activity Patterns and Exposure
Comment: Two commenters (0073, 0106) state that the exposure analysis employed by the EPA does not make use of widely accepted activity patterns, which results in an overestimation of potential risks.

Commenter 0075 states that

, in its estimation of chronic human inhalation exposure, the EPA did not consider short

- term or long

- term mobility of the exposed populations and its potential influence on their exposur e. The commenter (0075) adds that several methodologies are currently available to address the mobility of the population, including a 2011 report by Felter et al., which proposed guidance for cancer risk assessments for less

- than

- lifetime exposures based on current knowledge of mode of action and dose

- response.

31 U.S. Environmental Protection Agency, Office of the Administrator Science Advisory Board. Review of EPA’s draft entitled, “Risk and Technology Review (RTR) Risk Assessment Methodologies: For Review by the EPA’s Science Advisory Board with Case Studies

– MACT I Petroleum Refining Sources and Portland Cement Manufacturing.” EPA

- SAB

- 10

- 007. May 7, 2010. http://yosemite.epa.gov/sab/sabproduct.nsf/4AB3966E263D943A8525771F00668381/$File/EPA

- SAB

- 10

- 007

- unsigned.pdf.48

T hree commenters (0122, 0123 , 0272 ) disagreed with the use of a 24

- hour per day exposure over a 70

- year lifetime to estimate individual and population cancer risks for refined risk assessments. Acc ording to commenter (0122), this exposure assumption is inconsistent with the recommendations by the National Research Council and the Commission on Risk Assessment and Risk Management. In their Reports to Congress, these organizations support development of distributional approaches to exposure characterization based on knowledge of the characteristics of a population's variability. The commenter (0122) asks EPA to develop a refined exposure methodology that incorporates information available on population residency times that will more accurately reflect population risk estimates. The development of this exposure methodology should also include a probabilistic analysis of estimated exposures. Th e commenter (0122) states that the use of such an unrealistic assumption makes the results overly conservative and will lead to additional and unnecessarily stringent standards more frequently than necessary. The commenter (0123) states that the EPA has developed the risk assessment guidance necessary to apply more a ccurate exposure and believes that the EPA’s failure to apply such assumptions in the proposed ferroalloys NESHAP rulemaking is arbitrary and capricious.

The commenter 0272 states that the EPA failed to apply the best available scientific knowledge on publ ic exposure patterns, which results in overstating the risks. As an example, the commenter (0272) notes that the EPA’s assumption that a hypothetical person would spend their entire life outdoors at one precise location is contrary to common sense and to t he risk assessment improvements developed by the EPA since the Benzene NESHAP rulemaking in 1989. The commenter (0272) believes that the EPA possesses well

- supported alternatives that produce a very conservative high end assessment of maximum plausible exp osures. Therefore, the commenter (0272) believes that the EPA’s use of an implausibly high exposure assumption produced a 40 percent overstatement of the maximum individual non

- cancer risk (see Appendix A at Section 3.1.1).

The commenter (0272) further add s that in its statutorily required report to Congress on its approach to estimating residual risks under Section 112(f) of the Act, the EPA indicated that they estimate human health exposures in accordance with its 1992 guidelines. 32 The guidelines discuss the concept of a “maximum exposed individual” and explicitly distinguish such a receptor from a “worst case exposure.” The Guidelines, at 27 n.20, make clear that the “maximum exposed individual” should reflect the upper end of actu al exposures in the relevant population:
The term “worst case exposure” has historically meant the maximum possible exposure, or where everything that can plausibly happen to maximize exposure, happens. While in actuality, this worst case exposure may fall on the uppermost point of the population

32 Guidelines for Exposure Assessment, EPA/600/Z

- 92/00149

distribution, in most cases, it will be somewhat higher than the individual in the population with the highest exposure. The worst case represents a hypothetical individual and an extreme set of conditions; this wi ll usually not be observed in an actual population. The worst case and the so

- called maximum exposed individual are therefore not synonymous, the former describing a statistical possibility that may or may not occur in the population, and the latter ostens ibly describing an individual that does, or is thought to, exist in the population.
The Guidelines further provide that the high end exposure scenario should be “plausible” and should “fall within the actual distribution, rather than above it.” Id. The com menter (0272) believes that the “70

- year continuous maximum exposure” assumption relied upon by the EPA to define the “maximum individual risk” for the proposed ferroalloys NESHAP is not plausible and is above, rather than within, the range of exposures th at would ever be experienced by anyone in Marietta.
The commenter (0272) believes that the EPA’s “70

- year continuous exposure” assumption more closely reflects, in the terms of the Guidelines, a “theoretical upper bounding estimate” that reflects the mathe matical limit of potential exposure calculated by assuming the maximum values of each exposure factor (see the Guidelines at 77). Therefore, the commenter (0272) believes that this assumption is best suited for screening

- level use and not for residual risk determinations regarding the need for emissions controls. The commenter (0272) provided proposed exposure scenarios (see Appendix A) based on conservative high

- end assumptions from the EPA’s own Exposure Factors Handbook and other literature values, and b elieves that it is representative of the approach suggested in both the Guidelines and the EPA’s 1999 Residual Risk Report to Congress.
The commenter (0272) adds that the EPA’s reliance on a factually impossible exposure scenario is also inconsistent with EPA’s own acknowledgement years ago that use of a more reasonable exposure scenario is appropriate. The commenter (0272) notes that in the preamble to its final residual risk NESHAP for coke oven batteries, 70 Fed. Reg. 19991, 19999 (Apr. 15, 2005) that th e EPA acknowledged that the 70

- year maximum exposure assumption does not reflect actual exposures, and that the EPA intended in the future to use a more refined methodology that would incorporate more re alistic exposure considerations.

The commenter ( 0272 ) states that the EPA’s assumption that “the individual most exposed to emissions from a source” will be the same individual for a full 70

- year life is no longer consistent with the EPA’s own cancer risk assessment policies and practices. The commenter (027 2) notes that the most current EPA guidance should have been used in this risk assessment, which applies a 30

- year exposure duration in high

- end risk calculations involving Superfund sites, and more recently has recommended a 26

- year exposure duration. The commenter (0272) believes that the EPA’s inconsistent application of its guidance for high

- end residential exposure50

frequency and duration resulted in more than a 70 percent overstatement of the maximum individual cancer risk.

The commenter (0272) also no tes that the regulatory criteria for determining whether a particular risk is unacceptable are unique to Section 112, but the best available science is not. They believe that the EPA’s accepted methodology for quantifying a specific risk should not vary by regulatory program. They also believe that the cancer risk associated with inhalation exposure to a given concentration of a given pollutant is the same, regardless of whether that exposure results from an emission source regulated under the Clean Air Act or a source regulated under the Superfund statute. Nothing in the statutory language suggests that Congress intended otherwise.

The commenter ( 0272 ) states that the EPA has previously acknowledged the limitations of its conservative exposure assumptions i n the context of assessing acceptable risk under Section 112(f)(2) and found estimated cancer risks substantially greater than those estimated in this rulemaking to be acceptable in light of the conservatism of the 70

- year continuous exposure assumption. T he commenter (0272) notes that in the residual risk NESHAP for coke oven batteries, EPA’s risk assessment estimated the cancer MIR at 300 in 1 million (versus 20 to 100 in 1 million here), 70 persons exposed to a risk greater than 100 in 1 million (versus none here), 500,000 persons with a risk greater than 1 in 1 million (versus 31,000 here) and an excess cancer incidence of 0.6 cases per year (versus an incidence of 0.002 here). See 70 Fed. Reg. 19992, 19994 (Apr. 15, 2005).

The commenter (0272) also states that the EPA found such risks to be acceptable in the Coke Batteries residual risk NESHAP, in part because the “health protective assumption of a 70

- year exposure duration” produced risk estimates six times higher than if EPA had instead used the

na tional average residency time of 12 years. Id. The commenter (0272) notes that while no two risk assessments are identical, the conservatism of EPA’s outdated 70

- year exposure assumptions is a constant and there is no principled basis for EPA to acknowledg e and explicitly “temper” its risk conclusions on that basis in one rulemaking, while rigidly applying is in another.

Response: The commenters have commented on specific aspects of our exposure assessments from the 70

- year exposure duration to incorporatin g short

- term mobility into our assessments. Several specific points are addressed below . H owever, in general

, we strive to strike a balance in

our assessments , meaning that while some factors likely lead to overestimates of risk (e.g., 70

- year exposure dur ation), others likely lead to underestimates of risk (e.g., average annual emissions). We conclude that the risk assessment for this source category is sufficient to support a decision on the acceptability of the risk and ample margin of safety.

The comm enter is correct that the EPA did not consider short

- term or long

- term mobility in the assessment. Mobility was not considered because we do not believe that assumption, in combination with other modeling assumptions, lead to a significant bias in the risk results in any one direction. For example, the EPA does not consider that homes and businesses may locate51

closer to facilities over time, which could lead to an underestimation of risk. Additionally, estimates of the maximum individual risk (MIR) contain uncertainty, because they are derived at census block centroid locations rather than actual residences. This uncertainty is known to create potential underestimates and overestimates of the actual MIR values for individual facilities, but overall, it is no t thought to have a significant impact on the estimated MIR for a source category. Processes like deposition, plume depletion, and atmospheric degradation are not considered, which may introduce bias to the population exposure estimates. Finally, we did no t factor in the possibility of a source closure occurring during the 70

- year chronic exposure period, leading to a potential upward bias in both the MIR and population risk estimates; nor did we factor in the possibility of population growth during the 70

- year chronic exposure period, leading to a potential downward bias in both the MIR and population risk estimates. These uncertainties are described in section 4.1 of the risk assessment document.
In assessing risk, we estimate the MIR or the maximum HI, wh ich are defined as the risk (or hazard) associated with a lifetime of exposure at the highest concentration where we determine people may actually reside . For this assessment, we used the annual average ambient air concentration of each HAP at each census block centroid as a surrogate for the lifetime inhalation exposure concentration of all the people who reside in the census block. Basing exposure estimates at census block centroids may underestimate or overestimate actual exposure concentrations at some residences. Further reducing exposure estimates for the most highly exposed residents by modeling their short

- term behavior could add a systematic low bias to these results and is not expected to affect the MIR result

. Thus, t his risk analysis did not cons ider the short

- term human activity patterns and their potential influence on exposure. Our experience with the 1996 and 1999 National

- Scale Air Toxics Assessments (which modeled daily activity using the EPA’s HAPEM model) suggests that, given our current u nderstanding of microenvironment concentrations and daily activities, modeling short

- term activity would, on average, reduce risk estimates about 25 percent for particulate HAP; it will also reduce risk estimates for gaseous HAP, but typically by much less

. We agree that our assumption that people may be present at their homes for 24 hours per day over a 70

- year lifetime represents a scenario that likely overestimates the actual exposures received by people living near the facilities. Most people have daily activities that take them to areas where exposure concentrations are different and people may move to new residences periodically. Both of these behaviors will likely tend to lower lifetime exposures and, therefore, risk if they are no longer in the vicin ity of sources in the source category

. In our risk assessments, we estimate risk for the “maximum individual risk” (MIR) which is different than the “maxi mum exposed individual (MEI).” The MEI could be equal to or greater than the MIR as the MEI is the hi ghest estimated risk to a hypothetical exposed individual, regardless of whether people are expected to occupy that area. The MIR, on the other hand, is the highest estimated risk to an exposed individual in areas people may actually occupy. We are using t he MIR to be considered equivalent to the “individual most exposed” phrase from the52

CAA section 112(f)(2). This approach is consistent with the Commission on Risk Assessment and Risk Management report recommendation that exposure assessments should not be based on a hypothetical MEI.

2.2.3 Respirable Emissions
Comment: One commenter (0106) states that consideration of more plausible exposure assumptions to account for time spent indoors, and the reduction in ambient PM 2.5 concentrations indoors would reduce exposures to respirable manganese and hence, associated risk, by 40 percent. The commenter (0106) adds that correcting the modeled manganese particulate concentration for the fraction of PM 2.5 identified by US EPA would result in a further reduction in exposure and, hence, associated risk, by 59 percent. One commenter (0106) provides a detailed review of the EPA’s modeling and risk assessment, including the following points for the 2011 proposal :

 The EPA failed to accoun t for the fact that only those particles of “respirable” size (particles 2.5 micrometers in diameter or smaller) are toxicologically relevant when assessing potential manganese inhalation risks.

 The EPA assumed 100 percent of the air emissions were in a ga seous state, which is overly conservative since particle deposition decreases ambient manganese concentration. If the EPA has correctly applied the correct PM 2.5 fraction, then assuming 100 percent gaseous emissions is acceptable because PM 2.5 does not sig nificantly deposit over distances less than 10 km.
In their comments on the supplemental proposal, commenter 0272 reiterates that EPA assumed that all manganese particles emitted in ferroalloys production are capable of entering the blood stream and causin g adverse health effects, however scientific research shows that only inhalation of “respirable” manganese particles leads to adverse health effects (see Section 3.1.2 of Appendix A). They note that the EPA’s air program has adopted the position that “resp irable” generally means particles with an aerodynamic diameter of 2.5 microns or less (“PM 2.5 ”). As an example, the commenter (0272) points out in the EPA’s December 2009 “Integrated Science Assessment of Particulate Matter,” EPA/600/R

- 08/139F, at 3

- 3, the Agency acknowledged that a PM 10 cut point is commonly understood to define the “thoracic” fraction of inhaled particulates (small enough to reach the lung airways, but not the gas

- exchange region of the lungs), while a PM 2.5 cut point is generally conside red the measure of the “respirable” fraction.

In their comments on the supplemental proposal, two commenters (0266, 0271) believe that when modeling inhalation risk for any HAP, it is critical that only the respirable fraction (PM 2.5 ) of particulate be use d. One commenter (0271) notes that toxicity values for HAPs are often based on respirable fractions like the manganese RfC used for this modeling was developed and based upon respirable manganese (Roels et al.,1992). They also note that the EPA’s own guida nce53

states that risk modelers should use the same particulate fraction that the reference value is based

on.
The commenter 0271 states that the EPA has particle size emission data in AP

- 42, from multiple sources in multiple industries, including Section 12 .5., which indicate that only a fraction of emissions from various processes and control devices are respirable. They note that in the 2011 Regulatory Impact Analysis for Manganese Ferroalloys RTR report, EPA estimated the PM 2.5 percentage of total particu late emissions from the facilities covered by this rule was 41 percent. They believe that the EPA must conduct the risk assessment by modelling only the respirable fraction of total PM emissions.

Response: The point about time spent indoors was addressed in Section 2.2.2. As discussed in Section 2.1.1.1 , we do note that the size of the manganese

- containing particle has a bearing on the toxicity and some of the organizations listed in Section 2.1.1.1 have developed their reference values based on different size fractions. 33 The size fractions include PM 2.5 , PM 3.5 , PM 5 , PM 10 , and TSP. Given that some of these other agency values are based on size fractions greater than PM 2.5 , it remains reasonable to include larger size particles in this analysis. The use of P M 2.5 over PM 10 would necessitate a lower reference value to adjust for particles larger than PM 2.5 as done by other groups, e.g., American Conference of Governmental Industrial Hygienists (ACGIH) and Ontario Ministry of the Environment. This is especially important given that ACGIH, the International Standards Organization, and the European Standardization Committee have adopted a 50 percent cut point of 4 μm as an indicator of respirable particles. 34

2.2.4 Cumulative Risk
Comment: Commenter 0107 states that the E PA has failed to satisfy section 112(f)(2) or to follow scientific recommendations or the best available science regarding the need to assess the full, cumulative impact of HAP exposure for affected local communities, citing the EPA ’ s most recent report on the subject, “ Concepts, Methods and Data Sources for Cumulative Health Risk Assessment of Multiple Chemicals, Exposures and Effects: A Resource Document ” developed by the SAB. The commenter (0107) states that for both its inhalation risk assessment and it s multipathway risk assessment, the EPA fails to account for the impact of adding new air emissions to recent and past air emissions that the most

- exposed people have already experienced from this source category. As a result, according the commenter (0107 )
, the EPA fails to adequately assess the cumulative impact of exposure to this source category ’ s emissions. The commenter (0107) asserts that in many instances people living near these facilities already have background levels of past exposure and past pollution that increase their current health risk.

33 U.S. EPA. Mn and BTEX Reference Value Arrays (Final Reports). U.S. Environmental Protection Agency, Washington, DC, EPA/600/R

- 12/047F, 2013.

34 U.S. EPA, 2009. Integrated science assessment for particulate matter. EPA/600/R

- 08/139F. Research Triangle Park, NC. http://cfpub.epa.gov/ncea/cfm/recordisplay.cfm?deid=216546.54

The commenter (0107) adds that for areas like these, where there are multiple sou rces of air toxics and the individual sources in this category have emitted metals for years, the EPA must address background as well as new health risk.

The commenter (0107) states that the EPA ’ s refusal to assess cumulative impacts or risk here from mul tiple types or source categories of HAP emissions conflicts with its own recognition that considering the most

- exposed person ’ s full health risk is an important part of the section 112(f)(2) analysis. The commenter (0107) adds that this decision also confl icts with the recommendation from the S AB that in May 2010 urged the EPA to incorporate cumulative risks into its residual risk analysis. The commenter (0107) states that uncertainty is not a rational explanation for failing to address this important eleme nt of health risk and describes ways that the EPA can manage uncertainty

. NEPA and ESA both consider context of all other impacts.

Response: For the ferroalloys source category, the EPA conducted a n assessment of the cumulative cancer risks from emitted ca rcinogens and the cumulative noncancer hazard indices from all emitted non

- carcinogens affecting the same target organ system for the source category emissions. While the incorporation of additional background concentrations from the environment in our ris k assessments (including those from mobile sources and other industrial and area sources) could be technically challenging, they are neither mandated nor barred from our analysis. In developing the decision framework in the Benzene NESHAP currently used fo r making residual risk decisions, the EPA rejected approaches that would have mandated consideration of background levels of pollution in assessing the acceptability of risk, concluding that comparison of acceptable risk should not be associated with level s in polluted urban air‘‘ (54 FR 38044, 38061, September 14, 1989). Background levels (including natural background) are not barred from the EPA ’ s ample margin of safety analysis, but the EPA may consider them, as appropriate and as available, along with o ther factors, such as cost and technical feasibility, in the second step of its section 112(f) analysis. This assessment excludes background contributions because the available data are of insufficient quality upon which to base a meaningful analysis.

We d isagree with the comment that we failed to consider or account for cumulative risk. The individual cancer risks for each source category were aggregated for all carcinogens. In assessing noncancer hazard from chronic exposures for pollutants that have simi lar modes of action or (where this information is absent) that affect the same target organ, we aggregated the hazard quotients . This process creates, for each target organ, a target

- organ

- specific hazard index (TOSHI), defined as the sum of hazard quotien ts for individual HAPs that affect the same organ or organ system. All TOSHI calculations presented here were based exclusively on effects occurring at the “critical dose” (i.e., the lowest dose that produces adverse health effects). We also disagree with the commenter’s assertion that additional assessment of risks from sources outside the source category is required under the statute. The statute requires the EPA to provide the risk information necessary to inform RTR regulatory decisions and

, to this end, the EPA conducts a comprehensive assessment of the risks associated with exposure to the HAP emitted55

by the source category and supplements that with additional information that is available about other possible concurrent and relevant risks.

Further, the risk assessment modeling accounts for the effects of multiple facilities that may be in close proximity when estimating concentration and risk impacts at each block centroid. When evaluating the risks associated with a particular source categ ory we combined the impacts of all facilities within the same source category, and assessed chronic exposure and risk for all census blocks with at least one resident (i.e., locations where people may reasonably be assumed to reside rather than receptor po ints at the fenceline of a facility). The maximum individual risk considers the combined impacts of all sources in the category that may be in close proximity.

Comment: Commenter 0107 states that after assessing each type of risk, the EPA fails to combine all health risks. According to the commenter (0107) , leaving these risks segmented in its analysis prevents the EPA and the affected public from being able to perform a full assessment of the total health risk of the most

- exposed person. The commenter (01 07) notes that while the EPA did appropriately combine some risks (e.g., the risk from each individual carcinogen to create a total lifetime cancer risk), the EPA needs not only to sum this risk but also ensure that it assesses the synergistic, carcinogeni c (and other) effects of different pollutants. The

commenter (0107) describes specific deficiencies including the fact that the EPA does not create a combined acute risk number that would represent the total acute risk for all pollutants that act in a simi lar way on the same organ system or systems, similarly to the chronic TOSHI. The

commenter (0107) adds that the EPA has failed to perform a cumulative risk assessment that combines inhalation and multipathway risk for each pollutant, such as POM, that caus es both risks and that the EPA also fails to combine the multipathway risks created by POM and other persistent pollutants, such as arsenic and manganese. The commenter (0107) is also concerned that the EPA does not create any metric to assess the total, c ombined health risk that could be used to assess the cumulative impact of all of the types of risks. The commenter (0107) states that even though the EPA found a combination of cancer and noncancer risk to create “unacceptable” risk, the EPA also must crea te a cumulative burden metric to assess and consider the total, cumulative burden of the most

- exposed person. The commenter (0107) asserts that this is needed to assess the way different individual health risks (even if potentially “acceptable” on their ow n) combine to cause the full amount of “unacceptable” health risk for this source category. The commenter (0107) supports the EPA ’ s conclusion that cancer and chronic noncancer risks each contribute to create “unacceptable” risk and urges the EPA to finalize that determination and also to complete a full analysis of the cumulative burden that this source category creates.

The commenter ( 0107 ) states that to perform a cumulative impact analysis, the EPA should combine current baseline emissions, exposu res, and health impacts in addition to those of the specific source category the EPA is reviewing. The commenter (0107) states that the EPA should aggregate or add the emissions for the most

- exposed communities coming from: (1) the source category (includi ng all individual sources within it); (2) facility

- wide risk from collocated56

sources outside of this category; and ( 3 ) all other sources of toxic air pollution in the area. T he

commenter (0107) states that the EPA must also draw on the OEHHA community asse ssment approach.

Response: We have combined risk assessment results to the extent that it is appropriate to do so and as described in the previous response

. We consider the effect of mixtures of carcinogens and use a target organ

- specific hazard index (TOSHI) approach for our chronic noncancer

assessments

. We do not use a TOSHI approach for acute analyses nor do we combine the results of our inhalation and multipathway assessments

. Regarding the comment that the EPA should assess the synergistic and carcinogenic effects of pollutants, we do follow the EPA’s guidelines for mixtures because most of the receptors in these assessments receive exposure to multiple pollutants rather than a single pollutant. As desc ribed in the risk assessment report provided in the docket at proposal, we estimated the aggregate health risks associated with all the exposures from a particular source category combined. To combine risks across multiple carcinogens, our assessments use the mixtures guidelines 35
, 36 default assumption of additivity of effects, and combined risks by summing them using the independence formula in the mixture guidelines.

As described in the risk assessment report ( available in the docket for th is action ) , we do not sum results of the acute noncancer inhalation assessment to create a combined acute risk number that would represent the total acute risk for all pollutants that act in a similar way on the same organ system or systems (similar to the chronic TOSHI)

. T he worst

- case acute screen is already a conservative scenario

. That is, the acute screening scenario assumes worst

- case meteorology, peak emissions for all emission points occurring con currently and an individual being located at the site of maximum con centration for an hour

. Thus, as noted in section 2.7.2 of the Draft Residual Risk Assessment for the Ferroalloys Source Category, “because of the conservative nature of the acute inhalation screening and the variable nature of emissions and potential
expo sures, acute impacts were screened on an individual pollutant basis, not using the TOSHI approach.”

We did not combine the inhalation and multipathway risk assessment results for each pollutant because it is inappropriate to do so

. The multipathway risk as sessment conducted for proposal was a screening

- level assessment (i.e., Tier 1)

. It used highly conservative assumptions designed to ensure that facilities with results below the screening threshold values did not have the potential for multipathway impact s of concern

. The screening scenario is a hypothetical scenario, and due to the theoretical construct of the screening model, exceedances of the thresholds are not

35 US EPA, 1986. Guidelines for Health Risk Assessment of Chemical Mixtures. EPA

- 630

- R

- 98

- 002. http://www.epa.gov/ NCEA/raf/pdfs/chem_mix/chemmix_1986.pdf.

36 US EPA, 2000. Supplementary Guidance for Conducting Health Risk Assessment of Chemical Mixtures. EPA

630/R

- 00

- 002. http://www.epa.gov/ncea/raf/pdfs/chem_mix/chem_mix_08_2001.pdf.57

directly translatable into estimates of risk or hazard quotients for these facilities

. Rathe r, it represents a high

- end estimate of what the risk or hazard may be. For example, an exceedance of 2 for a non

- carcinogen can be interpreted to mean that we have high confidence that the hazard would be less than 2. Similarly, an exceedance of 30 for a carcinogen means that we have high confidence that the risk is lower than 30

- in

- 1 million. Our confidence comes from the conservative, or health

- protective, assumptions that are in the screens: we choose inputs from the upper end of the range of possible v alues for the influential parameters used in the screens; and we assume that the exposed individual exhibits ingestion behavior that would lead to a high total multipathway exposure. For this category

, we were able to conduct a more refined screening

level assessment that included some site

- specific information (i.e., Tier 2). This allowed us to remove some of the default information and replace it with actual conditions around these facilities (e.g., distance to a lake). While we were able to refine the as sessment somewhat, it remains a screening

- level assessment.
For the 2014 supplemental proposal and the 2015 final rule, we also conducted the Tier I and Tier II screens, but in addition, we conducted a refined multipathway assessment. For the refined

asse ssments, risk or hazard values are estimated, not exceedances of a screening threshold. Those estimated results can be added to the inhalation results, where appropriate, but the total number still serves as a conservative estimate of potential risks given that it is highly unlikely that the same receptor has the maximum results in both assessments. In other words, it is unlikely that the person with the highest chronic inhalation cancer risk is also the same person with the highest individual multipathway cancer risk. More information can be found in the risk assessment document or in the multipathway section of this response

- to

- comment document (Section 2.5).

In the Air Toxics Risk Assessment Reference Library, we developed the current persistent and bioac cumulative HAP (PB

- HAP) list considering all of the available information on persistence and bioaccumulation (see http://www.epa.gov/ttn/fera/risk_atra_main.html , sp ecifically Volume 1 Appendi x D). (The Air Toxics Risk Assessment Reference Library provides information on the fundamental principles of risk

- based assessment for air toxics and how to apply those principles in different settings (e.g., facility

- specific) as well as strategies for

r educing risk at the local level.) This list reviewed HAP identified as PB

- HAP by other EPA Program Offices (e.g., the Great Waters Program) and also used information from the PBT profiler (see http://www.pbtprofi ler.net/ )

. This list was peer

- reviewed by the SAB, and it is reasonable to use it in the RTR program

. Based on these sources and the limited available information on the persistence and bioaccumulation of arsenic and manganese, we do not believe that the p otential for multipathway risk rises to the level of the PB

- HAP currently on the list

. These HAP are not included as PB

- HAP on any of the lists referenced in the Air Toxics Assessment Library.58 2.2.5 Chronic risk assessment results
Comment: Commenter 0106 states that, due to the limited time provided to evaluate the basis for the 2011 proposed rule, they were unable to model relevant exposure concentrations for compounds other than manganese and instead relied upon the EPA's predicted exposur e concentrations in the analysis of such non

- manganese compounds. Based on the commenter’s finding that errors in the EPA's model overstated exposure concentrations of respirable manganese by a factor of eight, the commenter (0106) concludes that it is lik ely that exposure concentrations for other relevant compounds (including nickel and arsenic) are also overstated.

Response: As described elsewhere in this document, w e disagree that errors in the EPA’s model overstated exposure concentrations of respirable manganese by a factor of eight. The time to provide public comment was extended for the 2011 proposed rule, and industry came in several times to meet with EPA staff. Furthermore, after publication of the supplemental proposal, the public had an addition al opportunity to comment.

2.3 Acute Risk Assessment Issues
Comment: Commenter 0106 states that the EPA’s finding of acute offsite screening risks to exceed a hazard quotient of 1 for nickel and arsenic in the 2011 proposal significantly overestimate actual risks. The commenter (0106) adds that because the EPA only conducted a screening assessment of acute inhalation risks, screening results do not provide evidence that unacceptable risks for the population are present, only that a refined risk assessment is needed to evaluate population risks. The commenter (0106) states that the EPA has not established a basis upon which to reach conclusions regarding such risks.

Response : The commenter is correct that the acute risk assessment is a screening

- level

assessmen t designed to identify facilities and pollutants that need further analysis

. The commenter is not correct, however, that the screen cannot provide information about the risks that can feed into a decision

. The screen provides us information that for those facilities where the hazard quotients are less than 1, we do not expect acute effects, and for those situations where the hazard quotients are greater than 1, the potential for acute effects exists

. For those situations where the acute hazard quotients are greater than 1 based on our screening assessment, the fact that it is a screening

- level assessment is taken into consideration in the decision

. The finding of unacceptable risks is not based on any one risk metric (e.g., acute hazard quotients), but rathe r considering all of the health information available and the degree of uncertainty associated with that information

. In addition, the commenter does not provide additional information as to how the EPA’s finding of acute offsite screening risks are overes timated in the 2011 proposal

.
Comment: Commenter 0107 states that the EPA fails to calculate the maximum acute health risk based on a true “worst case” scenario. The commenter (0107) states that in addition to failing to address malfunctions, the EPA also did not address or account for higher amounts of emissions59

that routinely occur during periods of tapping, casting, maintenance, and other similar activities due to the inclusion of an excursion limit of 60 percent opacity for one 6

- minute period during the performance test. The commenter (0107) adds that “blowing taps, poling and oxygen lancing of the tap hole; burndowns associated with electrode measurements; and maintenance activities associated with submerged arc furnaces and casting operations are exempt from the opacity standards specified in §63.1653, but the EPA has failed to account for higher emissions that occur during these activities. The commenter (0107) also notes that this source category has a history of unusual incidents that are l ikely associated with acute health risks, for example the May 2008 fugitive emission incident at the Eramet facility in Marietta, Ohio. The commenter (0107) states that this incident and other similar information attached show the need for the EPA to calcu late a higher level of acute health risk to assess a “worst

- case” scenario under the existing standard.

The c ommenter ( 0107 ) notes that the EPA has estimated that the current NESHAP standard allows a range of 4.9 to 81.1 times the “actual” emissions to oc cur, and in view of this, the EPA cannot justify using a factor less than 81 to perform its acute risk assessment. The commenter (0107) adds because the reporting capture and control efficiencies are up to 99% for the 23 control devices in place, if the co ntrol equipment fails, emissions would be at least 100 times greater. The commenter (0107) concludes that a 10x margin simply does not make sense, and the EPA cannot rationally justify using only a factor of ten to assess the acute risk to the most

exposed individual and community.

Response: Sections 63.1650 through 63.1661 are being retained only until they are superseded by the RTR MACT requirements in §§ 63.1620

– 63.1630 upon the effective date of the new provisions. We believe that the final standard w ill address the concerns of the commenter related to excursions.

When screening for potentially significant acute exposures, we used an estimate of the highest hourly ambient concentration at any off

- site location as the surrogate for the maximum potential acute exposure con centration for any individual. These hourly concentrations are based on hourly emissions. Since information is not usually available on short

- term emission rates, we generally apply the assumption that the maximum one

- hour emission rate from any source is ten times the average annually hourly emission rate for that source. (The average hourly e missions rate is defined as the total emissions for a year divided by the total number of operating hours in the year.) This choice of a factor of ten for acute screening was originally based on engineering judgement and is used if no additional informatio n is available.
For the ferroalloys source category assessment, however, we did have additional information. In the ferroalloys risk assessment, we incorporated additional information and process knowledge in order to better characterize acute emissions. Using emissions data obtained from the ICR, knowledge from site visits, and the operating characteristics of ferroalloys emissions sources we developed and used process

- specific factors ranging from 1 to 4, not 10 as the commenter states.60

A default factor of 10 is used in situations where we do not have add itional information available. For the ferroalloys source category, we had information about the op erating hours for each process. Some processes operate continuously, so their maximum hourly emissions e qual the average hourly emissions. For other processes, they have specific cycles, with peak emissions occurring for a part of the cycle (e.g., 30 mi nutes during a 2

- hour period). Additional conservative assumptions are made for emission rates, meteorology , and exposure location (as described in the Risk Assessment document) :

 For facilities with multiple emission points, peak 1

- hour emissions were assumed to occur at all emissions points at the same time.

 For facilities with multiple emission points, 1

- hour concentrations at each receptor were assumed to be the sum of the maximum concentrations due to each emission point, regardless of whether those maximum concentrations occurred during the same hour.

 Worst

- case meteorology (from one year of local meteorolo gy) was assumed to occur at the same time the peak emission rates occur. The recommended EPA local

- scale dispersion model, AERMOD, is used for simulating atmospheric dispersion.

 A person was assumed to be located downwind at the point of maximum impact dur ing this same 1

- hour period, but no nearer to the source than 100 meters.

 The maximum impact was compared to multiple short

- term health benchmarks for the chemical being assessed to determine if a possible acute health risks might exist.

2.4 Facility

- wide Risk Assessment
Comment: Commenter 0075 asserts that the EPA does not have authority to consider “total facility” emissions in conducting the residual risk assessments for a given source category (even if the EPA did not conduct one in this case). The commente r (0075) states that the CAA requires residual risk determinations to be conducted on a category

- by

- category basis.

Commenter 0107 objects that the EPA has not considered facility

- wide risk in this rulemaking and states that the EPA has failed to justify this. The commenter (0107) describes substantial sources of toxic air emissions located at the same site as the Eramet facility (an existing chromium

- emitting operation under its own control at the same site and similarly collocated sources at the Felman f

acility). The commenter (0107) states that the EPA must perform a facility

- wide risk assessment for this source category. The commenter (0107) adds that a facility

wide risk assessment will only provide only part of the picture.

Response : As explained below, EPA has the discretion to conduct a facility

- wide risk assessment factoring emissions outside the source category, but in the context of this rulemaking, it was reasonable not to do so. We disagree that examining facility

- wide risk in a risk assessment conducted under section 112(f) exceeds the EPA’s authority

. While we did not conduct a facility

- wide risk assessment for this source category, we typically examine facility

- wide risks to provide additional context to the source category r isks

. The development of facility

- wide risk61

estimates provides additional information about the potential cumulative risks in the vicinity of the RTR sources, as one means of informing potential risk

- based decisions about the RTR source category in questio n

. We recognize that, because these risk estimates were derived from facility

wide emissions estimates which have not generally been subjected to the same level of engineering review as the source category emission estimates, they may be less certain than our risk estimates for the source category in question, but they remain important for providing context as long as their uncertainty is taken into consideration in the process

. We note, however, that section 112(f)(2) of the CAA expressly preserves our us e of the two

- step process for developing standards to address residual risk and interpret “acceptable risk” and “ample margin of safety” as developed in the Benzene NESHAP (54 FR 38044, September 14, 1989) . In the Benzene NESHAP , the EPA rejected approache s that would have mandated consideration of background levels of pollution in assessing the acceptability of risk, concluding that “...comparison of acceptable risks should not be associated with levels in polluted urban air. With respect to considering othe r sources of risk from benzene exposure and determining the acceptable risk level for all exposures to benzene, EPA considered this inappropriate because only the risk associated with the emissions under consideration are relevant to the regulation being e stablished and, consequently, the decisions being made.” (54 FR 38044, September 14, 1989) . Our authority to use the two

- step process laid out in the Benzene NESHAP, and to consider a variety of measures of risk to public health, is discussed more thorough ly in the preamble to the proposed rule. Nothing in the CAA or the Benzene NESHAP in any way forecloses us from considering facility

- wide risks in making a determination under section 112(f)(2), as such information can constitute relevant health informatio n.
Although not appropriate for consideration in the determination of acceptable risk, we note that background risks or contributions to risk from sources outside the source category under review could be one of the relevant factors considered in the ampl e margin of safety determination, along with cost and economic factors, technological f easibility and other factors. Background risks and contributions to risk from sources outside the facilities under review were not considered in the ample margin of safe ty determination for this source category, mainly because of the significant uncertainties associated with emissions estimates f or such sources. Our approach here is consistent with the approach we took regarding this issue in the Hazardous Organic NESHAP (HON) RTR (71 FR 76603, December 21, 2006), which the court upheld in the face of claims that the EPA had not adequately considered background (NRDC v. EPA, 529 F.3d 1077 (D.D. Cir. 2008)).

With respect to the ferroalloys source category, a facility

- wide r isk assessment was not performed because we do not have emissions data for any other operations at these facilities

. In addition, the other operations described at Eramet have either been permanently shut down (Simplex/Vacuum Furnace) or have been idle for some time ( electrolytic manganese and chromium processes). We received no indication from the facility that these processes will ever operate again. We also did not observe any sources of toxic emissions from sources collocated at62

the ferroalloy productio n facilities during ou r site visits to these facilities. Therefore, i t was assumed that the source category risks equaled the facility

- wide risks

. The finding of unacceptable risks from the ferroalloys source category was based on source category risk esti mates and emissions from the ferroalloys source category alone

. An evaluation of facility

wide risks would not change our decisions about acceptability and ample margin of safety of the risks associated with the source category

. Therefore, comments on how facility

- wide risks were used by the EPA in determining acceptable risks and ample margin of safety are not germane to the final rule.

2.5 Multipathway and Environmental Effects

2.5.1 Multipathway
Comment: According to c ommenter 0107 the EPA ’ s multipathway risk assessment falls short because the EPA did not complete this analysis for all persistent or bioaccumulative pollutants, it did not use “allowable” emissions for this assessment , and it did not assess all exposure routes

– particularly for children. The com menter (0107) states that it is also problematic that the EPA failed to use the information it found from the multipathway analysis in its overall risk analysis, because it did not add the multipathway risk found to the inhalation risk.

Commenter 0107 sta tes that the multipathway risk screening assessment for Ferroalloys was restricted to only those contaminants identified in the 2003 Risk Assessment Guidance as being both persistent and bioaccumulative in the environment (i.e., PB

- HAPs). They state that t his list of 14 PB

- HAPs is incomplete as it ignores other HAPs which present a multipathway risk.
Two commenters (0107, 0276) describe why they believe the 2003 Guidance is deficient and conclude that the EPA must perform a full multipathway risk assessmen t for all metals emitted by this source category, including arsenic, chromium, nickel, and manganese. The commenters (0107, 0276) note that California OEHHA has recommended multipathway assessment for these metals based on scientific research and developed a method to conduct this assessment, and the EPA should follow its lead. The commenters (0107, 0276) provide additional information for each of these pollutants for the EPA’s consideration, including information from recent studies showing the impacts of manganese ingestion (see pp. 21

- 22 of the commenter 0276 letter). The commenters (0107, 0276) conclude that the EPA simply may not assume that the ingestion and other multipathway risks are zero for these pollutants because doing so when science shows othe rwise is arbitrary and capricious. The commenters (0107, 0276) add that the failure to assess multipathway risk from exposure to these HAPs, both individually and cumulatively, results in an underestimate of the health risks of HAP emissions from this sour ce category. Commenter 0276 adds that this provides further support for the finding of unacceptability and the need for strong health risk

- based standards that assure an “ample margin of safety to protect public health” under section 7412(f)(2).63

The commen ter (0107) further describes those deficiencies in the multipathway screening analysis conducted for the 2011 proposal :

 I t is irrational and unjustified that the EPA relied on a NAAQS comparison for lead to assess multipathway risks from lead. The EPA shou ld have performed a full, multipathway risk assessment for lead that looks at the full exposure from ingestion and dermal pathways, including through soil and breast

- milk exposure.

 The EPA‘s “refined” screening analysis accounted only for exposure due to f arming and fishing scenarios, which assessed the “layout of the modeling domain (specifically, location of lakes and farms), and meteorological characteristics.” The EPA must conduct a full multipathway risk assessment for this source category that include s consideration of a child‘s multipathway exposure, in urban and rural residential scenarios. Of particular concern is the need to assess impacts on children of soil contamination using updated exposure values.

 The EPA must use the multipathway assessment appropriately, by adding the risk found there to the inhalation risks found, and then proceeding with the required section 112(f)(2) analysis to determine whether or not that total level of risk is acceptable, and

w hat standards are needed to reach an acceptable level and also to provide an ample margin of safety. The commenter (0107) adds that because the EPA treated multipathway risk separately from inhalation risk in its analysis, listing each of them, but not add ing them together in an appropriate manner to recognize their combined impact on the most

exposed people, the EPA thus failed to adequately assess or address the full risk to the

most

- exposed person from the combined impact of both inhalation and other rou tes of exposure, such as ingestion, breast

- milk exposure, and other pathways.

Response: We acknowledge we do not have screening values for some of the PB

- HAP but we disagree that the multipathway assessment is inadequate. In the Air Toxics Assessment Libra ry, we developed the current persistent and bioaccumulative HAP (PB

- HAP) list considering all of the available information on persistence and bioaccumulation (see http://www.epa.gov/ttn/fera/r isk_atra_main.html )

. This list reviewed HAP identified as PB

- HAP by other EPA Program Offices (e.g., the Great Waters Program) , as well as information from the PBT profiler (see http://www.pbtprofiler.net/ )

. This list was peer

- reviewed by the SAB and found to be acceptable and, therefore, we consider it to be reasonable for use in the RTR
program

. Based on these sources and the limited available information on the persistence and bioaccumulation of other HAP, we d o not think that the potential for multipathway risk from other HAP rises to the level of the PB

- HAP currently on the list

. With respect to conducting a multipathway assessment with the allowable emissions, the results from an allowable emissions

- based multipathway assessment would not have changed our risk acceptability decision . T he baseline risks from the category were determined to be unacceptable

,64

and that decision included risk results using actual emissions in the multipathway assessment. Using allowable emissions in the multipathway assessment , where available, would result in the same or higher risks than using actual emissions. For some pollutants, we did not have detailed enough information to perform a multipathway risk assessment wi th allowable emissions. For example, for POM there is not a MACT standard in the 1999 NESHAP and thus, we were unable to calculate MACT

- allowable emissions for POM

. In this instance, we set allowable emissions equivalent to actual emissions and as stated , actual emissions were included in the multipathway assessments for all rule stages. Further, we evaluated post

- control risks and determined them to be acceptable. The post

- control risks were based on emission limits that will lower “baseline” allowable emissions , including for those pollutants that were not estimated in the baseline allowable levels

.
We disagree with the commenter that a separate multipathway risk assessment should have been performed for lead. As noted in previous responses, the NAAQ S for lead was used as a health based standard in this review

. It was not simply adopted mechanically, but rather is justified under the independent decision framework in section 112(f)(2). We note that the NAAQS for lead was set to protect, with an adequa te margin of safety, the health of the most susceptible children and other potentially at

- risk populations against an array of adverse health effects, most notably including neurological effects, particularly neurobehavioral and neurocognitive effects (whi ch are the most effects to which children are most sensitive) (73 FR at 67007). We further note that in developing the NAAQS for lead, air

- related multipathway effects were already taken into account. That is, as noted at 73 FR at 66971: “As was true in th e setting of the current standard, multimedia distribution of and multipathway exposure to Pb that has been emitted into the ambient air play a key role in the Agency’s consideration of the Pb NAAQS.” More discussion on the use of the lead NAAQS in RTR can be found in Section 2.1.1.6.
Regarding incidental soil contamination, the EPA has estimated risks from both direct and indirect pathway s. Direct routes of exposure include direct ingestion of soil and ex posure through dermal contact. However, because it h as been demonstrated in past analyses that exposure levels associated with dermal contact are but a small fraction of exposure levels associated with ingestion and inhalation pathways, dermal exposures were not assessed for this source category.

The comme nter is incorrect in saying that the “ ‘ refined’ screening analysis (conducted for the 2011 proposal) accounted only for exposure due to farming and fishing scenarios.” The intermediate screen (or Tier 2 screen) used the full multipathway assessment conduct ed to develop the Tier 1 screening thresholds, but incorporated some site

- specific information to replace some default parameters , such as distance to the lake and local meteorological data

. The scope of the assessment did not change from Tier 1 to Tier 2

. The use of the Tier 1 screen and the development of the screening thresholds are described in the risk assessment document (and related appendices) available in the docket for the proposed action

. The description of the site

specific information used in the Tier 2 screen is also described in these same documents

. For the65

2014 supplemental proposal and the 2015 final rule, we conducted Tier I and Tier II screens and we also conducted a refined multipathway assessment.

The 2011 Exposure Factors Handbook was not available at the time the multipathway screen was conducted for proposal

. Since that time, however, it has been made available and the Tier 1 multipathway screening scenario has been updated to include the updated factors

. As stated in the risk assess ment document (see Appendix 4) , “The screening scenario is intended to represent a high

- end exposure for children via incidental soil ingestion

. The 2011 Exposure Factors Handbook recommended “upper

- percentile” soil ingestion rate (numeric percentile not s pecified) for children aged 3 to <6 years is 200 mg/d

. This is half of the value used in the previous [i.e., at proposal] scenario setup (i.e., 400 mg/d), which was set based on recommendations by the EPA in the 1997 Exposure Factors Handbook

. The EPA also recently published the Child

- Specific Exposure Factors Handbook (2008)

. No additional data or recommendations for child soil ingestion are presented in this source, and in fact an “upper percentile” value for this parameter is not provided

. Based on these sources, a value of 200 mg/d is used in the current RTR multipathway screening scenario for the child incidental soil ingestion rate.”

As discussed previously, w e have combine d risk assessment results to the extent that it is appropriate to do so

. The i ndividual cancer risks for the category were a ggregated for all carcinogens. We consider the effect of mixtures of carcinogens and use a target organ

- specific hazard index (TOSHI) approach for our chronic noncancer assessments. We do not use a TOSHI
approa ch for our acute analyses nor do we combine the results of our inhalation and multipathway assessments. The multipathway risk assessment conducted for proposal was a screening

- level assessment (i.e., Tier 1)

. It used highly conservative assumptions designe d to ensure that facilities with results below the screening threshold values did not have the potential for multipathway impacts of concern

. The screening scenario is a hypothetical scenario and

, due to the theoretical construct of the screening model, ex ceedances of the thresholds are not directly translatable into estimates of risk or hazard quotients for these facilities. Rather, it represents a high

- end estimate of w hat the risk or hazard may be. For this category

, we were able to conduct a more refine d screening

- level assessment that included some site

- specific information (i.e., Tier 2). This allowed us to remove some of the default information and replace it with actual conditions around these facilities (e.g., distance to a lake). While we were able to refine the assessment somewhat, it remains a screening

- level assessment

. For this category we were also able to develop a slightly more refined screening

- level scenario to characterize multipathway risks for those facilities that exceeded the Tier 1 sc reening thresholds by using some site

- specific information (i.e., Tier 2). This allowed us to remove some of the default information and replace it with actual conditions around these facilities (e.g., distance to a lake, size of lake, etc.).

Comment: In comments on the supplemental proposal, commenter 0276 said that rather than ignoring the health risks created by PCB emissions, the EPA should have used a default factor to account for these risks, based on chemical structure, available toxicologic al tests and model or experimental data, and data on similar chemicals that have been well

- studied as recommended by66

the NAS. The commenter (0276) added that the EPA has likely underestimated PCB emissions and that the EPA’s justification that emissions are low is invalid. Also, the commenter (0276) states that PCBs are extremely dangerous and persist and bioaccumulate in the environment so that small amounts add up, get worse and do not go away over time.

Response: We acknowledge we do not have screening val ues for some of the PB

- HAP but we disagree that the multipathway assessment is inadequate. As we explained in the emissions methodology memorandum

, 37 over half of the PCB compounds were reported as non

- detect. These emissions are unlikely to impact health r isks

. In the Air Toxics Risk Assessment Reference Library, we developed the current PB

- HAP list considering all of the available information on persistence and bioaccumulation (see http://www2.epa.gov/fera/air

- toxics

- risk

assessment

- reference

- library

- volu mes

- 1

- 3), specifically Volume 1 Appendix D). (The Air Toxics Risk Assessment Reference Library provides information on the fundamental principles of risk

based assessment for air toxics and how to apply those principles in different settings (e.g., facilit y

- specific) as well as strategies for reducing risk at the local level.) This list considered HAP identified as PB

- HAP by other EPA Program Offices (e.g., the Great Waters Program), as well as information from the persistent, bioaccumulative and toxic (PBT ) profiler (see http://www.pbtprofiler.net/). This list was peer

- reviewed by the SAB and found to be acceptable, and therefore we consider it to be reasonable for use in the RTR program. Based on these sources and the limited available information on the p ersistence and bioaccumulation of other HAP, we do not believe that the potential for multipathway risk from other HAP rises to the level of the PB

- HAP currently on the list.

Comment: Commenter 0107 states that by failing to account for multipathway risk due to allowable emissions (and for higher risk due to malfunctions), the EPA has not assessed the full potential for non

- inhalation health risk due to persistent and bioaccumulative emissions. The

commenter (0107) notes that intermittent or short spikes o f PB

- HAPs, can represent a significant health risk because the contaminants stay in the environment and small amounts can accumulate into larger amounts over time. The commenter (0107) states that failing to account for the full multipathway risk that the EPA ’ s existing standard allows, or for risk due to violations from that standard, violates the section 112(f)(2) requirement to protect the individuals “most exposed” to this source category.

Response: The point about using allowable emissions in multipathway assessments was discussed earlier in this section. We disagree with the commenter that emissions that are violations of the standards should be considered as part of the risk analysis

. The purpose o f the risk review is to evaluate whether the emission limits should be made more stringent to reduce

37 Memorandum from Bradley Nelson, EC/R Inc., to Phil Mulrine, EPA OAQPS/SPPD/MMG
, Revised Development of the Risk and Technology Review (RTR) Emissions Dataset for the Ferroalloys Production Source Category for the 2014 Supplemental Proposal

, August 26, 2014

.67

the risk posed after compliance with the underlying MACT standard

. To the extent that a source is violating the underlying MACT standard, no tightening of the emission standard under the residual risk rule will avoid or mitigate against such violations

. In other words, a source that is violating the MACT emissions standard promulgated under section 112(d) would not be any more likely to be able to avoid such violations and comply with a different presumably more stringent standard promulgated under section 112(f)

. Such events are violations and subject to enforcement by the EPA, the States, or citizens, and an action for injunctive relief is the most effectiv e means to address violations whether or not they are caused by malfunctions if an emissions event poses a significant health or environmental risk.

Comment: In their comments on the 2011 proposal, c ommenter 0106 asserts that the EPA improperly used Sectio n 112(d) to impose risk

- based standards in the absence of justification under Section 112(f). The commenter (0106) states that the EPA’s reliance on “potential” risks from a screening assessment to justify mercury controls is a misuse of the relevant scree ning tool, which should only be used to determine when a site

- specific risk assessment is called for to determine whether further emission controls are justified. The commenter (0106) states that there is no reason to expect that EMI’s very small mercury e missions (the maximum off

- site concentration predicted by the EPA is about one

- third of the average ambient concentration in the United States) would fail a multi

- pathway assessment based on more accurate air modeling and other risk assessment parameters.

Response: For the 2011 proposal, t he multipathway screen was conducted to assess risks under 112(f)

. The results of that assessment, and the fact that it is a screening

- level assessment, were considered in the acceptability decision under 112(f)

. However, the emission controls proposed to reduce mercury emissions (e.g., activated carbon injection, or ACI) were proposed under 112(d), the technology review section, not 112(f)

. Regardless of the risk assessment results, we had an obligation to address mercury emissions because all HAP from a major source category must be addressed by MACT under Sierra Club v. EPA, 479 F. 3d 875 (D.C. Cir. March 13, 2007). The limits in the rule are technology based, not risk based. The mercury emissions estimated by the EPA a re based on test data provided by the facility

, in addition to information related to the type of ferroalloy being produced in each of the furnaces

. Therefore, we di sagree with the commenter’s assertion that their modeling and parameters are more accurate. The basis for our selection of models and parameters is explained in emissions methodology memorandum 38 in the record for today’s rule. Further, as described earlier, a refined assessment was conducted (under 112(f)) for the 2 014 supplemental proposal and the 2015 final rule.

38 Memorandum from Bradley Nels on, EC/R Inc., to Phil Mulrine, EPA OAQPS/SPPD/MMG
, Revised Development of the Risk and Technology Review (RTR) Emissions Dataset for the Ferroalloys Production Source Category for the 2014 Supplemental Proposal

, August 26, 2014

.68

Comment: In their comments on the 2011 proposal, c ommenter 0106 states that as a result of their finding that errors in US EPA's model overstated ambient concentrations of manganese by a factor of three, i t is likely that ambient concentrations for mercury and POM used as the basis of the non

- inhalation pathway screening analysis are also overstated, but they were unable to quantify the degree of such overstatement. The commenter (0106) states that the POM and mercury intermediate screening threshold exceedances in US EPA's multipathway screening risk assessment are not evidence of unacceptable risks, noting that because of the conservative nature of screening assessments, only a refined risk assessment in a ccordance with US EPA guidance can provide a reliable conclusion that risk thresholds are exceeded. The commenter (0106) notes that the EPA did not conduct such an assessment of the multipathway exposures and risks. The

commenter (0106) also notes that the POM emission threshold used in the multipathway screen uses an uncertain toxicity value and it is inappropriate to apply that value to PAH that are not carcinogens. The commenter (0106) states that assuming five percent of the POM emissions are as toxic a s benzo(a)pyrene is not applicable to ferroalloy emissions because “emissions are different.”

In their comments on the 2011 proposal, c ommenter 0107 states that the EPA did not refine its analysis further for mercury or POM (or any other PB

- HAPs) and it h as no rational justification for finding a dramatically high multipathway risk and then discounting that analysis due to data limitation and failing to explain why it has not collected additional data and to describe what data it needs to complete its mult ipathway risk assessment.

Response: During the comment period after the publication of the 2011 proposal, t he commenter did not provide any additional information about the basis of the statement that mercury and POM concentrations are overstated (e.g., revised emissions information for mercury or POM)

. However, additional emissions were provided in the intervening years and t hose revised emissions estimates were used in the assessments for the supplemental proposal and/or final, depending on when it was provided. As described in the risk assessment report available in the docket for this proposed action, the mutlipathway scree n does not use the ambient concentrations obtained from the inhalation modeling, so the statement that the concentrations are overestimated is irrelevant

. The multipathway scree n compares facility

- level emissions to a screening level of emissions below whi ch we do not expect there to be multipathway effects

. The commenter is correct that the multipathway screen is a screening

- level assessment designed to identify facilities and pollutants that need further analysis

. The commenter is not correct however tha t the screen cannot provide information about the risks that can feed into a decision

. The screen provides us information that for those facilities whose emissions do not exceed the screening thresholds, we do not expect multipathway effects, and for those situations where the facility emissions are greater than the screening thresholds, the potential for multipathway effects exists

. For those situations where the facility emissions are greater than the screening thresholds based on our multipathway screen, the fact that it is a screen is taken into consideration in the decision

. The finding of unacceptable risks is not based on any one risk metric (e.g., potential69

multipathway risks), but rather considering all of the health information available

. As stated earlier, for the 2014 supplemental proposal and the 2015 final rule a refined multipathway assessment were conducted.
The commenter does not elaborate on what is meant by an “uncertain toxicity value” and does also not explain what is meant by the comment that ferroalloys “emissions are different.” These statements lacking additional information do not enable us to update our analysis in a meaningful
way

. The commenter is correct that some of the PAH are not considered carcinogens

. This determination was m ade after the risk assessment was conducted for the 2011 proposed rulemaking and has been corrected for the supplemental proposal and final rulemaking (i.e., the individual PAH species that are not carcinogens have not been included in the multipathway

scr een). More information is available in the risk assessment document.

Comment: In their comments on the supplemental proposal, commenter 0272 states that the EPA’s assumes that the Marietta area supports subsistence fishing, however the EPA presented no sub stantial evidence in the record that such an assumption is plausible for Marietta, Ohio. The

commenter (0272) believes that outside of indigenous populations in Alaska, there is scant evidence to support the existence of subsistence fishing in the United S tates. Therefore, the

commenter (0272) believes that the EPA should have modeled ingestion risks based on a high

end recreational angler receptor, which they believe is the most conservative and plausible receptor for purposes of this rulemaking (see Secti on 3.2.2.1 of Appendix A).

The commenter (0106) states that the EPA should have used a 95th percentile fish ingestion rate instead of the 99th percentile as the 99th percentile is unnecessarily conservative for assessing risks to the general population. In addition, the commenter (0106) notes that assuming th at 100 percent of the fish consumed is caught locally is not a reasonable assumption.

Response: The design of the multipathway screen is to reflect conservative assumptions, such that we are reasonably confident that at emission levels below the screening thresholds we would not see any multipathway effects. Given that design goal, using conservative assumptions for fish ingestion and local fish consumption are reasonable. The refined multipathway assessment includes an angler scenario, which represents an individual who regularly consumes fish caught in a freshwater lake in the vicinity of the source of interest over the course of a 70

- year lifetime (see Appendix 10 of the Risk Assessment Document

– Technical Support Document: Human Health Multipathway Resi dual Risk Assessment for the Ferroalloys Production Source Category). We review ed the potential lakes in the area to see if they are fishable by the general public (e.g., not located on gated, industrial property) and are of sufficient size to contain fish of higher trophic levels. Data is not available on the subsistence fishing activities in the area, but the presence of fishable lakes means it could happen.

Comment: In their comments on the 2011 proposal, c ommenter 0106 states the EPA's "maximum off

- site impact" modeling location for mercury compounds is actually on

- site at EMI.70

The commenter (0106) states that the correct off

- site location has predicted air concentrations for mercury compounds that are approximately one

- half of the values relied on by US EPA in its screening assessment.

Response: In response to the 2011 proposal, t he facility did not provide any additional information (e.g., a boundary map) to enable us to update our on

- site/off

- site locations. EMI has also not provided us any additional information about the mercury species to which they are referring in their comment (e.g., divalent or elemental mercury). However, the on

- site/off

- site nature of the receptor does not come into play in the multipathway screening assessment. As described in the risk assessment report available in the docket for this proposed action, the multipathway screening analysis does not use the ambient concentrations obtained from the inhalation modeling, so the statement that the concentrations are overestimated is i rrelevant. The multipathway screening assessment compares facility

- level emissions to a screening level of emissions below which we do not expect there to be multipathway effects. For our chronic and acute inhalation assessments, we do our best to estimate risks for off

- site receptors, as described in the risk assessment document.

2.5.2 Environmental Effects
Comment: In their comments on the 2011 proposal, c ommenter 0107 states that the EPA provides no conclusion on whether there is an adverse environmental effec t currently, or whether its proposed rule would prevent such an effect, as required by section 112(f)(2). The commenter (0107) states where there is such a high potential for multipathway risk to people, there is likely to be a parallel high risk due to in gestion and other non

- inhalation pathways of exposure for wildlife and other impacts to natural resources. The commenter (0107) states that the EPA must perform an ecological risk assessment for this source category, and may not simply rely solely on the human health assessment without a reasoned explanation for doing so that is not supported by scientific evidence in the record. The commenter (01 07) states the EPA’s health risk numbers are not below the threshold and, although the EPA states that the reference doses it is using are more protective than the EPA believes is necessary to protect laboratory animals such as rodents, the EPA gives no ba sis for why this is a sufficient way to prevent an adverse environmental effect for more sensitive wildlife or other environmental receptors. The commenter (0107) notes that the EPA says nothing at all about ESA consultation, which provides further evidenc e that it has not considered or addressed its duty to prevent adverse environmental effects, as recognized by the D.C. Circuit. The commenter (0107) adds that each of the significant flaws described above in the EPA ’ s human health risk assessment provides an additional reason why the EPA cannot rely on that alone for an environmental risk assessment.

Response: Since the time of the 2011 proposal, we have developed a more robust ecological risk assessment screening approach, as described in the preamble to the 2014 supplemental proposal and the risk assessment documents for the 2014 supplemental proposal and 2015 final rule.71

2.6 Environmental Justice Assessment Issues
Comment: Commenter 0075 asserts that the EPA does not have authority to consider demographics in conducting residual risk assessments. The commenter (0075) states that it would not be not reasonable to construe the term “public health” as used in section 112(f) as allowing consideration of demographic classifications that bear no relationship to th e potential health effects presented by the HAPs at issue for the given source category or subcategory. The

commenter (0075) adds that the EPA’s proposal would unreasonably inject racial, ethnic, and other policy considerations into a program designed to p rovide protection for the public at large, thus inappropriately causing arbitrary policy and political considerations to trump objective scientific analysis.

Response: While we did provide a demographic analysis of the at

- risk populations surrounding the f acilities within the source category addressed by this rule making, the results of our demographic analysis only serve to provide information about the demographic make

- up of the populations exposed to this source category which might benefit from the prop osed rule and did not affect any decision in this rulemaking

.
Comment: In their comments on the 2011 proposal, c ommenter 0107 notes that the EPA ’ s draft socioeconomic analysis is incomplete and it should add additional elements into this analysis to more fully assess environmental justice impacts. The commenter (0107) states that, in addition to looking at demographic census data, the EPA must also assess the starting point or baseline of “overall health” status of the affected individuals and communities using the best available data at a local and national level, including the baseline cancer levels. The commenter (0107) states that the EPA should follow the recommendations of the EPA ’ s own interim guidance and presented in the Environmental Justice Strategic Enforcement Assessment Tool (EJSEAT), and include other relevant EJ factors such as an assessment of the percent of population with limited E nglish proficiency, percent infant mortality, and percent low birth weight births.

The c ommenter ( 0107 ), with similar comments submitted by commenter 0065 (on the behalf of state and local air quality agencies), adds that the EPA must also analyze the dem ographics of the people who are the most exposed, within 5 km of existing plants, and for urban areas and perform this assessment within a 2 km radius of each facility . The commenter (0107) states that the EPA analyzed the demographics within a 5 km radius for the c hrome plating proposal and it must at least do the same for this source category. The commenter (0107) is concerned that failing to perform the localized analysis may miss environmental justice impacts if there is a minority or low

- income communi ty directly next to the facility but not significantly represented in the broader 50

- km area.

Both commenters (0065, 0107) state that the EPA should also use the most recent census data from 2010, to the extent it is available, rather than just data from 2000 for this analysis. One

commenter (0107) adds that the census data available for 2010 show the largest number of72

people living below the poverty level in the United States in the 52 years for which poverty estimates have been published.

The commenter ( 0107 ) states that the EPA must also incorporate this environmental justice assessment fully into the policy decision it chooses in the final rule, by recognizing that it is not fair or acceptable for particular individuals or communities to have this type of disproportionate impact.

Furthermore, the c ommenter ( 0107 ) states that, as part of providing sufficient information to affected local communities, the EPA should publish a plain

- language statement of the health risks and benefits from the EPA ’ s final action, and in future rule proposals. The commenter (0107) states that providing a meaningful opportunity for comment, particularly where disproportionate health impacts are concerned, is an environmental justice issue. Both

commenters (0065, 0107) state t hat it is important that the EPA provide a statement and analysis in this residual risk rulemaking (and all others) on the real world impacts of the EPA ’ s rulemaking, so that the affected public has a clear understanding of what the risk is, and precisely what types of harm to public health EPA is determining are “acceptable” and “unacceptable.”

One commenter ( 0107 ) notes that the EPA released the Plan EJ 2014 to direct ways the agency intends to address environmental justice impacts, and it includes the d evelopment of scientific tools on cumulative impacts. The commenter (0107) states that the EPA must not wait to employ the best available science now, in this rulemaking, to protect local communities that face disproportionate impacts from these and other sources of toxic air emissions.

Response: With respect to the EJSEAT tool, we disagree that it should be used in our demographic analyses

. At the time of the 2011 proposal, EJSEAT was a draft tool in development. Thus, it ha d not undergone a sufficient level of peer review to be incorporated into our analyses. Through the EPA’s interim guidance on EJ and the Action Development Process, the agency is encouraging rule writers and policy makers to look at the whole range of facto rs that impact communities and population groups when crafting rules. The EPA is continuing to discuss and pilot approaches that are consistent with the agency’s responsibilities regarding EJ as outlined in EO 12898

. The EPA defines “environmental justice” to mean fair treatment and meaningful involvement of all people, and this definition represents a commitment to ensuring that EPA works to improve conditions affecting the public health of all Americans so that everyone has access to clean water, clean ai r and healthy communities. In the Urban Air Toxics Strategy Report to Congress we acknowledge that national rules and standards can address part of the risk to communities, but because the assessments did not include background risks or contributions to ri sk from sources outside the facilities more needs to be done at the community level with other tools available within the Clean Air Act and within state, loca l, and other federal programs. EPA is committed to our efforts to make a difference in communities of concern and developing an73

integrated strategy focusing work in communities with the m ost need for EPA’s assistance. We have been, and will continue to work in thousands of c ommunities across the country. Over the next years we will look for opportuniti es to enhance our partnership with communities to strengthen and improve their health

– bo th environmental and economic. This effort to enhance coordination across our EPA programs and with other federal agencies will improve how we
sup port community needs

. We will focus on those communities where we think we have opportunities to leverage resources and acti ons to make a real difference. As we learn lessons on coordinating and focusing our efforts, we will use these lessons to help more communities in the f uture.
The EPA agrees that the estimate of the percentage of people in poverty has increased between the 2000 Census (13 percent) and the 2010 Census (14 percent). At the time of the 2011 proposal, the 2010 census data was not available for us to use. Sinc e that time, we have incorporated it into all of our modeling assessments, and it was used in the demographic assessments for the 2014 supplemental proposal and the 2015 final rule.

The commenter is correct that we performed the demographic analyses for th e ferroalloys source category differently than we did for the October 2010 proposed RTR for the Hard and Decorative Chromium Electroplating and Chromium Anodizing Tanks source categories. We performed the demographic analyses for the chromium source catego ries using two approaches as examples of how such analyses might be developed, and invited public comment on the approaches used and the interpretations made from the results. In the first approach, we focused the analysis on the total populations residing within 5 km of each facility, regardless of their estimated risks, and examined the distributions of estimated risk across the various demographic groups within those 5 km circles

. That analysis was a “proximity” analysis in that it considered only the di stance from the emission sources to surrounding populations, and not the estimated risks to those populations.

In the second approach, we focused the analysis on the populations within 5 km of any facility estimated to have exposures to HAP which result in cancer risks of 1

- in

- 1 million or greater or

non

- cancer hazard indices of 1 or greater. We examined the distributions of those risks across various demographic groups. In each approach, we compared the percentages of particular demographic groups to the t otal number of people in those demographic groups nationwide

. We stated in the proposed rule for the chromium source categories that in future rules we planned to extend these analyses to cover the entire modeled domain for a facility (50 km radius) to cap ture all individuals with risks above 1

- in

- 1 million or greater or non

- cancer hazard indices of 1 or greater. We also stated that generally we have found that using a 5 km radius in the analysis will capture more than 90 percent of all the individuals with cancer risks above 1

- in

- 1 million.

In the February 2012 supplemental proposal for the RTR for the chromium source categories, our demographic analyses included populations within 50 km of each source (including those very near the sources) with risks abov e 1

- in

- 1 million or greater or non

- cancer hazard indices of74

1 or greater

. (77 FR 6628, Feb 8, 2012)

. We did not include analyses using a 5 km radius in that supplemental proposal nor in the RTR proposal for the ferroalloys source category

. We think that, w here a risk assessment has been performed, it is more informative to consider the demographics of all populations (including those beyond 5 km) with elevated risks than to limit the demographic analysis to populations located within 5 km of a facility

. Whe re a risk assessment has been performed, these populations are identified, and the source stack parameters are taken into account

. As discussed above, we have found that most exposure locations with the highest estimated risks are within 5 km of a facility , so extending the radius to 50 km has little impact on an analysis based on risks, but makes more sense because 50 km corresponds to the risk modeling radius and includes all populations with elevated risk estimates

. It is the EPA’s goal to make all rule preambles and risk assessments in plain language and we think we have done so as much as possible. However, as future assessments are written we will consider the comments provided above, and to the extent possible, incorporate those that will make our risk and rulemaking documents more informative.

We are not able to determine the baseline health status of individuals or communities in a national rulemaking. Individual privacy issues as they relate to health records and the costs that

w ould be associated with such an analysis make the analysis infeasible. Through the EPA’s interim guidance on E nvironmental J ustice and the Action Development Process, the agency is encouraging rule writers and policy makers to look at the whole range of fa ctors that impact communities and population groups when crafting rules. The EPA is continuing to discuss and pilot approaches that are consistent with the agency’s responsibilities regarding EJ as outlined in EO 12898. In determining the need for tighter residual risk standards, the EPA strives to limit to no higher than 100

- in

- 1 million the estimated cancer risk for persons living near a facility if exposed to the maximum pollutant concentration for 70 years and to protect the greatest number of persons t o an individual lifetime risk of no higher than 1

- in

- 1 million. Considerations are made for all people regardless of racial or socioeconomic status, and the EPA does not believe it is necessary to establish a default factor to account for socioeconomic and other community

based stressors.

Comment: Commenter 0065 commends the EPA for considering environmental justice issues by expressing concern about the disproportionate impacts of HAP emissions on certain social, demographic and economic groups. In additio n to making the improvements suggested in the above comment, t he commenter (0065) adds that the EPA can improve the EJ analysis by working with the EPA EJ office to develop criteria and specific guidance on how to interpret and apply the outcome of these t ypes of analyses in the rulemaking process.

Response: W e note that we are working with the Office of Environmental Justice in an ongoing effort to develop new tools for considering environmental justice in rulemakings. We also note that our ability to quan titatively assess EJ issues is evolving; over time we expect it to become75

more robust, sophisticated, and capable of ensuring that we are meeting our mission as an
agency.
The EPA continues to evaluate and refine environmental justice analysis, such as th e proximity analysis performed for the Definition of Solid Waste. The draft EPA document Technical Guidance for Assessing Environmental Justice in Regulatory Analysis is currently undergoing Science Advisory Board (SAB) review. The Office of Air and Radiat ion is contributor to this draft document and cites numerous examples of EJ analysis performed in agency rulemakings. Environment justice considerations are a part of the rulemaking process; however, various factors influence the scope and complexity of an assessment. These factors may include, but are not limited to statutory mandates, data availability, resources and/or timeframe limitations.

Comment: Commenter 0070 asserts that the EPA’s failure to assess the substantial body of science concerning mangan ese amassed since 1994 is not consistent with the Agency’s environmental justice objectives (bringing “the best science to decision

- making around environmental justice issues.”) The commenter (0070 ) states that continuing anxiety among residents of areas n ear Eramet are reinforced by the EPA’s reliance on outdated RfC values, when the latest science may confirm that such anxieties are baseless.

Response : See responses In Section 2.1 related to the EPA’s use of RfC values.

2.7 Other Modeling Methodology Issues

Comment: In their comments on the 2011 proposal, t wo commenters (0073, 0106) assert that the EPA failed to follow the Agency’s own modeling guidance and, as a direct result, the EPA’s residual risk assessment was based on overstated and invalid estimates o f off

- site manganese
exposures. One commenter (0106 ) provides a detailed review of the EPA’s modeling and risk assessment, including the following points for the 2011 proposal :

 The EPA failed to base its model the most representative meteorological data, f rom the Parkersburg, West Virginia airport (5 miles away), and instead used meteorological data from the Charleston, West Virginia airport (70 miles away).

 The EPA relied on a single year of meteorological data, rather than five years of such data to accou nt for year

- to

- year variability.
Additionally, in their comments on the 2011 proposal, the commenter (0106) states that the EPA’s modeling errors resulted in estimates that overstated off

- site respirable manganese concentration by 88 percent and thus produ ce scientifically unreliable exposure estimates, which the commenter confirmed via a validation test against the EPA’s own field monitoring data. The commenter (0106) adds that the EPA's air modeling analysis overestimates the maximum manganese air concent ration near the EMI facility by a factor of eight and that the EPA's air modeling analysis greatly overestimates the overall area and population exposed to manganese76

emissions from EMI. The commenter (0106) provides corrected modeling files, which predict significantly lower off

- site exposure concentrations for use in a residual risk assessment.

Moreover, the commenter (0272) states that the EPA modeled manganese emissions from the EMI facility as if they behave as a gas (i.e., EPA assumed zero losses due t o ground deposition), which is a reasonable approximation for PM 2.5 emissions, but not reasonable for modeling the dispersion of larger, heavier particles. It is unfair and unreasonable for EPA to bias the residual risk assessment by simultaneously (i) max imizing estimated air dispersion by treating all emissions as light PM 2.5 particles and (ii) maximizing predicted exposure concentrations by deriving them from total PM, rather than constructing a scientifically consistent model based on respirable PM 2.5 e missions.

The commenter (0272) also states that the EPA provides no explanation in the docket for its assumption that all PM emitted in ferroalloys production is small enough to be respirable. The commenter (0272) notes that the RIA filed with the 2011 pr oposal states that 41 percent of such total PM emissions meet the Agency’s definition of respirable (i.e., PM 2.5 ), and EPA’s Ferroalloys Cost Memo for the 2014 proposal asserts that PM 2.5 accounts for only 21 percent of the total PM emissions.

The comment er (0272) provided modeling results for both PM 2.5 and PM 5 based on particle size distributions from existing EPA guidance on emissions from ferromanganese and silicomanganese production 39 (see Section 3.1.2 of Appendix A). The section estimates that total PM from production of 80 percent ferromanganese and silicomanganese consists of particles ranging in size from at least as small as 0.5 microns to greater than 20 microns. The commenter ( 0272) notes that the particle size distributions provided in this section of AP

- 42 illustrate the error of assuming that 100 percent of such emissions are respirable. The commenter (0272) believes that by failing to model for the respirable particle size ( i.e., PM 2.5 ) overstates risk by 38 to 48 percent, and failure to even model for PM 5 overstates risk by about 30 to 36 percent.

Response: When we began performing RTR risk assessments, we chose meteorological data considering the amount of data quality ass urance needed and AERMOD run times. We restricted our meteorological data to that collected prior to the installation of the Automated Surface Observation System (ASOS). The ASOS had been found to omit the ceiling height for a large percentage of observati ons at a number of meteorological stations. Because installation and operation of ASOS equipment began in 1992, we selected the year 1991. As newer, higher quality ASOS data have become available, we have added newer data and additional data site locations to the meteorological data library we use in our risk assessments. Recently, we updated our meteorological data library to include data for more than 800 National Weather Service

39 AP 42, Fifth Edition, Vo lume I, Chapter 12 (Metallurgical Industry), Table 12.4

- 4, http://www.epa.gov/ttn/chief/ap42/ch12/final/c12s04.pdf77

(NWS) surface and upper air stations across the continental United States, A laska, Hawaii, and Puerto Rico. We obtained calendar year 2011 Integrated Surface Hourly Data (ISHD) for these stations, as well as ASOS 1

- minute data for each surface station. The Parkersburg, WV station is in our library of meteorological data, and it wa s used for both facilities in the risk assessment conducted for this final rulemaking.

Although 5 years of meteorological data is preferred for assessing chronic exposures and risks, we use a single year of meteorological data in our risk assessments beca use of AERMOD model run times. Because we frequently run AERMOD for entire source categories with many individual emissions points and for many receptors, using 5 years of meteorological data would increase already significant model run times by a factor o f five compared to a single year. In a sensitivity analysis of the impact of using a single year of meteorological data compared to 5 years, we found that modeled concentrations differed by less than ten percent on average and thus, the use of one year of meteorological data is not likely to appreciably affect the results of the risk assessment. 40

We did indeed treat the manganese compounds as 100 percent gaseous when we performed risk modeling using the HEM model. We agree that modeling the pollutant as a particulate could result in lower estimated air concentrations by accounting for dry depletion. However, the impact of dry depletion for particulate emissions depends on multiple factors, including the distance from the source to the receptor, and parti cle properties. The impact of depletion on maximum estimated air concentrations and risks likely would be minimal because of the short distance between the sources and receptors (the locations of the MIR). At longer distances (i.e., greater than 10 km), th e impact would be greater, but the extent of that impact is difficult to estimate because we typically do not have sufficient particle property data (aerodynamic particle diameters, particle densities, and mass fractions) to model depletion. Also, deposite d emissions can be re

- suspended in the air, and plume depletion does not account for that process.

The modeling files provided by the commenter in response to the 2011 proposal contain the stack parameters and the emissions that the EPA used in th at propos al. However, t hey used a shorter averaging time than in our assessment (24 hours vs 1 year) and only estimated the concentrations at three discrete receptors (the school monitors discussed in Section 2.8 below). It is unclear how these “corrected” files co ntain new information that can be used to update the EPA’s assessment. AP

- 42 does provide particle size information for ferroalloys production furnaces, however these particle size distributions are based on particulate matter and do not provide any inform ation on particle sizes for the metal HAP. Therefore we modeled all metal HAP to provide a conservative estimate for risk. For the supplemental proposal, the commenter

40 US EPA, 2009: Risk and Technology Review (RTR)

– Risk Assessment Methodologies: For Review by the EPA’s Science Advisory Board; Case Studie s

– MACT I Petroleum Refining Sources and Portland Cement Manufacturing; U.S. Environmental Protection Agency, Office of Air Quality Planning and Standards, Health and Environmental Impacts Division, Research Triangle Park, NC, EPA

- 452/R

- 09

- 009, June 2009, Page 4

- 6.78

did provide model results based on different PM fractions, but not the modeling files or any actual particle size information from their facility. As described above (in Sections 2.1.1.1 and 2.2.3) we disagree with the commenter that only the PM 2.5 fraction should be used.

In regard to the PM 2.5 percentage, no particle size testing was perfor med and therefore in order to calculate the PM 2.5 benefits we had to estimate the percentage of PM 2.5 based on information from numerous sources. For the 2011 proposal we estimated PM 2.5 to be 41 percent of the total PM based on information from the EPA SPECIATE database. For the 2014 supplemental proposal, we estimated PM 2.5 to be 21 percent of the total PM based on information we have on PM 2.5 data collected in the Marietta area.

Comment: In their comments on the 2011 proposal, c ommenter 0106 st ates that US EPA's model validation attempt, which compares modeled vs. monitored manganese air concentrations, is flawed and misleading. According to the commenter (0106), the EPA compared 16 days of monitoring in 2009 to annual average model results from 1991. The commenter (0106) concludes that when you compare daily modeling outputs to these monitored values, there is very poor correlation and in fact the comparison shows that there is another source of manganese in the area other than Eramet.

Response: For the 2011 proposal, we compared risk modeling results to monitoring data that was collected as part of the EPA's "School Air Toxic Monitoring Study

. " The School Air Toxics data was comprised of 12

- 16 samples collected over a three month period during t he summer and fall of 2009. Th ese data are available on the EPA website at: http://www.epa.gov/schoolair . The EPA considers that a 3

- month time period, that spans two seasons, is a sufficient length of time to g ive a rough indication as to the weather patterns that may affect the wind flow patterns near the subject schools. The modeling results were based on emissions collected from ICR data for several years prior to 2011, not 1991. While the EPA agrees with the commenter that the sample set is small, the comparison between the school monitor data and the model was included only to serve as a ground

- truth exercise, not a detailed model to monitoring comparison study. Further, the EPA thinks that this exercise sho ws good agreement between the measured and modeled ambient levels leading us to believe that the Eramet facility is the primary contributing source of manganese at the schools. A model

- to

- monitor comparison was not conducted for the 2014 supplemental propo sal for the 2015 final rule because the time separating the emissions data used in those modeling assessments and the school air toxics monitoring data was too great.

Comment: One commenter (0271) stated that there are problems with applying the AERMOD Model to estimated fugitive emissions. They state that AERMOD has been shown to perform poorly at low wind speeds, with low

- level sources, with intermittent sources, and in compl ex terrain. They believe that despite EPA’s recent efforts to refine modeling guidance and tools, the refinements, using fugitive PM air dispersion modeling without making adjustments to the modeling protocol overestimates potential exposure and risk and i s arbitrary and punitive when emission limits are established based on overly conservative air dispersion modeling protocols.79

They state that the EPA has been presented with viable alternatives during the 10 th Modeling Conference and should apply these pro tocols before arbitrarily establishing compliance obligations using inaccurate air dispersion tools when assessing ambient exposure risks from fugitive PM emission sources.

Response: In the commenter’s letter, they specifically refer to fugitive sources such a roadways and material storage. It is important to note that these sources are not included in this assessment. With respect to the modeling approach, the risk assessment followed the current EPA modeling guidance as prescribed in Appendix W 41 and cl arification memos posted on the EPA TTN SCRAM website. 42 With respect to AERMOD performance at low wind speeds, as discussed in the risk assessment document, at the time we conducted the processing of the meteorological data in AERMET, the public version of AERMET did not include the surface friction velocity adjustment (u*). Also at the time, an updated version of AERMET was under development that incorporated further surface friction velocity adjustments to AERMET version 12345. In anticipation of the upda te, EPA processed meteorological data using a pre

- public release version of AERMET and incorporated the updated surface friction velocity adjustment in the output. It was EPA’s judgement that the pre

- public release version of AERMET would generate AERMOD

- r eady meteorological data very close to that generated with the 13350 version of AERMET. The AERMET meteorological data posted on EPA’s FERA website under the HEM model page was generated with the pre

- public release version of AERMET 13350.

Comment: In thei r comments on the 2011 proposal

, c ommenter 0122 identified errors in the physical parameters associated with the area sources in the AERMOD air dispersion model used to estimate residual risks associated with the EMI facility’s manganese emissions. Specifi cally, the commenter ( 0122 ) states that the release height for fug i tive emissions from tapping and casting at Furnaces 1 and 12, casting at MOR and crushing/screening should be set at the height of the facility’s roof monitors (100 ft), which is generally consistent with the NATA 2005 data set. Also, the commenter ( 0122 ) states that the dimensions of the facility roof monitors through which the fugitive emissions exit are generally understated and should be revised to lengths corresponding to 1/3 of the bui lding roof monitor length in the end of the building where the relevant process is located, which is also generally consistent with the NATA 2005 dataset. Finally, the commenter ( 0122 ) states that the physical parameters for the Furnace 1 baghouse outlet u sed in the modeling supporting the proposed rule were based on data for the wet scrubber that was replaced by the baghouse in 2011 and should be updated to reflect current conditions.

41 EPA 2005: 40 CFR Part 51 Revision to the Guideline on Air Quality Models: Adoption of a Preferred General Purpose (Flat and Complex Terrain) Dispersion Model and Other Revisions; Final Rule; Federal Register/Vol. 70, No. 216/Wednesday, Novembe r 9, 2005. 68218

- 68261

42 http://www.epa.gov/ttn/scram/guidance_clarificationmemos.htm)80

Response: The modeling files have been updated to reflect our current un derstanding of baseline conditions to assess the impacts of the final control options and have been corrected consistent with the changes suggested by the commenter. In addition, we checked the orientation of the area source fugitive emissions to the furna ce buildings, and determined that these emissions should be oriented to be parallel to the buildings at both plants. We have made this correction as well to the final modeling files. See section 1.10 for more information on development of the final modelin g files.

2.8 Community Health Impacts and Concerns

2.8.1 Community Issues
Comment: Two commenters (0085, 0107) describe a recent pilot study 43 run by University of Cincinnati researchers that found the following:

 Estimated annual average ambient air Mn concentrations in the study area obtained from AERMOD varied from 0.02 to 2.61 mg/m 3

.

 Mean blood and hair Mn values were 9.12 mg/L (SD 3.90) and 5.80 mg/g (SD 6.40 mg/g), respectively and were significantly correlated (r = 0.30, p < 0.01).

 The average bl ood lead value was 1.75 μg/dL.

 The relationship between hair Mn and estimated ambient air Mn became significant when genes for iron metabolism were included in linear models.

 Length of time lived at their current residence and the number of years lived i n the area were significantly correlated with blood Mn (Table 2).

 The preliminary ambient air and biological concentrations of Mn found in this population demonstrate the need for further research into potential health effects.

One commenter (0107) also referenced another local pilot study 44 that concluded: “Preliminary findings suggest subclinical impairment in postural balance among residents chronically exposed to ambient Mn.”

The commenter (0107) describes an ongoing community health study 45 , Communiti es Actively Researching Exposure Study (“CARES”), which is a joint project of Marietta College and the Department of Environmental Health at the University of Cincinnati to study neurobehavioral effects of manganese exposure on children living near the Era met facility, particularly on

43 E. Haynes, P. Heckel, P. Ryan, S. Roda, Y. Leung, K. Sebastian, P. Succop, Environmental manganese exposure in residents living near a ferromanganese refinery in Southeast Ohio: A pilot study, NEUROTOXICOLOGY 31 (2010) 468

–

474

44 Standridge et al., Effect of chronic low level manganese exposure on postural balance: A pilot study of residents in southwest Ohio, J. Occup. Envtl. Med (Dec. 2008), 50(12): 1421

– 1429

45 CA RES Website, http://www.eh.uc.edu/CARES/81

neuromotor function. The commenter (0107) states that the EPA should communicate with the research team to receive more information about this research and get a summary of the preliminary findings and data so far for the EPA to review during this rulemaking. The

commenter (0107) urges the EPA to consider these findings and recognize that these show the need for stronger emission standards from the Ferroalloys source category to protect exposed people in Marietta and other loca l communities affected.

In addition, the commenter (0107) describes that as part of the CARES study, researchers also surveyed air quality

- related concern and risk perception in Washington County, Ohio. They found that the vast majority of surveyed residen ts (91%) were “very concerned” to “concerned” about the quality of the air, 75% were similarly concerned about odor, and 77% were similarly concerned about manganese exposure. It also found that the vast majority of respondents “perceived air quality to in fluence their health (93%) and the health of their children (94%).” Researchers found that the local community is especially concerned about air pollution

- related cancer, respiratory health threats, brain development, and threats to children‘s health.

Dr. Erin Haynes from the University of Cincinnati summarizes the findings of her research and provides copies of manuscripts for the EPA’s consideration

, as part of comment 0085 . Following is a brief description of the relevant studies provided by Dr. Haynes:

 Standridge et al 2008 46 found a significant positive association between hair Mn concentration and sway area and sway length. Postural balance of residents in the smelter community was significantly larger than controls in 5 out of 8 postural balance outcom es. The primary sites of excessive Mn deposition within the brain are the globus pallidus and putamen within the basal ganglia. One important function of the basal ganglia is the integration of sensory feedback from the visual, proprioceptive and vestibula r systems suggesting that Mn exposure at concentrations experienced by Marietta residents resulted in negative impacts on their motor control feedback mechanisms, thereby impairing their balance.

 Haynes et al 2010 47 is a full pilot study of 141 Marietta are a residents who participated ranging from 2

- 81 years of age. Mean blood and hair Mn values were 9.12 μg/L (SD 3.90) and 5.80 μg/g (SD 6.40 μg/g), respectively and were significantly correlated. Blood and hair Mn was significantly associated within families , respectively. Estimated annual average ambient air Mn concentrations in the study area obtained from AERMOD varied from 0.02

- 2.61 μg/m 3 . The relationship between hair Mn and estimated ambient air Mn

46 Standridge et al., Effect of chronic low level manganese exposure on postural balance: A pilot study of residents in southwest Ohio, J. Occup. Envtl. Med (Dec. 2008), 50(12): 1421

– 1429

47 E. Haynes, P. Heckel, P. Ryan, S. Roda, Y. Leung, K. Sebastian, P. Succop, Environmental manganese exposure in residents living near a ferromanganese refinery in Southeast Ohio: A pilot study, NEUROTOXICOLOGY 31 (2010) 468

–

47482

became significant when genes for iron metabolism were included in linear models. This study further supports the literature that genes involved in iron metabolism play an important role in Mn metabolism. In our pilot study, 58% had hair Mn values >3.0 μg/g; the geometric mean of hair Mn in children (n=12) was 3.42 μg/g. In addition, an inverse association between hair Mn and IQ was found in 6th grade children living near a hazardous waste site in Oklahoma. The mean hair Mn levels for children in our pilot study were 12 times higher than the hair Mn levels foun d in the hair of these Oklahoma children living near a hazardous waste site.

 Following the pilot research, NIEHS funded a study 48 assessed the neurobehavioral effects of manganese exposure on children living near the ferromanganese refinery. Currently in th e 4th year of funding, the study has enrolled 322 children in the study are and control area, with the goal of enrolling 300 or more children from the Marietta area. The average concentration recorded from a stationary air sampler operating at Marietta Col lege from October 2008 to September 2010 was 17.44 ng/m 3

. Personal air sampling and postural balance testing was also conducted on a small cohort of children

. Although the data from the entire study cohort is not complete to determine the significance of M n exposure through air, diet and home dust and their effects on multiple neurobehavioral outcomes, we have completed 2 sub

- studies that do have adequate sample size to determine significance: personal air sampling and postural balance. The commenter (0085) describes these results in more detail.

Dr. Haynes concludes that overall, the findings from our studies indicate that residents of Marietta, Ohio are exposed to concentrations of ambient air Mn that can result in adverse neuromotor consequences. The comm enter (0085) urges the panel to also consider genetic variance in iron metabolism, as this population may have the ability to absorb and retain higher concentrations of Mn than other populations. The commenter (0085) adds that the CARES research study is s till generating data that can be useful to the EPA’s deliberations.

Another commenter (01 0 6) states that, in attempting to determine whether the existing ferroalloys NESHAP exposed off

- site residents to unacceptable residual risks, the EPA relied entirely on modeling and thereby failed to properly credit a peer

- reviewed, site

- specific epidemiological study 49 of actual conditions that found no clinical evidence of manganese

related health effects among Marietta, Ohio residents and concluded “Associations betw een mid

air and adverse [central nervous system] effects are thus unlikely to occur.” The EPA’s elevation of conservative theoretical estimates of risk over direct health studies, like its failure to account

48 E. Haynes et al., Developing a Bidirectional Academ ic

- Community Partnership with an Appalachian American Community for Environmental Health Research and Risk Communication, ENVIRONMENTAL HEALTH PERSPECTIVES, 10.1289/ehp.1003164 (available at http://dx.doi.org/ ), Online 16 June 2011

49 Kim, Y; Bowler, RM; Abdelouaha, N; Harris, M; Gocheva, V; Roels, HA. 2011. "Motor function in adults of an Ohio community with environmental manganese exposure." Neurotoxicology 32(5):606

- 614.83

for actual field measurements of particulates, r eflects an arbitrary process that is not designed, as Congress intended, to address “real world risks.” Accordingly, there is no risk

- based justification for the EPA’s proposed requirement that EMI retrofit its process buildings to capture all fugitive
par ticulate emissions at a cost up to $41 million in new capital expenditures and increased operating costs of over $12 million per year.

In their comments on the supplemental proposal, commenter 0272 reiterated that the EPA failed to incorporate results of r ecent health studies 50 of the Marietta population, which demonstrate that the impacts implied by the EPA’s modeling results are not occurring. The commenter (0272) notes that although the EMI facility has been in operation for 60 years (and historical emiss ions were undoubtedly much higher than today), their reviewers found no clinical evidence of the predicted chronic health effects in Marietta, aside from higher anxiety, which could easily be associated with the widespread public campaigning of those that believe such effects must be occurring. The commenter (0272) notes that levels of manganese in blood in Marietta residents were no different than in the control group studied by their reviewers (see Section 3.1.3.2 of Appendix A). The absence of observed a dverse health effects is consistent with recent studies that have not found elevated concentrations of manganese in the blood of children in Marietta.

The commenter (0272) continues that health effects data are reinforced by local ambient air monitoring da ta that shows such levels to be very low in comparison to the levels at which adverse health effects would be expected to occur. The 2012 Haynes, et al. study 51 , which published results of a personal air monitoring study of Marietta school children, found t hat actual measured exposures to respirable manganese averaged over 90 percent below the manganese MRL (5.45 to 10.33 ng/m 3 vs MRL of 300 ng/m 3 ) among both Marietta school children and at the fixed monitoring station at Marietta College. The Haynes results for respirable manganese concentrations are themselves consistent with the very low levels of total manganese or PM 10 manganese directly measured by EPA and ATSDR in Marietta over the last decade.

The commenter (0272) states that the EPA labels the estima tes produced by its computer modeling as “facts,” while making no mention of and assigning no weight to the results of actual studies that directly measured manganese levels and health conditions in Marietta, Ohio. The commenter (0272) states that the CAA does not mention computer modeling, much less mandate reliance on such modeling over site

- specific data, and the courts have observed that Congress intended for the residual risk process to address “real world risks.” However, the commenter (0272) notes th at the EPA has acknowledged that use of directly measured data is preferable to reliance on modeling and that even if modeling is necessary, any directly measured data that is available should be considered. In this matter, manganese exposures in Marietta have been

50 Kim, Y; Bowler, RM; Abdelouaha, N; Harris, M; Go cheva, V; Roels, HA. 2011. "Motor function in adults of an Ohio community with environmental manganese exposure." Neurotoxicology 32(5):606

- 614.

51 Haynes, et al., “Assessment of personal exposure to manganese in children living near a ferromanganese refine ry,” Sci. Total Environ. (2012), doi :10.1016/ j.scitotenv.2012.03.03784

actively investigated by multiple researchers looking for evidence of the sort of risks predicted by EPA’s modeling. Where the results of those studies contradict EPA’s modeling predictions, real world data should be given precedence over mathema tical predictions. The commenter (0272) believes that at a minimum, the EPA should have used that information to adjust its modeling assumptions for maximum agreement between estimated conditions and directly measured conditions. The commenter (0272) belie ves that the model’s predicted manganese concentrations at the site of the Marietta College air monitor should be no more than equal to the measured concentration from all sources.
However, the commenter (0272) states that the EPA’s predicted manganese con centrations at the location of the Marietta College air monitor during the time periods when air concentrations were directly measured, when adjusted to include only the respirable PM 2.5 size fraction are six times larger than the actual concentrations: 32 ng/m 3 manganese PM 2.5 (modeled) vs. 5.5 ng/m 3 manganese PM 2.5 (measured) during April

- May 2009 and 67 ng/m 3 manganese PM 2.5 (modeled) vs. 10.3 ng/m 3 manganese PM 2.5 (measured) during March

- June 2010. They believe that even if 100 percent of the manganese actually measured in Marietta is attributed to EMI, EPA’s modeling has still overestimated the actual respirable manganese concentrations in the community by six times, and since EPA used total PM as a surrogate for respirable PM, the modeled manganese con centrations that EPA chose to use in reaching its risk conclusions actually exceeded the directly measured respirable concentration by about nine times (see Section 2.3 in Appendix A). The commenter (0272) states that EPA’s failure to account for real worl d data in its assessment meant the difference between a computer

- estimated “risk” and a directly

- measured “no risk.”

Commenter 0073 states that the EPA’s analysis focused on its own overly

- conservative exposure assessment, and ignored other valid data ind icating risk levels lower than the EPA’s estimates. The commenter (0073) specifically notes that the preamble mentions, but disregards a 2011 EPA study of chronic adult exposure to ambient manganese near EMI, which found “no significant differences in bloo d manganese concentrations or major health outcomes between residents living near the facility and residents in a comparison town[.]”

In comments on the supplemental proposal, commenter 0270 states appreciation that the EPA acknowledged that risk to Marietta’s citizens from manganese exposure is too high. The ambient air monitoring in the mid

- 2000’s showed manganese within a 5

- mile radius of the plant at levels 2 to 60 times the existing federal health standard. The commenter (0270) suggests that air monitoring again be done in Marietta, Boaz and Vienna for a period of at least 2 years.85

The commenter (0270) is disappointed that Dr. Haynes’ manganese study on area children 52 is not being taking into account. To ignore the most recent study of the most re levant population to the EPA’s decision seems irresponsible and unfathomable. The commenter (0270) urges the EPA to take into account Dr. Haynes’ findings when finalizing the ferromanganese rules.

Response: A large number of documents were submitted for consideration in relation to this rulemaking, both in response to the 2011 proposal and the 2014 supplemental proposal . These documents included scientific studies published in the peer

- reviewed literature, su mmaries of unpublished studies, government reports and other materials. The EPA appreciates receipt of these materials; however, a thorough evaluation of this information is not within the scope of this action. These studies are potentially relevant to the upcoming revision of the EPA’s dose

response assessment for manganese. The Agency has an established process for updating its dose response assessments that includes a thorough review and evaluation of the scientific literature and peer review of the fin al results. Any partial review of the manganese scientific literature for the current action would be premature and inconsistent with the Agency standards of practice regarding scientific quality of assessments including thoroughness, quality control and p eer review.

2.8.2 Local Resident Concerns Regarding Health and Air Quality
Comment: In response to the 2011 proposal, a group of commenters ( 0068, 0077, 0089, 0090, 0091, 0093, 0094, 0097, 0098, 0099, 0100, 0101 , 0247, 0257 ) described their personal experience w ith air quality problems in the Marietta, Ohio area. One commenter ( 0091 ) notes that she has lived in Marietta for 24 years, raising two children, and has had concerns about the amount of local air pollution (especially manganese) on health. Another commen ter ( 0093 ) remembers that a number of years ago, the commenter’s parents put a brass light on their porch. The commenter (0093) states that the finish was guaranteed for life, but it didn't take long for it to become tarnished. The commenter (0093) continu es that the manufacturer replaced it once but refused to honor any future warranty on the finish because the air quality was so bad. The

commenter (0093) asks that if the air isn't safe for metal, how it can be safe for humans.

One commenter ( 0098 ) states that her family has lived here (Marietta, Ohio area) for 20 years now, and though they love this area, many times we have considered moving away because of the extreme air pollution. The commenter (0098) adds that there have been many nights that she has been startled from a sound sleep by the toxic air rolling in through the open window. They ask why it is legal for a business to pollute the air but individual citizens would be arrested, convicted and jailed if they were to dump our trash on the lawn, our neighbor’s lawn, or a public

52 Haynes, et al., “Assessment of personal exposure to manganese in children living near a ferromanganese refinery,” Sci. Total Environ. (2012), doi :10.1016/ j.scitotenv.2012.03.03786

space. In addition, they ask why a large French corporation (Eramet) is able to pollute the air to the point where they cannot sleep at night.

One commenter ( 0089 ) states that they first became aware of the pervasive odors and particulate soot emitted from (then) Elkem Metals, (now) Eramet Marietta in 1995 when they purchased land and began building a home just north of downtown Marietta, Ohio. The commenter’s (0089) journey to find the source of the odors that awakened us during the night and the soot that covered our freshly painted porch railing, led us to the ferroalloy factory, Eramet which was 4

- 5 miles away. The commenter (0089) adds that their family live every day with the br eathing problems, headaches and constant worry about what they are being exposed to. The commenter (0089) adds that asthma rates are high and our small rural communities support two very busy and always expanding cancer centers, Strecker Cancer Center in M arietta and Camden Clark Comprehensive Cancer Center in Parkersburg, WV

– within a 12 mile radius.

Similarly, o ne commenter ( 0077 ) states that she is very concerned about the toxic air pollution from Ferroalloys, because of the Eramet plant in Marietta, O H. The commenter (0077) lived in Marietta, OH for 6 years and developed asthma and chronic sinusitis after moving to Marietta. Since the commenter (0077) moved away from Marietta, OH, 5 years ago, the frequent sinusitis has stopped and she rarely has a whe ezing experience. Another commenter ( 0090 ) states that asthma and respiratory problems in general are rampant in this valley and are a serious and growing problem nationally. The commenter (0090) adds that inhalation of small particle pollution is directly linked to these problems.

One commenter (0094), a physician and property owner in Washington County Ohio

, writes to urge the EPA to move forward with a new Clean Air Act Rule providing much needed protection from toxic air pollution emanating from the Er amet plant in Marietta, Ohio. The commenter (0094 ) states that it is unavoidably obvious to local residents and anyone spending time in Marietta and environs that Eramet emits gross quantities of toxic chemicals into the atmosphere. The commenter (0094 ) ad ds that these emissions particularly occur during hours of the night in a transparent effort to conceal clearly unacceptable operations. The commenter (0094 ) states that it is well known that these emissions contain manganese and other substances known to be carcinogenic and deleterious to human health and that immediate action is mandatory.

One commenter (0097) asks that the EPA not delay any longer the strengthening and enforcement of the Clean Air Act which will provide better air quality to this commun ity. The

commenter (0097 ) adds that the air quality has forced some residents to move elsewhere, and other prospective residents not to settle here. Similarly, a nother commenter (0101) states that had they known about Marietta’s pollution problems they never would have moved there 13 years ago. The commenter (0101) hopes to sell his house and move to a location with cleaner air.

As a public health official, one commenter (0100) has been worried for a very long time that we were putting children at risk for impaired mental function and seniors at higher risk of87

developing Parkinson’s

. The commenter (0100) is currently collaborating with the University of Cincinnati to study on the effects of exposure to manganese, and hopes that the question of health effects will be answered soon.

One commenter (0091) states that the affected community needs the EPA to set strong emission standards to provide an "ample margin of safety to human health," and urges the EPA to review all the community health studies done in our area

- especially the CARE study to be sure that those "margins of safety" take into consideration at risk groups such as pre

- natal, pregnant women, children, and the elderly, as well as the general population. The commenter (0091) urges the EPA to require more protection than the proposed rule would provide. The commenter (0091) agrees that the EPA needs to look at all of the community health studies on the Marietta community, includin g the CARE study. Additionally, t wo o ther commenters (0077, 0099) agree that the EPA needs to look at all of the science showing the need to protect everyone, and especially the children, from manganese and other pollutants.

Two c ommenters (0089, 0098) ar e concerned about long

- term effects of low levels of manganese inhalation over time and the cumulative effect of being exposed to many sources that are emitting toxic substances. One commenter (0089) adds that the Marietta area is an example of a community overburdened with pollution from local industry. A quick drive along Ohio Route 7 will expose you to carbon black from Degussa, manganese, chromium, etc. from Eramet, very heavy Styrene odors from Americas Styrenics and who knows what Marietta Industrial Enterprises does within its secret little world? The commenter (0089) adds that because of our exposure to various chemicals the children and adults of our area have become guinea pigs for health studies for PFOA from DuPont and are now participating in he alth studies for heavy metal exposure. The commenter (0089) states that there are reports that physicians all around the country ask if the patient spent any amount of time living in the mid

- Ohio Valley.

Two commenters (0077, 0099) urge the EPA to set strong standards that will protect the Marietta, OH community from toxic air pollution. The commenters (0077, 0099) are especially worried about chronic and acute health impacts from manganese, lead and other pollutants. The

commenters (0077, 00 99) understand that the EPA’s proposed rule would reduce the cancer risk in the community and agree that it important to set standards that will prevent a cancer risk above 1

- in

- 1 million. The commenters (0077, 0099) add that the EPA should make sure that no child is exposed to an unacceptable level of health risk. The commenters (0077, 0099) believe that there is need for a real margin of safety to protect public health from the pollution and asks the EPA to require even more protection than the proposed r ule would provide. The commenters (0077, 0099) add that while it is positive that the EPA is proposing to set standards for the first time for pollutants that have not had any limit before, like mercury, what is needed is stronger protection from all of th e pollution from this source, including fugitive emissions.

Commenter 0068 adds that it essential to base emission standards on health data. Several groups have begun to study the Marietta “laboratory” and the University of Cincinnati, University of88

San F rancisco and the Agency on Toxic Substances and Disease Registry studies are finding is that Marietta’s children are likely most affected by manganese exposure. The commenter (0068) states that we should be setting our expectations for industry based on th e needs of our weakest populations, instead of allowing the industry to dictate what is possible.
In their comments on the supplemental proposal, commenter 0247, a local government representative, states that the EPA needs to ensure that Mn levels below 0 .1 μg/m3 to protect vulnerable populations. The commenter (0247) noted that there are documented exposures of 0.25 μg/m3 in the recent past in Vienna, WV approximately 5 miles away. The commenter (0247) believes that particulate collection at the roof and assuring levels less than 0.1 μg/m3 at the fenceline are important, and advocates particulate monitoring in communities surrounding the facilities.

One commenter (0257) stated in their comments on the supplemental proposal that that these standards should have been in place a long time ago.

Response: The EPA sympathizes with the concerns expressed above. This final rule seeks to reduce emissions from the ferroalloy production source category under the authority provided by the Clean Air Act

. A s we stated i n the preamble

, the RTR rules for this source category require that existing sources in the category achieve substantial emission reduction s of both carcinogens and non

- cancer HAP. We anticipate these rules will further reduce the emissions from ferroalloy s production that impact the local communities.

3.0 D ECISION

3.1 Finding of Unacceptable Risk is Justified
Comment: In their comments on the 2011 proposal, c ommenter 0107 supports the EPA ’ s determination that the current level of health risk is unacceptable and states that this determination is well

- supported. According to the commenter (0107) , in addition to a high cancer and chronic noncancer risk, there is a high acute health risk which is 10 times the EPA ’ s presumed safety threshold, and high multipathwa y risk from mercury, POM, and lead (as well as other pollutants that the EPA did not assess). The commenter (0107) adds that communities in this source category have faced unacceptable levels of toxic air pollution from this source category for many years. The commenter (0107) believes that immediate action is vital to protect the local community from extremely high and unacceptable health risk. The commenter (0107) adds that omissions in the EPA ’ s own analysis and uncertainties also weigh in favor of a fin ding that health risk is “unacceptable.”

In comments to the supplemental proposal, commenter 0276 agrees that the EPA should finalize the proposed determination that health risks are unacceptable due to the combination of high cancer and non

- cancer chronic health risks from inhalation, particularly due to manganese. The89

commenter (0276) adds that the EPA has likely undercounted and underestimated the health risks.

Response: We acknowledge your support. As mentioned previously, the emissions were revi sed for the final rule as a result of the comments received on the 2014 supplemental proposal , and the risk assessment has been re

- done. However, we continue to conclude that baseline risks are unacceptabl e

.
Comment: Commenter 0122 conducted an independent evaluation of the residual risk after enhanced fugitive emission source control in response to the 2011 proposal . As described in a comment to its original comment, the commenter (0122) revised the area source and p oint source parameters in the AERMOD model to reflect (1) the fugitive source controls described by the commenter in their comments, (2) the corrected physical parameters described in their comments, and (3) the baseline and controlled emission estimates d escribed in their comments. The commenter (0122) presents the resulting HQ for a range of potential manganese reference concentrations (RfCs) under several modeled scenarios: (1) corrected meteorological data, (2) corrected meteorological data and adjustme nt of exposure concentrations to reflect a 41 percent respirable manganese fraction, and (3) these two adjustments plus the use of a more “reasonable” MIR exposure period to reflect time indoors and time away from home. The results of this analysis are sum marized in Table 1, below.

Table 1 . Residual Risks after Additional Source Control

Exposure Scenario (EPA Model with Various Revisions) Maximum Off

- site Manganese HQ at Various RfC Values Use of Parkersburg Meteorological Data Use of

Respirable Fraction (PM 2.5 ) Exposure

Adjusted for Time Indoors and Away from Home Highest

Calculated Off

- site Manganese Concentration (μg/m 3 ) 0.05

μg/m 3 0.1

μg/m 3 0.5

μg/m 3 1

μg/m 3 2

μg/m 3

■ 0.145 3 1 0.3 0.1 0.07

■ ■ 0.055 1 0.6 0.1 0.06 0.03

■ ■ ■ 0.033 0.6 0.3 0.06 0.03 0.02

Response: We appreciate the commenter’s attention to detail in providing their supporting information. As mentioned in previous sections, we have incorporated some suggestions provided by the commenter (e.g., meteorological data in section 2. 7) and we disagree with the commenter on other suggestions (e.g., exposure scenarios in Section 2.2.2). As described in these (and other) sections, we have considered the comments related to the modeling files and developed final modeling files based on o ur analysis of the comments received. Based on this analysis, we conclude that the findings of unacceptable baseline risk and acceptable post

- control risk are reasonable.90

3.2 Finding of Unacceptable Risk is Not Justified
Comment: In their comments on the supplemental proposal, commenter 0272 does not agree with the EPA's conclusion that risks are unacceptable. The commenter states that the cancer risk and multipathway risks clearly meet the EPA’s stated “acceptable risk” criteria for those conditions, and therefore cannot serve as a principled justification for EPA’s finding. Commenter (0272) notes that the EPA’s estimate of the MIR cancer risks from EMI’s emissions are 80 percent lower than the acceptability threshold, and they co ntinue to meet the 100

- in

- 1 million acceptability threshold even under EPA’s worst

- case assumption that EMI’s emissions increase in the future to the maximum levels allowed by law. In their comments on the supplemental proposal, commenter 0269 also notes t hat the EPA calculated a potential maximum individual risk (MIR) estimate for Felman’s potential cancer emissions to be 20

- in

- 1 million, which meets the applicability threshold. The commenter (0272) notes that the EPA’s unacceptable risk finding relies in part on predicted multipathway exposures representing an MIR noncancer HQ of 1, which the commenter notes, does not represent unacceptable risk by definition.

The commenter (0272) states that although a noncancer HQ of 1 corresponds to an exposure

concent ration at which no adverse health effects will occur, the EPA has historically declined to define a MIR HQ of 1 to be the noncancer risk acceptability standard. The commenter (0272) also noted that the EPA predicted that EMI’s post

- control actual emissions would present a MIR HQ of 2 in the 2011 proposal in this rulemaking, and the EPA concluded that such risks were acceptable. The commenter (0272) states that the EPA’s estimate of an MIR HQ of 4 is entirely dependent upon the incorporation of fugitive emis sion factors that overstate the level of ferroalloys tapping and casting fugitive emissions. They believe that the EPA’s adoption of “at the source” emission factors derived for basic oxygen furnaces (“BOFs”) used in steelmaking causes the model to over

- pr edict directly measured concentrations of respirable manganese by a factor of six to nine. When ferroalloys fugitive emissions are approximated through the more reliable BOF “at the monitor” emission factors, the modeled MIR exposure concentration for
mang anese under EPA’s model is 0.31 ug/m 3 , which produces an HQ of 1 using the ATSDR MRL and an HQ of 0.1 using the scientifically adjusted MRL. The commenter (0272) states this conclusion is supported by data from health studies conducted in Marietta, which f ound exposures to be far lower than EPA has predicted and an absence of the health effects expected at exposure concentrations predicted by the EPA’s modeling. The commenter 0269 also believes the maximum risk estimates are substantially greater than any p otential actual risks due to the EPA’s data inputs and methodologies that are biased to overestimate potential risk, such as using a 70

- year exposure duration, using data for non

- detected emissions at half the detection limit and using an overstated mangan ese RfC value.
The commenter (0272) states that the EPA’s determination of unacceptable risk is based on allowable emissions calculated using the 1999 emissions standards. They believe that this allowable scenario is not plausible and should be based on the technology

- based limits that the EPA is proposing under Section 112(d).91

The commenters (0269 and 0272) believe that incorporating appropriate and well

- established modeling assumptions to reflect the best available facts and science would confirm that f erroalloys emissions meet EPA’s standards for acceptable risk. The commenter (0272) notes that Eramet’s emissions also meet the Section 112(f) “ample margin of safety” standard, which they believe should preclude the imposition of any additional limits or controls to further reduce theoretical cancer risks.

Response: In the risk assessment for the supplemental proposal and the final rule, we conclude d that the risks are unacceptable based on all the available information, including the fact that the

noncanc er hazard quotient ranges from 4 based on actual emissions to 40 based on allowable emissions. We have not established under section 112 of the CAA a numerical range for risk acceptability for noncancer effects as it has with carcinogens, nor ha ve we deter mined that there is a bright line above which acceptability is denied. However, we have established that, as exposure increases above a reference level (as indicated by a HQ or TOSHI greater than 1), confidence that the public will not experience adverse h ealth effects decreases and the likelihood that an effect will occur increases. For the ferroalloys source category, the potential for members of the public to be exposed to manganese at concentrations from 4 up to potentially 40 times the MRL reduces our confidence that the public is protected from adverse health effects and diminished our ability to determine that such exposures are acceptable. We also considered the fact that the cancer risk estimate for actual emissions is 20

- in

- 1 million and potentiall y up to 100

- in

- 1 million for allowable emissions. While 20

- in

- 1 million is well within the acceptable range, risks from allowable emissions are at the upper end of the range of acceptability. Th ese results combined with a refined multipathway HQ for mercur y that is at the level of the RfD, leads us to conclude that the risk from this source category is unacceptable. All the risk results (including metrics not brought up by the commenter such as population exposures, incidence, and acute values) are conside red together in the risk acceptability decision, not just one metric individually.

These results are based on the emission estimates, both process and fugitive, using multiple test data from the facilities and emission factor s from AP

- 42. E mission factor s are commonly used by plants to estimate emissions from their processes

. We reviewed the factors and determined that the use of the BOF tapping and hot metal transfer as surrogates for ferroalloys tapping and casting are appropriate, given the absence of AP

- 42 factors specific to ferroalloys. However, we disagree with the use of the “at the monitor” factors suggested by the commenters.

First, we note that these emission factors were not based on emissions collected at the roof monitor, but instead collect ed in hoods or ductwork located above the actual emission source and estimates of assumed capture efficiency were applied to estimate the “uncontrolled” portion. This differs from a measurement of actual emissions at the roof monitor. Second, the respectiv e BOF tapping and hot metal transfer tables each include a second emission factor associated with each operation (“at the source.”) For tapping the factor is 0.291 lb/ton and for hot metal transfer the factor is 0.19 lb/ton. These factors are also based on tests that sampled the air inside a hood or duct ( assumed to be closer to the source of the emissions than the “at the monitor” collection92

sites) with assumptions made about capture efficiency to determine uncontrolled emissions. We decid ed to use the higher emission factors in our calculations because we believe these factors are likely to more accurately reflect actual emissions from these sources

. As stated throughout this document, we also disagree with the comment that we should use t he reference value for manganese that the commenter has provided (see Section 2.1.1), that our exposure assumptions are incorrect (see Section 2.2.2), and that we should use their estimate of respirable emissions (see Section 2.2.3). Responses to these in dividual points are explained elsewhere in this document and therefore are not repeated here.
With respect to the commenter’s point that EPA already proposed an HI of 2 to be acceptable (in the 2011 proposal) and that nothing else has changed since that time, we disagree. At the time of the proposal, we were using the IRIS RfC for manganese. A value using analytical approaches consistent with EPA practices is now available (the ATSDR MRL) and we have used this value in the 2014 supplemental proposal and the 2015 final rule. As discussed in Section 2.1.1.1, ATSDR used up

- to

- date information in the derivation of the MRL, including information on the kinetics of manganese to ensure the derived MRL value did not approach exposure levels which would lead to toxicity. T herefore we have more confidence that exceeding this value has more potential for adverse health effects than exceeding the IRIS value by the same magnitude. In addition, the following have also changed: the station used for meteorological da ta, the versions of AERMET and AERMOD used in the assessments, the input parameters to the model, the user receptors, and most importantly, the emissions estimates. At the time of the 2011 proposal, the fugitive emissions were calculated using a mass bala nce calculation approach, while for the 2014 supplemental proposal, more reliable emission factors were used (as described above in this response). In addition, more stack tests were conducted during the intervening years and therefore we have more confid ence in the emissions relied on for the final rule. When making a risk management decision, all risk assessment results are considered together along with their associated uncertainties. The final rule risk assessment has reduced uncertainties (e.g., for emissions and the manganese reference value used) compared to the assessment conducted for the 2011 proposal and as a result we have more confidence in our assessment. Given all the changes described above (most notably the change in emissions and the ma nganese reference value since the 2011 proposal), it is reasonable to conclude that the health risks at baseline ( based o n consideration of all risk results and health factors along with the associated uncertainties) are unacceptable.

3.3 Finding of Acceptable Post

- Control Risk is Deficient
Comment: In their comments on the 2011 proposal, c ommenter 0107 states that the EPA does not require enough emission reductions to achieve an “acceptable” level of health risk

, and the EPA must provide notice of the level of cancer risk that its standard would allow, based on “allowable” emissions. The commenter (0107) states that the EPA must reduce cancer risk to a lower level and aim to achieve a cancer risk below 1

- in

- 1 million

, and the commenter discusses93

how this is con sistent with community norms and as intended by Congress. The commenter (0107) adds that the EPA ’ s proposed rule would still expose at least 1,300 people to a cancer risk above 1

- in

- 1 million and states that the EPA has failed to justify not requiring additional emission reductions to provide stronger protection for the most

- exposed people.

The commenter (0107) states that the EPA ’ s proposed rule will not reduce chronic non

- cancer risk enough to achieve an “acceptable” level and argues that the EPA must reduce the TOSHI presumptive acceptability threshold to 0.2 or below, per the EPA’s own staff’s 2002 recommendation, to protect the most

- exposed people in local communities experiencing impacts from multiple sources and types of toxic air pollution. Comme nter 0065 is also concerned that the EPA has not reduced the chronic noncancer risk to below 1, but the commenter recognizes that the proposed measures would provide dramatic decreases to the TOSHI. The commenter (0107) adds that the EPA should take an esp ecially protective approach on chronic noncancer risk due to manganese because of the significant evidence of harm from manganese inhalation, the fact that the EPA ’ s risk assessment for manganese is likely to underestimate the full risk, and because of the EPA ’ s own recognition that the science includes uncertainty on the full risk. The

commenter (0107) cites the other deficiencies in the risk assessment (e.g., failure to assess facility

- wide risk or cumulative risk) as further reason to take a more protect ive approach regarding chronic non

- cancer risk.
Additionally, the commenter (0107) states that the EPA’s proposal would still allow multipathway risk due to POM that is 20 times the EPA’s safety threshold. The commenter (0107) states that the EPA has fail ed to justify allowing such a high level of risk, particularly when this is cancer risk that will occur in combination with the inhalation

- based cancer risk. According to the commenter (0107), as a result of this high multipathway risk, the most exposed
pe rson will face a total cancer risk that is significantly higher than the 5

- in

- 1 million that the EPA describes. The commenter (0107) concludes that the EPA must require further reductions in multipathway risk to achieve an acceptable level.

T he commenter ( 0107) further states that the EPA fails to provide any reasoned explanation for not requiring a greater reduction in acute health risk. The commenter (0107) states that the EPA ’ s acute health risk number does not include the combined acute health risk that can occur due to multiple pollutant emissions simultaneously in an acute health incident. The commenter (0107) notes that the EPA did not consider the combined acute health risk for multiple pollutants, did not assess the acute health risk based on allowa ble emissions scenario and did not calculate or provide any information on facility

- wide acute health risk. The commenter (0107) states that the EPA fails adequately to explain how an acute health risk of 0.3 could be safe or acceptable, when it has failed to assess what the cumulative health burden would be for this source category, especially when its own staff have recommended preventing exposure above 0.2.

Response: As an initial matter, we note that i n 1990 Congress codified in section 112(f) (2)(B) of the C lean A ir A ct the approach we use for our residual risk analyses. Under that approach, the94

100

- in

- 1 million cancer risk is not a bright line indicat ing that risk is “acceptable.” Conversely, cancer risks greater than 1

- in

- 1 million are not automati cally considered “unacceptable” as implied by the commenter saying we have to reduce risks to levels below 1

- in

- 1 million. Rather, we consider th is health metri c conjunction with a variety of health factors and their associated uncertainties to determine w hether the risk is acceptable

. Where we conclude that the risk is not acceptable, we cannot and do not consider costs in requiring controls to bring risks down to an acceptable level. However, the analysis of whether risk is acceptable is not the endpoint. Once we determine that controls are sufficient to ensure that risk is acceptable, we again review the health metrics (e.g., cancer and chronic non

- cancer risks) and their associated uncertainties in conjunction with the costs of controls , technical feasi bility, and other relevant factors to determine whether further additional controls should be required to provide an ample margin of safety to protect public health.
We further note that we generally draw no bright lines of acceptability regarding cance r or noncancer risks from source category HAP emissions . I t is always important to consider the risk results along with specific uncertainties of the emissions and health effects information regarding the source category in question when deciding exactly what level of cancer and noncancer risk should be considered acceptable. In addition the source category

- specific decision of what constitutes an acceptable level of risk should be a holistic one; that is, it should simultaneously consider all potential he alth impacts

– chronic and acute, cancer and noncancer, and multipathway,

-- along with all their uncertainties, when determining the acceptable level of source category risk. In other words, we look at the risk numbers within the context of uncertainty a ssociated with emissions and health benchmark values.
Also, the level of cancer risk that the revised standard would allow (i.e., “allowable” risks), are indeed provided in the preamble. Since the post

- control risks were based on estimates of post

contr ol emissions, which were designed to reflect the level of emissions after implementation of the proposed standards, we maintain that the post

- control scenario is reflective of allowable risks of the proposed standards. While the comment specifically refer s to the risks at proposal, the same comparison holds true for the final rule. The risks estimated for the post

- control scenario are the risk estimates that would be “allowed” by the final standards.
The EPA disagrees with the commenter’s notion that any TOSHI value greater than 0.2 should be considered unacceptable. We note that pollutant

- specific reference concentrations (RfCs) are not absolute thresholds, but estimates of chronic inhalation exposures at or below which health effects would not be expect ed to occur after a lifetime of exposure, including in sensitive subgroups. We further note that these RfCs are developed using a health

- protective approach (see uncertainty discussion in risk assessment document section 4.2), that TOSHI values of 1 or les s are generally considered to carry no appreciable risk of adverse health effects and that there is generally no need to compound this protection by suggesting that any source category maximum TOSHI value would need to be at or below 0.2 before we would co nsider it to be acceptable. Finally we note that the commenter’s source for its statement that default limits HI95

should or must be establish at 0.2 rest on an internal EPA staff memo (from 2002) which was never adopted as agency policy (and never reviewed by the public or by any peer review body) and consequently carries no precedential weight.

Regarding the multipathway risks in the 2011 proposal , we disagree with the commenter that “multipathway risk due to POM is 20 times the EPA’s safety threshold.” As described earlier, the emissions are used in the multipathway assessment and are compared to multipathway screening emissions thresholds, not risks. It is not a measure of “safety” but rather a measure of where more analysis may be needed considering the availability of appropriate site

- specific data and time and resource constraints. In this case t he “20” is an upper bound estimate of possible cancer risks , meaning the actual cancer risks will be less than 20

- in

- 1 million , but it is inappropriate to say t hat the risk is 20. As discussed in a previous response, it is not appropriate to combine the results of a refined inhalation assessment with those from a screening

- level multipathway assessment. A refined multipathway assessment was conducted for the
sup plemental proposal and the final rule, and those results are provided in the respective preamble and risk assessment documents.
Regarding the acute health risks, as described in the risk assessment report available in the docket for the proposed action and elsewhere in this document , we do not sum results of the acute noncancer inhalation screen because of its conservative nature and the variable nature of emissions and potential exposures. The use of allowable emissions is also not considered due to the co nservative assumptions used to gauge worst

- case potential acute health effects. The conservative estimates built in to the screen include 1) worst

- case meteorology (from one year of local meteorology); 2) that a person is located downwind at the point of m aximum impact during this same 1

- hour period; and 3) that all emission points have their peak emission rates occur simultaneously. Thus, performing an acute screen based on allowable emissions would be overly conservative and at best, of questionable utili ty to decision makers. Finally, as mentioned previously, for the ferroalloys source category, a separate facility

- wide assessment was not performed because there are no other operating sources present at these facilities. However, if a facility

- wide assess ment had been performed, acute risks would not have been part of that assessment. The emissions included in a facility

- wide assessment have generally not been subjected to the same level of engineering review as the source category emission estimates and

a re likely to be less certain than our emissions estimates for the source category. That, combined with the already conservative nature of the acute assessment, would lead us to not conduct an acute risk assessment using facility

- wide emissions. Finally we note that the commenter’s source for its statement that default limits HI should or must be establish at 0.2 rest on an internal EPA staff memo (from 2002) which was never adopted as agency policy (and never reviewed by the public or by any peer review bod y) and consequently carries no precedential weight.

Comment: Commenter 0107 states that the EPA fails to show that its proposed rule will reduce cumulative health risk to an “acceptable” level. The commenter (0107) states that the EPA must aggregate health risk for the source category and decide whether the total health risk from each96

pollutant, pathway, and risk, and from all combined is acceptable. The commenter (0107) states that in order to protect local communities, particularl y children, the EPA must account for the history of exposure to toxic air pollution, and for ongoing exposure to the source category ’ s toxic air emissions combined with other HAP emissions from multiple sources, by applying additional safety factors in its acceptability determination. The commenter (0107) adds that, in addition, even if the risk is below the listed contribution or threshold levels, the EPA still needs to determine case

- by

- case whether stronger limits are needed (based on the types of pollut ants emitted, and each of the scientific factors relevant to protect public health, especially for children and other vulnerable individuals).

The commenter (0107) states, in conclusion, that the EPA must set a standard that will achieve a cancer risk bel ow 1

- in

- 1 million (the statutory goal), a chronic non

- cancer risk below 0.2 and an acute health risk below 0.2 (per EPA ’ s 2002 staff memo), a multipathway risk below 1, and a cumulative burden that ensures the combined health risks to this community are no t as a whole unacceptable.

Response: We have combined risk assessment results to the extent that it is appropriate to do so

. We do consider the effect of mixtures of carcinogens

. We do not use a TOSHI approach for acute noncancer like we do for chronic non cancer

. We also do not combine the results of our inhalation and multipathway assessments

. The basis for each of our methodological decisions on which sets of results to combine is explained in the risk assessment document 53

. Moreover, to provide the quantitative risk information necessary to inform RTR regulatory decisions, the EPA conducts a comprehensive assessment of the risks associated with exposure to the HAPs emitted by the source category (i.e., those emissions that can actually be affected by the specific rulemaking) and supplements that with additional available information about other possible concurrent and relevant risks. In some cases, we have additional information about HAP emissions that are outside the scope of the particular rulemaki ng but within the boundaries of the subject facilities. In other cases, we may have ambient HAP monitoring data that can be considered as part of the regulatory decision

- making. In still other cases, we may have very little additional risk information that can be considered. In all cases, however, when we consider additional information about risks, we also consider its attendant uncertainties, and information which carries significant uncertainties generally carries much less weight in the overall regulato ry decision.
All of the quantitative risk assessment information about HAP emissions from the source category under consideration is also considered in the manner prescribed by the decision framework set forth by the CAA for residual risk decision

- making ( i.e., the Benzene NESHAP decision framework), and this means that the general guidelines of risk acceptability have been

53 E PA Office of Air Quality Planning and Standards, Residual Risk Assessment for the Ferroalloys Source Category in Support of the September Supplemental Proposal, September 2014. (EPA

- HQ

- OAR

- 0895

- 0136)97

developed in a way that they already take into account the impossibility of accurately quantifying the health risks posed by outside fo rces on every individual in the population. This acknowledgment allows the EPA to make risk

- based decisions by focusing on the risks associated with the emissions that are themselves the subject of regulation being considered.
While the incorporation of ad ditional background concentrations from the environment in our risk assessments (including those from mobile sources and other industrial and area sources) could be technically challenging, they are neither mandated nor barred from our analysis. In develop ing the decision framework in the Benzene NESHAP currently used for making residual risk decisions, the EPA rejected approaches that would have mandated consideration of background levels of pollution in assessing the acceptability of risk, concluding that comparison of acceptable risk should not be associated with levels in polluted urban air‘‘ (54 FR 38044, 38061, September 14, 1989). Background levels of certain HAP can be relatively high, perhaps even above a level that might be considered “safe.” Backg round levels (including natural background) are not barred from the EPA ’ s ample margin of safety analysis, but the EPA may consider them, as appropriate and as available, along with other factors, such as cost and technical feasibility, in the second step of its section 112(f) analysis.

As discussed above in response to the previous comment , the EPA disagrees with the commenter’s notion that any TOSHI value, or acute HQ value, greater than 0.2 should be considered unacceptable. We further note that we gener ally draw no bright lines of acceptability regarding cancer or noncancer risks from source category HAP emissions, and that it is always important to consider the specific uncertainties of the emissions and health effects information regarding the source c ategory in question when deciding exactly what level of cancer and noncancer risk should be considered acceptable. In addition, the source category

- specific decision of what constitutes an acceptable level of risk should be a holistic one; that is, it shou ld simultaneously consider all potential health impacts

-- chronic and acute, cancer and noncancer, and multipathway,

-- along with their uncertainties, when determining the acceptable level of source category risk. Experience with source category rulemaki ngs in the past tells us that this means that drawing bright lines for such decision

- making is impossible. The Benzene NESHAP decision framework of 1989 acknowledged this; in today’s world, such flexibility is even more imperative, because new information relevant to the question of risk acceptability is being developed all the time, and the accuracy and uncertainty of each piece of information must be considered in a weight

- of

- evidence approach for each decision. This relevant body of information is growin g fast (and it will continue to grow faster and faster), necessitating a flexible weight

- of

- evidence approach that acknowledges both complexity and uncertainty in the simplest and most transparent way possible. While this challenge is formidable, it is non etheless the goal of the EPA’s RTR decision

- making, and it is the goal of the risk assessment to provide the information to support the decision

- making process.98

3.4 The Rule Does Not Provide an Ample Margin of Safety
Comment: Commenter 0107 states that the EPA fails to set a residual risk standard that provides the requisite ample margin of safety to protect public health, pursuant to CAA section 112(f)(2) and cites several deficiencies, including:

 The EPA ’ s proposal would still expose people to a cancer ri sk significantly higher than the 1

- in

- 1 million target of section 112(f)(2), to chronic non

- cancer risk that is 2 times the EPA ’ s safety threshold, and to multipathway risks that are 60 times greater than the EPA ’ s threshold.

 The E PA fails to consider whether the uncertainty that has likely led it to underestimate health risk in the first place requires a greater margin of protection at this final rulemaking stage.

 The EPA also fails to assess what margin of safety would be ample to protect the health

o f exposed children.

 By failing to address cumulative impacts in its ample margin analysis, the EPA has failed to assess or address the full health risk that local communities face from these source categories.

 The EPA failed to assess facility wide risk an d takes no account of risks from other toxic air emissions in the vicinity and the combined impact for nearby communities, as it must.

 The EPA needs to address environmental justice factors in deciding what margin is needed to provide ‘ample’ protection fo r public health.

 The EPA fails to consider or determine whether its proposed rule provides the maximum feasible protection against health risks for the greatest number of people.

T he commenter (0107) further states that the EPA does not explain how it foll ows that because the EPA has been unable to identify less expensive options, the margin of safety is “ample.” The

commenter (0107) states that the EPA may not put cost above health by failing to consider health at all from the perspective of the most

- expos ed person. The commenter (0107) adds that the EPA has not explained in the record how it made the cost

- based decision i n the ample margin determination. The commenter (0107) states that the EPA should have considered additional options for reductions , such as any controls, practices, or processes used at the Eramet's sister facility in Norway and set emission standards for the U.S. source category that are at least as protective.

In comments submitted in response to the supplemental proposal, commenter 027 6 states that to assure the requisite “ample margin of safety to protect public health,” the EPA should determine the level of emission limitation and the resulting ambient air level of pollutants that is necessary to assure the statutory level of protecti on for the pollutants driving risk, including manganese. The commenter states that without this information, the EPA does not show how compliance with the requisite margin of safety is assured. T he commenter (0276) believes the EPA could accomplish this sh owing partly by requiring a compliance determination on actual emissions,99

similar to that used for the Primary Aluminum Production standard, and by requiring ambient air monitoring similar to what the South Coast Air Quality Management District is requirin g for secondary lead smelters. The commenter (0276) added that the EPA can make any modifications needed, such as to EPA Method 14, to measure emissions from roof ventilation.

Response:
The “deficiencies” listed by the commenter have been addressed in pr evious comments and responses and are not repeated here. The commenter’s misuse of the chronic noncancer and multipathway “thresholds” warrants further explanation. The chronic noncancer RfC is not a safety threshold, as stated by the commenter. It is a level (or air concentration) below whic h, we do not believe there to be adverse effects given a lifetime of exposure to this concentration . This does not mean that concentrations above this level are unsafe. It means there is more potential to see an effect than at a lower concentration . Furthe r, the multipathway screening threshold, as has also been described previously (S ection 2.5.1 ), is not meant to be used to produce a quantitative result of multipathway risks (i.e., the multipathway risk from POM does not equal 60

- in

- 1 million ), but rather to identify pollutants or facilities that may warrant further analysis. It is not a regulatory number and should not be interpreted as a safety threshold.

When making its ample margin of safety determination, the EPA does consider health risks and their a ssociated uncertainties, but also considers costs, technical feasibility, and other factors . For the ferroalloys source category, in Step 1 of the Benzene NESHAP framework, the risks were determined to be unacceptable given all of the health information. S tandards were proposed to bring the risk down to acceptable levels, not considering costs. Once the risks were determined to be at acceptable levels, Step 2 of the Benzene NESHAP framework requires the EPA to again consider health risks, but also cost, tec hnical feasibility, and other factors , in determining if any additional controls should be required to achieve an ample margin of safety. For the ferroalloys source category, at proposal and again in the supplemental proposal , the EPA propos ed that it

was not appropriate to require additional controls (either based on costs, feasibility, or availability) beyond what were proposed to achieve acceptable risks , regardless of health risks, thus we concluded that the proposed standards to address unacceptable ri sks also achieve d an ample margin of safety. The same decision framework was used for the supplemental proposal and the final rule. While updates were made to emissions and the risk assessment as described throughout this document, when considering the re sults available for the final rule, our decision

making process produced the same result as in the supplemental proposal regarding acceptability and ample margin of safety.
Regarding investigation of European technologies and their costs, it is very diffi cult to compare them to U.S. standards because of differences in the way emissions are reported and control requirements are put in place. For the stack limits, we investigated the possibility of promulgating even lower standards at existing sources (even lower than the PM limits being promulgated in the final rule, as described in the preamble to the final rule) based on the levels100

that could be achieved by replacing the existing scrubber at Eramet with a new fabric filter

. However, given the additional ca pital and annualized costs that would be imposed on the one facility under this option (in addition to the costs for the substantially improved fugitive emission controls described in the preamble), and given the relatively minor additional emissions reduc tions that would be achieved under this option, we conclude that this option is not cost effective ( at approximately $63,000 per ton of PM reduced ) for this source category

. In the revised technology review for the 2014 supplemental proposal, we did not id entify any new developments in practices, processes, or control technologies that have been implemented since the proposed rule was published, and therefore have established emission limits based on the current level of control.

4.0 PREVIOUSLY UNREGULATED POL LUTANTS AND EMISSION POINTS AND TECHNOLOGY REVIEW

4.1 Regulating Previously Unregulated Pollutants and Emission Points
Comment: Commenter s 0074, 0075 and 0106 state that the EPA’s 2011 proposed rule exceeds the bounds of its authority by attempting to establish new MACT standards for HAPs that are not covered by the 1999 MACT standards for ferroalloy production (formaldehyde, hydrochloric acid, mercury, and PAH), and commenter 0106 states the EPA also erroneously includes pollutants not regulated by the current MACT standards in its residual risk assessme nt under Section 112(f) (nickel, mercury, chromium, lead and arsenic).

The commenter (0106) states that the EPA m ay n ot r egulate HAPs for the f irst t ime u nder Section 1 1 2(d)(6) of the Act

, and commenter s 0074 and 0075 state that section 112(d)(6) does not provide broad authority to reconsider aspects of previously issued MACT standards unrelated to “developments in practices, processes, and control technologies ." C ommenter (0074) states that the EPA cannot merely change its mind about what standards are required to comply with CAA sections 112(d)(2) and (3), nor can it fill “gaps” in existing MACT standards or recalculate a MACT floor based on subsequent performance. Commenter (0075) notes tha t Section 112(d)(6) expressly authorizes EPA to review existing determinations and provides specific criteria to guide and constrain the review. The commenter (0075) asserts that the existence of this express authority forecloses the Agency’s ability to di rectly invoke sections 112(d)(2) and (3) for a given source category when a MACT determination has already been issued for the source category. The commenter (0074) notes that challenges to MACT standards must also be raised within 60 days of their promulg ation. C ommenter s (0074 and 0106 ) state that even if the EPA did have authority to go back and change the existing MACT standards, it would have to justify why the decisions reflected in the current standards are wrong and why the new standards meet the re quired criteria that the EPA must satisfy in issuing MACT standards under CAA sections 112(d)(2) and (3). Commenter 0106 asserts the proposed MACT standards for pollutants other than manganese were not properly promulgated and are legally invalid.101

The com menter (0106) asserts that the EPA may not address residual risk under Section 112(f) for HAPs without MACT standards, stating that the scope of EPA’s authority does not extend to an evaluation of all risks presented by all HAP emissions of a source catego ry, but rather is limited to an evaluation of the residual risks from pollutants that have been subjected to technology

- based standards

. The commenter (0106) adds that the only pollutant subject to technology

- based standards in the original 1999 rulemaking was manganese and, therefore , the EPA ’s residual risk assessment should have been limited to residual risks attributable to those manganese emissions regulated unde r the 1999 rulemaking. T he commenter (0106) asserts that the EPA ’s imposition of a risk

- driven standard for mercury (and indirectly for PAH, since the EPA’s justification for a 90% reduction in PAH emissions is that the technology used to reduce mercury emissions will also reduce PAH emissions) was unlawful. T he commen ter (0106) also

asserts that the EPA should revisit its unacceptable risk determination, this time based solely on manganese risks. The commenter (0106) states that if such a review is based on corrected air modeling, reasonable exposure assumptions and an RfC that reflects current science , the EPA will find that EMI’s manganese emissions do not present an unacceptable risk. The commenter (0106) adds that since the EPA ’s selection of a “beyond the MACT floor standard” was explicitly and impermissibly based on risk, that standard should be removed and (at most) replaced with a technology

- based standard consistent with Section 112(d)(3), with appropriate consideration for the product being produced and the mercury co ntent of the ore involved.

In their comments on the supplemental proposal, commenter 0272 reiterates that EPA’s authority does not extend to the evaluation of all risks presented by HAP emissions from a source category, but is limited to an evaluation of the residual risks from pollutants after they have been regulated under technology

- based standards. They believe that two of the three unacceptable risk findings are based on predicted risks (cancer and multipathway) attributed to compounds other than manganese, and include arsenic, cadmium, chromium , PAH and mercury, for which there are no technology

- based standards. They believe by doing this, EPA has disregarded Congress’ intent and direction in Section 112 that these risks can only be considered after technology

- based MACT limits have been applied . Therefore, the commenter (0272) believes that EPA should remove all risk assessments and screening assessments addressing non

- manganese compounds and reassess it s unacceptable risk determination based on manganese emissions.

In contrast to these comments , commenter 0107 states that the statute does not say: only promulgate section 112(f)(2) standards for the already regulated emission points within each such category , but instead says to promulgate section 112(f)(2) standards 8 years after promulgation of standards for each source category. The commenter (0107) concludes that the promulgation of any section 112(d) standard for a source category is what triggers the EPA’s obligation to conduct a complete section 112(f)(2) rulemaking for the entire source category (or subcategory), including all HAP emissions and emission points, including but not limited to any emission points that the section 112(d) standard previously covered. The commenter (0107) describes the legislative history supporting this interpretation.102

Response: In Medical Waste Institute v. EPA, 645 F. 3d 420, 425

- 27 (D.C. Cir. 2011), the D.C. Circuit held that the EPA may permissibly amend improper MACT determinations, including amendments to improperly promulgated floor determinations, using its authority under section 112 (d)(2) and (3). The absence of standards for these HAP is not proper. National Lime , 233 F. 3d a t 633

- 34; see also Medical Waste Incinerator, 645 F. 3d at 426 (resetting MACT floor, based on post

- compliance data, permissible when originally

- established floor was improperly established, and permissibility of EPA’s action does not turn on whether the p rior standard was remanded or vacated

. ) The D.C. Circuit’s December 9, 2011in Portland Cement Ass’n v. EPA (D.C. Cir. No. 10

- 1358) confirms that the EPA is not constrained by section 112 (d)(6) and it may reassess its standards more often, including revisi ng existing floors if need be. Slip op. p. 17. The commenters are thus incorrect that section 112 (d)(6) provides the exclusive authority to address mercury, PAH, formaldehyde, and HCl emissions here. Put another way, if the EPA did not adopt a proper MACT standard initially, it is not amending a MACT standard but adopting one for the first time. That is the case here for mercury, PAH, formaldehyde, and HCl emissions. Here , the EPA adopted no MACT standard at all for these HAP, an approach soundly rejected by the D.C. Circuit in National Lime , 233 F. 3d at 633

- 34. Consequently , the EPA is not barred from making MACT floor determinations and issuing MACT standards pursuant to section 112 (d)(2) and (3) here.

4.2 Technology R eview
Comment: Commenter 0107 states that section 112(d)(6) serves as an ongoing ratchet to continually require EPA to update standards to keep pace with new technology in order to decrease emissions. The commenter (0107) further states that section 112(d)(6) requires EPA to recalculate the MACT floor when there have been advances in technology, practices, and processes, and while the court in NRDC v. EPA , 529 F.3d 1077, 1084 (D.C. Cir. 2008) explained that recalculating the floors was not necessary because “petitioners have not identified an y post

1994 technological innovations that the EPA has overlooked,” the MACT floors must be recalculated when there is information showing that greater emission reductions have been “actually achieved.” In fact, we conclude that it is appropriate to promul gate MACT limits for these previously unregulated HAP, as we have done in today’s final rule and as explained in the preamble to the final rule.

Response: As part of the section 112(d)(6) technology review, we reviewed the MACT limits for stack emissions a nd revised them to reflect recent test data regarding the performance of the control devices that are in use in the industry and reduced those limits consistent with the UPL
process . In terms of advances in technology, practices, and processes, we consider fabric filter control to be the state

- of

- the

- art. Consequently, we evaluated the impact of replacing the existing remaining scrubber with a baghouse. Because of the relatively low level of emissions reduction and the substantial capital and annualized cos ts that would be imposed on one facility in addition to the costs for the required fugitive emissions controls (described in the preamble to the final rule), we determined that such a replacement would not be cost effective for this source category103

at appr oximately $63,000 per ton of PM reduced , and therefore not a feasible advancement in technology. We have, however, required enhanced monitoring of the control devices, particularly a requirement for sources to install and operate bagleak detections systems . This change, which does represent an advancement in operational technology, should result in better operation of the source’s baghouses.

Comment: Commenter 0107 states that the EPA must both “look back” to recalculate the MACT and perform a beyond

- the

- floor analysis and “look around” to assess emission reduction “developments” in current industry “practices, processes, and technologies” in performing its section 112(d)(6) review. The commenter (0107) stat es that the EPA fails this effort by interpreting the term “developments” too narrowly. The commenter (0107) states that the EPA needs to consider an increase in acceptance and utilization of a technology or process within a category as a development warra nting consideration during a review. The commenter (0107) adds that the EPA needs to consider whether technology has advanced so that higher efficiency has been achieved in practice or that a control device, that had been considered experimental, is

now co mmercially demonstrated. The commenter (0107) states that m erely noting the existence of a technology or practice in the initial rulemaking can hardly form the basis for declining to evaluate it during the 8

- year review. The commenter (0107) also states th at the EPA’s analysis is deficient because it did not look to jurisdictions with the most stringent standards for HAP emissions or to gather data from facilities about control systems that are attaining the highest control efficiencies, including requireme nts for similar source categories.
Additionally, the commenter (0107) states that the EPA collected emission test data for this source category that allows it to fully recalculate the existing MACT (which was designed for only one source, and there is now a new source in the category )

. The commenter (0107) states that the EPA overlooks the potential lower emissions that sources are achieving by failing to use actual emission test data and ignores the potential HAP emissions that the control devices themselv es emit by failing to collect such emissions data from facilities that have installed control devices. The commenter (0107) states that information EPA did collect suggests that it should require greater emission reductions for this source category, but ye t according to its own analysis, its limits would not require any new controls to be installed (beyond the enclosure provision).

The commenter (0107) further states that the EPA has not considered the greater emission reductions achieved by Eramet ’ s Norway facility and that the EPA must consider what controls, practices, and processes that facility uses to achieve lower emissions.

Response: We have reviewed the operating permit limits for not only the two facilities in the source category, but for other do mestic ferroalloy producers. These permits reflect state requirements and none of them are more stringent than the proposed and final revised limits. We believe that the focus on capture and control of process fugitives in today’s final rule goes beyond wh at states currently require and will achieve substantial reductions in HAP emissions104

from these facilities. Regarding investigation of European technologies, it is very difficult to compare them to U.S. standards because of differences in the way emissions are reported and control requirements are put in place.

In developing the emission limits for this source category, we collected numerous stack test data (22 PM stack tests total) and established a PM limit (used as a surrogate for metal HAP) in the
supp lemental proposal that reflects the current control technologies used in this industry. This established limit is much lower than the standards in the 1999 NESHAP and is based on available PM test data from several emissions tests conducted over the past s everal years. Further details on how the limit was derived is provided in the Technology Review memoranda which are available in the docket for this action. We estimate that the PM standard, in addition to the HAP standards for hydrogen chloride, mercury, polycyclic aromatic hydrocarbons and fugitive emissions capture, will reduce risk and provide HAP reductions of 76 tons per year.

Comment: Commenter 0073 reiterates the requirement that since the EPA has identified new technology deemed to be available bas ed on application in a similar industry, the new developments must either represent a new MACT

- level technology, or must be justified as a beyond

- the

- floor standard based on cost, non

- air

- quality health and environmental impacts, and energy requirements. T he commenter (0073) asserts that the total building

- wide negative pressure environment that the EPA seeks to require does not exist, and that the CCMA facility that the EPA relies on as the basis for its finding does not use a negative

- pressure PTE at all, but instead relies on targeted equipment controls together with fugitives management practices. The

commenter (0073) states that because the PTE EPA has proposed has not yet been used within the metals manufacturing industry as EPA presumed, it is not a “ development” in “control technologies” under Section 112(d)(6). The commenter (0073) asserts that even if the PTE were an available control technology (or EPA amended the proposal to require the use of the type of controls used at CCMA), the Agency would s till need to demonstrate that the controls qualify as MACT

– either as MACT floor level control, or as “beyond

- the

- floor” controls to be required considering costs, other environmental impacts, and energy considerations

. The commenter (0073) states that th ese controls are clearly not MACT floor level controls (no facility within the Ferroalloys Production source category is currently using either the full

- building PTE proposed by the EPA or the controls used by CCMA), and thus must be evaluated as a “beyond

- the

- floor” level of control

. The commenter (0073) further asserts that the proposed standards have been evaluated for only one of the three congressionally

- mandated factors (costs).

Response: We proposed full building enclosure with negative pressure in 2011 to reduce risk under section 112(f)(2) and as part of technology review under section 112(d)(6). Making a MACT floor determination was not part of the process. We agree that we overstated the connection to the building ventilation system at CCMA, give n the requirement to maintain negative pressure at building openings at proposal. Both plants provided cost and engineering assessments of the impacts of requiring a total building enclosure to be maintained at negative pressure, which is costly, as they d emonstrate. As described in the preamble , we have reassessed105

the costs and impacts of requiring total building ventilation systems (with negative pressure) and local capture options and have decided not to require such controls

. We have considered costs, economic impacts, and other environmental impacts to the extent possible, consistent with our obligations under the Act

.
Comment: Commenter 0073 requests that the EPA take the following actions to account for its errors in technology review: (1) subcatego rize among the various operations; (2) regardless of whether the Agency subcategorizes, reevaluate the controls in place at CCMA to redefine the scope of the “beyond

- the

- floor” technology the Agency seeks to impose; (3) perform a full analysis of these red efined controls, including their costs, their non

- air

- quality environmental and health impacts, and their energy impacts; and (4) provide Felman and other interested parties with the opportunity to comment on the Agency’s revised technology description and cost

benefit analysis.

Response: EPA’s obligation under the Admin i strative Procedures Act is to propose requireme nt s, take comments on those requirements, and be responsive to those comments in the promulgated regulations. We can make changes to the propo sal to the extent that the changes are construed as a logical outgrowth of the original proposal. However, after reviewing the comments, concerns, additional data and information on the 2011 proposed amendments to subpart XXX (76 FR 72508), we determined that wa s appropriate to revise some of the analyses and publish ed a supplemental proposal that addresses these issues. This included revisions to the particulate matter emission standards for furnaces and local ventilation control devices, technology review, revisions to the emission limits for mercury, polycyclic aromatic hydrocarbons (PAH), and hydrochloric acid (HCl) from the furnaces, and changes to the compliance requirements for fugitive emissions. In addition, we received additional test data that

w ere used to develop the final emission standards and improve the dataset used for the risk

assessment.

Comment: Commenter 0107 states that the EPA should also consider requiring additional emi ssion reductions based on EPA ’ s review of practices, processes and technologies in use at the Eramet Norway facility, which has substantially lower levels of dust emissions.

Response: As described earlier, it is very difficult to compare emissions between European requirements and U.S. requirements. In this case, we have extensive data from the two plants subject to the NESHAP, and we are promulgating requirements that will satisfy the risk reduction and technology review requirements of the Act.

Comment: I n comments on the supplemental proposal, two commenters (0270, 0276) state that the EPA has not adequately supported its assumptions underlying the PAH limits and should strengthen these before finalizing the rule. First, the commenters (0270, 0276) want t he EPA to investigate evidence that reducing the coal tar pitch allowed in the Soderberg paste may dramatically reduce the PAH/POM emissions. Both commenters (0270, 0276) provided studies106

supporting this potential for emission reduction and note that low P AH paste or petroleum

- based asphalt is available and could be used by the sources in FeMn and SiMn production. One commenter (0276) states that the EPA must review the use of low PAH paste as a “development: under section 7412(d)(6), and as a method to ass ure an “ample margin of safety to protect public health” under section 7412(f)(2). The commenter (0276) points to the phasing out of PFOS

based fume suppressants in the Chrome Plating NESHAP as precedent to require use of a less toxic input or material as a reason to revise the standards. Response: We reviewed the information provided by the commenter and obtained information from other vendors and studies

. The commenter provided MSDS sheets for the paste, but provided no emissions data from the use of this paste. The studies that we located involved using different Soderberg paste base materials, which resulted in a lower VOC paste, however none of these stu dies measured organic HAP emissions during use of this paste

. Therefore at this time,

we are unable to make a definitive determination that reducing the coal tar pitch in the Soderberg paste would dramatically reduce PAH/POM emissions.

Comment: C ommenter ( 0276) disagrees with the EPA’s basis is for concluding to distinguish and subcategorize the sources in terms of PAH emissions. The commenter (0276) states that the EPA has not met the test to show that the two existing sources fall into such different “cla sses, types, and sizes” of sources that would justify separate subcategories under the Act. Response: We disagree with the commenter and believe it is appropriate to subcategorize the furnaces for PAH emissions. We found a significant statistical differen ce in the furnace PAH emissions between SiMn production and FeMn production

. Even though the furnaces are comparable in how they operate and they use the same Soderberg paste , the raw materials used to produce the different products are very different. Amo ng other factors, t he raw materials for FeMn production include more carbon in comparison to the raw materials used for SiMn production. We believe the additional carbon sources needed by the FeMn process is the reason for the higher PAH emissions during F eMn production. Therefore, we determined that the PAH emission limit should be subcategorized by the product being produced (e.g., SiMn, FeMn).

Comment: Commenter 0107 states that it is unclear why EPA ' s proposed rule under section 112(f)(2) almost exactly matches EPA ’ s proposal under section 112(d)(6). The commenter (0107) states that the measures required to comply with the EPA ’ s proposed rule do not have high costs, as EPA has recognized in the record (although it is not lawfully allowed to consider

cost s at the acceptable stage). The commenter (0107) notes that by stating that no additional controls would be required to comply with these proposed limits, it appears that the EPA may have unlawfully considered cost to propose the residual risk standards. T he commenter (0107)

states that the EPA must explain why these proposed rules match, and how the proposed standards meet each of the legal tests under section s 112(f)(2) and (d)(6). The commenter (0107)

notes that the EPA may not set a residual risk standa rd that sets limits just based on the (unlawfully) narrow view of its duty to assess developments under section 112(d)(6)

.107

Response: In conducting our technology review under section 112(d)(6), the EPA identifies all known control options, and those same options are considered in our residual risk evaluation if they have the potential to reduce risks . It is often the case that we propose (and finalize) requirements under both 112(f)(2) and 112(d)(6), as was the case in the Ferroalloys proposal (and is the case in the final rule). The commenter is correct that controls needed to bring risks to an acceptable level must be required regardless of cost, and we did not consider cost in our selection of the controls being required under our 112(f)(2) acceptability determination. The finding in our 112(d)(6) analysis that the controls are cost

- effective did not factor into our selection of controls needed to reduce risks to an acceptable level. We also note that technically feasible, cost

- effective control options b eyond those that we proposed in our supplemental proposal were not identified.

Comment: Several commenters (0068, 0077, 0089, 0092, 0098) state that stricter air pollution regulations are long overdue. One commenter (0089) notes that over the last 14 years a group of concerned citizens, who became Neighbors for Clean Air, have worked tirelessly to get the attention of Eramet officials, Ohio EPA officials and US EPA officials. The commenter (0089) states that citizens are tir ed of breathing the excess emissions of an aging factory which has been exempt from strong enough regulations that would have protected the health and quality of life of generations of citizens had they been put in place years ago, when they should have be en.
Three commenters (0077, 0092, 0098) ask EPA to adopt regulations that will protect the public health and safety from emissions arising from ferroalloy manufacturing and then enforce those limits. One commenter (0092) notes that people say that we need jobs, and this is true, but not jobs that compromise the health of children and adults. The commenter (0092) states that there should not be large loopholes where many toxic substances are able to be "not counted". The

commenter (0092) states that her org anization has met with the management of Eramet many times and they have stated that the regulatory environment is part of the decision as to whether or not investment is made in a facility in terms of pollution

- control upgrades. The commenter (0092) concl udes that if the regulatory environment is lax, the investment will not be made.

Commenter 0068 states that it is imperative that stricter standards be set for emissions from manganese refineries like Eramet Marietta Incorporated. The commenter (0068) has worked with neighbors of the Eramet facility for more than a decade, helping them to conduct a “good neighbor” campaign that resulted in more than 58,000 letters and petitions to company decision makers that prompted Eramet to announce $150 million in inv estments designed to improve efficiency and environmental performance. The commenter ( 0068 ) attached a copy of a documentary titled “Eramet Neighbors Speak Out,” which was produced in 2007 as part of a joint grassroots campaign conducted with Neighbors for Clean Air , as part of comment 0105

. Several private citizens (0 078, 0079, 0080, 0081, 0082
, 0083, 0084, 0086, 0087, 0088, 0093, 0095, 0096, 0102, 0103, 0104 ) submitted the following identical comment regarding the need for strong, health

- based standards:108

Identical Comment : As a concerned Ohioan, where according to U. S. EPA, we rank #1 for toxic air pollution, these are my comments on the proposed new rules for ferroalloys facilities. Eramet Marietta Incorporated is the largest ferroalloy producer in Nort h America. Thanks to them, the community of Marietta has become a perfect laboratory for studying the impact of airborne manganese on humans. The University of Cincinnati, University of San Francisco and Agency on Toxic Substances and Disease Registry have all done community health studies there just since 2007. I encourage U. S. EPA to look at all the science available and to set rules that create a real margin of safety to protect people from manganese and other pollution from ferroalloys plants. Specific ally, people need full protection from fugitive emissions and from emission spikes during tapping and casting. U.S EPA should require full enclosure of furnace buildings and remove all exemptions for fugitive emissions from protective standards. EPA needs to make sure there is proper testing and reporting so that there are no more high spikes in emissions during tapping and casting or malfunctions. Thank you for considering my comment.

Response: We think the final rule will provide the environmental protection the citizen commenters are seeking.

Comment: Three private citizens (0077, 0089, 0099) state the need for more stringent requirements, including:

 Set stronger emission limits than the EPA has propo sed for all pollutants that will prevent us from facing cancer risk above 1

- in

- 1 million and other unacceptable chronic health risks from manganese.

 Set a more stringent opacity limit that is no higher than 10%, and do not allow any exceedances of this for any period of time, rather than finalizing a “one 6

- minute period” exemption as proposed.

 Provide full protection from fugitive emissions and from emission spikes during tapping and casting.

 Finalize a strong, numerical limit on manganese that is lower th an the limit EPA has proposed, and require monitoring at the fenceline, so we can tell whether we are getting health protection we need.

 Make sure there is proper testing and reporting so that there are no more high spikes in emissions during tapping and c asting or malfunctions.

Response: As described in the proposal notice, the EPA does not define “rigid lines[s] of acceptability” for MIR, but rather considers broad objectives to be weighed with a series of other health measures and factors.

The final rul e includes stringent requirements for the capture and control of process fugitive emissions. These include improved primary capture and control of process and secondary109

capture and control of fugitive emissions for an overall capture and control of 95% of process fugitive emissions

. In addition to more stringent control requirements, the final rule also contains extensive monitoring, reporting, recordkeeping, and testing requirements to ensure that the sources comply with the rule on a continuous basis. Th ese include monitoring of control equipment to ensure they are operating correctly, weekly opacity measurements from the furnace and MOR building using DOCS, and HAP emission standards

.
Comment: Two c ommenter s ( 0073
, 0106 ) assert that the EPA ’s c ost and feasibility assessments were erroneous, resulting in gross underestimates of implementation costs for the new control requirements in the proposed rule.

Response: See Sections 4.3 and 4.5.1 for more details and the EPA ’s response.

4.3 Stack Emission L imits
Comment: Commenter 0073 agrees with the Agency’s decision to reduce the stack emissions limit, but requests that this limit be phrased in terms of mass instead of concentration.

Response: EPA appreciates the support. See section 4.8.2 for our respons e regarding the format of the final standards.

Comment: Commenter 0107 states that it is legally unjustifiable that the EPA has proposed a weaker limit for existing furnaces than for new/reconstructed furnaces . The EPA provides no justification at all, much less a rational one, for setting a weaker limit for existing sources, particularly when those are the sources currently threatening human health. The only possible rationale for setting a weaker limit for existing so urces could be cost. At the acceptability stage

, the EPA may not lawfully consider cost . The EPA therefore must finalize the standards necessary to achieve acceptable risk for all sources, including existing sources (which would be no higher than the lower limit of 9.3 mg/dscm, instead of 24 mg/dscm).

Response: We determined that the risks for this source category at baseline were unacceptable and are finalizing tighter PM emission limits for the stacks, which significantly reduce risk due to allowable emi ssions . We are also reduc ing risk due to process fugitive emissions by requiring a system of primary hoods (that capture process fugitive emissions near the source) and/or secondary capture of fugitives (which would capture remaining fugitive emissions nea r the roof

line). W e estimate that the actions finalized under CAA section 112(f)(2) to address unacceptable risks, will reduce the MIR to 10

- in

- 1 million. The cancer incidence will be reduced to 0.002 cases per year and the number of people estimated to h ave cancer risks greater than 1

- in

- 1 million will be reduced to 26,000 people. The chronic noncancer inhalation TOSHI will be reduced to 1 and the number of people exposed to a TOSHI level greater than 1 will be reduced to 0. In addition, the potential mul tipathway impacts will be reduced. Based on these results, w e concluded that these risks, after the implementation of proposed controls, w ill be acceptable.110

Nothing in the statute compels the emission standard for new sources to be the same as the standar d for existing sources under section 112(f), provided that both standards achieve acceptable risk. In the ample margin of safety analysis, where cost is among the factors to be reviewed, it is possible that different conclusions could be reached as to whe ther further emission reductions are needed to achieve a margin of safety that is ample.

Comment: Commenter 0107 states EPA ’ s proposed regulatory language does not actually match the proposed limit for the MOR (1.5 mg/dscm corrected to 2 percent CO2), but instead is higher (3.9 mg/dscm). The commenter states that the EPA must at least finalize the residual risk limit proposed ( 1.5 mg/dscm).

Response: The 1.5 mg/dscm limit described on page 72531, column 2, of the proposal notice was listed in error. The correct value is 3.9 mg/dscm, which was described on page 72533, column 3, and is consistent with the MACT floor analysis for the proposed rule in the project docket.

Comment: Commenter 0073 asserts that the UPL analysis for the MACT floor does not address “abnormal” operations because it is based solely on stack test data which does not reflect the full range of “normal” source operation. The commenter (0073) notes that the resultant MACT standard is set at a level that a well

- operated source should be able to meet during 99% of future stack tests , but the limit applies at all times. The commenter (0073) points out that compliance determinations are not limited to stack test periods and thus if compliance is required at all times, the data set which MACT is based on should include the full range of operating conditions. The

commenter (0073) adds that if the EPA intends to establish MACT based on limited stack test data, they could establish MACT based on 100% of the stack test data, or clarify that the credible evidence rule does not apply under the Ferroalloys NESHAP and that compliance with the MACT limits may be determined solely on the average of thre e stack test runs.

Response: Ideally, sources would be equipped with continuous emissions monitors and the resulting long

- term data could be used to set MACT standards. However, typically , costs and other practical realities often mean that the best availa ble data are obtained through stack emissions tests. We believe that the use of the UPL analysis is an appropriate approach to address variability in emissions between stack tests. We also note that compliance with the stack limits are based on periodic stack tests, not CEMS. Therefore, the stack limits should be achievable under these conditions.

Comment: In their comments on the supplemental proposal , commenter 0269 expressed

concern s that emissions from tapping operations are subject to two separate an d inconsistent requirements. First, tapping emissions are directly regulated as furnace emissions under §63.1623(a). This section requires Felman to install, operate, and maintain an “effective” capture system that collects tapping emissions (along with th e furnace emissions) and routes them to a control device meeting the applicable emissions standard. Second, tapping emissions are also11 1

regulated as a “process fugitive emissions source” §63.1623(b). This requirement obligates Felman to install, operate, an d maintain a capture system that is designed to collect at least 95% of emissions from process emissions sources, which are defined under §63.1622 to include tapping emissions, and to convey those emissions to a compliant control device.

The commenter (026 9) believes that the regulation of tapping emissions as part of the furnace operations under § 63.1623(a) does not reflect the physical configuration of the furnace control design. They note that emissions from operating the furnace (e.g., charging and mel ting) originate from the same location: the top of the furnace, where the raw materials and catalyst are exposed to the atmosphere. However, they note that tapping emissions originate from the bottom of the furnace ; therefore these emissions cannot be capt ured and managed via the same fans and equipment that capture emissions from the furnace.

The commenter (0269) is also concerned that as drafted, the supplemental proposal may require it to install a separate control system around the tapping area to provi de “effective” capture of tapping emissions. They state that this requirement is inconsistent with the “area

- wide” control approach that they intend to install to manage fugitive emissions from the furnace, tapping, casting, and raking and skimming operati ons. They believe that requiring this additional layer of controls would impose significant additional costs and would provide no additional environmental benefits. They state that the rule also provides no guidance on what degree of controls would be cons idered “effective,” making it impossible to even attempt to design such a system.

The commenter (0269) requests that the reference to “tapping operations” be removed from §63.1623(a). They believe that these emissions are fugitive and therefore are more ap propriately regulated under the process fugitive provisions at §63.1623(b).

Response: We agree with the commenter and have removed the reference to tapping operations from §63.1623(a).

Comment: In their comments on the supplemental proposal, commenter 0269 states that §63.1623(b) requires that all process fugitive emissions be managed via a system that is designed to provide at least 95% capture; compliance with this obligation is demonstrated pursuant to §63.1624(a). Section 63.1624(a), in turn, requires a detailed engineering plan, “designed to achieve sufficient air changes to evacuate the collection area frequently enough to ensure process fugitive emissions are effectively collected by the ventilation system”; the plan must also account for “variables t hat affect capture efficiency such as operations that create cross

- drafts[.]” §63.1624(a)(i).

The commenter (0269) believe s that these requirements are inappropriately stringent and unfeasible for the operations in question. As Felman has previously docume nted to the EPA, its furnace building is both extremely large and very old, with a large number of openings and leaks. The controls necessary to capture and manage fugitive emissions within such a large, unique112

space cannot simply be bought off the shelf. Instead, Felman’s entire control plan has been individually designed and represents a control system that has never before been applied within the ferroalloy industry.

Furthermore, the commenter (0269) believe s that there are very few engineers who are capable of designing such a system, much less preparing the extensive documentation required by EPA. In fact, all of the consultants that Felman has contacted to generate the required plan documentation have insisted on conducting modeling before they will certify that the plan will meet all of the criteria set forth in the proposal; however, given the size and complexity of the building, and the novel nature of the planned controls, these consultants do not believe they have sufficiently concrete data on t he required model input parameters to do so. To date, Felman has not identified a consultant that has agreed to perform the modeling required to demonstrate compliance with all of these criteria.

The commenter (0269) requests that these extremely detailed criteria be streamlined into a broader requirement that the plan be designed based on the best available information and engineering principles, and that the specific details of what that entails be left to the discretion of the relevant permitting authori ty.
Response: The facility provided a fugitive capture design narrative in their supplemental comments to the proposed rule. The proposed design improves the existing direct exhaust system while providing a secondary exhaust system in order to fully captur e and contain process fugitive emissions that are generated. The use of both a primary hood exhaust system and a general secondary exhaust system in conjunction wa s estimated to provide a total building capture rate of approximately 95%, including the tapp ing; casting; crushing/screening and skimming/slag raking processes. This design narrative include s ACGIH elements and design principles and we believe will be able to achieve the requirements in the final rule.

4.4 Object to UPL Methodology
Comment: Two comm enters (0065, 0107) support the EPA’s decision to set limits for previously uncontrolled sources of emissions, including mercury, PAH, HCl, and formaldehyde because this is consistent with section 112(d) which requires the EPA to set emission standards for all emitted pollutants. One commenter (0107) adds that closing loopholes and correcting problems that exist in the existing standard is an important part of the EPA’s job under section 112(d)(6). The commenter (0107 (and in its comments on the supplementa l proposal

- 0276)) disagrees, however, with the EPA’s use of such a high variability factor in setting the MACT standards for these pollutants as it is unsupported and results in a standard that is higher than appropriate. The commenter (0107) states that using an upper prediction limit to set standards reflecting the worst performance these sources could have in a purely statistical sense does not yield an accurate picture of the best sources’ actual performance, and it is especially arbitrary in the abse nce of any explanation of why the EPA thinks that the relevant best sources’ performance would ever113

be so bad, other than the fact that it is statistically possible. The commenter (0276) also states that the EPA has not clearly explained its approach in th e limited data sets memo or the UPL memo
The commenter (0107) adds that, even if the EPA could justify using an upper predictive limit (UPL) of 99% for some source category, it has failed to provide any rational explanation for using it for the Ferroalloys source category.

Commenter 0107 further adds that the EPA’s dataset also includes other uncontrolled HAP emissions, including hydrogen fluoride (HF) and naphthalene emissions, and the EPA has failed to propose a limit to control these emissions. The comme nter (0107) states that Section 112 requires EPA to set an emission standard to control all HAPs emitted. The EPA must do so, at least by setting the limit at the detection level if emissions fall below that.

Commenter 0272 recommended using ProUCL for ca lculating UPLs for MACT limits. They note that ProUCL is a tool for statistically evaluating data for environmental decision making and has been supported through the EPA ORD.
Commenter (0276) objects to the EPA’s use of a representative detection level (R DL) to increase the limit for HCL and states that this decision is not justified based on the science, record or what has been achieved. The commenter 0276 also notes that the EPA appears to propose to continue to use the UPL to set floor standards, even a fter the D.C. Circuit remanded EPA’s use of that method in NACWA. The commenter (0276) states that the EPA appears to be attempting to evade the Court’s direction to follow the plain text of § 7412(d)(3) to set standards based on the “average emission limi tation achieved.” According to commenter 0276, the EPA has failed to justify its interpretation of the statute’s direction for this “average,” § 7412(d)(3), and has failed to provide the necessary factual support to use the approach it chooses even if it c ould be considered to meet the statutory test.

Response: As stated in the memorandum entitled “Use of the Upper Prediction Limit for Calculating MACT Floors” (Docket No. EPA

- HQ

- OAR

- 2010

- 0895

- 0179) (“UPL memorandum”), i n “ the context of development of MACT floors, the UPL is a value, calculated from a dataset, which identifies the average emissions level that a source or group of sources is meeting and would be expected to meet a specified percent of the time that the source is operating. That percent of ti me is based on the confidence level used in the UPL equation, as explained in more detail below. For a single best controlled emission source that serves as the basis for a new source MACT floor, the 99 percent UPL is the emissions level that the source

wo uld be predicted to be below during 99 out of 100 performance tests, including emissions tests conducted in the past, present, and future, based on the short term stack test data available for that source. It is important to note that the UPL does not repr esent the worst emissions performance of the best performing units at any time, but rather the average level expected to have been achieved over time, as the first element of the UPL equation is the average of the short

- term emissions test data from the be st performing units. In other words, the 99 percent UPL is the level of emissions that we are 99 percent confident is achieved by the average source represented in a dataset (in the case of MACT standards, the dataset representing the114

performance of the be st performers as specified in the CAA) over a long

- term period based on its previous, measured performance history as reflected in short

- term stack test data.” Contrary to the commenter’s assertion, the NACWA court did not find the UPL to be an arbitrary a pproach, but simply asked for a better explanation from the Agency. The UPL memorandum provides the explanation of what the UPL represents sought by the NACWA Court. It also explains why the UPL is representative of the level of performance achieved by the best performing unit or units. The court did not state that the “average emissions limitation achieved by the best performing 12 percent” must be equal to the mean of the available data, as suggested by the commenter, and in past decisions the court has u pheld that it is appropriate for EPA to account for variability when establishing numeric MACT standards. See Mossville Environmental Action Now v. EPA , 370 F.3d 1232, 1241

- 42 (D.C. Cir. 2004).

We also refer the commenter to the proposal MACT floor memoran dum, which is in the rulemaking docket. This memorandum provides a detailed discussion of the EPA’s authority to consider variability, especially given that MACT and other technology

- based standards are necessarily derived from short term emissions test da ta and such data are not representative of the range of operating conditions that the best

- performing facilities face on a day

- to

- day basis. In statistical terms, each test produces a limited data sample, not a complete enumeration of the available data fo r performance of the unit over a long period of time. The EPA, therefore, often needs to adjust the short

- term data to account for these varying conditions in order to properly estimate these sources’ performance over time. The types of variability that th e EPA accounts for include variability between and within tests at the same unit as well as between units in the pool of “best performing units.” This memo also describes the EPA’s selection of the UPL methodology to address such variability.

For some HA P (e.g., dioxins and furans, PCBs, and hydrogen fluoride ) the majority or even all of the test samples were below the limit of detection for the test method. We do not believe we

can establish an appropriate MACT floor limit for this source category for th ese HAP when there is so much uncertainty that the pollutant s are even being emitted.
While naphthalene was modeled separately from the other PAH s in the risk assessment

, with regard to MACT standards, naphthalene is a PAH and is one of the PAHs covered by PAH MACT limit (via method 429). Therefore, there is no reason to establish a separate limit for napthalene because it is being regulated along with the other PAH compounds by the PAH limit

.
Comment: Commenter 0073 agrees that the EPA may establish limi ts based on what MACT can achieve during normal operations, and not at some higher level that would encompass all conceivable malfunctions, but notes that if the EPA bases standards on an emissions level that MACT can achieve only 99 percent of the time, t hey must first ensure that MACT

- level technology can actually comply with these emissions limits during all normal operations (the 99 percent), and then provide an adequate exemption for the other 1 percent of the time, when even properly maintained and op erated MACT

- level technology cannot comply.115

Response: The 99 percent UPL is a standard statistical analysis to address variability between stack tests, and the EPA believes it is an appropriate basis on which to establish stack limits based on test data.

4.5 Emission Averaging Across Multiple Furnaces
Comment : Commenter 0107 states that the EPA must not allow emissions averaging under section 112(f)(2) or section 112(d) for the following reasons:

 When the EPA sets an emission standard for each source, it must apply to each source, continuously without exception, because averaging means that some sources under common ownership at the same location can emit above the level allowed by the standard if others are operating below that standard and this is unlawful. E missions averaging is bad for public health and the environment because the end result is an amount of emissions not allowed by the standard.

 EPA has found that current health risk is unacceptable and that specific emission reductions are required to achie ve an acceptable level of health risk. Section 112(f)(2) requires EPA to set a standard to ensure those reductions and achieve an acceptable level of risk, and the EPA may not provide an alternative compliance option under which sources could exceed the ve ry emissions limits it has found necessary to achieve acceptable risk.

 EPA attempts to justify this proposal based on EPA ’ s general policy of encouraging the use of compliance approaches that are more flexible and less costly alternative to controlling cer tain emission points to MACT levels. This statement shows that the EPA has improperly considered cost at the acceptability stage of the section 112(f)(2) analysis

. The EPA may not lawfully consider cost at all at this stage.

 EPA may not justify the use of emissions averaging under section 112(d), because that provision requires EPA to set and ensure compliance with an emission standard that meets the requirements of section 112(d)(2)

- (3). Allowing averaging is a way of circumventing the requirement that emi ssion standards must apply at all times.
In their comments on the supplemental proposal, commenter 0276 supports the EPA’s removal of the emissions averaging allowance.

Response: As described in section 4.10.2 , we have decided to retain a concentration format for the final stack standards. While we believe this is the best format for this NESHAP, we have determined that it is not the best format to consider under an emissions averaging option. We are concerned that emissions from a large furnace emitting a lower than average concentration could still emit more emissions than a small furnace with a higher than average concentration. This could result in a net increase in emissions from the two furnaces compared t o their emissions if they were not allowed to average emissions. For this reason, we have deleted the emissions averaging provisions from the final rule.116

Comment: Commenter 0073 supports EPA’s decision to allow for emissions averaging across multiple furn aces to demonstrate compliance with the applicable emission limits

. Response: EPA appreciates the support ; however, as noted in the previous response, we have removed the emissions averaging provisions from the final rule

.
Comment: Commenter 0073 states t hat the EPA has not provided sufficient information to allow
response to the EPA ’s request for comments on “discount factors”, specifically a definition of what the “discount factor” means, and how it would be applied to stack emission factors

. The

commenter (0073) states that if they have interpreted the proposal correctly ( e.g. if a facility operates two furnaces, each subject to an emissions limit of X, should the emissions averaging approach establish a limit of 2X, or should that combined li mit be established at some lower value, such as 90% of 2X), then they disagree with the EPA ’s proposal and reiterate their previous comments regarding subcategorization for different processes and the need for a mass

based emission limit.

Response: As desc ribed in section 4.8.1, we have determined that it is neither desirable n or appropriate to subcategorize by process/product for the metal HAP/PM stack emission limits. As noted in the previous response, we have removed the emission averaging provisions fro m the final rule. Without the provisions for emission averaging, we do not believe that the use of discount factors is appropriate. Therefore, the discount factors have been removed from the final rule.

Comment: Commenter 0073 states that they are unable t o respond to the EPA ’s request for comment on the potential for averaging emissions from crushing and screening equipment with other emission groups including furnace stacks or process fugitives because the preamble is unclear about how EPA proposes to ave rage such emissions when the equipment at issue is subject to different emission limitations and with and without CO2 standardization.

Response: As discussed in this section, we have removed the emissions averaging provisions from this rule. Therefore, there is no need to provide guidance for averaging equipment with different emissions limitations. We agree that it would be difficult to average together units, some of which had a CO2 standardization factor and others that did not.

4.6 Fugitive Emissions Cap ture

4.6.1 Total Negative Pressure Enclosure
Comment: C ommenter 0261 recommended that the EPA not base the acceptance of a suitable system to capture fugitive emissions based on the guidelines by the American Conference of Governmental Industrial Hygienists (ACG IH). They note that the guidelines are intended to reduce worker exposure and do not provide any assurances of capture efficiency of fugitive emissions. They provided an article outlining techniques used by EAFs in Japan to reduce fugitive emissions and an EPA manual for measurement of fugitive emissions from roof117

monitors. The commenter (0261) recommends using computational fluid dynamics or emission testing of the roof monitoring ventilation.

Response: In addition to our own analyses, w e also consulted wi th ventilation experts working with hot process fugitives like those found in the ferroalloys industry (e.g., electric arc furnace steel mini

- mills and secondary lead smelters) who stated that a fugitive capture system should be based on guidelines from the ACGIH. In addition, we have included requirements for process fugitive emissions capture to be designed to achieve sufficient air changes to evacuate the colle ction area frequently enough to ensure process fugitive emissions are effectively collected by the ventilation system and ducted to the control device(s). We believe these requirements will achieve 95% capture of process fugitive emissions from the furnace building.

Comment: Commenter 0073 disagrees that a total building negative

- pressure environment is either necessary or feasible to mitigate the health risks EPA has assumed, The commenter (0073)

states that the EPA ’s selection of this control scheme is b ased on a significant misunderstanding of the scope of controls that have been used within the industry, which lead the Agency to overstate the benefits associated with enclosure of the building under negative pressure compared to the demonstrated benefits of localized control efforts. The commenter (0073) asserts that the total building enclosure and control system in the proposed rule is not representative of any sources in the ferroalloy industry. The commenter (0073) states that the EPA ’s assertion that such a system has been successfully used at a non

- manganese ferroalloy producer fundamentally misrepresents what that technology is and exactly what it does. The

commenter (0073) notes that the existing furnace building ventilation system on which EPA bas es the proposed rule (at CC Metals & Alloy, Inc.’s facility in Calvert City, Kentucky) is not sealed, and is not under negative pressure. The commenter (0073) states that the EPA ’s residual risk standard under section 112(f) and its technological update un der section 112(d)(6) are based on the assumption that a negative pressure permanent total enclosure is a technology achieved in practice within the industry, however, no one has ever employed a negative pressure permanent total enclosure within the ferroal loy manufacturing industry.

Commenter 0106 asserts that the total building enclosure and control system is entirely novel to the ferroalloys industry, and that the referenced example

- CCMA, is not a sealed, negative pressure system. The commenter (0106) states that the CCMA facility is far smaller than EMI’s furnace buildings, and the CC Metals facility does not meet the performance standards imposed under the proposed rule, capturing a much smaller fraction of its fugitive emissions than the proposed rul e requires.

Response: We re

- evaluate d the proposed negative pressure ventilation requirement and concluded that the full

- building enclosure option may not be feasible and would have significant economic impacts on the facilities. Based on this re

- evaluation , we concluded that an option based on enhanced local capture and control of process fugitive emissions using a combination of primary and secondary hoods is a feasible and cost

- effective approach to achieve significant118

reductions in fugitive HAP emissions. Therefore, in the 2014 supplemental proposal, instead of full building enclosure, we proposed that facilities would need to install and operate a local capture system using a combination of primary and/or secondary hoods that is designed to achieve at least 95 percent capture and control of process fugitive emissions. In the final rule we are promulgating requirements (based on mainly on enhanced local capture and control) that are very similar to the requirements we proposed in the 2014 supp lemental proposal.

Comment: Commenter 0069 states that the EPA has misrepresented the fugitive dust controls in place on CCMA's #15/16 furnace building, and that the control system in place at CCMA is nothing like the total building capture and control system mandated by the proposed rule

. The

commenter (0069) notes that the proposed rule envisions the permanent total enclosure of shop buildings under negative pressure, while in actuality, the building is not sealed and has “open area of roughly 20 perce nt of the exterior wall area.” The commenter (0069) describe s their existing building ventilation system in this manner:
“In the early 1990’s, CCMA entered into an agreement with the State of Kentucky Division of Air Quality to augment their existing exhau st system in the #15/16 building with spare capacity in the #6 baghouse serving the adjacent production area referred to as the #6 furnace area. This was accomplished by construction of a duct from the #6 building to the #15/16 building and splitting that duct to vent a casting operation of a specialty product, and secondarily, the production area roof vent. This was done to augment the existing system and help reduce emissions from the building roof vent.

There was no intent to evacuate a significant porti on of the building. It was recognized that due to the fact that the particulate is entrained in hot air, it is buoyant, and therefore, rises to the roof vent area. It is therefore a natural location to collect hot air that at times was not collected by the individual vent systems associated with various processes at the facility.”

The commenter (0069) adds that this misrepresentation of their existing controls results in a gross underestimate of the cost of the proposed requirement to reduce fugitive emissi ons (i.e., putting shop buildings under a negative pressure of at least 0.007 inches of water). The

commenter (0069) states that despite the fundamental difference in the systems , the EPA performed their cost estimate as if the proposed rule requirement wa s similar to CCMA's facility.

The commenter (0069) incorporates by reference Felman’s comments providing a more accurate estimation of the costs to install a building ventilation system that would comply with the language of the proposed rule.

Response: We agree that the CCMA operation lacks a negative pressure component, with the result that use of that system as currently configured is not an accurate model for the proposed building ventilation system we described in the 2011 proposal

.119

Comment: Commente r 0073 asserts that the Agency’s cost analyses for the “beyond

- the

- floor” level of control are critically flawed in several ways:

 The Agency relied on a single vendor, who provided a single quote on what the proposed technology might cost.

 The quote dramat ically understates the true cost of the required controls, largely due to misunderstanding of the amount of air flow a PTE would require to maintain a negative pressure environment while ensuring that the air inside meets the acceptable OSHA PEL for mangan ese. (The commenter (0073) provides detailed cost estimates showing actual costs over fifteen times higher than those in the EPA ’s proposal.)

 The quote provided by the EPA ’s vendor assumed an airflow requirement of 150,000 actual cubic feet per minute (“AC FM”), while data gathered by the commenter (0073) demonstrates that the required airflow is 1.24 million ACFM

– nearly ten times higher than the EPA ’s assumption.

The commenter (0073) estimates that the total capital investment required for Felman to compl y with the proposed rule’s building enclosure requirement is over $45 million, more than fifteen times EPA’s estimate. The commenter (0073) estimates that the annual operating costs for the equipment are more than three times EPA’s estimate, while the amor tized capital cost over 20 years totals over $4.2 million. The commenter (0073) describes significant flaws in the EPA ’s analysis of costs for total building ventilation and control to address fugitive emissions because of EPA’s assumption that the CC Meta ls and Alloys facility in Kentucky is a comparable scenario, when in fact it is not.

Commenter 0106 also provides an extensive analysis of the deficiencies in the EPA ’s cost analysis and offers an alternative methodology based on using the costs of maintai ning a 0.007 inches of water at building openings and sufficient air changes to support industrial hygiene requirements

, which results in significantly higher air flow requirements to the new baghouse. The commenter (0106 ) states that EMI would require new equipment to provide 2.5 million additional cfm of ventilation

– more than 8 times the amount calculated by the EPA . The

commenter (0106 ) concludes that establishing complete building ventilation and capture systems for EM I’s three furnace buildings would cost more than $41 million to install over the next two years (rather than $6.3 assumed by the EPA ) and would increase annual operating costs by more than $9.7 million per year (rather than $1.5 million per year assumed by the EPA ).

Response: We re

- evaluated the option based on negative pressure and building ventilation as described in the 2011 proposal. This control option involves installation of full building ventilation at negative pressure for furnace buildings instead of installing fugitive controls on individual tapping and casting operations. This option would require installation of ductwork from the roof vents of furnace buildings, additional fans, structural repairs to buildings and a new fabric filter for each bu ilding.120

We thoroughly reviewed the information provided by the companies along with information gathered from other sources, and then revised our cost analyses accordingly for th e supplemental proposal. We estimate d that the full building enclosure option would reduce PM emissions from the facilities by 252 tons per year (and total HAP emissions by 83 tons per year). The total estimated capital cost for these fugitive controls is $61 million. Annualized capital cost and operational and maintenance costs ar e estimated at $19 million per year, which results in an estimated cost per ton of metal HAP removed of $226,000 per ton and a cost per ton of PM removed of $74,200 per ton and achieve PM 2.5 emission reductions of 53 tons, resulting in a cost per ton of PM 2.5 removal of $353,000 per ton. The incremental cost effectiveness comparing the enhanced capture option to the building ventilation option is $501,000 per ton of PM removed, $2.4 million per ton of PM 2.5 removed and $2.2 million per ton of HAP removed. B ased on these analyses, we conclude that the full

- building enclosure option with negative pressure may not be feasible and would have significant economic impacts on the facilities (including potential closure for one or more facilities). However, we concl ude d that the enhanced local capture option is a feasible and cost

- effective approach to achieve significant reductions in fugitive HAP emissions and will achieve almost as much reductions as the full building enclosure option (229 vs 252 tons PM reductions) thus achieving most of the risk reductions.

Comment: C ommenter 0265 states that the capture of casting fugitive emissions should be reviewed to determine if additional controls can be reasonably implemented at Eramet.

Response: Based on the pr oposed ventilation plans submitted by the facilities and the fugitive capture requirements in this rule, we conclude that fugitive emissions from the casting process es will be substantially reduced through implementation of the requirements in the final ru le. We also conclude that no further reductions will be needed beyond those reductions that we expect will be achieved through this final rule

.

4.6.2 Enhanced Local Capture Option
Comment: Commenter 0073 asserts that the EPA overstates the benefits of total buil ding enclosure in comparison to other, more targeted control technology and emission reduction efforts. The commenter (0073) notes specific steps taken by CCMA to minimize fugitive emissions (tightening furnace doors, enclosing tapping operations) and asse rts that the emissions reductions at CCMA are largely a result of the type of localized emission reduction and control efforts summarily rejected by the EPA in the proposed rule as insufficient to limit risks.

Commenter 0106 states that the local emission capture approach achieves almost half the predicted emission reductions of total building capture at six percent of the required capital investment and six percent of the annual operating cost. The commenter ( 0106 ) asserts that resultantly, localized captu re is seven times more cost

- effective for PM control and eight times

more cost

- effective for HAP control than total building capture when viewed on an aggregated basis for both their operating furnaces, while cost

- effectiveness for their EAF No.1 is even m ore121

attractive given the absence of need for additional baghouse installation to achieve this local capture.
In supplemental comments, two commenters ( 0122, 0123 ) proposed that controlling process fugitive sources with enhanced source control would cost s ignificantly less than the proposed total building enclosure and satisfy the residual risk requirements of s ection 112(f). Both commenters (0122, 0123) based their proposed strategies on an overall assumption that improvements could be made to existing ope rations to achieve 95 percent capture for process fugitives. The commenters (0122, 0123) also proposed that all capture systems should have a minimum hood face capture velocity of 300 fpm based on acceptable engineering standards such as those published by the American Conference of Governmental Industri al Hygienists. Both commenters (0122, 0123) retained ventilation engineering firms to assess their current (baseline) process fugitives capture systems and prepare draft plans to improve performance to achie ve the stated objectives of their process fugitives strategy.

Based on the engineeri ng analysis, one commenter (0122 ) proposed to make improvements to tapping operations by installing an enhanced hood system extending over the charge ladle, adding hoods fo r the casting beds at the two furnaces and adding new retractable hoods for slag raking a nd skimming. The commenter (0122 ) also proposed modifying the pour/casting station for the MOR tapping (pouring) and casting process. The commenter (0122 ) proposed installation of additional control equipment where needed to address the additional captured emissions. The commenter ( 0122 ) also proposed that they could enclose a section of the MOR building roof to capture fugitive (secondary) emissions not captured by the close fitting primary hoods in the MOR building. In addition, the commenter (0122 ) proposed changes to facilitate close capture of fugitive emissions such as adding a rail car transfer system to the tapping area and to make structural changes to preven t the overhead crane operation from interfering with the new tapping and casting hoods. 54

Commenter 0123 proposed to repair the existing direct exhaust system, which they determined was operating under capacity. According to the commenter ( 0123 ), the origin al ventilation system for the existing furnaces and casting/tapping process was not designed for the current, lower temperature ferroalloy process, which had resulted in a lower ventilation rate of approximately 180,000 CFM compared to the original rate of 250,000 CFM, a 30 percent decrease in capacity. The commenter ( 0123 ) proposed to add new fans and motors to bring the system up to the original design capac ity. Similarly, the commenter (0123 ) proposed to install new fans/motors to increase the capacity o f the crushing capture system and to install a curtain wall to reduce cross contamination between the hot metal bay and crushing/ screening area. The

54 For additional detail on specific proposed changes, se e the QSEM Solutions, Inc. report, “Technical Comments to Alternative Approach).122

commenter (0123 ) also proposed to install new casting “shields” to capture and direct emissions to the cast ing hood and to enclose the tapping areas.

The c ommenter ( 0123 ) also proposed to install a general exhaust system to collect all emissions above the roof rafters that are missed by the direct exhaust system, including emissions generated during the skimmin g/slag raking processes. The commenter ( 0123 ) proposed to use this system because source control of these emissions would not be possible because installation of ductwork in the area to capture emissions locally would interfere with overhead crane traffic. 55

One commenter ( 0122 ) also proposed that the proposed design standards be supplemented with the visible emissions standard that would limit visible emissions from any building housing a ferroalloy EAF, MOR, or casting operation to 20 percent or less, meas ured as a 6

- minute average, except for one 6

- minute period. For more discussion of the opacity standard, see section 4.8

.
Both commenters (0122, 0123 ) proposed that controlling process fugitive sources with enhanced source control would cost significantly less than the proposed total building enclosure and satisfy the residual risk requirements of section 112(f). Both commenters (0122, 0123) based their proposed strategies on an overall assumption that improvements could be made to existing operations to ac hieve 95 percent capture for process fugitives. The commenters (0122, 0123) also proposed that all capture systems should have a minimum hood face capture velocity of 300 fpm based on acceptable engineering standards such as those published by the American Conference of Governmental Industrial Hygienists. Both commenters (0122, 0123) retained ventilation engineering firms to assess their current (baseline) process fugitives capture systems and prepare draft plans to improve performance to achieve the stated objectives of their process fugitives strategy.

Based on the engineering analysis, one commenter (0122) proposed to make improvements to tapping operations by installing an enhanced hood system extending over the charge ladle, adding hoods for the casting beds at the two furnaces and adding new retractable hoods for slag raking and skimming. The commenter (0122) also proposed modifying the pour/casting station for the MOR tapping (pouring) and casting process. The commenter (0122) proposed installation of additional control equipment where needed to address the additional captured emissions. The commenter (0122) also proposed that they could enclose a section of the MOR building roof to capture fugitive (secondary) emissions not captured by the close fittin g primary hoods in the MOR building. In addition, the commenter (0122) proposed changes to facilitate close capture of fugitive emissions such as adding a rail car transfer system to the tapping area and to make

55 For additional detail on the specific proposed changes, see the July 9, 2012 Chu and Gassman “Design Narrative.”123

structural changes to prevent the overhead c rane operation from interfering with the new tapping and casting hoods. 56

One commenter (0123) proposed to repair the existing direct exhaust system, which they determined was operating under capacity. According to the commenter (0123), the original ventila tion system for the existing furnaces and casting/tapping process was not designed for the current, lower temperature ferroalloy process, which had resulted in a lower ventilation rate of approximately 180,000 CFM compared to the original rate of 250,000 C FM, a 30 percent decrease in capacity. The commenter (0123) proposed to add new fans and motors to bring the system up to the original design capacity. Similarly, the commenter (0123) proposed to install new fans/motors to increase the capacity of the crus hing capture system and to install a curtain wall to reduce cross contamination between the hot metal bay and crushing/screening area. The commenter (0123) also proposed to install new casting “shields” to capture and direct emissions to the casting hood a nd to enclose the tapping areas.

The commenter (0123) also proposed to install a general exhaust system to collect all emissions above the roof rafters that are missed by the direct exhaust system, including emissions generated during the skimming/slag rak ing processes. The commenter (0123) proposed to use this system because source control of these emissions would not be possible because installation of ductwork in the area to capture emissions locally would interfere with overhead crane traffic. 57

Response : As described above, we have significantly revised our view of the role that local ventilation can and should play in designing an optimized building ventilation system. Regarding costs, see the discussion s in the preamble s of the supplemental proposal an d final rule

.
Comment: Commenter 0270 believes that the EPA should evaluate the capability of achieving emissions that provide acceptable public health protection. The commenter (0270) suggests that by starting with an acceptable ambient concentration of t he hazardous pollutants and employing the various EPA receptor models, the total plant emissions can be estimated. Then the EPA could assess whether it is reasonable to expect a well

- designed ventilation system to achieve the percent capture combined with the emissions from add on controls to achieve emissions that pass the screening levels. The commenter (0270) states that this would be best implemented by compliance determination in a manner similar to that used for the Primary Aluminum Production standar d, recognizing that the EPA will need to make minor modifications of EPA Method 14 for measuring the emissions from roof ventilation.

56 For additional detail on specific proposed changes, see th e QSEM Solutions, Inc. report, “Technical Comments to Alternative Approach).

57 For additional detail on the specific proposed changes, see the July 9, 2012 Chu and Gassman “Design Narrative.”124

Response: We appreciate the suggestion from the commenter. However, we think we have taken the proper steps to evaluate acceptable health protection using the modeling risk assessment approach that we used. There were a number of issues with trying to install a roof top measurement system because of the age of the building and other factors

. We think the proposed tight opac ity limit s (which would be measured at the emissions sources), along with the proposed requirements to install, operate and maintain effective fugitive capture and control systems, emissions limits for the stacks and various parametric monitoring requireme nts, are appropriate control requirements to ensure effective capture and control of emissions.

4.7 Ambient Air Monitoring Option
Comment : Commenter 0107 states that the EPA should strengthen the ambient concentration limit to require reductions so that the mo st exposed person, at the fenceline, is not exposed to manganese emissions at two times the safety level but instead require emission reductions to ensure no one is exposed above the child

- specific reference level that California OEHHA has created, which i s 0.03 mg/kg/day . The commenter (0107) adds that the EPA should require ambient air monitoring for manganese to assure compliance with the emission standards and allow EPA to assess the ongoing status of public health in the affected communities. The

commenter (0107) notes, however, that this limit alone could not satisfy section 112(f)(2), which must include specific numerical emission limits on all emitted HAPs. The commenter (0107) adds that the EPA may not use manganese as a surrogate for all HAP metals, including the

cancer

- risk drivers which may be emitted at a lower level and still cause a substantial cancer risk.
In comments on the supplemental proposal, commenter 0276 is disappointed that the EPA is proposing not to finalize the alternative approach on ambient air fenceline monitoring. The commenter (027 6) states that the EPA should at least require monitoring in addition to the emissions standards like the requirements the SCAQMD has established for secondary lead smelting. The SCAQMD existing rules require that:

 Minimum of four monitors at facility loca tions approved by the Executive Officer;

 Samples collected once every 3 days;

 Results reported monthly;

 Daily sampling if 0.120 μg/m 3 is exceeded after January 1, 2015.

 Curtailment of operations if lead and arsenic exceed certain monitored levels.

The comm enter (0276) adds that SCAQMD is proposing to strengthen the requirements to include daily sampling for lead and arsenic, provisions for monitor failure and 1

- year sample retention. The commenter (0276) states that the EPA should consider requiring similar provisions for at least manganese, lead, arsenic and cadmium and other toxic metals the EPA recognizes are significant and driving risk.

Response: In reviewing the information received on fenceline monitoring, we determined there were various issues assoc iated with fenceline monitoring at facilities within this source category,125

including highly variable wind patterns, uncertainties as to how to account for background concentrations and road dust and the large difference between emissions release heights (f rom the high roof vents and stacks) compared to heights where fenceline monitors would be located (near ground level). Therefore, we are n ot includ ing fenceline monitoring in the final rule as an alternative method to demonstrate compliance with a specific ambient level as was described in the 2011 proposal. We believe the proposed tight opacity limit (which would be measured at the emissions sources), along with the proposed requirements to install, operate and maintain effective fugitive capture and control systems, emissions limits for the stacks and various parametric monitoring requirements, are appropriate control requirements to ensure effective capture and control of emissions.

Also, as discussed earlier, the RfC or MRL is not a “safety level” so being exposed to an air concentration above the RfC does not necessarily indicate an “unsafe” situation

. Second, the child

- specific reference level of 0.03 mg/kg/day that the commenter mentions is an oral reference dose, not an inhalation value

. It woul d be inappropriate to use an oral value to develop an ambient air standard

. Third, also discussed earlier, this value was developed for a specific school siting program in California

. It was not developed for use in their Hot Spots program, and it was

not developed by the EPA

- approved methods

.
Comment: Commenter 0073 supports the inclusion of a fenceline monitoring compliance option, but objects to a limit based on the Mn RfC in its current form. The commenter (0073) asserts that the EPA should set the a mbient air concentration limit on the latest analyses of leading health authorities and the recent pharmacokinetic modeling data and exposure studies. The commenter (0073) notes that the health risks associated with manganese arise from chronic, not acute exposure, and that the monitoring frequency should be commensurate with the risk. The

commenter (0073) requests that the EPA revise the monitoring provisions to require monthly monitoring and a 6

- month rolling average.

Commenter 0106 supports flexibility in compliance options, but an alternative “fenceline” standard is not warranted in this case because additional manganese controls are not warranted. The commenter (0106) adds that, if such a standard were established, it should be es tablished as part of a work practice standard under Section 112(h), reflecting the fact that uncontrolled fugitive emissions are not reliably measurable. The commenter (0106) states that consequently, exceedance of the fenceline standard would not constitu te a violation of the Act, but rather would be a trigger for follow

- up to evaluate the causes of the exceedance and the potential need to modify fugitive practices within the facility. The commenter (0106) adds that since the fenceline standard is based on ambient monitoring, such an evaluation might also determine that a fenceline exceedance resulted from non

- regulated sources and no modifications were required.

The commenter (0106) further states that the monitoring frequency and fenceline threshold shou ld also be adjusted to reflect the facts that (1) the relevant manganese risks are based on chronic exposures, so short

- term exposures to slightly elevated levels would not warrant126

significant modifications, and (2) ambient concentrations at the fenceline would not represent exposure concentrations, because receptors do not live along EMI’s fenceline. The commenter (0106) adds that a 60

- day rolling average is unjustified to address chronic exposures, which are typically evaluated on the basis of annual expo sures. The commenter (0106) suggests that a more reasonable standard would be based on a rolling average of at least six months of data, with samples collected no more frequently than monthly. The commenter (0106) asserts that to calculate a scientifically defensible fenceline standard, the analysis should be based on a range of 4 ug/m 3 manganese PM 2.5 to 14 ug/m 3 manganese PM 2.5 , which corresponds to an HQ of 2 at the range of manganese RfCs identified in Bailey et al., and then be adjusted to a total mang anese concentration of 9.8 ug/m 3 to 34 ug/m 3 based on the 41 percent fraction used by the EPA in this rulemaking.

In their comments on the supplemental proposal, commenter 0269 strongly supports the EPA’s proposed decision in the supplemental proposal to r eject fenceline monitoring for manganese emissions this alternative. As discussed in their previous comments, ferroalloy facilities may be located in industrialized areas; Felman, for example, is located adjacent to two power plants, one of which is being decommissioned, and the other of which continues to operate. Given the variability in topography, wind patterns, and release heights, it would be infeasible to attempt to identify which portion of any monitored concentrations are due to Felman’s operations and which are due to those of its neighbors.

Response: As we explained in the preamble to the supplemental proposal, the final preamble and elsewhere in this document, we have decided not to require fenceline monitoring in the final rule. The rationale for such decision is also explained in the preambles of the supplemental and/or final rules and elsewhere in this RTC document. So, we are not repeating that information here. Comments on how to structure a fenceline monitoring requirement including the is sues of frequency and authority, are mooted by the decision not to require fenceline monitoring.

Comment: The commenter 0271 states that fenceline monitoring is not an accurate measure of

s ource

- s pecific e missions nor is an i ndicator of PM e ffects from th ose s ources on a c ommunity

. They note that these monitors would capture emissions from stationary and mobile sources not covered by th is rulemaking and not owned or controlled by the affected facilities. In addition the

commenter ( 0271 ) believes that the b ackground contributions from other sources would not be able to be accurately distinguished from the affected facility sources.

Commenter (0272) stated in their comments on the supplemental proposal states that the EPA’s fenceline monitoring proposal is no t adequately described and is not capable of producing relevant emissions information. The commenter notes that the supplemental proposal does not discuss how the location or height of the monitors would be determined, and the EPA should not take further a ction on this proposed research project before issuing a specific, adequately defined project for public notice and comment.127

The commenter notes that EPA admits that fenceline monitoring does not measure emissions, but instead it measures ambient condition s that may contain emissions as well as any number of additional, indistinguishable sources of particulates and/or manganese. The commenter disagrees that such monitoring, even with “meteorological data and modeling tools” would be capable of quantifying e missions entering or leaving EMI’s property , and there is no way to attribute such emissions to particular EMI sources. The commenter also states that while such monitoring may be technically feasible, collecting legally relevant data from such monitoring is infeasible, and EPA’s curiosity about “trends in ambient concentrations” does not fall within the statutory objectives of Section 112.

Response: We agree with the commenter and have not included any requirements for fenceline monitoring in the final ru le.

4.7.1 Activated Carbon Injection
Comment: In comments on the supplemental proposal, commenter 0276 states that the EPA should evaluate address the use of activated carbon injection to reduce the mercury and dioxin emissions and strength the mercury and dioxi n limits accordingly.

Response: We reviewed information on the reduction of mercury and organic HAP using ACI from many different sources. For mercury, we determined that ACI was not cost effective for existing sources producing SiMn or FeMn. We were unab le to quantify the reductions of organic using ACI from the information , and therefore no changes to the emission limits were developed.

Comment: Commenter 0106 states that the EPA overstated the technical ability of ACI to reduce emissions, specifically EPA ’s assumption that ACI would capture 90% of mercury and PAH emissions from EMI’s two furnaces using wet scrubbers, even though the addition of ACI to other wet scrubbers has almost never reduced mercury emissions by more than 30%, and is typically close r to 20 percent

. Response: See pollutant specific responses for mercury and formaldehyde , below

. In the case of PAH, there have been a few studies that have shown significant PAH reductions with the installation of ACI. Albemarle, a company that provides mercury control equipment to industries, noted in a presentation 58 that 9 out of 10 conventional boilers equipped with ACI reported PAH analytical results below the detection limit. The other boiler reported PAH results that were only 10 percent above the d etection limit. Another study 59 found that ACI can achieve 74

- 91 percent reduction in PAH emissions depending on the concentration of activated carbon in

58 Presentation by Dr. Ronald R. Landreth, Albemarle, Alternative Method of Hg and THC Control Using Existing Cement Kiln Particulate Control Equipment , February 9, 2010.

59 Hong

- Cang Zhou, Zhao

- Ping Zhong, Bao

- Sheng Jin, Ya

- Ji Huang, and Rui Xiao, Experimental study on the removal of PAHs using in

- duct activated carbon injection, Chemosphere, November 17, 2004.128

the flue gas. Based on this information, we think that an activated carbon system that is designed

to a chieve up to 90 percent reduction in mercury emissions

, should also achieve significant reduction s in PAH. Nevertheless, as explained in the supplemental proposal preamble, final rule preamble, and elsewhere, we decided not to require ACI controls on these sources because of costs and economic factors.

4.7.2 Mercury Control
Comment: The commenter 0271 states that

, in the preamble to the supplemental proposal, the EPA suggests that trials using brominated ACI at a taconite facility in Minnesota resulted in 75
perc ent mercury removal. The commenter (0271) notes that the study was done in two phases, and the second phase of testing provided total mercury removal rates ranging from 25

- 61 percent.

C ommenter 0265
, in their comments on the supplemental proposal believes that beyond the floor requirement of ACI for new facilities is too burdensome and can cause closure of the affected facilities.

Response: The referenced study was based on ACI in conjunction with a wet scrubber and was used to estimate the mercury reduction of a furnace equipped with a wet scrubber. We are not requiring beyond the floor mercury control for existing sources , and therefore det ermination of the actual mercury reduction from this study is not necessary. However, we believe that new furnaces would be equipped with baghouses and can install and operate an ACI system and achieve 90% reduction of mercury emissions

.

4.7.3 Formaldehyde Cont rol
Comment: Commenter 0106 states that formaldehyde is a polar molecule, while activated carbon is composed of largely neutral carbon atoms with no electrical gradients between molecules, and thus, carbon does not attract polar molecules. The commenter (0106) asserts that polar compounds like formaldehyde therefore have a poor affinity for carbon compared to non

- polar compounds , and f

urther, it is difficult to retain formaldehyde on carbon due to its high volatility. The commenter (0106) states that no d ata supporting removal of formaldehyde to the very low concentrations equivalent to the proposed standard (201 ug/dscm or approximately160 parts per billion) were found. The commenter (0106) asserts that b ased on these considerations , the EPA ’s assumption of 90 percent formaldehyde removal by ACI in EAF#1 and EAF #12 has no scientific basis.

Response: The proposal preamble correctly states our conclusions regarding formaldehyde control efficiency using ACI: We recognize the potential for some co

- c ontrol of formaldehyde emissions that would be achieved by using activated carbon injection to control mercury emissions, but we were unable to quantify those reductions. (p.72528, column 1) The proposed (and final) formaldehyde limit is based on the MACT floor dete rmination and should not result in the need to install controls specifically to reduce formaldehyde emissions. We have revised129

our post

- control modeling scenario to remove the assumption that 90 percent of formaldehyde would be reduced to an assumption tha t none would be because we lack information to support a specific reduction capability at this time.

4.8 Opacity S tandards
Comment: Commenter 0073 states that, given EPA’s new residual risk standard incorporating total building negative pressure enclosure prop osed in the 2011 proposal , there is no legal basis for retaining any opacity standard, much less adopting a more stringent one. The commenter (0073) adds that if the EPA modified its proposal to require more targeted controls , the EPA still has not identif

ied any “improvements” in fugitive control technology or practices that would support tightening the standard. The commenter (0073) notes that the EPA ’s evaluation of opacity performance within the industry identified several incidents that would have exce eded the new proposed 10 percent standard, which suggests this limit does not reflect the 99 percent UPL.

Response: T he opacity standard is a main piece of the compliance strategy for the process fugitive emissions standards. A key aspect of the opacity limit is that it can be used by the source to establish a correlation between successful operation of capture system parameter values (capture system fan motor amperes and all capture system damper positions or volum etric flow rate through each separately ducted hood that comprises the capture system) and opacity levels, and then the source can continuously monitor the parameters to help ensure the opacity limits are achieved continuously and that the capture and cont rol system is effectively capturing fugitives on a continuous basis . This combination yields an enforceable parameter limit that is designed to ensure continuing operation of the capture system at a level consistent with operation during the performance te st.
Theoretically, a perfectly designed building ventilation system should always exhibit 0 percent opacity. However, we conclude this scenario would not be feasible for these facilities. G iven that these are retrofit situations and there may be short

- term process fluctuations, we felt that it was important to allow for the presence of at least minimal fugitive emissions in setting the standards. We note that the historical opacity data observations that were above 10 percent obviously do not reflect the ad dition of improved local capture . We believe that the installation and operation of a well

- designed local capture system can meet the opacity standards in the final rule.
We note that the historical opacity data observations that were above 10 percent obvi ously do not reflect the addition of improved ventilation systems

. In addition, we note that we are no longer requiring total building negative pressure enclosure.

Comment: In their supplemental comments, commenter 012 2 suggests that their proposal for enhanced fugitive control would include a 20 percent opacity limit for visible emissions, measured as a 6

- minute average, from any building housing a ferroalloy EAF, MOR or casting operation, except for one 6

- minute period per hour.130

Response : We believe that the robust local ventilation systems, combined with rooftop capture, suggested by the plants will result in a high degree of control for reducing process fugitive emissions of approximately 80 percent . Furthermore, both plants have suggested controls on ladle raking and slag skimming operations, which are not represented in the emission modeling files because we lack information (emission factors) to estimate emissions from these operations. The control of these addition al, previously uncontrolled, process fugitive sources should address the remaining sources of rooftop emissions that could result in elevated opacity readings

. In fact, we believe these additional capture devices and controls will be able to keep the opaci ty at or below an 8% average for each furnace cycle. Thus, as described in the preamble to the final rule, we are promulgating an average opacity limit of 8%.

We believe that a n 8

- percent opacity limit is consistent with stringent capture and control of
pr ocess fugitive emissions

. Furthermore, to accommodate potential short

- term higher emissions, as described in the preamble to the final rule, we are allowing opacity to be as high as 20% for any 2 consecutive 6

- minute readings. We do not believe there is ju stification for including a 6

- minute exemption, because the capture equipment should be operating at all times the processes in question are being operated.

Comment: In their comments on the supplemental proposal, commenter 0269 supports the EPA’s conclusi on that compliance with the limits on process fugitive emissions should be demonstrated through opacity observations because other alternatives are not feasible and would not generate reliable data. One possible alternative, direct monitoring of fugitive e missions, is technologically infeasible; given the number and size of the openings in the Felman building, and the variations in airflow through the buildings and across the openings, it would not be possible to accurately capture both concentration and fl ow across each of these openings over the course of a test period.

The commenter (0269) believes that the 8 percent opacity standard required by the proposal is unnecessarily stringent and not supported by the record. The commenter (0269) notes that opacit y observations are the judgment of individual observers under varying atmospheric conditions. Hence, compliance requirements were historically drafted in 20 percent increments. More recent standards have reduced some of these requirements to 10 percent inc rements (e.g., an hourly average of 10 percent opacity, with a not

- to

- exceed limit of 20 percent ). The

commenter (0269) believes that reducing the allowed opacity limit to 8 percent implies a degree of precision that the observation methodology was simply not designed to meet.

The commenter (0269) notes that the 2011 proposal included a 10 percent opacity standard, which was based on total building enclosure. The new approach, of providing partial primary and secondary

- level controls, is designed to achieve a 95 percent reduction with an 8 percent opacity, which is lower than that assumed by the original proposal. The commenter (0269) states that the supplemental proposal identifies no basis for this illogical conclusion.131

Response : The commenter is correct t hat individual opacity readings are read in increments of 5%, however the 6

- minute reading is an average of multiple individual readings (24 readings total). These 6

- minute readings are then averaged over the entire furnace cycle. Because the opacity stand ard is based on multiple readings, the determination of the opacity average over the furnace cycle does not need to be in 10 percent or 20 percent increments. The commenter is correct that the proposed rule did include a proposed 10 percent opacity require ment. However, as explained in the supplemental proposal preamble, after further evaluation, we decided that an average opacity limit of 8% for the entire furnace cycle was more appropriate to reflect effective capture and control of process fugitive emiss ions. The determination of the 8 percent opacity standard was based on averaging opacity data provided by the facilities and includes opacity data for the various process cycles in the production of ferroalloys and also based on consideration of the emissi ons reductions that would be achieved through the enhanced local capture and control systems described in the supplemental proposal. After reviewing these data and after considering the significant improvements that are expected regarding the capture and c ontrol of process fugitive emissions, we believe that the average opacity can be reduced to 8 percent or lower using the enhanced capture systems that will be required to comply with the final rule.

Comment: In their supplemental proposal comments, comment er 0269 believes that the EPA has provided no basis for replacing the existing provisions allowing higher short

- term opacity levels as a result of specific operating conditions (e.g., oxygen lancing) with a much more limited 20 percent opacity limit. While these events are infrequent, they are unavoidable and necessary in certain situations. Furthermore, the quantity of emissions during these short

- term events may temporarily overwhelm even the best

- designed fugitive control system. During the development

o f the prior NESHAP, the EPA agreed that these kinds of events merited a higher short

- term opacity limit. The Agency has identified no basis for reversing its position in the current proposal.

Response : The EPA recognizes that longer term averaging periods allows facilities to incorporate greater operational variability within a compliance regimen. Without an appropriate averaging time, h igh emissions events may quickly force a non

- compliant situation that is unavoidable, as the commenter points out, where a longer term average allows for such an event to not trigger an enforcement action where operations are generally stable and emissions are well controlled. We believe the final opacity limits accommodate these concerns by providing a sufficient averaging t ime for both the average opacity limit of 8% (averaged over an entire furnace cycle) and for the maximum opacity limit of 20% (for any 2 consecutive 6

- minute readings, or 12 minutes).

Comment: Two commenter s (0265 , 0272 ) in their comments on the supplemental proposal state that the opacity requirements in the supplemental proposal require a tap to tap opacity reading from each of the furnace buildings. They note that the building that house the MOR and Furnace 18 would con sidered by the definition in the rule as a shop building. However, the commenter132

notes that only the MOR is in operation in that building and that operation does not include any tapping.

Response: The EPA thanks the commenter for the additional information and will modify the final rule to require opacity observations on emissions from the MOR building to a better suited time period for that operation.

Comment: In their comments on the supplemental proposal, commenter (0272) states that the process fugitive emissions provision in § 63.1623(b)(3), is ambiguous regarding the link between the proposed 8 percent average opacity requirement and § 63.1623(b)(3)(ii), which requires that, if an opacity test finds the average to exceed 8 percent over one process cycle, two additional furnace cycles must be observed over a seven

- day period and the average opacity over the entire three

- cycle period must be 8 percent opacity or less. The commenter believes that the EPA should have add ed the following words, “Unless you mee t the criteria of § 63.1623(b)(3)(ii),” to the beginning of § 63.1623(b)(3), which will then read: “Unless you meet the criteria of § 63.1623(b)(3)(ii), you must not cause emissions exiting from a shop building, to exceed an average of 8 percent opacity durin g furnace process cycles at all times.”

Response: The EPA a grees with the commenter and has included the change in the rule text.

Comment: In comments on the supplemental proposal, two commenters (0270, 0276) state that the EPA should establish an opacity limit with a form that limits the duration of the required observation to a period that spans the operation with the highest potential for visible emissions rather than a full heat. For example, the commenters (0270, 0276) note, pouring and tapping operati ons would be expected to provide the greatest challenge in capturing fumes from the operation. The commenters (0270, 0276) state that the proposed form is significantly less stringent than opacity standards that were established in the 1980’s for basic oxy gen furnaces, electric arc furnaces at Steel Production plants, Steel Foundries and Gary Iron Foundries. The commenters (0270, 0276) also state that these processes are very similar to the operations at Ferroalloys plants and there is no reason why the vis ible emissions from the facility cannot be maintained at least as stringently as with these sources. The commenters (0270, 0276) add that this approach would allow the facility and other observers to more easily identify when adjustments are required to ma intain good emissions control performance. It would also decrease the burden to comply with the monitoring component of the rule by limiting the observation period to the time associated with these higher potential emissions.

Response : The EPA disagrees with the commenter in that where batch processes are involved (such as a furnace heat cycle) emissions should be averaged throughout the entire batch to adequately understand the emissions potential of all periods of normal operation in discrete sets.

Comment: In comments on the supplemental proposal, two commenters (0270, 0276) state that the EPA should require the use of the best available testing method, digital opacity monitoring. The commenters (0270, 0276) describe the benefits of the DCOT compare d to Method 9 and133

provide supporting documentation. In particular, one commenter (0276) supports the DCOT because it is EPA certified as a valid test method for opacity and approved for its use, the use of a camera creates a good electronic record of the o bservations, conditions, location, etc. and a number of regulated entities are using this method to assess opacity. The commenter (0276) adds that using cameras can save resources, citing a Department of Defense project to reduce Method 9 certification cos ts. The commenter (0276) adds that the EPA should also require opacity determinations to be documented on an electronic form and proved on the Internet in real time for public review.

The commenter (0276) adds that the EPA should not allow Method 9 to be u sed, unless there is a power outage requiring the facility to go to the use of Method 9 to assure opacity standard compliance. They also add that instead of Method 9, the EPA should require a source to use either continuous opacity monitor or DCOT.

Respons e : We appreciate the information from the commenters and moved forward with requiring the DOCS for measuring opacity from the furnace and MOR buildings. We also agree with the commenter that the DOCS creates a record of the opacity observation and conditio ns, and also provides a n objective record supporting the determination of the opacity. The EPA does not believe that Method 9 observations would be useful in a compliance determination if there were there to be a power loss at the facility as the source an d associated controls would malfunction immediately.

Comment: In comments on the supplemental proposal, two commenters (0270, 0276) provide additional comments on the proposed §63.1625(d), compliance demonstration with the shop building opacity standards . First, one commenter (0276) states that the EPA has not shown how a facility could develop a correlation or benchmark for a parameter during a compliance test of three runs. In a laboratory assessment, it requires a minimum of seven tests to statisticall y evaluate a parameter. Even with a statistically valid assessment, it is unclear that knowledge of the fan’s operation would detect excess opacity due to atypical furnace operation. The commenter (0276) adds that the alternative use of an engineering asse ssment to establish operating parameters could be even further removed from actual data on opacity than a compliance demonstration. Nor has the EPA shown how that such an assessment could be adequate to determine compliance according to the commenter.

Both commenters (0270, 0276) suggest that instead, testing should be required and compliance determined as required for Primary Aluminum, e.g., use of Method 14 (or modified Method 14), with the target analytes would be PAH, PM, extractable organic matter and metals (manganese, arsenic and chromium). The c ommenters ( 0270 , 0276) suggest that annual testing should be required to assure compliance and allow action to be taken to reduce emissions and risks if estimates and assumptions do not match on

- the

- ground res ults. One commenter (0270 ) adds that if the results of 3 years of annual testing substantially below the emission level associated with a unit risk index would allow a reduction in the frequency of emission testing to once every 30134

m onths or once every 5 y ears. Both commenters (0270 , 0276) reference EPA technical documents that would support development of a method appropriate to ferroalloys (see p, 37 of comment letter 0276).

Commenter 0276 adds that should the EPA decide that a total emission rate is imp ossible to establish and continue with the 95 percent capture efficiency alone, then in addition to the building monitor testing, the emissions captured by the ventilation system should also be measured in order to determine the percentage of PM, PAH, Mn a nd other key risk

- driver pollutants are actually captured.

The c ommenter (0276 ) states that, between performance tests the opacity during one furnace cycle should be determined by CO MS or COCS, not just Method 9. The c ommenter (0276) adds that it should al so be required that the facility post the results of the opacity or COMs reading to the Internet within 1 week of the test, at the latest. If the DOCS system is used, the images taken at 15

- second intervals should be available on the Internet for public vi ew in real time. The facility should review the images each day and select the top three 12

- minute periods which appear to contain the greatest opacity and submit the 24 minutes bracketing the center of those 12 minutes of which the maximum 12

- minute opaci ty will be determined. This opacity should be posted to the web for public review. The EPA should determine a procedure for the facility to retain the complete record of the 24

- minuete images and require retention of a least one image per minute.

As an ind icator of continuing capture and control, both commenters (0270 , 0276) said that the EPA should require daily monitoring of parameters indicative of continued operation as demonstrated during the compliance test. For the air pollution control device, the E PA should consider requiring the installation of a bag leak detector (Triboflow, nefelometer, particle counter) which is more sensitive than opacity monitoring. The commenters (0270, 0276) add that the EPA should require daily opacity monitoring as the pri mary indicator of performance between compliance tests, even if the compliance tests includes no periods of opacity over 5 percent

. Also, as described above, the opacity limit should be in a form that limits the duration of the required observation to a period that spans the operation with the highest potential for visible emissions rather than a full heat.

Both commenters (0270 , 0276) state that the EPA should obtain opacity data from a representative number of well operating electric arc furnaces in Ste el Mills, Steel Foundries, Gray Iron Foundries and Basic Oxygen Furnaces to establish the performance of well

- designed ventilation systems. Alternatively, the commenters (0270, 0276) suggest, the EPA should establish the opacity limit during the performanc e test based upon the observations during the six or twelve minutes with the greatest average opacity. One commenter (0276) suggested that in addition to using the three tapping and pouring periods during the performance test, the EPA could allow the addit ion of the tapping and pouring periods just before or after the performance

tests.135

Response: The EPA disagrees with the commenter in that we have a long history of using three test runs to establish operating parameter limits that function as compliance as surance monitoring between compliance tests. In lieu of requiring Method 14 tests, we are requiring weekly opacity monitoring at each of the ferroalloy process building using digital opacity camera technique (DCOT), where a record of the visual emissions w ill be taken and analyzed by a computer to determine the opacity. We think this will provide assurance that the fugitive emission requirements are being met by the facilities. In addition, facilities will be required to do daily checks of control equipment to ensure that they are operating in a manner consistent with the manufacturer’s specifications.

Comment: One commenter (0272) in their comments on the supplemental proposal states that they do not object to the inclusion of opacity standards to reflect proper operation of control equipment. However, the commenter states that the technology review provides no factual basis for the selection of an opacity standard or the conclusion that the limit is achievable through implementation of enhanced local fugi tive capture. In addition, the commenter states that an opacity standard cannot be justified based on risk reduction, because opacity measurements cannot be equated to a mass emissions rate. If the EPA intends to require additional fugitive controls, the c ommenter recommends that the existing opacity standard be applied until the additional controls are put in place and performance testing can be performed to establish a limit based on the actual operation of such controls. The commenter also requests origi nal opacity standard be maintained until additional data can be collected to measure opacity during non

routine operating conditions (e.g., blowing tap, oxygen lancing, electrode burndowns and some furnace blows).

Response: The EPA disagrees in that we ha ve been provided with visible emissions data from the facilities that demonstrates they are capable of meeting the proposed opacity limits throughout a substantial portion of their operations even before additional controls are in place. We expect that wit h the additional capture and control systems envisioned with this rule, that facilities will be able to maintain opacity levels at or below the limits being finalized in today’s final rule. Furthermore, we believe the opacity limit will provide a benchmark to indicate whether or not the controls are operating as designed.

4.9 Fugitive Dust
Comment: Commenter 0107 states that the EPA has proposed no requirements to address fugitive dust emissions outside of the facility, but EPA should do so. The commenter (0107)

states that the EPA should require material control and handling requirements that it has required for other source categories, such as enclosure

, and that the EPA should also require a numerical limit as a direct restriction on emissions that appli es to fugitive dust as section 112 requires.

Response : The revised subpart retains the same requirements for outdoor fugitive dust sources as does the existing subpart. See new §63.1625(b) and existing §63.1654(a). Enclosures are generally not appropriate for these types of fugitive dust enclosures and information on136

emissions and effectiveness of work practices are largely limited to use of AP

- 42 emission factors. In the absence of more detailed information, we determined that retaining the current require ments to develop and implement a fugitive dust control plan is reasonable.

Comment: Commenter 0271 in their comments on the supplemental proposal , states that the inclusion of outdoor fugitive emission sources such as roadways, yard areas and outdoor mater ial storage and transfer operations in the RTR air dispersion modeling risk assessment has the potential to significantly over predict PM concentrations and their associated impacts. The commenter states the CAA directs the EPA to make revisions as may be necessary to eliminate any significant over

- predicting of air quality effects of fugitive particulate emissions.

Response : Outdoor fugitive emission sources were not included in the air dispersion modeling for this source category.

4.10 Format of the Regulation

4.10.1 Need to Retain Subcategories
Comment: Commenter 0073 states that the EPA should subcategorize the industry to account for varying emissions of different processes, and notes the effect this might have on cost

- benefit calculations. The commenter (0073) notes that if most of the risks are attributable to a certain type of product or furnace, then controlling only those operations (for example, through enhanced localized controls) would allow EPA to maximize the emissions reductions and health benefits, wi thout requiring unaffordable generalized controls on equipment that does not pose such risks. The commenter (0073) requests that the EPA reassess its beyond

- the

- floor analysis under Section 112(d)(6) taking subcategorization into account.

Response: Regard ing subcategorization, we believe there is no reason to do so for PM or HAP metals emissions based on the available data and based on the capture and control technologies in use. The commenter’s issue also relates to their contention that the EPA should fo cus on manganese content (because silicomanganese production emits less than ferromanganese in terms of tons of emissions per ton of product produced). Our final rule is based on the revised risk analysis, including taking into account that EMI sometimes p roduces silicomanganese instead of ferromanganese at one or more furnaces. In any case, we conclude the baseline risk s due to HAP emissions are still unacceptable for the source category (which includes both products/companies )

. T herefore, we conclude that it is appropriate that the standards for process fugitive emissions should apply to both plants and that both plants will need to improve controls to reduce fugitive emissions

.

4.10.2 Concentration Format is Not Appropriate
Comment: Commenter 0073 asserts that t he EPA ’s switch from a mass emission limit to a concentration

- based standard is inappropriate and that the EPA has not provided a reasoned justification for the change. The commenter (0073) note s that both the furnace and building137

enclosure systems capture large volumes of ambient air, which dilutes pollutant concentrations and makes a standard based on concentration impractical. The commenter (0073) suggests that a standard based on the overall mass of pollutant per ton of alloy produced would avoid this
p roblem. The commenter (0073) adds that mass

- based limits create incentives for pollution prevention, encourage improvements allowing for multi

- pollutant reductions, avoid concerns about dilution, and limit total pollutant emissions rather than allowing potentially unlimited quantities of pollutants to be emitted, so long as other materials in the stack exhaust provide sufficient dilution to remain below the concentration limit. The commenter (0073) requests that the EPA change the format of the proposed MACT standards for PM, mercury, PAH, HCl, and formaldehyde to units of mass of pollutant per ton of ferroalloy produced or, if the EPA rejects their comment, explain the basis for changing the format of the standard and provide opportunity for review and c omment.
Response: We recognize that there are many advantages to a production

- based format for an emissions standard. However, neither the data from the ICR test program nor the historical compliance data were collected is such a way to provide consistent information of pro duction during the emissions tests. Even where data were provided on amount of product tapped, we have no assurance that the tapping periods were consistent from test to test. The current rule states that the furnace stack test must be conducted such that at least one tapping period, or at least 20 minutes of a tapping period, whichever is less, in included in at least two of the three test runs. This means that a third tapping period could be included in the third test run, or that only partial tapping per iods are included at the beginning or end of the test run.

Comment: Commenter 0106 states that load

- based limits are more appropriate for this category, because the emission standards at issue in this rulemaking address chronic, rather than acute, risks. The commenter (0106) states that the principle focus of the emission standards in this matter should be mass loading, rather than simple concentrations. The commenter (0106) adds that concentration

- based limits discriminate against sources, such as EMI’s M OR unit, that produce very low levels of emissions and, as a consequence, present less practical significance. The commenter (0106) requests that the final rule should continue to express limits in terms of pounds per hour, as EPA elected to more appropria tely address the types of HAPs emitted by this category in the original MACT.

The commenter (0106) adds that a concentration

- based limit requiring correction to 2% CO2 is not rational for building emissions that consist almost entirely of ambient air. The commenter provides (01060 additional analysis in Appendix B of this topic. The commenter (0106) states that both the building ventilation option and the existing configuration of EMI’s furnace #1, draw significant ambient air, such that the concentration o f CO2 is very low and equivalent to background levels, i.e., at 390 ppm (0.039%), consistent with the general atmosphere, without applying any correction factor. The commenter (0106) notes that correcting to 2% CO2 notwithstanding the ambient air makeup of the exhaust, would require corrections that render the proposed limit for building ventilation baghouse emissions (including Furnace #1) far more138

stringent than the EPA has suggested. The commenter (0106) explains that, to achieve 24 mg/dscm expressed at 2% CO2, the exhaust gases would actually need to contain less than 0.48 mg/dscm particulates [24*(0.039/2)], which is an unrealistically stringent limit that is not supported by the EPA ’s residual risk assessment or any other aspect of the proposed rule.

Response: We continue to believe that a concentration format is preferable to a pounds per hour format in this rule. This is because the majority of the control devices are fabric filters, which are constant outlet devices. We recognize there may be some c oncern about excess dilution air being used as a technique to ensure compliance, but feel that this is unlikely as control devices are designed for specified flow rates taking into account the cost of achieving those flow rates.

We agree with the commente r that the CO2 concentration correction poses a problem in both the building ventilation option and the Furnace #1 configuration. While such a concentration correction is appropriate for combustion sources such as boilers, we agree that its use in the

cont ext of ferroalloys production is not helpful. The final limits in the rule have been recalculated to remove the correction factor.

4.10.3 PM Cannot be Used as a Surrogate
Comment: Three c ommenter s ( 0107
, 0270, 0276) state that the EPA has failed to justify using PM as a surrogate for all HAP metals under section 112(d). Two commenter s (0107 , 0276 ) explain that a surrogate is reasonable only if it meets three conditions: (1) the target pollutant(s) must invariably be present in the surr ogate; (2) the control technology used to control the surrogate must indiscriminately capture both the surrogate and the target pollutant(s); and (3) control of the surrogate must be the only means by which facilities achieve reductions in the target pollu tant(s). The se commenter s (0107 , 0276 ) state that the EPA has not shown that this source meets factor three, in view of the potential variety in raw materials used for Ferroalloys, and the agency must investigate whether these may lead to specific metal em issions that are not always proportional to PM. The commenter s (0107 , 0276 ) conclude that the EPA must fully analyze the reduction methods for manganese and other metals, and should set a HAP

- specific, numerical emission standard that limits each of these pollutants, and allows both the EPA and the public to assess compliance.

In their comments on the 2011 proposal, c ommenter 0107 states that under section 112(f)(2), the EPA may not use PM as a surrogate for all HAP metals. The commenter (0107) adds that

a lthough courts have allowed EPA to use this to meet the MACT requirements of section 112(d) in certain instances, the EPA has no legal basis to use a surrogate in the context of public health under section 112(f)(2). The commenter (0107) states that the EP A instead must finalize emission limits for all regulated HAPs which will ensure an acceptable level of health risk and provide an ample margin of safety to protect public health. The commenter (0107) continues that, even if the EPA could use PM as a surro gate in any circumstance under section 112(f)(2), the EPA has not shown that using PM as a surrogate satisfies the three

- part test. The commenter (0107) states that the EPA must address whether different raw materials going into the139

Ferroalloys source cate gory may significantly affect the specific emission of different HAP metals, without having a proportional relationship to PM.

Two commenters (0270, 0276) note that one would expect that a good surrogate would have a high correlation with the target pollutant at concentrations near the regulated limits, especially in the case of manganese. However, the commenters (0270, 0276) present analysis showing that wh en all tests containing filterable particulate and manganese analysis were evaluated, the correlation between the two was less than 15%. When the test data is limited to fabric filter controls, the best correlation was 0.208 using a power equation. The com menters (0270, 0276) presented correlation data for arsenic, chromium, nickel, cadmium and lead (see pp. 30

- 33 in comment letter 0276) and conclude that the data do not adequately demonstrate a surrogacy relationship for PM and the HAP metals of concern.
Both commenters (0270, 0276) suggest that the EPA should consider using EPA Method 29 to quantify metal emissions at a small incremental cost to the overall collection of PM emissions.

One commenter (0270) recommends that the EPA should base the emission l imitation for the facilities on the measurement of emissions of the pollutant with the greatest risk (minimum of PAH and manganese) and any use of a surrogate pollutant with a poor relationship to the target pollutant producing the greatest potential risk should accommodate the correlation uncertainties. The commenter (0270) believes that any surrogate that has a correlation lower than 70% at levels near compliance concentration levels is less than acceptable for use in assessing compliance without signific ant adjustment due to correlation uncertainties.

Response: The rule does meet the tests for using PM as a surrogate. First, metal HAP emissions were measured during the stack tests and in fabric filter dust. Second, the particulate matter control devices u sed in the industry (fabric filters and scrubbers) achieve broad spectrum control of PM emissions and the associated metal HAP. In a similar fashion, the EPA identified PM as a surrogate for metal HAP emissions in establishing MACT standards for Iron and S teel Foundries (Foundry MACT). When promulgating the Foundry MACT standard, the EPA explained that PM is a reasonable surrogate in this context because the ‘technologies currently used by foundries that reduce metal HAP emissions are those specifically des igned to control PM.’ Foundry metal HAP emissions, particularly those associated with melting processes, include PM emissions in the exhaust stream. Thus, the use of control devices (e.g., fabric filters and wet scrubbers) to reduce metal HAP emissions to comply with the Foundry MACT will also result in the control of PM.
The commenter is correct that theoretically there could be variations in metal HAP content over time due to variations in the raw materials used at different plants and variations in raw materials from the same source. We are not aware that any source in the category treats the raw material input prior to use in a manner that would reduce HAP. We also lack information to establish the exact nature of the variability. However, even if we ha d such information, the record reflects that140

PM controls are the only approach sources use to reduce metal HAP, and we know of no way to selectively control specific metal HAP. Furthermore, the small number of units in each subcategory limits the impact of raw material variability on the metal HAP emissions. All the sources in each subcategory are included in the MACT floor calculation so all the raw material input variability for the sources is reflected in the data and by extension considered in the MACT floor analysis. For example, ferromanganese production occurs only at the Eramet plant and only from two furnaces that share common ore sources. The performance of these two furnaces does not depend on a lower HAP source of ore. While silicomanganese is p roduced at two plants with separate sources of ore, having only five furnaces in total in operation at these plants requires the ore sources of both plants be reflected in the MACT floor. See CAA 112(d)(3)(B) (existing source floors for categories and subc ategories with less than 30 sources are based on the average of the best 5 performing sources). Because all the sources were considered, the input variability of all the sources is reflected in the data for the different sources. In addition, the end of st ack PM control devices are the only methods, practices, or processes that we are aware of that reduce metal HAP at these sources. Therefore, the use of PM as a surrogate ensures that metal HAP is indiscriminately controlled along with non

- metal HAP PM

.
For HAP metals, the manganese emissions dominate all other HAP metal emissions at both plants (approximately 27 tons per year under the estimated final controls). All other HAP metals emissions are estimated to be less than 4 tons per year from both plants un der the final controls. We do not have sufficient data to determine the proportional relationship of each metal HAP to PM, but note that the PM control device should be capable of addressing any variation in emissions to the same high degree of reduction a s for PM in general. Thus, we believe that setting limits for individual HAP would only add unnecessary complexity to the rule, without changing the overall level of HAP reduction that is obtainable.

4.11 Compliance Testing Requirements
Comment: In comments on the supplemental proposal, commenter 0276 states that the EPA should strengthen performance test requirements in several areas. First, the commenter (0276) states that the EPA should require that every run include a tapping period and that the facility sho uld test a full cycle (i.e., the test duration is equal to the time between taps.) The commenter (0276) states that the EPA has not given a reasoned explanation for limiting test to just 20 minutes of a tapping period and that the proposed method would und erestimate emissions.

The commenter (0276) adds that only Method 3A should be allowed if the test is of a positive pressure baghouse. The commenter (0276) states that the Fyrite and Orsat analyses are likely to be too imprecise and will undermine accuratel y determining dilution of the flue gas.

Response: Where test results require correction to diluent concentrations, such as 7% O 2 , the EPA requires the use of Method 3B (Orsat) or Method 3A (Instrumental) measurements. Orsat measurements are the reference m ethod for oxygen and carbon dioxide and are no less accurate than Method 3A when done appropriately. Fyrite analysis is only allowed if oxygen and carbon141

dioxide measurements are being taken solely for the purpose of calculating the molecular weight of the emissions gas stream and, in that role, are adequate for measurement purposes.

Comment: Commenter 0276 provides several comments of use of EPA test methods.
For Method 30B, the commenter states that the EPA should add a requirement that if any test run

e xceed the acceptability limits of Method 30B, then a repeat test should be conducted within 90 days, at the latest. The commenter (0276) states that three consecutive tests with at least one run excluded due to QA criteria should be considered to be non

- co mpliance with the standard.

For Method 14, the commenter (0276) states that the EPA should revise provisions for quantifying PAH, metals and PM. For PAHs, the EPA should require a facility to retest any time that the QA criteria of CARB Method 429 is not m et. The commenter (0276) states that this includes the need for the laboratory to dilute the sample such that the surrogate spikes are no longer within the calibration range of the analysis. The commenter (0276) adds that submitting a noncompliance test sh ould not allow a source to show compliance.
The commenter (0276) states that since one group of HAP compounds are semivolatile compounds, the EPA Method 5 is an inappropriate surrogate for PAH compounds. The commenter (0276) recommends that compliance by t est methods which measure the pollutants that are intended to be controlled. The commenter (0276) suggests that Method 5 in combination with Method 202 could be used following periodic tests using both the methods which measure the target pollutants and wh ich measure total PM.
The commenter (0276) adds that any testing of the building ventilation should cover at least 6 hours per test run to assure accuracy and complete data.

Response: Method 30B is a self

- validating method whereby each measurement set provides enough QA/QC to validate the results. The test method allows for the discard of a test run where these criteria are not met, however we recognize that a valid Method 30B test cons ists of three valid test runs. As such, testers are wise to bring analytical equipment with them on site to make such determinations while they are still able to collect additional data if need be. The General Provisions (60.8 and 63.7) allow for a regulat ory authority to base a compliance decision on two test runs if a sample is lost enroute to a lab, or other extenuating circumstance.

With PAH testing, the EPA believes that a source would be unable to demonstrate compliance with a test where a lab had to dilute a sample so many times that they lost the isotope trace. Where this potential exists we allow for sources with high PAH emissio ns to also resolve their sample concentrations using low resolution mass spectrometry internal standard recovery.

Comment: Commenter 0276 said that the EPA should require at least annual testing for the building monitors and the control devices. The comm enter (0276) is concerned that the proposed 5

- year testing schedule would allow a source to be noncompliant for 5 years without any142

knowing and would dramatically weaken the data available to any seeking to assure compliance. The commenter (0276) states th at the EPA has provided no valid justification for delaying testing by more than 1 year, particularly for sources for which the health risks are severe and which the EPA has recognized as unacceptable under section 7412(f)(2).

Commenter 0270 states that th e EPA should require that compliance determinations be based upon annual tests if the measured total facility emissions are expected to result in an estimated risk greater than a risk index of 0.5 with a reduction to every 3 years if the measured total fac ility emissions are expected to result in estimated risk that is above 0.3 and a reduction to every 5 years if the estimated risk is below 0.3. The commenter (0270) adds that as is done in part 75, the use of a test company that uses a filed team lead that is a Qualified Source Test Individual in the test methods used for determining compliance and be employed by an accredited test company.

Response: The EPA disagrees with the commenter in that we employ parametric monitoring between compliance tests to dem onstrate continuous compliance with emissions limitations. The commenters input disregards the value of those monitoring approaches wherein we see great value and have a long history of such.

4.12 Monitoring, Reporting and Recordkeeping Requirements
Comment: Co mmenter 0107 states that the EPA should fully investigate the past compliance, malfunction, and May 2008 cloud

- like incidents that have occurred from this source category in the past. The commenter (0107) states that the EPA should fully review the monitor ing requirements it has proposed and ensure that they are stringent enough to ensure that the EPA

, states, and citizens can easily assess whether a facility is in full compliance with the standards within a short period of time of any violation. The commen ter (0107) presents the following suggested changes:

 Because of the history of non

- compliance incidents for this source category , the EPA should require performance tests every year instead of every 5 years.

 The commenter (0107) supports EPA‘s proposal fo r electronic reporting because fast, accurate, electronic reporting will help strengthen EPA, state, and citizen enforcement, and provide prompt information transparency for local communities near facilities in this source category. However, it is importan t that the EPA ensure immediate disclosure of these reports to the public on the Internet within 7 days of receipt of a report, without the need for any person to submit a FOIA request.

 In comments to the supplemental proposal, commenter 0276 reiterates s upport for electronic reporting and the importance of ensuring that the information is promptly made available online to the public in an accessible format.

 EPA must require continuous monitoring of emissions from this source category using available techn ology to perform CEMS for Hg, HCl, HF, PM, and opacity . The EPA should require the use of this technology for this source category, particularly due to the143

problematic compliance and exceedance history . The EPA should require immediate reporting on the Int ernet of all monitoring reports.

Response: Both EPA Region V and the Ohio EPA are fully aware of the compliance issues described by the commenter. Regarding the performance test requirements, we believe that an annual frequency is not required for all HAP given that the rule now requires sources that operate fabric filters (the predominant control device) to install and operate bag leak detection systems. We consider these systems to be a form of continuous monitoring. The rules also requires continuous pa rameter monitoring of elements associated with the other control devices (wet scrubber) as well as elements related to the capture system. Given the already high capital costs of complying with the final rule, we believe these monitoring technologies are b oth reliable and appropriate

. We note that it is not physically possible to install CEMS on the positive pressure baghouses in use in this industry without substantial retrofit costs

. Similarly, there is not a current technology of conduct ing continuous op acity monitoring at building roof monitors.

Comment: In their comments on the supplemental proposal , commenter 0269 state s that the existing baghouse and baghouse monitoring system at the Felman site constrain the kinds of monitoring and monitoring systems that Felman can use. T he y note that an automatic leak detection system has never been demonstrated on a positive

- pressure baghouse. In addition, they state that the facility uses a computerized system that automatically adjusts the damper position based o n the fan amperage , which means that these two variables are interdependent, not independent as the rule assumes.

To reflect these physical constraints, the facility requested flexibility in the monitoring requirements for the baghouse itself and its assoc iated capture system . S pecifically, that the baghouse leak detection system requirement be removed, and that Felman be allowed to conduct an engineering assessment that would (i) identify the appropriate parameters and limits necessary to ensure ongoing compliance with the capture system requirements, and (ii) set forth a schedule for monitoring these parameters with appropriate frequency.

The commenter (0269) states that the proposed regulation adopts these changes for baghouses used to control process f

ugitive emissions, see §§63.1625(d)(2), 63.1626(g)(2), but still appears to retain the original requirements for baghouses used to control furnace emissions, see §§63.1625(c)(iii), 63.1626(d). However, the baghouse used to control process fugitives is the same baghouse that is used to control furnace emissions. T herefore , the commenter (0269) requests that EPA revise the requirements for baghouses used to comply with §63.1623(a) to be consistent with the requirements for baghouses used to comply with §63.16 23(b).

Any other alternative would effectively require Felman to replace its existing control system with a negative

- pressure baghouse, simply to meet the baghouse monitoring requirement. This requirement would impose very significant additional costs

– co sts that would likely force the plant out of business

– for no additional environmental benefit; indeed, Felman is not aware of144

any situations where EPA required the replacement of emissions controls that were fully capable of meeting the substantive MACT emissions standards, solely because a different design allows for improved monitoring. That is the tail wagging the dog. Commenter 0269 does not believe that EPA intended such a draconian result here and therefore requests that the proposed regulations be revised to require only that monitoring that the current positive

- pressure baghouse can feasibly and reasonably accommodate.

Response: The EPA has knowledge of BLD s being used on positive pressure baghouse systems including those baghouses with large area roof emissions points. A change to a negative pressure baghouse would not be necessary. Manufacturers of BLDs would have information on how best to deploy their instruments on the outlet of a positive pressure baghouse.

Comment: The commenter 0271 believes that using a portable filter to quantify process fugitive emissions leaving a furnace building through a roof vent is not a reliable measure of emissions and only should be done using approved isokinetic sampling techniques. They also note that
p ortable f ilters may capture PM that may normally settle in the building and do not measure a specific emission source; but all sources in the building.

The commenter (0271) also states that a utomated opacity monitoring cameras do not accurately interpret visible emissions from roof vents. Issues that may affect performance include; variability in meteorological conditions ( e.g., rain, snow and fog) and interference from steam leaving the roof vents . In addition, the commenter (0271) states that opacity cam era do not have the ability to discern the difference between visible e mission plumes and steam plumes. They note that ASTM D7520

- 13 states that steam plumes cause significant errors in measuring opacity. Another issue with opacity monitoring cameras is th e images must be sent to a third

party for analysis. Therefore, there is a long lag time before results are obtained, which puts the

source at a disadvantage as it will not be able quickly investigate and take corrective actions.

Response: The EPA does not believe that there are significant sources of water in a melt shop that would cause a substantial steam plume to develop from these processes without such an event causing a substantial malfunction of equipment and controls.
The DCOT camera provides an image that the facility could access immediately, with QA/QC done within 45 minutes (according to comments received) to validate the image and initial readings. Consider that it takes (beyond the act of reading visible emissions manually) about 30 minutes for an observer to return from the field and average their manually assembled data such that they can report the average that they recorded over the previous ninety minutes of observations. We view the initial visible recording as sufficient evidence to pr ovide a facility enough reason to initiate, investigate and correct concerns that may create elevated visual emissions observations and the 45 minute turnaround time on actual opacity values to be quick enough to provide a facility the confirmation they wo uld need to be assured that they have taken appropriate action.145

Comment: C ommenter 0255 provide d information on laser based and LED based opacity monitors which could be used to measure opacity on partially covered roofs, and asked if these could be viable options for measuring opacity in the rule.

Another commenter (0260) provided their experience with the Virtual Technology, LLC Digital Opacity Compliance System (DOCS II) which measures opacity using ASTM D7520/EPA Alternative Method 082. The commenter ( 0260) stated that this system never failed any certification and was better than average in comparison with human VE readers. They believe this system would provide a cost savings to the industry in comparison to certifying staff to perform the opacity rea dings. The commenter (0260) also added that the system can be configured to capture opacity at different times during the day.

C ommenter 0262 states that digital cameras or recorders can be used in conjunction with ASTM D7520/EPA Alternative Method 082 to provide near continuous monitoring of VE. The y provided an example of a n opacity monitoring setup at Felman Production using a two camera system.
Response: Opacity monitors that meet the requirements of PS

- 1 and its associated Procedure 3 QA/QC document will satisfy o pacity monitoring requirements of this rule for point source emissions. We thank the commenters for sharing their information and experience wi th the DOCSII system.

Comment: The commenter (0272) states in their comments on the supplemental proposal that the EPA proposes to further expand EMI’s monitoring and reporting obligations, but does not identify the legal authority under which such obligat ions might be imposed. They believe that the requirements are only put in place to collect various types of data that the EPA believes would be interesting to see. Considering the substantial increase in opacity monitoring costs that the 2014 proposal alre ady entails, the commenter strongly objects to these proposed requirements as unnecessary, unreliable and unlawful.
They commenter (0272) believes that the EPA’s rooftop monitoring proposal is too vague, infeasible and would not provide relevant data for p urposes of Section 112. The commenter is unaware of any commercially deployed systems of this type and EPA does not adequately describe the type of equipment that it would seek to adapt for this research project. They note that the supplemental proposal st ates that it would involve “no less than 3” systems, but does not specify whether this means three per facility, three per shop building or three per furnace. This detail impacts cost, feasibility and the nature of the data that would be collected. In addi tion, the commenter states that it is impossible to comment on sampling duration and frequency without a better understanding of what equipment would be deployed and where. The commenter believes that the EPA should provide a specific monitoring proposal, not just a couple of conceptual sentences, for public review and comment.146

The commenter (0272) believes that this research project would be far more expensive and provide far less useful information tha n periodic Method 9 opacity measurements. The

commente r also notes that the proposed rooftop monitoring is infeasible at EMI because the fugitive roof emissions occur through long, rectangular roof monitors and the location of such emissions from the roof monitors varies constantly depending upon a range of p rocess and meteorological variables that are constantly changing. In addition, the commenter notes that the roofs of EMI’s furnace buildings are not designed or equipped to bear the loads that would be associated with installing and maintaining test equipm ent. The commenter states that t here is no statutory need or justification for the proposal.

Response: The EPA has a long history of establishing and enforcing opacity monitoring requirements from building vents, including long rectangular roof openings s uch as those described by the commenter. We specifically requested public comment on various approaches for these facilities as we recognize there are expenses and shortcomings involved in requiring certified Method 9 observers to conduct visible emissions surveys over extended periods on a frequent basis. Where superior, less expensive or more reliable monitoring approaches can be found we find it prudent to seek input from public and private industry and construct rules that we feel are at once workable a nd appropriate to an emissions standard that is protective of the environment.

C omment: In their comments on the supplemental proposal, commenter 0272 states that the EPA’s fixed digital camera monitoring requirement is not adequately explained and has not been shown to be a demonstrated alternative to Method 9 for purposes of assessing compliance with the opacity standards. The note that the supplemental proposal does not describe in sufficient detail how many fixed digital cameras would be required or specify a methodology for determining that number. The commenter believes that the open continuous roof monitors would make this approach infeasible or would require to o many fixed cameras that it would be unreasonably costly. The commenter believes th at the EPA should provide a specific proposed requirement and allow public review and comment before finalizing any such requirement.
The commenter states that pictures for digital cameras are an unproven substitute for Method 9

measurements. The commenter views the technology as less reliable than Method 9 measurements by a trained and certified reader, because a fixed, automated camera is incapable of taking into account all of the potential confounding factors, such as sun position, meteorological variab les, and visible non

- regulated emissions such as steam plumes.

While the 2014 proposal includes an unreasonable frequency of opacity measurements, the commenter is open to considering less labor

- intensive options that are capable of providing valid data . H owever, the commenter believes that the provision in the 2014 proposal that permits voluntary use of digital camera technology is not the appropriate approach.147

Response: The EPA has codified digital camera technology as a validated and accepted approach f or continuous visible emissions analysis. Additionally we are aware of ASTM standards that also define and support appropriate use of this technology. We specifically requested public comment on various approaches of reading visible emissions for these fac ilities as we recognize there are expenses and shortcomings involved in requiring certified Method 9 observers to conduct visible emissions surveys over extended periods on a frequent basis.

4.13 Compliance Date
Comment: Commenter 0107 states that the 2

- year co mpliance delay i s unlawful and arbitrary

, and i t cannot be reconciled with the EPA ’ s own recognition that HAP emissions from this source category are unacceptable . The commenter (0107) adds that Eramet emits persistent and bioaccumulative pollutants that have already built up in the air, soil, and people ’ s bodies, including those recognized by the EPA

– lead, mercury, and POM

– and those not recognized by the EPA

– manganese, nickel, arsenic, and naphthalene. The commenter (0107) states that because of the history of exposure in the affected communities, there is an even greater health risk from each additional day of exposure than there would be if none of the pollutants were PB

HAPs. The commenter (0107) states that there is evidence of manganese in the h air of children living near the Marietta facility and the Ohio Health Department has placed Marietta, OH on the list of “high risk” zip codes for lead poisoning. The commenter (0107) also notes that some of the individual pollutants emitted by this source category, such as lead, are pollutants for which there is no safe level of inhalation exposure, and yet people in this area are being exposed both to this and to all other emitted pollutants combined. The commenter (0107) adds that the EPA is already sever al years behind in its obligation to conduct the RTR, which was required in 1999. The commenter (0107) adds that the EPA must not waive critical emission reduction requirements for 2 years when local communities immediately need these protections.

The com menter (0107) concludes that because the EPA has also delayed the compliance date of the MACT update under section 112(d)(6) based on the section 112(f)(2) compliance delay, the proposed 2

- year MACT compliance delay is also unlawful for reasons similar to those described above. The commenter (0107) adds that , the EPA also has not met the standard under section 112(i)(3) to demonstrate that a MACT compliance date for existing sources ―shall provide for compliance as expeditiously as practicable.

Moreover, th e commenter (0107) provides an extensive analysis of the Clean Air Act waiver provisions.

Response: EPA is of course aware of the requirements of section 112 (f)(3) and (4). See 76 FR at 72508, November 23, 2011

. The EPA is not ignoring the requirements of this provision. Rather, as documented in the memorandum “ Estimated Time Needed to Achieve Compliance with the Proposed Revision to the MACT standard for Ferroalloys Production ” , the EPA has made case

by

- case findings for each existing source as to the amount of time required to comply with the risk based stack and fugitive emission standards for HAP . The EPA does not interpret §63.6148

(i)(4)(ii) of its regulations to mandate individual app lications when all of the necessary information is already before the EPA
, and the EPA applies that information in an individualized, case

- by

- case manner, as done here. Moreover, section 112 (f)(4)(B) is a direct grant of authority which can be implemented not just by regulation but by other EPA action, as done here. As documented in the memorandum cited above, the existing sources discussed in the memorandum will need to undertake such improvements to the capture system , and addition of control devices for fugitive control (with such attendant interim steps as obtaining capital, purchase and delivery of equipment, installation of equipment, and shakedown operation). These activities simply cannot be accomplished in 90 days, and 2 years is a reasonable amoun t of time to carry them out.

The statute likewise contains the requirement that the EPA must find that “steps will be taken during the period of the waiver to assure that the health of persons will be protected from imminent endangerment” in order to exte nd the compliance date. We note first that the EPA does not believe that any unacceptable risk under section 112 (f) automatically equates to an “imminent endangerment”, given that Congress authorized extensions of the compliance date. We note further that existing ferroalloys production sources are already controlled to some degree, and will necessarily make further reductions of their emissions as they implement steps toward full compliance. For example, we note that the sources have been making improveme nts since the ICR test program (including development of improved fugitive emissions capture of tapping and casting operations at Felman and installation of a new baghouse to control F urnace 1 at EMI (the largest furnace at the plant). We anticipate that t he sources will begin making changes in an incremental fashion to ensure they are in compliance by the specified date, resulting in additional pre

- compliance emission reductions. Under these circumstances, the EPA believes that steps will indeed be taken i n the period before full compliance to reduce emissions and prevent an imminent endangerment.

Comment: Three private citizens (0077, 0091, 0099 ) believe that the final rule should require compliance within a short time frame, e.g., within 90 days. OCA enc ourages the EPA to approve and enact these rules as swiftly as possible, before the proposed implementation date of 2014. The commenters (0077, 0091, 0099) add that the people of Marietta have suffered for generations from emissions from this facility and everything possible must be done to hasten their relief.

Commenter 0106 states that the EPA should not finalize the ACI and building ventilation requirements in the 2011 proposal, but, if the EPA decides to finalize those requirements, and even if EMI coul d somehow afford to implement the proposed ACI and building ventilation controls required under the proposed rule, 2 years is not a sufficient period for budgeting, designing, permitting, procuring, installing, and testing those complex, overlapping emissi on controls. The commenter (0106) states that the EPA should exercise its authority under the Clean Air Act to set a 3

- year compliance schedule for standards established under Section 112. The

commenter (0106) provides several instances justifying a longer time frame:149

 EMI’s analysis of building ventilation shows that EMI actually would need to install a total of eight to ten, 250,000

- cfm systems and the amount of work involved in installing so many systems is not reflected in the memorandum from the EPA ’s c onsultant on which EPA bases its compliance period.

 The EPA incorrectly assumes that obtaining funding for the projects would take just 2 to 3 months in today’s conservative lending atmosphere. Even if projects are funded using internal cash flow, EMI’s budget allocation process takes a year to implement.

 Also, the consultant memorandum does not allow sufficient time for engineering of the fugitive emission controls.

 There is no evidence that the EPA accounted for the time needed to apply for and obtain

s tate and local authorizations, such as air permits for control devices or local building permits that may be required for aspects like large elevated ductwork.

 Concerns regarding expected availability of necessary engineering contractors, equipment, and su pplies in the current market, which has experienced a significant increase in demand from the overlapping impacts of so many recent EPA initiatives.
According to the commenter (0106 ) , under a proper reading of the statute, the EPA can allow up to 3 years u nder Section 112(i)(3)(A), while Section 112(f)(4) prohibits it from requiring compliance in less than 90 days and also allows case

- by

- case waivers of up to 2 years in cases where EPA decides to allow less than 2 years on a category

- wide basis under Sectio n 112(i)(3)(A). The commenter (0106) concludes that, regardless of EPA’s views regarding residual risk standards, there is no reason to doubt EPA’s authority under Section 112(i)(3)(A) to allow 3 years for compliance with MACT standards promulgated pursuan t to Section 112(d)(6).
One commenter (0272) stated in their comments on the supplemental proposal that the EPA should exercise its authority under the Act to set a three

- year compliance schedule for standards established under Section 112. The commenter notes that the EPA’s two

- year proposal is based on several unrealistic assumptions which include: obtaining funding for the projects would take just two to three months, sufficient time for engineering of the fugitive emission controls, time needed to appl y for and obtain state and local authorizations, such as air permits for control devices or local building permits, and obtaining the necessary engineering contractors, equipment, and supplies in the current market, which has experienced a significant incr ease in demand from the overlapping impacts of so many recent EPA initiatives.

In proposing a two

- year compliance period, the EPA refers to its authority under Section 112(f)(4)(B) of the Act to grant a facility

- specific waiver from compliance with residua l risk standards for a period of no more than two years. This ignores EPA’s broader authority under Section 112(i)(3)(A) to allow up to three years for achieving compliance on a category

- wide basis with standards issued under any provision of Section 112. Under a proper reading of the150

statute, the EPA can allow up to three years under Section 112(i)(3)(A), while Section 112(f)(4) prohibits it from requiring compliance in less than 90 days and also allows case

- by

- case waivers of up to two years in cases wher e EPA decides to allow less than two years on a category

- wide basis under Section 112(i)(3)(A).
Under Section 112(i)(3)(A), EPA must require compliance with any standard issued under Section 112 as expeditiously as practicable, but in no event later than t hree years after the effective date of the standard. The language in Section 112(i)(3)(A) allowing for a three

- year compliance period covers “any emission standard, limitation, or regulation promulgated under this section.”. “Section,” by definition, refer s to all of Section 112, including subsections (d)(2)

- (3), (d)(6), and (f)(2).

Section 112(f)(4)(A) further specifies that EPA may not set a compliance deadline of less than 90 days for a residual risk rule, and EPA may grant a waiver of up to two years fo r such rules under Section 112(f)(4)(B) in cases where it has decided under Section 112(i)(3)(A) to allow less than three years on a category

- wide basis. For example, if EPA establishes a general category

wide compliance schedule of one year under Section 112(i)(3)(A), a facility could still be granted up to one additional year to comply under Section 112(f)(4)(B) if it faces unique circumstances. This reading of the statute gives meaning to the plain language of both Section 112(f)(4) and Section 112(i)(3) (A).
As an example, the commenter notes that the EPA previously acknowledged this when developing standards for halogenated solvent cleaning. In the proposed rule, EPA said that “CAA section 112(i)(3)(A) by its terms applies to ‘any’ standard promulgated u nder CAA section 112, which includes those under CAA section 112(f), in allowing up to a three year compliance period for existing sources.” 71 Fed. Reg. 47670, 47686 (Aug. 17, 2006). In the final rule, EPA allowed three years for achieving compliance on t he grounds that “CAA section 112(i) was the controlling provision that addresses compliance deadlines for existing sources with regard to standards promulgated under CAA sections 112(d)(6) and 112(f)(2).” 72 Fed. Reg. 25138, 25146 (May 3, 2007).

The comme nter believes at a minimum that the EPA should allow three years for compliance with any standards imposed under Section 112(d). They note that several recently issued risk and technology review rules allow three years for compliance with such standards. F or example, in the final rule for wood furniture manufacturing, EPA allowed three years for existing facilities to comply with formaldehyde coating/contact adhesive limits and other requirements promulgated under Section 112(d)(6). 76 Fed. Reg. 72050, 7205 5 (Nov. 21, 2011). They also note that the facilities need time to develop a fundamental understanding of the factors that influence the variability in such emissions and to develop cost

- effective approaches to manage those factors and reduce variability.151

Response: We disagree with commenters who state that a 90

- day compliance period is possible for implementing these new, more stringent requirements. We agree that the time required to design, purchase, and install large control devices and new or enhanced ventilation systems will take a matter of many months, not days. Once installed, the new equipment must be tested and compliance demonstrated. Therefore, we believe that the practical requirements of the steps required to demonstrate compliance with the pr omulgated standards indicate that we should allow the full 2

- year compliance period as proposed. We note that the sources have been making improvements since the ICR test program (including development of improved fugitive emissions capture of tapping and casting operations at Felman and installation of a new baghouse to control furnace #1 at EMI (the largest furnace at the plant). We anticipate that the sources will begin making changes in an incremental fashion to ensure they are in compliance by the
spec ified date, resulting in additional pre

- compliance emission reductions.
We disagree with the commenter’s claim that we can allow up to 3 years under section 112(i)(3)(A) for requirements developed under the Section 112(f) residual risk process. We note tha t Section 112(i)(3) establishes the compliance timeframe for any standard issued under section 112 for existing sources and provides that the compliance date shall be as expeditious as practicable but no later than 3 years following the effective date of t he standard. Section 112(f)(4), however, expressly provides more specific requirements for standards issued under section 112(f) and thus for section 112(f) standards those more specific requirements (i.e. a specific requirement for section 112 (f) standar ds) govern in place of the more general compliance date requirements in section 112(i)(3). Specifically, section 112(f)(4) provides that a source cannot emit an air pollutant in violation of a standard issued under subsection (f) except that the standard w ill not apply until 90 days after its effective date. It also provides that the Administrator may grant a waiver for a period of up to 2 years from the effective date if necessary for the installation of controls and if measures will be taken in the interi m to ensure public health is protected from imminent endangerment.

5.0 ECONOMIC IMPACTS OF PROPOSED RULE

5.1 Impacts on Economy and National Interests
Comment: T wo commenter s (0073, 0106) note that ferroalloys producers operate in an extremely difficult competitive environment

- EMI operates the only remaining ferromanganese production furnaces in the U.S.

, and they are the only two domestic silicomanganese production facilities. The commenters (0073, 0106) state that their primary com petitors are foreign companies not subject to U

. S

. environmental regulations. One commenter (0106) notes that foreign competition from China and other countries that control 80% of the U.S. ferroalloys market effectively prevent them from recovering enviro nmental control costs through higher prices. Both commenter s (0073 , 0106 ) state that up

- front capital costs are critical, because equipment must be paid for when installed, not over 20 years, and states that if their corporate parent no longer profits from its investment in their operations or concludes they could earn a152

greater return elsewhere, it would close the company. The commenter (0269) adds that the EPA seems to believe the ultimate ownership of the companies is a relevant question to its EIA, whic h they believe is not. The commenter (0269) asserts that any owner will invest in a business venture only if there is a reasonable likelihood to earn a rate of return comparable to other investment options. Owners of the ferroalloy facilities will not cont inue to invest in emission control devices for their facilities in the United States unless these operations can produce a product at a competitive price and provide a competitive rate of return. The commenter (0269) notes that the EPA has acknowledged thi s business reality in other rulemakings such as its recent Underground Storage Tank rulemaking’s economic impact assessment.

C ommenters (0073, 0106) note the potential effects of this rule if it force s the U

. S

. ferroalloys industry to go out of business

, including effects on local power prices , increased unemployment, and nationa l security (because the facilities are the only two remaining U.S. suppliers of silicomanganese, an ingredient in military grade armor plate steel.)

One commenter (0073) states tha t because of the competitive, low

- margin nature of the silicomanganese business

, the up

- front capital investments required by the proposed rule could put them out of business. The commenter (0073) notes that the true costs they have estimated for the build ing

- wide negative pressure PTE are more than fifteen times their annual capital expenditures for 2011 and more than double the company’s current net worth.

One commenter (0106) states that the new emission controls proposed by the EPA are economically uns ustainable by EMI. The commenter (0106) provides detailed economic and engineering analyses showing that the actual costs of the regulation may be up to $71 million in capital expenditures over the next two years with increased annual operating costs of $1 1.6 million. The commenter (0106) states that these costs are far greater than the EPA ’s flawed analyses project and are greater than the commenter’s ability to pay

. Furthermore, the commenter (0106) states that since, due to foreign competition, they can not raise prices to recover additional production costs, those costs must be absorbed through lower profit margins. The commenter (0106) provides economic analyses showing that when their projected costs of compliance with the proposed rule are converted t o cost per ton of product sold, they far exceed EMI’s average net margin per ton over the past three years, and would consume more than 70% of its net profit margin during its most profitable recent years. In their comments on the supplemental proposal, co mmenter 0272 states that the EPA’s economic analysis does not provide any basis for the assumption that Eramet could afford to implement either the 2011 or the 2014 proposal. T he commenter notes that their analysis shows Eramet is unable to pass cost for f

ugitive controls on to customers through higher prices or absorb these costs out of profits.

The commenter (0106) agrees with the EPA that that the proposed rule should not affect ferroalloy prices, but notes that this is because ferroalloys are a commodity product where price153

is largely controlled by the lowest cost producers, primarily foreign competitors who will not be subject to the costs of proposed rule. C ommenter (0106 , 0269 ) note that the International Trade Commission (IT C) has found their foreign competitors sometimes use their competitive advantages to “dump” ferroalloys on the U.S. market at below

- market pricing. Commenter 0269

note s that their decision in 2013

- 2014 to curtail production due to lower demand and higher

o perating costs demonstrates the intense, international competition in the industry. The

commenter (0106) also states that when new compliance costs must be absorbed without price increases, affected businesses will experience reduced profits, which may tur n negative and result in plant closure, and that even if profits have a chance of remaining positive, the affected businesses may not be able to obtain the financing necessary for compliance, and would thereby also be forced to close. The commenter (0269) believes that the EPA’s regulation must be tailored to the actual potential hazards and must be as cost

- effective as possible to preserve manufacturing jobs in the United States.

In their comments on the supplemental proposal , commenter 0271 states that EP A’s proposed rule affects the steel industry’s ability to compete in a global market and to procure resources from reliable domestic producers. They state that the ferroalloys production industry is critical to the steel industry, which is critical to nati onal security. They believe that if this rulemaking were adopted as proposed, it could have devastating effects on the ferroalloys production industry in the U

. S

. in the form of lost jobs to overseas markets. They also note that the loss of the ferroalloys industry in the U

. S

. would cause reliance on foreign

- produced ferroalloy product s, which do not necessarily have U.S. interests in mind.

C ommenter 0265 believes that the companies may be in jeopardy of closure due to the significant capital and operating costs in the rule.

Response: The statements on economic impacts provided by each commenter are sensitive to a major degree on their position that the EPA has underestimated the 2011 proposal’s compliance costs by a large margin.

While ferroalloys are a c ommodity whose price is set on a worldwide market as mentioned by the commenters, and that EMI and Feldman are therefore price takers , this has not kept these companies from being profitable currently. For example, the report by NERA that constitutes much of EMI’s comments on the economic impact analysis for the proposal indicates indirectly that EMI has been profitable in 2010 and 2011, though not profitable in 2009. We note that EMI was not profitable in 2009, an entire year, but the Marietta, OH plant co ntinued to operate and was not closed by EMI or its parent, Eramet Group. This reality is in contradiction to the commenter’s statement that if the corporate parent no longer profits from its investment in a facility, as was the case in 2009 based on the c ommenter’s own report, then the plant will simply close. Clearly, this did not take place at the Marietta, OH plant

.154

The use of a 3

- year period by the commenter for establishing a baseline for impact calculation is inconsistent with the EPA ’s use of a single year baseline (2011, roughly

– generally the latest calendar or fiscal year) for estimating costs and other impacts in the RIA for th e 2011 proposal. The use of a 3

- year period includes 2009 as part of an argument to show that the costs of complianc e will be more than the commenter can afford, yet this was a year in which the commenter was not profitable but did not close. Use of a latest year for a baseline would undoubtedly lead to different conclusions regarding the affordability of the capital in vestment in pollution control for compliance with the rule.

While a 20

- year investment in pollution control technology may be problematic to incorporate into economic forecasting at the firm level, it should be noted that there are deductions allowed in b oth the U.S. Tax Code and various states’ tax codes to reduce the tax burden associated with pollution control investment. Section 169 of the U.S. Tax Code allows for deductions, and Ohio allows firms to exempt pollution control investments from property t axes as noted at http://codes.ohio.gov/orc/5709.25

. The U.S. Department of Defense (DOD) in 1982 established a Stockpile Upgrade program to have an inventory of key materials available for use in U.S. mili tary applications. Ferroalloys was one material whose domestic production was encouraged by this program. The Stockpile Upgrade program was disbanded in the mid

- 1990s, however, as a result of changing U.S. military priorities emerging from the end of the C old War, and was never resumed despite the continued decline of ferroalloys production capacity since that time in the U.S. In addition, the U.S. DOD has not been a participant in the Work Group for this proposal, nor has it been a commenter on the propose d rule. Thus, the U.S. DOD does not appear to regard the contribution of domestic ferroalloy production to the national security to the degree it once did, and therefore may not perceive this rule to increase risk to national security by its implementation

.
Comment: Commenter 0106 disagrees with the EPA ’s assertion that economic impacts on EMI will be “low,” because the EPA ’s estimate of the increased annual operating costs required by the proposal are small compared to EMI’s annual sales and small compared to the annual revenues of EMI’s parent company. The commenter (0106) states that this analysis is incorrect because it is net profits, not sales revenue

, which determine the resources a company has available to support increased production costs. The commenter (0106) asserts that the EPA ’s comparison to parent company sales is also unreasonable because it implies that comp anies will operate unprofitable businesses so long as the company has other businesses that generate enough profits of their own to cover the losses of the unprofitable businesses.

Commenter 0073 adds that the EPA has compounded the error of vastly undere stimating compliance costs by assuming that Felman’s parent company will invest more than Felman’s current net worth to comply, because it represents “only” 0.1% of the parent company’s global sales. The commenter (0073) suggests that the likely result of these costs will be the end of ferroalloys manufacturing in the United States. The commenter (0073) provides a study155

“Economic Impact of Felman Production, Inc. on West Virginia 2011

, ” which details the number of employees at their facility, the percentage it represents of manufacturing works in their county, and the significant effects which closing the plant could have on the economy of West Virginia

. Response: While net profits are more useful in calculating impacts to firms than sales data, it is noted that reported profits often reflect legally available deductions for tax purposes at both the Federal and state level, and thus official reported profits are often not a true indicator of the economic profits to the firm. This is a key reason why metrics for small business impact analysis as done by the EPA include sales rather than profits. The RIA’s economic impact chapter explains why this is so. Felman’s presumption that its parent company will not invest funds for compliance equipment at its facility are predicated on the presumption that the EPA ’s compliance costs are vastly underestimated. Thus, the statement of the costs being more than Felman’s net worth is only true if Felman’s estimate of the costs is accurate or close to being

accurate

.
Comment : Commenter 0101 states that the "Toxic Soup" (air quality in Marietta, Ohio) affects the economy as well as the health of the residents of Marietta.

Response: We performed analyses that show that this action will reduce health

- based risk in addition to providing monetary benefits for the areas where the plants are located. These monetary benefits include; reduced exposure to HAPs, including arsenic, chromium, nickel, manganese, mercury and polycyclic aromatic hydrocarbons

, and improvements to both
ecosys tems and visibility. This action is also expected to reduce the cancer incidence, target
organ

- specific hazard index (TOSHI) and the maximum individual risk (MIR) associated with these HAP compounds. More details on the risk assessment and the economic ben efits can be found in the preamble for this action.

Comment: C ommenter 0263 states that the EPA failed to consider the social benefits and social costs of additional energy usage as a result of this rulemaking. The commenter (0263) states that the proposed rule proposes limits and controls on fugitive emissions which increase energy consumption, but the economic impacts do not provide an estimate of the energy consumption or the impact on GHG emissions. They note that this exclusion is inconsistent with the EPA’s approach in other rulemakings which provide the social cost of carbon (SCC). The commenter (0263) recommends that the EPA include SCC costs for this rulemaking consistent with OMB Circular A

- 4 and include the total energy implications across the eco nomy.
Response: OMB Circular A

- 4 requires agencies to prepare and submit to OMB a Statement of Energy Effects for significant energy actions, to the extent permitted by law. This Statement is to include a detailed statement of “any adverse effects on energ y supply, distribution, or use (including a shortfall in supply, price increases, and increased use of foreign supplies)” for the action and reasonable alternatives and their effects.156

It was determined that the proposed rule was not a significant energy a ction as designated by the Administrator of the Office of Information and Regulatory Affairs because it is not likely to have a significant adverse impact on the supply, distribution or use of energy. In addition, this action will not create any new requir ements, and, therefore

, no additional costs for sources in the energy supply, distribution or use sectors.

5.2 Benefits Analysis

5.2.1 Regulatory Comments
Comment: Commenter 0073 states that the benefits analysis is flawed because it focuses on benefits from additional PM controls, while the NESHAP is a HAP standard, and PM is not a HAP

. The commenter (0073) asserts that the EPA has overreached by stating that the health risks it seeks to prevent are largely caused by manganese, while ignoring significant variations in
manganese emissions between the different products covered by the proposed rule. The

commenter (0073) states that through their adoption of overly broad PM controls

, the EPA uses the façade of a HAP focused regulation to maximize the reduction of non

- HAP emissions, which is not what the CAA envisioned. The commenter (0073) adds that the courts have specifically limited EPA’s ability to rely on non

- HAP surrogates to sp ecific, limited circumstances and that the EPA ’s reliance on PM 2.5 benefits subverts the purpose of Section 112.

Response: The commenter is confusing quantifiable benefits with total benefits. While the EPA is only able to quantify the co

- benefits from red uctions in ambient PM 2.5 , the rule itself results in substantial reductions in the HAP that are the focus of the rule. Specifically, the controls expected to be adopted as a result of this rule will reduce emissions of metal HAP by 78 percent

. While we can not quantify the effects of these reductions, they are indeed a benefit of this rule and in fact are the goal of the rule. In addition , the EPA disagrees with commenter that the benefits of the rule do not focus on the benefits from reducing the pollutants regulated under this rule. The monetized benefits of this rule reflect the co

- benefits to health achieved via PM 2.5 reductions due to HAPs control in particular manganese. While the benefits of reducing manganese emissions are not monetized

, the co

- benefits from PM 2.5 largely outweigh the cost of implementation. Other HAPs controlled by the ferroalloys rule were likewise not quantified due to data, resource and methodological limitations. Even if we were able to fully monetize the public heal th benefits of reducing exposure to all HAPs, it is likely that the PM benefits would continue to dominate the total monetized benefits due to the size of the exposed population and the severity of the associated health effects. In line with EPA and OMB gu idance , the EPA estimates all of the anticipated costs and benefits associated with a regulatory action, to the extent feasible. We further note that if we were able to fully monetize all of the benefit categories, the benefits would exceed the costs by an even greater amount than we currently estimate.

Comment: Commenter 0106 states that in the absence of any identifiable benefits from reducing HAP emissions , the EPA instead claims that by coincidentally reducing PM 2.5 emissions, the157

proposed rule will del iver huge benefits, more than offsetting the tens of millions of dollars of added compliance costs that the rule imposes. The commenter (0106) states that such a justification is not a valid basis for this rulemaking, because (1) Congress intended Section 109 of the Act, not Section 112, to inform regulatory decisions on whether regulations are warranted to achieve such benefits (to the extent they exist), and (2) the non

- scientific “hand waving” used to generate EPA’s massive “co

- benefits” is unworthy of j udicial deference.

The commenter (0106) adds that the net effect of all of the deficiencies in the EPA ’s analysis, described in further detail in section 6.2.2, is that the EPA ’s attempt to establish a simple conversion factor (to assign a dollar value to PM 2.5 ) through which it can effortlessly convert pounds of particulate reductions into tens of millions of dollars of rulemaking “benefits” comes at the expense of far too many requirements of basic scientific inquiry. The commenter (0106) states that whil e the EPA is entitled to deference when forced to make difficult judgment calls

, the EPA was not obligated by Section 112 to develop such a conversion factor and deference to judgment does not extend to allowing EPA to simply ignore the scientific realitie s that render that conversion factor impossible to calculate.

Response : Consideration of PM 2.5 health co

- benefits is expected as a result of direct PM 2.5 reductions as directed by OMB Circular A

- 4 (p. 26, available at: http://www.whitehouse.gov/omb/circulars_a004_a

- 4/ ):

“Your analysis should look beyond the direct benefits and direct costs of your rulemaking and consider any important ancillary benefits and countervailing risks. An ancillary benefit is a favorable impact of the rule that is typically unrelated or secondary to the statutory purpose of the rulemaking (e.g., reduced refinery emissions due to more stringent fuel economy standards for light trucks ) while a countervailing risk is an adverse economic, health, safety, or environmental consequence that occurs due to a rule and is not already accounted for in the direct cost of the rule (e.g., adverse safety impacts from more stringent fuel

- economy stan dards for light trucks).”

It is also directed by the EPA ’s Guidelines for Preparation of Economic Analyses (p. 11

- 2, available at: http://yosemite.epa.gov/ee/epa/eed.nsf/pages/Gui delines.html ):

“An economic analysis of regulatory or policy options should present all identifiable costs and benefits that are incremental to the regulation or policy under consideration. These should include directly intended effects and associated costs, as well as ancillary (or co

- ) benefits and costs.”

In line with this guidance , the EPA estimates all of the anticipated costs and benefits associated with a regulatory action, to the extent feasible. We further note that if we were able to fully158

mon etize all of the benefit categories, the benefits would exceed the costs by an even greater amount than we currently estimate.

EPA also notes that while the PM co

- benefits are appropriately included in the benefit

- cost analysis accompanying the rule, the b enefit

- cost analysis is not the justification for the rule. The rule is justified based on the requirements of the CAA, which requires EPA to issue standards to reduce HAPs for listed source categories.

5.2.2 Methodology Comments

5.2.2.1 Double counting of PM benefits i n NESHAP, a pollutant regulated under NAAQS
Comment: Commenter 0106 states that the EPA includes no discussion of the extent to which those PM 2.5 emissions eliminated by the proposed rule would otherwise meet or exceed the NAAQS, under which EPA has alread y determined the level of PM 2.5 emissions that will protect public health with an adequate margin of safety. According to the commenter (0106) , to the extent the eliminated PM 2.5 emissions would have caused an exceedance of the NAAQS, the proposed rule is unnecessary and the claimed benefits “double

- count” benefits that would be provided by the NAAQS. The commenter (0106) states that , to the extent the eliminated emissions would not have caused an exceedance of the NAAQS, the benefits claimed do not justify the proposed rule because they arise from more stringent reduction of PM 2.5 than the Administrator has determined is necessary to protect public health under Section 109, which Congress intended to be the statutory basis for such determinations. The comme nter (0106) concludes that the EPA ’s complete reliance on PM 2.5 emissions reductions to justify the proposed rule is contrary to the plain purposes of both Section 109 and Section 112 of the Act.

Furthermore, the commenter (0106) states that the EPA is dou ble

- counting the PM 2.5 co

- benefits reported in this RIA if the PM 2.5 emissions that would be reduced under the Proposed Rule are likely to be subject to control under a forthcoming PM 2.5 NAAQS SIP.

Response : The EPA disagrees with the commenter that the quantified PM 2.5 health benefits are double

- counted with the health benefits achieved by other regulations . The EPA ’s standard practice for its rules is to estimate, to the extent data and time allow, all benefits of the emissions reductions achieved by a rule beyond control requirements for other rules. If this rule was duplicative with other rules, then there would be no additional costs or benefits attributable to this rule.

When the EPA estimates the benefits for rules like this one , the EPA includes other rules in the “baseline”. Any emission changes expected as a result of this rule are additional emission reductions beyond those regulations that were considered to be part of the baseline. Therefore, the benefits from particle reductions are not double counting

– they are real health benefits from emissions reductions achieved by this rule alone.159

Further, the PM 2.5 health benefits expected from this rule are not double

- counted with benefits estimated in the NAAQS Regulatory Impact Assessments. The NAAQS RIAs illustrate the potential costs and benefits of attaining a new air quality standard nationwide based on an array of emission control strategies for different sources. In short, NAAQS RIAs hypothesize, but do

n ot predict, the control strategies that States may choose to enact when implementing a NAAQS. The setting of a NAAQS does not directly result in costs or benefits, and as such, the NAAQS RIAs are merely illustrative and are not intended to be added to the costs and benefits of other regulations that result in specific costs of control and emission reductions. However, some costs and benefits estimated in this RIA account for the same air quality improvements as estimated in the illustrative PM 2.5 NAAQS RIA.
In implementing these rules, emission controls may lead to reductions in ambient PM 2.5 below the PM NAAQS in some areas. It is important to emphasize that NAAQS are not set at a level of zero risk. Instead, the NAAQS reflect the level determined by the A dministrator to be protective of public health within an adequate margin of safety, taking into consideration effects on susceptible populations based on the scientific literature available at the time the standard is set. While benefits occurring below th e standard may be less certain than those occurring above the standard , the EPA considers them to be legitimate components of the total benefits estimate.

5.2.2.2 Use of a “benefits per ton” rather than location

- specific air quality modeling
Comment: Commenter 010 6 states that the EPA ’s co

- benefit estimates in the RIA are based on a generic analysis of PM 2.5 concentrations resulting from emissions from the “ferroalloys sector” of the U.S. as a whole, and subsequent derivation of a “benefits per ton” (BPT) that migh t be reduced by the sector. The commenter (0106) states that the emissions patterns, and hence the BPT estimates used to produce the RIA’s co

- benefits estimates are clearly not relevant to the changes in PM 2.5 emissions that will result from this Proposed Rule. According to the commenter (0106) , the EPA ’s technical document implies that there are four areas of the U.S. that the EPA ’s BPT analysis assumes are affected by this sector’s emissions: two in south

- cent ral Alabama, one in south

- central West Virginia, and one on the Ohio River in Ohio , but the Proposed Rule would only affect emissions from two production facilities, both of which are situated on the Ohio River.

The commenter (0106) states that a n importa nt aspect of having the emissions be correctly located in a BPT analysis is that the predicted impacts to public health per ton emitted are highly dependent on the number of people living in the areas that are projected to have increased ambient concentrat ions as a result of the tons emitted. The commenter (0106) speculates that at least one of the Alabama areas appears to be in or near Montgomery County, with a population density of about 283 people per square mile , and the West Virginia area appears to be close to Kanawha County, with a population density of about 222 people per square mile. In contrast, the

commenter (0106) states, the Felman plant is in Mason County, West Virginia, which has a160

population density of about 60 people per square mile, and th e EMI plant is in Washington County, Ohio which has a population density of about 100 people per square mile. The

commenter (0106) concludes that a more correct location

- specific modeling of the PM 2.5 impacts from the EMI and Felman facilities would likely indicate EPA’s predicted co

- benefits would be less than half what EPA’s RIA reports. The commenter (0106) describes inconsistencies in the tons of PM 2.5 models vs. the proposed emissions reductions to be achieved by the rule. Th e commenter (0106) states t hat either the sector

- specific BPT analysis is completely unreliable for assessing the co

- benefits from this particular rule, or the RIA’s estimate of total tons of PM 2.5 that the Proposed Rule will reduce at these two facilities is far overstated. The com menter (0106) concludes that e ither of these possibilities implies that the EPA ’s estimates of co

- benefits in the RIA are invalid and should be disregarded.

Response: As discussed in the Fann, Fulcher and Hubbell (2009) article describing the benefit
per ton methodology , the EPA is aware that differences between the source modeling used to derive the benefit per ton estimates and the policy context in which these coefficients are applied can introduce analytical uncertainty. Such differences can include th e characteristics of the emitting source, the population density proximate to sources and meteorology, among others. While a similar limitations section does not currently appear in the “Estimating the Benefit per Ton of Reducing PM 2.5 Precursors from the Ferroalloy Sector” Technical Support Document (TSD) , the EPA will be adding such a section to future versions of the TSD. Modeling limitations typically preclude the development of localized benefit per ton estimates, though efforts are underway to develop regional benefit per ton estimates from the sector

- based source apportionment modeling. At this time, however, only national level estimates are available for each sector. The Felman and Eramet plants are located in rural areas, suggesting that the benefi t per ton estimates for directly emitted particles could be much lower than the national average. However, it is important to note that the benefits from HAP reductions (that we are currently unable to quantify) and not the co

- benefits from PM reductions a re used to determine the merits of the regulation.

5.2.3 Uncertainties in the Benefits Analysis
Comment: Commenter 0106 states that US EPA's use of PM 2.5 as a surrogate for HAPs in the cost benefit analysis is highly uncertain because ferroalloy

- associated PM 2.5 is likely to be toxicologically very different from ambient PM 2.5 . The commenter (0106) adds that the uncertainty in using the concentration response functions (CRFs) for ambient PM 2.5 to estimate benefits associated with reducing ferroalloy emissions is so significant as to render this approach too speculative to form a reliable basis for decision making.

The commenter (0106) discusses the impacts of regional differences in PM 2.5 health effects and concludes that extrapolating a CRF for ambient PM 2.5 to P M 2.5 associated with fugitive emissions from the EMI facility is highly uncertain, as the chemical composition of ferroalloy

- associated PM 2.5 may be very different from that of ambient PM 2.5 . The commenter (0106) states that US161

EPA should either provide do cumentation that ferroalloy

- associated PM 2.5 is sufficiently similar to ambient PM 2.5 , or at a minimum discuss uncertainties with using ambient PM 2.5 as a surrogate for ferroalloy

- associated PM 2.5 . Response: Ambient PM is comprised of a wide variety of dif ferent chemical species, including metals such as those emitted by ferroalloy plants. The air quality modeling used in estimating the benefit

- per ton took into account emissions’ contribution from ferroalloy plants to ambient levels of PM 2.5 . Current advic e from both the Clean Air Scientific Advisory Committee and the Advisory Council on Clean Air Compliance, which is to assume equal toxicity between all PM species because the science is not yet sufficient to allow differentiation of effect estimates by
par ticle type. The commenter has not provided any support to the claim that particles directly emitted from ferroalloy plants are any less toxic than the ambient mix. In fact, several studies in the PM ISA indicate that metals could be more toxic than the amb ient mixture. To the extent that these metals are more toxic, the benefits would be underestimated.

Comment: Commenter 0106 states that a key source of uncertainty in the ambient PM 2.5 concentration response functions ( CRF ) relates to whether there is a threshold for adverse effects. Specifically, exposure measurement error, which is inherent in air pollution studies (including those by Pope et al ., 2002 and Laden et al ., 2006) due to use of measurements from centrally locat ed monitors that can differ substantially from individual exposures, can cause a nonlinear CRF to appear linear. There is also uncertainty in the studies by Laden et al . (2006) and Pope et al . (2002) , and the commenter describes some inconsistent/unexplain ed findings, such as:

 Statistically significant associations between PM 2.5 and mortality observed only for people with high school education or less;

 Cardiopulmonary and lung cancer mortality paradoxically greater (although not significant) in never vs

. current smokers;

 Protective effect of carbon monoxide on cardiopulmonary mortality and lung cancer; and

 Protective effect of total suspended particles on lung cancer.

The commenter (0106) states that a nother source of uncertainty in CRFs for PM 2.5 is US EP A's reliance solely on the studies by Pope et al . (2002) and Laden et al . (2006).

Response : The EPA notes that we use concentration

- response factors from the broadest time periods available to take advantage of the available data most comprehensively. The choice of relative risk estimates from Pope et al. (2002) and Laden et al. (2006) is supported by the EPA Advisory Council on Clean Air Compliance Analysis (Hammitt et al. 2010, available at: http://yosemite.epa.gov/sab/sabproduct.nsf/9288428b8eeea4c885257242006935a3/59e06b6c5ca 66597852575e7006c5d09!OpenDocument&TableRow=2.3#2 .) :162 “Overall, the HES finds the EPA analyses, data choices, and methodologies to be sound . The EPA bases its estimates of the mortality benefits of reducing fine particulate matter (PM 2.5 ) on data analyzed from two large, long

- running landmark studies on the health effects of a ir pollution, the Harvard Six Cities Study and the American Cancer Society (ACS) Cancer Prevention Study (CPS). The HES finds the selection of these cohort studies as the underlying basis for PM mortality benefit estimates to be a good choice” (p. 1).

We f urther note that we also estimate mortality using functions derived by 12 experts in an EPA

sponsored expert elicitation (Roman et al. 2008). The Pope et al. (2002) and Laden et al. (2006) studies were found to be near the 25th and 75th percentiles of the mortality effect estimates garnered from the expert elicitation. Our use of the expert elicitation functions provides one estimate of the range of possible impacts.

5.2.4 Limits of Statistical Analysis
Comment: Commenter 0106 notes that in 2009 , the EPA decided to extrapolate the PM 2.5 - mortality association to assume risks from PM 2.5 exposures at levels of PM 2.5 that are far below the lowest level of ambient PM 2.5 for which any statistical association has ever been observed. The lowest measured level (LML) in an y of the long

- term PM 2.5 exposure studies represents the lowest possible bound for which there is any scientific evidence at all about shape of relationship. The commenter (0106) asserts that any assumptions about the shape of the dose

response relationshi p below the LML is unsupported scientifically because there is a strong presumption that the degree of risk per incremental unit of PM 2.5 exposure is likely to decline as PM 2.5 concentrations fall to levels nearing zero. The commenter (0106) states that, t o the extent that this presumption is valid for PM 2.5 as it is for most other compounds, the risk estimates resulting from the EPA ’s extrapolation are biased upwards and there is very little chance that the uncertainty would include a higher risk estimate.

The commenter (0106) states that t he types of statistical analyses being used may be able to detect the existence of an association between mortality risk and long

- term PM 2.5 exposure, but those methods are very limited in their ability to define the shap e of that function, even within the range of observed data (i.e., above the LML). The commenter (0106) adds that t he problem becomes more pronounced at the lower concentrations and is concerned about the extent to which it has driven baseline estimates of PM 2.5 mortality risks upward.

Furthermore, the commenter (0106) states that the EPA has never been able to identify the particular types of causes of death that account for its PM 2.5 - mortality associations, but usually argues that cardiovascular deaths are the most likely candidate. According to the commenter, i n 2005, 35% of deaths in the U.S. were due to major cardiovascular diseases. The commenter (0106) states that i f the predicted PM 2.5 - related deaths are indeed cardiovascular in nature, 22% of all deaths being “due to PM 2.5 ” would mean that nearly two

- thirds of all cardiovascular deaths163

in 2005 were “due to” PM 2.5 . The commenter (0106) states that, g iven all of the other risk factors that are considered major contributors to cardiovascular mortalit y, such as smoking and weight, it is not credible to have a PM 2.5 co

- benefit estimate that is implicitly assuming almost two

- thirds of those types of deaths are due to PM 2.5 . The commenter (0106) concludes that the EPA ’s co

benefits estimates should be vie wed as highly overstated just from these statistical implications.

Response : The EPA disagree s with the commenter that the EPA has never been able to identify association of exposure to PM with cardiovascular diseases. While the EPA ’s risk assessment did not quantify cardiovascular

- related premature deaths, several recent studies have found consistently strong relationships between long

- term PM 2.5 exposure and cardiovascular

- related mortality risk. In its recent synthesis scientific statement, the American Heart Association (AHA) observed that “the overall evidence is consistent with a causal relationship between PM 2.5 exposure and cardiovascular morbidity and mortality, stating:

“Many credible pathological mechanisms...lend biological plausibility to [the] f indings” and that PM 2.5 exposure increases the risk of premature death. It also concludes that: “PM 2.5 exposure is deemed a modifiable factor that contributes to cardiovascular morbidity and mortality.”

Another most recent extended analysis of the American Cancer Society Cohort by the Health Effects Institute, HEI reported the greatest PM 2.5 risk estimates for ischemic heart disease

- related death.

The EPA adopted a no

- threshold approach for benefits analyses, and updated its method for characterizing the uncertainty in its benefits estimates. This updated method is based on the number of estimated premature deaths at different PM 2.5 concentrations including the lowest measured levels (LML) from the underlying epidemiology studies. Based on the science on P M 2.5 and health , the EPA is confident that health effects occur below the levels in the considered studies

– 10 μ g/m 3 in one study, and 7.5 μ g/m 3 in the other. We do however have somewhat less confidence in estimating the magnitude of those health effects at low levels. Actual benefits at those low levels could be higher or lower than we estimate, so we use the best estimate. More recent studies, including the new extended reanalysis of the American Cancer Society cohort, suggested that we should have confi dence in our mortality estimates down to at least 5.8 μg/m 3 , the LML in this new study, and somewhat less confidence in estimates below 5.8 μg/m 3 . In addition, when we have sufficient air quality modeling data for a rule, LML analyses estimate the percenta ge of PM 2.5 - related premature deaths avoided at or above the LML. The number of premature deaths at different concentrations is a good approximation of the monetized, PM 2.5 - related benefits at those concentrations.164

6.0 STARTUP, SHUTDOWN AND MALFUNCTION ( SSM ) PERIODS AND AFFIRMATIVE DEFENSE

6.1 SSM

Comment : Commenter 0074 states that the EPA does not have authority to amend existing MACT standards to make them more stringent. The commenter (0074) asserts that the EPA’s authority under CAA section 112(d)(6) is to “ review and revise as necessary (taking into account developments in practices, processes, and control technologies), emissions standards promulgated under this section no less often than every 8 years.” According to the commenter (0074) , the EPA did not in voke its section 112(d)(6) authority to support the proposed SSM provisions, but even if it had, section 112(d)(6) does not provide broad authority to reconsider aspects of previously issued MACT standards unrelated to “developments in practices,
processes , and control technologies.” Thus, the commenter (0074) concludes, the EPA cannot simply revisit and redo a MACT determination long after it has been issued, as the EPA attempts to do with the proposed SSM provisions.

Response: As discussed elsewhere in this document, the EPA retains significant discretion in balancing relevant factors in determining whether it is “necessary” to revise the existing technology

- based MACT standards. Sierra Club v. EPA, 325 F. 3d 374, 378 (D.C. Cir. 2003). In reviewing secti on 112 (d)(2) standards, and determining whether to revise them is “necessary” under section 112 (d)(6), the EPA may take into consideration cost and feasibility when evaluating developments in practices, processes, and control technologies. Indeed, it is reasonable that any such “review” consider the same factors which the EPA is required to consider under section 112 (d)(2)

– cost, non

- air environmental impacts, potential impacts on energy usage among them.
Additionally, the EPA relies on the Sierra Club decision for the elimination of the SSM exemption, not for its determination to require that during periods of startup and shutdown and during periods of malfunction, sources must meet the standards that apply during normal operations. The EPA’s rationale for the standards that it set was discussed in the preamble for the proposed rule and elsewhere in this section.

Comment : Commenter 0074 states the proposed SSM provisions are not required in order to be consistent with Sierra Club v. EPA . The commenter (0074) states that the Sierra Club decision does not prevent the EPA from adopting emission standards for SSM periods that are different from those required during periods of normal operation. The commenter (0074) adds that the Sierra Club decision does no t mean that the EPA is barred from using a “requirement relating to the operation or maintenance of a source to assure continuous emission reduction” as the emission standard that applies during such events. The commenter (0074) asserts that the Sierra Clu b decision only rejected the EPA ’s assertion that it had discretion to decide not to impose any emission standard covering SSM periods. Thus, according to the commenter (0074) , despite the165

EPA ’s implications to the contrary, the Sierra Club decision expressly recognized that different standards, including non

- numerical standards, may (and in some cases must) apply during non

standard operating conditions, such SSM.

First, the commenter (0074) explains that the Sierra Club decision interpreted the NESH APs General Provisions. The commenter adds that it did not by its terms address what the EPA may or may not include in category

- specific MACT standards. Second, the commenter (0074) states that the Sierra Club decision did not say that the same emission li mitations that the EPA has derived for normal operations must also apply during SSM events. The commenter (0074) states that Sierra Club does not preclude the EPA from applying different standards during SSM events than apply during normal operations. The commenter (0074) concludes that there is ample precedent for the EPA applying a different standard during SSM events.

Third, the commenter (0074) states that the Sierra Club decision did not address whether the EPA could use a “design, equipment, work pra ctice or operational standard,” as authorized under CAA section 112(h) and included in the definition of “emission limitation” and “emission standard” in CAA section 302(k), in lieu of a numerical emission limitation during SSM events. The commenter adds t hat the EPA cannot hide behind the Sierra Club decision as a justification for ignoring an inability of even the “best performers” to achieve during SSM events the emission limitations the EPA has established for normal operations. Moreover, the commenter concludes (0074) that the approach the EPA is proposing would not establish “continuous section 112

- compliant standards” that the Sierra Club decision concluded are required.

Commenter 0073 states that the EPA has interpreted the Sierra Club decision regar ding SSM too broadly, that the decision focused on the manner in which the EPA had implemented the SSM exemption under section 112

– not the validity of the exemption itself. The commenter (0073) asserts that the Sierra Club decision requires the EPA to es tablish standards under section 112 that apply during all facets of a facility’s operation

– whether an emission standard under section 112(d) or a work

- practice standard under section 112(h), but that it did not overrule significant
pre

- existing case law controlling how these standards must be developed. Thus, the commenter (0073) reasons, because a MACT standard is technology

- based, it must be based on what technology can achieve, with the only difference being how the EPA must treat the 1% of operational periods when the EPA’s 99% UPL predicts even MACT cannot achieve the emission standards. The commenter (0073) states that these periods must be included within the MACT standard itself, regulated through an independent standard, such as a work practice st andard where a specific emissions limit is impracticable, or excused through the mechanism of an affirmative defense. The commenter (0073) agrees with the EPA’s decision that an affirmative defense is the appropriate mechanism to implement the Sierra Club decision but it must remain in compliance with established case law regarding development of MACT standards.

Response : The EPA does not claim that the Sierra Club case constrains its authority to prescribe different standards for periods of start and shutdown or for periods of malfunction. However, as166

explained in the preamble to the proposed rules, the EPA has determined that CAA section 112 does not require that emissions that occur during per iods of malfunction be factored into development of CAA section 112 standards. The EPA must establish emission standards that “limit the quantity, rate, or concentration of emissions of air pollutants on a continuous basis.” 42 U.S.C. § 7602(k) (defining “ emission limitation and emission standard”). See generally Sierra Club v. EPA , 551 F.3d 1019, 1021 (D.C. Cir. 2008) (emissions limitations under CAA section 112 must both continuously apply and meet section 112’s minimum stringency requirements, even durin g periods of startup, shutdown and malfunction). We have set the MACT standard at a level that a well

- operated source should be able to meet during 99% of all stack tests, which we believe sufficiently accounts for variability.

The EPA disagrees with the commenters’ contention that the Sierra Club decision addresses in any way the EPA‘s current approach to setting standards under 112(d)

. As explained in the preamble of the proposed rule, the EPA has determined that CAA section 112 does not require that em issions that occur during periods of malfunction be factored into development of CAA section 112 standards

. While the EPA accounts for variability in setting emissions standards, a malfunction is a failure of the source to perform in a ‘‘normal or usual ma nner’’ and no statutory language compels the EPA to consider such events in setting section 112 standards. Further, accounting for malfunctions in setting emission standards would be difficult, if not impossible, given the myriad different types of malfunctions that can occur across all sources in the category and given the difficulties associated with predicting or accounting for the frequency, degree and duration of various malfunctions that might occur. As such, i n the event that a source fails to comply with the applicable CAA section 112 standards as a result of a malfunction event, the EPA would determine an appropriate response based on, among other things, the good faith efforts of the source to minimize emissions during malfunction periods, i ncluding preventative and corrective actions, as well as root cause analyses to ascertain and rectify excess emissions. The EPA would also consider whether the source’s failure to comply with the CAA section 112 standard was, in fact, ‘‘sudden, infrequent, not reasonably preventable’’ and was not instead ‘‘caused in part by poor maintenance or careless operation.’’ 40 CFR § 63.2 (definition of malfunction).

Comment : Commenter 0074 states that the EPA must fully justify applying the same emission limitations during startup and shutdown as during normal operations. The commenter (0074) states that there are numerous reasons why a source might not be able to comply, during periods of startup or shutdown, with emission limitations established based on performance during steady

- state operation, even if the control devices used are started up before the process units and are operational during the shutdown phase of a process. The commenter (0074) believes th e EPA must conduct a thorough analysis and determine whether it is representative of the performance of best

- performing sources (the MACT floor) to require ferroalloys plants to achieve the same emission limitation during startup and shutdown as during nor mal operations. The commenter (0074) states that the EPA cannot conclude that special provisions for emissions during startup167

and shutdown are not needed based on “mere speculation.” The commenter (0074) believes that the default assumption must be that th ey are needed. The EPA previously determined, in establishing the existing s ubpart XXX standards, that the best performers on which the MACT standards were based may not achieve those standards during startup and shutdown. The

commenter (0074) is skeptical that the EPA has conducted a sufficient analysis to demonstrate the achievability of the MACT emission limits established for normal operations during startup and shutdown events, because of likely limitations in the available data.

The commenter (0074) n otes there are several reasons why adequate data often do not exist to allow the EPA to conclude that an emission limitation established for normal operations also represents the performance of the best demonstrated control technology during startups and

s hutdowns. The commenter (0074) adds that these factors would cause the EPA to understate emissions occurring during startup and shutdown.

The commenter (0074) adds that an additional problem is that it can be unclear whether a condition that leads to exce ss emissions should be characterized as a startup or shutdown event or a malfunction event. The commenter (0074) believes that without a clear demarcation (both in the EPA regulations and in practice), the EPA may be analyzing data sets that exclude events that were treated as malfunctions but that the EPA would say should be included in calculating average performance as startup or shutdown conditions.

Response : As noted in the proposal preamble, we considered startup and shutdown periods. Information on p eriods of startup and shutdown received from the industry in the ICR indicate that emissions during these periods do not increase. Control devices such as baghouses for metal HAP particulate control and activated carbon controls for mercury are started up before the process units, and are operational during the shutdown phase of a process. No increase in emissions is expected during these periods. Building or localized ventilation systems for process fugitive emissions will be in place at all times. Therefo re, separate standards for periods of startup and shutdown were not proposed. Periods of startup, normal operations, and shutdown are all predictable and routine aspects of a source’s operations and not exempting emissions from compliance during these peri ods does not increase the stringency of the standard.

Additionally, as part of the ICR data collection for this rule, the EPA requested that sources provide available data on whether the emission profile of the process units differs during startup and shu tdown than during normal operating conditions and whether there is a temporary change to the emission profile of the furnace when starting a new furnace, one with a cleaned

- out hearth, or one with a cold hearth after a long shutdown. One company simply res ponded “no.” The other company responded that they do not have any test data to indicate that the emissions profile is different during startup and shutdown events. The EPA notes that the control device must be operating during startup and shutdown events, which would ensure that the source (i.e., the furnace) would continue to meet the emission standards throughout these events.168

In response to treatment of test data that might include malfunctions, if any occurred, they should have been identified in the test report.

Comment : Commenter 0074 believes the EPA is required to take malfunctions into account when adopting emission standards. The commenter (0074) states that the EPA offers very little support for their assertion that “EPA ’ s approach to malfunctio ns” in setting emissions standards “is consistent with CAA section 112 and is a reasonable interpretation of the statute.” The

commenter (0074) states that there is nothing in CAA section 112 that allows the EPA to ignore malfunctions and set MACT standard s based on a level of emissions that even best

- performing sources only achieve part of the time.

The commenter (0074) believes the EPA offers a backwards, results

- driven rationale for ignoring malfunctions, which directly contravenes congressional intent t hat MACT floor standards be based on what the best sources actually achieve: “accounting for malfunctions could lead to standards that are significantly less stringent than levels that are achieved by a well

- performing

non

- malfunctioning source.” The comme nter (0074) states that the EPA cannot ignore the requirement that MACT floor standards reflect performance actually achieved just because the EPA would like the standards to be more stringent than that actual performance reflects.

The commenter (0074) be lieves that by proposing MACT standards that the EPA recognizes even the best performing existing sources cannot achieve part of the time, the EPA is going beyond the MACT floor, yet without making the demonstrations that the statute and case law require t he Agency to make in order to impose beyond

- the

- floor MACT standards. The

commenter (0074) disagrees that the EPA acknowledges that malfunctions are inevitable, even for the best performing sources, and yet refuse to include emissions data representing mal functions in calculating the MACT floor, and then require that those MACT floor limitations be met even during malfunctions. The commenter (0074) asserts that if it is possible to gather sufficient representative data reflecting emissions during malfunctio ns, then the EPA is obligated to consider those data in its MACT floor calculations for steady

- state operating conditions.

The commenter (0074) suggests several options the EPA could use for setting MACT standards under CAA section 112 that would apply during malfunction events. The commenter (0074) states that the EPA might be able to establish an emission limitation that applies at all times, b ut that has an averaging time of sufficient duration that short, infrequent spikes in emissions due to malfunctions would not cause the source to exceed the emission limitation (while at the same time ensuring that the source does not operate in a way that causes frequent, lengthy excursions above the normal controlled emission rate). As an alternative, the commenter (0074) suggests that the EPA also could use the flexibility accorded by CAA section 302(k) (defining “emission limitation” and “emission stand ard” to include “any requirement relating to the operation or maintenance of a source to ensure continuous emission reduction, and any design, equipment, work practice or operational standard promulgated under” the CAA) to address emissions during malfunct ion events through operational requirements rather than by applying the same limits on169

pollutant concentrations in exhaust gases that apply during normal operations. The commenter (0074) adds that the EPA could have concluded that it has grounds to exercis e its authority under CAA section 112(h) to promulgate a design, equipment, work practice, or operational standard, or combination thereof, because it is not feasible to prescribe or enforce an emission standard.

The commenter (0074) states that the propos ed affirmative defense is not a substitute for addressing malfunction events in the emission standards themselves. The commenter (0074) asserts that the Proposed Standards, incorporating the affirmative defense, still do not represent emission limitations “achieved” by best

- performing existing sources under CAA section 112(d)(3), nor do they meet the criteria for establishing beyond

- the

- floor emission standards under CAA section 112(d)(2).

Response : The EPA must establish emission standards that “limit the quantity, rate, or concentration of emissions of air pollutants on a continuous basis.” 42 U.S.C. § 7602(k) (defining “emission limitation and emission standard”). See generally Sierra Club v. EPA , 551 F.3d 1019, 1021 (D.C. Cir. 2008) (emissions limitation s under CAA section 112 must both continuously apply and meet section 112’s minimum stringency requirements, even during periods of startup, shutdown and malfunction). Thus, we are required to ensure that section 112 emissions limitations are continuous.

With respect to periods of startup and shutdown, the EPA agrees that in some circumstances separate standards for such periods may be appropriate. However as explained in the preamble to the final rule, we considered startup and shutdown periods. Informati on on periods of startup and shutdown received from the industry in the ICR indicate that emissions during these periods do not increase. Control devices such as baghouses for metal HAP particulate control and activated carbon controls for mercury are star ted up before the process units, and are operational during the shutdown phase of a process. Therefore, no increase in emissions is expected during these periods. Building or localized ventilation systems for process fugitive emissions will be in place

at all times. Therefore, separate standards for periods of startup and shutdown were not proposed. Periods of startup, normal operations, and shutdown are all predictable and routine aspects of a source’s operations and not exempting emissions from compliance during these periods does not increase the stringency of the standard.

As the EPA further explained in the preamble to the proposed rule, the EPA has determined that CAA section 112 does not require that emissions that occur during periods of malfunctio n be factored into development of CAA section 112 standards. A malfunction is a failure of the source to perform in a ‘‘normal or usual manner

. ’’ As the EPA further explained, accounting for malfunctions would be difficult, if not impossible, given the myr iad different types of malfunctions that can occur across all sources in the category and given the difficulties associated with predicting or accounting for the frequency, degree, and duration of various malfunctions that might occur. Setting work practic e standards for malfunction periods under section 112 presents the same issues as setting numerical emission limits given the varied nature170

of malfunctions. Thus the EPA does not agree with commenter’s suggestion that the EPA apply work practices for malfu nction events. Regarding the suggestion to establish very short averaging times, we believe that this suggestion is more relevant to standards that rely on continuous emissions monitoring systems (CEMS). In this case, sources demonstrate compliance with em issions tests or opacity observations, which are by their nature, based on discrete periods of observation. In the case of fenceline monitoring, a relatively long averaging period is required to account for fluctuations in emissions and site conditions

.
Additionally, the EPA does not agree that it is possible to gather representative data reflecting emissions during malfunctions, in order to consider malfunctions in its MACT floor calculations. The EPA asserts that data collected during an event that meet s the definition of malfunction is only representative of that malfunction, and the EPA could not assert that the event would be representative of the same kind of malfunctions that might happen in the future, even at the same source. The EPA further disag rees that the EPA could characterize any specific malfunction event or events as representative for a source category

.
Comment : Commenter 0074 states that the EPA has not justified changing the conditions that apply to performance testing. The commenter (0074) notes that t he Proposed Rule would eliminate previously applicable portions of the NESHAPs General Provisions that (a) require that performance tests be conducted under “representative performance” conditions “(i.e., performance based on normal oper ating conditions) of the affected source” and (b) specify that “[o]perations during periods of startup, shutdown, and malfunction shall not constitute representative conditions for the purpose of a performance test.” The commenter (0074) refutes the EPA’s explanation for adding proposed §63.1625(a)(5) and eliminating reference to the NESHAPs General Provision on representative performance testing, that the former “ eliminates the reference to SSM exemptions applicable to performance tests,” stating that the preamble does not even mention the similar provisions in proposed §63.1656(a)(6). The commenter (0074) states that the D.C. Circuit did not vacate the provision the EPA proposes to replace, in Sierra Club v. EPA . The commenter (0074) believes that decision in no way authorizes the EPA to (a) change existing MACT standards so that (b) the EPA could direct a source to conduct performance testing during abnormal operations, such as startups, shutdowns or malfunctions.

The commenter (0074) states that requiring sources now to demonstrate compliance with numerical emission limitations in the existing MACT standards, using performance tests or continuous monitoring, even while the source is in startup or shutdown mode or is experiencing a malfunction, definitely h as the effect of making those existing MACT standards more stringent. The commenter (0074) asserts that the EPA cannot simply “amend” existing MACT standards in a way that can make those standards more stringent without first, providing an adequate justifi cation for departing from the EPA’s previous judgment about the appropriate level of the standards and the appropriate conditions for performance testing, and, secondly, demonstrating that the revised standards would still meet the criteria of CAA section 112(d).171

Response : The EPA inadvertently omitted specific references to changes made to §63.1656(a)(6) in the proposal preamble . However, as noted, we did discuss the comparable changes made to §1625(a)(5). The EPA does not find it necessary to change or su pplement the rule, which specifies the conditions under which performance testing is to be conducted. The conditions for performance tests are contained in §§63.1625(a)(3) and 63.1656(a)(3), which specify that testing must be conducted under conditions tha t are representative of normal process conditions. We received no additional information from commenters to the proposed rule indicating that conditions during startup and shutdown warrant different emissions limitations. As explained above, this finding w as confirmed by two individual company’s responses to the ICR

.
Comment : Commenter 0074 states that the EPA has not justified adding new “general duty” language to the existing s ubpart XXX MACT standards and recommends deleting proposed §§63.1623(h) and 63.1652(f) from the final rule

. The EPA proposes to replace the NESHAPs General Provisions section that establishes a “general duty” to operate a source consistent with safety and good air pollution control practices for minimizing emissions, with somewhat different “general duty” language in proposed §§63.1623(h) and 63.1652(f). The commenter (0074) states that since this change is not being proposed under CAA sections 112(d)(6) or 112(f), the EPA therefore lacks authority to make this change to the existi ng MACT standards for Ferroalloys Production. The commenter (0074) refutes the EPA’s only explanation for proposed §63.1623(h) that the new general duty provisions are “to replace General Provisions requirements that reference vacated SSM provisions,” poin ting out that the preamble does not even mention proposed new 63.1652(f).

The commenter (0074) states that even if the EPA had authority to make changes to the existing MACT standards not required to address residual risk or new technology, the EPA would h ave to provide a cogent explanation of why the old rule was unacceptable and the new rule is necessary, which the EPA has not done so. The commenter (0074) states that the EPA would need to re

propose the provision with some explanation of the basis and pu rpose for the provision, to allow the public an opportunity to provide meaningful comments, as required by CAA section 307(d)(3).

Response : The EPA disagrees with the comment er , in that the EPA does not lack authority to make the changes proposed. The EPA explained in the proposal that we were adding language to this regulation to replace General Provision requirements that reference vacated SSM provisions. (See Federal Register /Vol. 76, No. 226 /Wednesday, November 23, 2011 / Proposed Rules 72523, 72534 a nd 72536). The EPA, to be consistent with the Sierra Club decision, has modified the general duty requirements that were contained in §63.6(e) and placed them, modified, in §§63.1623(h) and 63.1652(f). The general duty requirement language was modified to remove references to startup, shutdown, and malfunction plans that are no longer required and no longer apply in the absence of SSM exemptions, and references to SSM periods which are no longer exempt from applicable standards, but periods during which the general duty still applies.172

6.2 Affirmative Defense
Comment : Commenter 0107 states that the affirmative defense allows facilities to escape penalties due to malfunctions if they meet factors that the EPA defines, which reduces the deterrent value of the MACT standard and undermines the ability of people living near facilities that violate the standard to receive effective relief from unlawful emissions. The commenter (0107) adds that this new loophole reinforces the need to recognize the additional risk that would occur from malfunctions. The commenter (0107) states that the new affirmative defense may make it more likely that malfunctions happen, by giving industry a way to evade penalties if facilities can show a violation was due to a malfunction. The comme nter (0107) describes how they believe that affirmative defense that the EPA proposes goes against Congressional intent. In addition, according to the commenter (0107) , the EPA has failed to demonstrate any need or rational justification for an affirmative defense to penalties to be written into the regulations and cause the harm that will result. The commenter (0107) concludes that even if the EPA had the authority to promulgate any type of affirmative defense, the EPA should make the following changes to promulgate strong reporting, monitoring, and other compliance requirements:

 A specific amount of compensatory penalties should apply to each reported malfunction (consistent with the Act). These funds should be dedicated to enforcement, inspections, and mo nitoring in the local community around the specific facility, to create greater assurance that malfunctions will not happen again.

 The EPA must modify the regulations so that the affirmative defense cannot be used by a specific facility or company more th an once within a set period of time, such as 10 years. The affirmative defense should become automatically unavailable to a facility that has previously had a malfunction within the last 10 years, to ensure that this defense does not swallow the value of t he standards.

The commenter (0107) urges the EPA not to adopt an affirmative defense that undermines citizen rights and remedies under the Clean Air Act because people living near Ferroalloys Production Plants are exposed to unacceptably high levels of haz ardous air pollution that no one should have to face simply because of where they live. The commenter (0107) concludes that the EPA must not retract or weaken citizen rights and remedies by making it more difficult for people to win meaningful relief from facilities that have released toxic air pollution into their communities for years.
In comments on the supplemental proposal, commenter 0276 supports the EPA’s removal of the proposed affirmative defense for civil penalties in the event of a malfunction. T he commenter (0276) states that such provisions are unlawful, as the D.C. Circuit has held and the EPA appropriately determined it should be withdrawn.

Response: This comment is related to the affirmative defense provisions that were include in the 2011 pr oposed rule (76 FR 72508). The affirmative defense provision was struck down in NRDC v. EPA , 749 F.3d 1055, 1063 (D.C. Cir. 2014). For this reason, the EPA has removed the173

affirmative defense provisions in the 2014 supplemental proposal (79 FR 60238). Therefore, this comment on the provisions to affirmative defense is no longer applicable.

Comment : Commenter 0074 states that the EPA has not addressed apparent limitations and shortcomings of the affirmative defense, which make it an entirely inadequate s ubstitute for setting MACT standards that include provisions for SSM events. The commenter (0074) states that the EPA has provided no analysis that would supersede its long

- standing determination that it is not desirable to rely on enforcement, rather than regulatory language, to address the inability to comply with technology

- based standards during SSM events.

The commenter (0074) also states that if the EPA refuses to set alternative emission standards that apply during SSM periods and continues to rely i nstead on the proposed affirmative defense, the affirmative defense must be substantially modified for it to provide any significant relief. First, the affirmative defense needs to state clearly that a source that qualifies for the affirmative defense shal l not be deemed to have violated the applicable standards during that time. If the EPA does that, it may be unnecessary to state also that the affirmative defense relieves the source from liability for all types of penalties and injunctive relief (save cri minal penalties), but that should be the clear effect of qualifying for the affirmative defense.

Response: While the EPA accounts for variability in setting emissions standards, a malfunction is a failure of the source to perform in a ‘‘normal or usual man ner’’ and no statutory language compels the EPA to consider such events in setting section 112 standards. Further, accounting for malfunctions in setting emission standards would be difficult, if not impossible, given the myriad different types of malfunct ions that can occur across all sources in the category and given the difficulties associated with predicting or accounting for the frequency, degree and duration of various malfunctions that might occur. Based on the test data received from the facilities, we determined that no separate standards are needed to address emissions during these periods.

Comment : Commenter 0074 states that the EPA offers no defensible rationale for excluding startup and shutdown events from the proposed affirmative defense. The commenter (0074) believes that there is no rational basis for the EPA not to provide the same kind of affirmative defense that it proposes to provide for malfunctions if in fact excess emissions from those units cannot reasonably be avoided during a startu p or shutdown, not because of failure of a process or equipment but because of the nature of conditions while starting up or shutting down the source.

Response : We determined that facilities in this source category can meet the applicable emission standard s in the Ferroalloys Production NESHAP at all times, including periods of startup and shutdown; therefore, the EPA determined that no separate standards are needed to address emissions during these periods.

Comment : Commenter 0073 states that, in general, the affirmative defense language should be replaced with the language used at 40 CFR 122.41(n), the upset defense provided under the Clean Water Act. The commenter (0073) adds that the language is generally too narrow and174

restrict ive, noting that the proposed rules would excuse only events that do not “stem from any activity or event that could have been foreseen and avoided, or planned for”, while it is possible that events such as power failure or natural disasters may be “forese en” and “planned for,” but still interfere with a facility’s ability to comply with the standards. The commenter (0073) states that these types of foreseeable yet unpreventable events must either be reflected in the overall MACT requirements, or excused as a malfunction. The commenter (0073) also states that the EPA should expand the proposed defense to address foreseeable yet unpreventable events.

Response : This comment is related to the affirmative defense provisions that were include in the 2011 proposed rule (76 FR 72508). The affirmative defense provision was struck down in NRDC v. EPA , 749 F.3d 1055, 1063 (D.C. Cir. 2014). For this reason, the EPA has removed the affirmative defense provisions in the 2014 supplemental proposal (79 FR 60238). Therefore, this comment on the provisions to affirmative defense is no longer applicable.

Comment : Commenter 0074 believes that many aspects of the affirmative defense would make it unavailable as a practical matter for many, if not most, malfunctions. The commenter (0074) states that many of these limitations on the affirmative defense also are not directly related to the question of whether an exceedance of the emission limitations due to a malfunction should be excused. The commenter (0074) adds that several of th e conditions for establishing an affirmative defense in proposed §63.1627(a) list numerous items which may be appropriate considerations in determining whether excess emissions during a malfunction should be considered a violation, but should not to be lis ted as mandatory criteria. The commenter (0074) states that a number of the conditions for establishing an affirmative defense use phrases that are subject to a wide range of interpretations and that on their face do not recognize any need for reasonablene ss or cost

- effectiveness. The commenter (0074) believes that the affirmative defense, as proposed, leaves open the possibility that a source will be considered to be in violation because the enforcement authority decides subjectively that in one or more re spects it would have been “proper” or “possible” for the source to take further steps to prevent or minimize the malfunction.

Three commenters (0071, 0073, 0074) suggest modifying the affirmative defense language if it is to be retained. Two commenters (00 71, 0074) suggest specific language to remove ambiguity and contradictory language, and allow for notification via electronic communication methods. Specific comments regarding the affirmative defense criteria follow:

 Notification Requirements : One comment er (0073) states that availability of the affirmative defense should not be negated by a failure to notify, especially for events with small emissions. The commenter (0073) adds that the immediate notification requirements are duplicative of notification r equirements under other rules, but do not include emission threshold triggers which reduce the burden of the other requirements.

 Infrequent Events : One commenter (0073) states that restricting the malfunction defense to “infrequent” events is legally acceptable only if more “frequent” events are either175

included within the 99% UPL or excepted under some version of the startup/shutdown defense. The commenter (0073) adds th at determining whether the event is sufficiently “infrequent” to merit application of the defense is highly subjective and vague and does not put Felman on notice of the type of behavior that is necessary to comply with the law.

 Off

- Shift and Overtime Labo r : One commenter (0073) requests that the EPA delete the requirement to use off

- shift and overtime labor because it impairs the ability to respond in a manner that is most appropriate to the circumstances.

 Severe Property Damage : According to one commenter (0073) , the word “severe” should be removed from the requirement for measure of property damage due to its ambiguity.

 Signed Operating Logs : One commenter (0073) states that the requirement for “signed” operating logs should be removed because it conflict s with the common practice of using electronic logs.

 Control Systems Were Kept In Operation “If at All Possible ”: One commenter (0074) states that the proposed §63.1627(a)(6) requires, as a condition for the affirmative defense, that all emissions “control systems were kept in operation if at all possible.” The

commenter (0074) believes that the phrase “if at all possible” should not be used because it is an extreme term that bears no relation to good air pollution control practices. Additionally, the comme nter (0074) believes that this provision should be qualified, as the EPA has qualified similar provisions in the NESHAP General Provisions in §63.6.

 By Passing Control Equipment : One commenter (0074) is also against the proposed §63.1627(a)(4) that would p reclude a facility from taking advantage of the affirmative defense if the malfunction involved bypassing control equipment or a process and the bypass was not “unavoidable to prevent loss of life, severe personal injury, or severe property damage.” The co mmenter (0074) states that this language is stated in such strong terms that it may be difficult or impossible for a source to demonstrate that it meets this criterion, even though bypassing the control equipment or the process was an appropriate exercise of good air pollution control practices. The commenter (0074) adds that there is nothing inherent to standards under CAA section 112 that requires a source to avoid bypassing control equipment to such a degree. Lastly, the commenter (0074) states that it i s not apparent, and the EPA has not attempted to explain, why the CAA would disfavor bypassing “a process” in this way.

 Excess Emissions : One commenter (0074) believes the paragraph in proposed §63.1627(a)(5) should be eliminated: “All possible steps were taken to minimize the impact of the excess emissions on ambient air quality, the environment and human health.” In addition to the subjective term “all possible steps,” the commenter (0074) believes this provision again presents a disconnect between the ab solute and extreme requirement of the affirmative defense and the provisions of the CAA designed to attain ambient air quality standards and protect human health and the environment. The

commenter (0074) states that the CAA does not require sources to take “all possible steps” to control emissions, even to minimize the impact of hazardous air pollutant176

emissions on human health under CAA section 112(f). In addition, the commenter (0074) finds it is unclear how this criterion for qualifying for the affirmati ve defense differs from proposed §63.1627(a)(3) which requires that the frequency, amount, and duration of excess emissions “were minimized to the maximum extent practicable.”

 Malfunction Report : Commenter 0074 requests that malfunction reporting be requi red on a semi

- annual basis, for malfunctions that occurred during the preceding 6 months, which is the same frequency as similar reports pursuant to NESHAPs and Title V requirements. The commenter (0074) states that this change would enable the EPA to revi ew the source’s compliance history and the measures being taken to address malfunctions, without imposing unworkable reporting deadlines, or potentially encouraging sources to bombard the Agency with reports for malfunctions that may not ultimately result in the source exceeding the 30

- day average emission limitation. The commenter (0074) adds that the EPA has not justified departing from its conclusion, reflected in the current subpart XXX standards, that semi

- annual reporting of malfunctions is sufficient

.
Response: This comment is related to the affirmative defense provisions that were include in the 2011 proposed rule (76 FR 72508). The affirmative defense provision was struck down in NRDC v. EPA , 749 F.3d 1055, 1063 (D.C. Cir. 2014). For this reason, the EPA has removed the affirmative defense provisions in the 2014 supplemental proposal (79 FR 60238). Therefore, this comment on the provisions to affirmative defense is no longer applicable.

Comment : Commenter 0074 states that the requirement in propose d §63.1627(a)(9) that the source “have prepared a written root cause analysis to determine, correct and eliminate the primary causes of the malfunction and the excess emissions resulting from the malfunction event at issue” again does not implement the sta tutory criteria for standard

- setting under section 112. The commenter (0074) is concerned that read literally it would mean that a source could never take advantage of the affirmative defense if the source was unable to determine the primary cause of the m alfunction or was unable to correct that cause. The EPA has defined a malfunction as an event that is “unavoidable” and unforeseeable, and “not reasonably preventable.” It therefore should be expected that in many cases the primary cause(s) of the malfunct ion will not be ascertainable, or it will not be possible to identify a way to ensure the malfunction will not recur. In addition, the commenter (0074) is concerned that requiring the facility to eliminate the primary causes of the malfunction, without reg ard to “taking into consideration the cost of achieving such” elimination and the “non

- air quality health and environmental impacts and energy requirements” associated with its elimination is unreasonable and entirely inconsistent with the criteria for sta ndards established under CAA section 112(d).

Commenter 0073 states that the requirement to perform a root cause analysis is vague and does not put Felman on notice of the type of analysis that the EPA will deem sufficient, or the time in which such an an alysis must be performed. According to the commenter (0073) , such an analysis177

is also unnecessarily burdensome and serves no environmental protection purpose for many malfunction events where the “root cause” is clearly identifiable (e.g., power outage, hu rricane).

Commenter 0071 asserts that the EPA’s use of the term “root cause analysis” implies a specific formal process. The commenter (0071) notes that for many malfunctions, the cause is immediately obvious and a formal process for determining the cause is not needed. The

commenter (0071) adds that a formal root cause analysis is typically limited to very significant events or repeat events (e.g., the first time a thermocouple fails, the most likely cause is a bad thermocouple, but if a second one fails w ithin a short period of time, then something else may be causing that event to happen and a more detailed analysis may be needed.) The commenter (0071) adds that the proposed language assumes that all malfunctions are equally significant and need an identi cal degree of investigation ( e.g. , a missing data point due to a malfunction of the data acquisition system is not as significant as a power failure or a catastrophic event such as fire or explosion). The commenter (0071) believes that a formal root cause analysis should only be used when other reasonable methods fail to show what caused the malfunction or when the serious nature of an event might make such an analysis necessary. The commenter (0071) states that other tools may be more appropriate (e.g., fa ilure mode and effect, fault tree, etc.) or more powerful tools may be introduced in the future. The commenter (0071) concludes that the facility is the only one that can and should decide what tool to use to determine the cause of the malfunction.

The co mmenter (0071) states that if the EPA intends for the facility to investigate and fix the source of the malfunction so that it is less likely to recur, the y support that concept but suggests that the Agency use an alternative term that does not carry a spe cific meaning. However, if the Agency envisions a formal process for determining the root cause for every malfunction, no matter how simple, the commenter (0071) believes this is unnecessary and would result in excess efforts with no environmental gains.

Response: This comment is related to the affirmative defense provisions that were include in the 2011 proposed rule (76 FR 72508). The affirmative defense provision was struck down in NRDC v. EPA , 749 F.3d 1055, 1063 (D.C. Cir. 2014). For this reason, the EPA has removed the affirmative defense provisions in the 2014 supplemental proposal (79 FR 60238). Therefore, this comment on the provisions to affirmative defense is no longer applicable.

Comment : Commenter 0071 expresses concern that labeling malfunctions as an affirmative defense before it has been established to be a deviation improperly shifts the burden to the facility. The commenter (0071) suggests that the EPA should establish a rebuttable presumption wher e it is presumed that the facility did everything in their power to minimize emissions during malfunctions, unless the Agency proves certain facts that are enumerated in the rules, allowing the Agency to challenge the alleged deviation without compromising the legal rights of either party

.178

Commenter 0074 states that even if the proposed affirmative defense were not unreasonably restrictive, being able to assert a defense obviously is not the same as complying with emission limitations that are properly set in accordance with CAA section 112. The commenter (0074) believes that the affirmative defense places the source in the position of proving its innocence, rather than the EPA or another enforcement authority having to prove that the source violated the CA A.

The commenter (0074) also finds it unclear where the EPA finds the legal authority in the CAA to shift the burden to the regulated community of proving (or disproving) essential elements of an alleged violation. The commenter (0074) states that the EPA has not provided any statutory authority for requiring a source to prove its innocence, including fully demonstrating its innocence within 45 days of the event, without even being charged.

Response : This comment is related to the affirmative defense provisions that were include in the 2011 proposed rule (76 FR 72508). The affirmative defense provision was struck down in NRDC v. EPA , 749 F.3d 1055, 1063 (D.C. Cir. 2014). For this reason, the EPA has removed the affirmative defense provisions in the 201 4 supplemental proposal (79 FR 60238). Therefore, this comment on the provisions to affirmative defense is no longer applicable.

Comment : Commenter 0074 believes it is not clear what the affirmative defense covers. According to the commenter, where the EPA states that the affirmative defense is “to a claim for civil penalties for exceedances of such standards that are caused by malfunction, as defined in §63.2 ,” the term “civil penalties,” is ambiguous. The commenter (0074) states that it is also unclear ho w the affirmative defense would apply to enforcement actions by State and local governments, or to private citizen enforcement actions under CAA section 304.

The commenter (0074) also states that the preamble to the Proposed Rule does not give any explana tion for why the affirmative defense would not apply to injunctive relief. The commenter (0074) states, as a matter of law, injunctive relief may not be available in cases where a civil penalty cannot be imposed. The commenter (0074) adds that maintaining liability for injunctive relief renders the affirmative defense particularly ineffective with respect to citizen suits. According to the commenter (0074) , if the source is even potentially subject to injunctive relief, and therefore could be required to pa y the citizen

- plaintiff’s attorneys fees even if the source successfully demonstrated that it otherwise qualified for the affirmative defense, then the affirmative defense would not accomplish the EPA’s stated objective of providing relief in situations wh ere the emission limitations cannot be met despite proper design and operation of process and control equipment.

The commenter (0074) believes, at a minimum, the EPA should state that the affirmative defense applies to civil penalties, civil administrative penalties, noncompliance penalties, and injunctive relief, in an action brought by the EPA, a state, or a citizen

- suit plaintiff. The commenter (0074) adds that the EPA also should reword the “affirmative defense,” so that it states that a source179

“will no t be deemed in violation of” the MACT standards for excess emissions or other deviations from the standards, associated with a startup, shutdown, or malfunction event, unless the event, and the source’s response to the event, do not meet the criteria spell ed out in the regulations. The commenter (0074) suggests this provision for malfunction should be called something other than an “affirmative defense,” such as an “alternative standard for SSM events.”

Response : This comment is related to the affirmative d efense provisions that were include in the 2011 proposed rule (76 FR 72508). The affirmative defense provision was struck down in NRDC v. EPA , 749 F.3d 1055, 1063 (D.C. Cir. 2014). For this reason, the EPA has removed the affirmative defense provisions in the 2014 supplemental proposal (79 FR 60238). Therefore, this comment on the provisions to affirmative defense is no longer applicable.

7.0 OTHER COMMENTS

7.1 Overall Support
Comment : According to commenter 0107 even though EPA ’ s proposed rule needs improvement,

t he commenter appreciates that the EPA is proposing standards that the EPA believes will reduce health risk. The commenter (0107) also commends EPA for collecting emission test data from existing facilities using section 114 of the Clean Air Act. The commen ter (0107) agrees that this is an important starting point for the EPA ’ s rulemaking. The commenter (0107) adds that, as the agency has recognized, in explaining the need for electronic reporting: “EPA and other authorities such as state, local and tribal a gencies must have performance test data to conduct effective reviews of CAA sections 112 and 129 standards, as well as for many other purposes including compliance determinations.”

Response: The EPA appreciates the commenter’s support.

Comment: Because of the adverse health effects associated with exposure to the substances emitted by Ferroalloys Production facilities, commenter 0065 is pleased that the EPA is proposing additional control requirements in this action. The commenter (0065) commend s EPA for identifying additional HAP for control (HCl, mercury, PAH and formaldehyde) and for proposing new limits that reflect technological advances and the reduced emissions of which sources are capable.

Response: The EPA appreciates the commenter’s sup port.

Comment: One commenter (0268) supports the supplemental proposal.

Response: The EPA appreciates the commenter’s support.

7.2 Request for Extension/Additional Review
Comment : Prior to the end of the original public comment period deadline (January 9, 2012 ), three commenters (0051, 0053, 0055) requested that the EPA extend the original comment180

period on the proposed rule by 45 days, to a total of 90 days

. The commenters (0051, 0053, 0055) noted the complexity of the rule, the lack of a ferroalloys trade association to provide assistance in developing comments, the short duration of the original comment period, the federal holidays included in the comment period, and the EPA ’s initial failur e to provide certain necessary information. After receiving tentative notice from the EPA that the comment period would be extended by 22 days, one commenter ( 0051 ) entered another comment (0059) repeating their original request for a total of 90 days.

Res ponse: The EPA formally extended the comment period by 22 days to January 31, 2012 in a Federal Register announcement published on December 29, 2011 (76 FR 81903). The length of the comment period was balanced against the time needed for the EPA to evaluat e the public comments and prepare the promulgation package to meet the required court settlement date of June 29, 2012. The EPA believes that the 45

- day comment period and the additional 22

- day extension provides sufficient time to comment on the proposed rule.

Comment : Prior to the end of the supplemental proposal public comment period deadline ( November 20 , 201 4 ), t wo commenters (0051 , 0053) requested that the EPA extend the co mment period on the supplemental proposal by 7 5 days, to a total of 12 0 days. The commenters (0051
, 0053) noted the complexity of the rule requires a multidisciplinary technical review

, a 120

- day public comment period would allow EMI to submit additional emissions data, the lack of a ferroalloys trade association to provide assistance in developing comments, the short duration of the original comment period, the federal holidays included in the comment period, and the EPA’s initial failure to provide certain necessary information. After receiving tentative notice from the EPA that the comment period would be extended by 18 days to December 8, 2014

, one commenter ( 0051 ) entered another comment (0059) requesting an additional extension of 11 days to December 19, 2014.

Response: The EPA formally extended the comment period for th e supplemental proposal by 18 days to December 6, 201 4 in a Federal Register announcement published on November 14 , 201 4 (7 9 FR 68152 ). Based on the additional request, t he EPA further extended the comment period for the supplemental proposal by an additio nal 11 days in a Federal Register announcement on December 5, 2014 (79 FR 72160). EPA believes that the 45

- day comment period and the additional 2 9

- day extension provides sufficient time to comment on the supplemental proposal

.
Comment : In their comments on the supplemental proposal , commenter 0272 states that the 74

- day public comment period did not provide a meaningful opportunity to participate in the complex rulemaking. They noted that the 1999 NESHAP only addressed a single HAP (e.g., manganese), whereas the supplemental proposal regulates 5 HAPs under a broad range of regulatory rationales under Section 112 of the CAA and include a MACT Floor under Section 112(d)(3), technology review under Section 112(d)(6), and risk based standards u nder Section 112(f)(2). They believe that the complexity of this rulemaking affects the amount of time181

reasonably necessary to review and comment on the supplemental proposal, in addition to the 22 separate requests in the supplemental proposal for comment

.
The commenter ( 0272 ) also added that EPA only provided a portion of the technical basis for the supplemental proposal and fail ed to provide the digital files necessary to reproduce and meaningfully review the air modeling and risk assessments that were used for this rulemaking. They believe that the items that were put in the docket only provided EPA’s conclusions, but did not provide enough information to understand how and why these conclusions were reached.

Response: The preamble to the proposed rule originally provided for a 45

- day comment period. The EPA received numerous requests for extending the public comment period and, based on the information provided in the requests, the EPA determined that an extension of 29 days was appropriate. In additio n to the files in the docket, we provided additional digital data summary files to the commenters that allowed them to review and reproduce the findings in the supplemental proposal. We believe that the extended public comment period and the digital data

s ummary files have been sufficient as evidenced by the detail of the responses received.

7.3 Object to Additional Testing or Data Gathering
Comment : Commenter 0069 states that they complied with the EPA ’s April 2010 information collection request, including performing an extensive stack and solids test program. The

commenter (0069) notes that the EPA reserves the right to gather additional information on the

non

- manganese producing ferroalloy facilities

, and o bjects to the gathering of additional information from these "other types of ferroalloys production facilities

, " noting that they were subject to the same extensive ICR test program as the two ferrosilicomanganese facilities, and they do not believe that any additional mandatory testing or data gathering should be imposed on the remainder of the industry.

T he commenter (0069) states that the EPA has not identified the legal basis for its authority to require additional data collection from the ferroal loy industry, and reserves its right to object to duplicative or excessively burdensome data requests in the future. The commenter (0069) remind s EPA that it must have the approval of the Office of Management & Budget before requiring ferroalloys facilitie s to incur additional data collection costs.

Response: The EPA will conduct any future information gathering consistent with the authority provided by section 114 of the CAA.

7.4 Citizen Involvement in the Rulemaking Process
Comment : Two commenters (0077, 0099) state that they are glad that the EPA collected emission information to use in this rulemaking from the industry. The commenters (0077, 0099) add that as members of a local group, Neighbors for Clean Air, in Marietta , Ohio, they have worked on this i ssue for over 10 years. The commenters (0077, 0099) wish that that the EPA had182

contacted them about this rulemaking so that they could have provided information sooner in the EPA ’s process.

Response: The agency believes that it is important to work closel y with community organizations, local and state governmental agencies and with its regional offices, to ensure that the public is made aware of its rules and policies and is provided with the opportunity to provide feedback. Additionally, part of the agenc y’s community outreach strategy is to disseminate information to the public in a manner that is accessible to everyone. The agency will continue to conduct outreach with communities on the Ferroalloys rule, and we encourage your participation in these effo rts.

7.5 Other
Comment: Commenter 0107 provides information on several compliance and violation issues associated with the Eramet facility, including an inciden t in 2008 when an Ohio EPA official took photographs of a substantial brown, reddish cloud coming from the facility and released them. The commenter (0107) states that the facility was unable to identify the cause of this incident and the community continue s to be concerned about uncontrolled emissions

. The commenter (0107) provides additional compliance and violation information that is in the record, including OH EPA orders from 2005, 2007, and 2009.

Response: We have made several revisions to the existin g rule that we believe will substantially improve the capture and control of emissions from both plants in this source category. We have also provided enhanced monitoring provisions that will help the plants maintain the performance of their control system s by providing timely feedback in the need for system adjustments and repairs.

Comment: In their comments on the supplemental proposal, commenter 0272 believes that they should not be compelled to publish Method 9 opacity test results on its company websit e and/or “State dashboards.” They stated that the EPA cites no statutory authority under Section 112 or otherwise for the premise that it may dictate the information private parties place on their websites, including the specific location within those webs ites, nor is the commenter aware of such authority. Since the results of compliance tests will be provided to regulatory authorities, who are free to publish such results in a variety of ways, including through their own websites, this concept amounts to g overnment

- compelled private speech without any substantial justification.

Response: The final rule does not contain any requirements for the facility to publish Method 9 opacity results on its company website and/or “State Dashboards.”