E.O. 12866 Review 2060-AQ42 Email thread 1 122810 .txt

From: Nizich.Sharon@epamail.epa.gov

Sent: Tuesday, December 28, 2010 11:10 AM

To: Laney, Michael N.; Hanzel, Veronica

Subject: Fw: Part of E.O. 12866 Review: EPA Staff Response to "Supplementary 

Information for RTR -- Primary Lead Smelting" [2060-AQ42]

Attachments: DRAFT_PrimLead_RTR_Tech_Sup_Doc_12_28_10.doc; Prim Lead RTR 

Technology Review Memo_12_28_10.doc

Categories: Yellow Category

another email for docket.

Sharon V. Nizich

Metals and Minerals Group

Sector Policies and Programs Division

OAQPS - US EPA

RTP NC 27711

919/541-2825

----- Forwarded by Sharon Nizich/RTP/USEPA/US on 12/28/2010 11:10 AM

-----

 

 

 From: Sharon Nizich/RTP/USEPA/US 

 To: "Higgins, Cortney" <Cortney_Higgins@omb.eop.gov> 

 Cc: Fred Talcott/DC/USEPA/US@EPA, Michael Stewart/RTP/USEPA/US@EPA 

 Date: 12/28/2010 11:10 AM 

 Subject: Re: Part of E.O. 12866 Review: EPA Staff Response to 

"Supplementary Information for RTR -- Primary Lead 

 Smelting" [2060-AQ42] 

 

 

Hello CortneyPlease find attached the required documents.

The EO 12898, (page 135), last two paragraphs will be REPLACED with the 

language below. Note that Fred in OP, and OGC have not reviewed yet, so this 

language could change.

THANKS.

Page 1
E.O. 12866 Review 2060-AQ42 Email thread 1 122810 .txt

(See attached file: DRAFT_PrimLead_RTR_Tech_Sup_Doc_12_28_10.doc)(See

attached file: Prim Lead RTR Technology Review Memo_12_28_10.doc)

 In the case of Primary Lead Processing, we focused on populations

within 50 km of the one facility in this source category with emission

sources subject to the MACT standard. More specifically, for these

populations we evaluated exposures to HAP which could result in cancer

risks of 1-in-1 million or greater, or population exposures to ambient

lead concentrations above the level of the NAAQS for lead. We compared

the percentages of particular demographic groups within the focused

populations to the total percentages of those demographic groups

nationwide. The results of this analysis are documented in section

IV.C.1 (see Table 5), as well as in a technical report located in the

docket for this rulemaking. In brief, our analyses show that although

there is the potential for adverse environmental and human health

effects from emissions of lead, there are no disparate impacts on

environmental justice populations (see section IV.C.1). Notably

however, the proposed rule would require additional control measures to

address the identified environmental and health risks and would

therefore, decrease risks to any populations exposed to these sources.

Sharon V. Nizich

Metals and Minerals Group

Sector Policies and Programs Division

OAQPS - US EPA

RTP NC 27711

919/541-2825

Page 2
E.O. 12866 Review 2060-AQ42 Email thread 1 122810 .txt

 

 

 From: "Higgins, Cortney" <Cortney_Higgins@omb.eop.gov> 

 To: Sharon Nizich/RTP/USEPA/US@EPA, Steve Fruh/RTP/USEPA/US@EPA 

 Cc: Ann Johnson/DC/USEPA/US@EPA 

 Date: 12/22/2010 03:46 PM 

 Subject: Supplementary Information for RTR -- Primary Lead Smelting 

Hi Sharon and Steve,

We’ve received the RTR Primary Lead Smelting Preamble and Reg Text.

Thanks! Can you send over these documents cited in the preamble (should be 4 

or 5):

 - Draft Residual Risk Assessment for the Primary Lead

 Smelting Source Category (p 44)

 - Risk and Technology Review – Analysis of Socio-Economic

 Factors for Populations Living Near Primary Lead Smelting

 Operations. (p. 61)

 o Is this the same as the following? If not, can you send

 this as well?:

 The methodology and the results of the demographic analyses

 for this source category are included in the technical

 report available in the docket for this action. (p. 63)

 - Actual to Allowable Emissions Memo (p. 135)

 - In EO 12898 Section (EJ), discussion of 2 approaches to

 inhalation risk estimates that are laid out in memos (p. 135) --

 we’ll need to see both

Thanks,

Cortney

202.395.7856

Page 3
Primary Lead Smelting NESHAP Technical Support Document 

Risk and Technology Review 

National Emission Standards for Hazardous Air Pollutants 

(NESHAP) for the Primary Lead Smelting Source Category 

Technical Support Document 

DRAFT 12/28/10

Docket No. EPA-HQ-OAR-2004-0305 

January 31, 2011 
Primary Lead Smelting NESHAP Technical Support Document 

i

Table of Contents 

1.0 Residual Risk Analysis - Development of the Emissions Dataset for the Primary Lead Smelting 

Source Category ............................................................................................................................... 1 

1.1 Emissions Data Sources ...................................................................................................... 2 

1.2 Risk Analysis Emissions Data Set ...................................................................................... 2 

1.2.1 Actual Emissions ................................................................................................... 3 

1.2.2 Allowable Emissions ............................................................................................. 4 

2.0 Calculation of Proposed Emission Limits Based on Modeled Concentrations ................................ 7 

3.0 Estimated Costs of Proposed Revisions to the Primary Lead Smelting NESHAP ........................ 10 

3.1 Emission Control Costs for Acceptability Reductions ..................................................... 10 

3.2 Emission Control Costs for Ample Margin of Safety Reductions .................................... 11 

3.3 Additional Testing and Monitoring Costs ......................................................................... 13

Tables 

Table 2.1 Calculations of Emission Limits Based on Modeled Concentrations 

Table 2.2 Calculation of Proposed Refinery Operation Emission Limit based on Modeled 

Concentrations 

Table 3.1 Cost Effectiveness of Upgrading Baghouses to Membrane Bags for Baghouses 7, 

8 and 9 

Table 3.2 Cost Effectiveness of Adding Additional Baghouses to Control Emissions for 

Baghouses 7, 8 and 9 

Table 3.3 Cost Effectiveness of Upgrading Baghouses to Membrane Bags for Main Stack 

Table 3.4 Cost Effectiveness of Adding Additional Baghouses to Control Emissions for 

Main Stack 

Table 3.5 Additional Testing and Monitoring Costs
Primary Lead Smelting NESHAP Technical Support Document 

1

1.0 Residual Risk Analysis ­ Development of the Emissions Dataset for

the Primary Lead Smelting Source Category

This memo describes the development of the dataset used to conduct the residual risk analysis 

under Section 112 (f)(2) of the Clean Air Act (CAA) for the Primary Lead Smelting source 

category. 

Section 112 of the Clean Air Act (CAA) establishes a two-stage regulatory process to address 

emissions of hazardous air pollutants (HAP) from stationary sources. In the first stage, after 

EPA has identified categories of sources emitting one or more of the HAP listed in section 

112(b) of the CAA, section 112(d) of the CAA calls for us to promulgate a National Emission 

Standard for Hazardous Air Pollutants (NESHAP) for those sources. These technology-based 

standards must reflect the maximum degree of emission reductions of HAP achievable (after 

considering cost, energy requirements, and non-air quality health and environmental impacts) 

and are commonly referred to as maximum achievable control technology (MACT) standards. 

The NESHAP for the Primary Lead Smelting source category was promulgated on June 4, 1999. 

The EPA is then required to review these technology-based standards and to revise them “as 

necessary (taking into account developments in practices, processes, and control technologies)” 

no less frequently than every 8 years, under CAA section 112(d)(6). In conducting this review, 

EPA is not obliged to completely recalculate the prior MACT determination. NRDC v. EPA, 

529 F.3d 1077, 1084 (D. C. Cir., 2008). 

The second stage in standard-setting focuses on reducing any remaining “residual” risk 

according to CAA section 112(f)(2) and requires EPA to determine for source categories subject 

to certain MACT standards, whether the emissions standards provide an ample margin of safety 

to protect public health. If the MACT standards apply to a source category emitting a HAP that 

is “classified as a known, probable, or possible human carcinogen do not reduce lifetime excess 

cancer risks to the individual most exposed to emissions from a source in the category or 

subcategory to less than one-in-one million,” EPA must promulgate residual risk standards for 

the source category (or subcategory) as necessary to provide an ample margin of safety to protect 

public health. CAA section 112(f)(2)(A). In doing so, EPA may adopt standards equal to 

existing MACT standards if EPA determines that the existing standards are sufficiently 

protective. 

In order to conduct the risk analysis of sources in the Primary Lead Smelting source category, a 

dataset was developed that included estimates of individual HAP emissions from each HAP 

emitting source as well as source characteristics. The dataset used includes both actual and 

allowable facility emissions and would be used in the emissions modeling exercise to determine 

concentrations of various HAPs at the modeled receptor locations. Those concentrations would 

be compared to the established risk-based threshold for each HAP to determine the potential for 
Primary Lead Smelting NESHAP Technical Support Document 

2

residual risk from the emissions. The methods, thresholds, and results of risk analysis and 

modeling are described in the “Residual Risk Assessment for the Primary Lead Smelting Source 

Category” memorandum included in this docket. Below is a discussion of the sources of the 

actual and allowable emissions data and source characteristics used in the risk analysis and 

modeling exercise. 

1.1 Emissions Data Sources

The preliminary sources used to gather emissions and source characteristic data included the 2002 

National Emissions Inventory (NEI) Final Inventory, Version 1 (made publicly available on 

February 26, 2006), and the 2005 National Emissions Inventory (NEI), version 2.0 (made 

publicly available in October 2008). The 2005 NEI was updated to develop the 2005 National 

Air Toxics Assessment (NATA) Inventory. NATA inventory updates for the primary lead 

smelting category included SIP data provided by the state of MO to EPA. These data sets 

include information about sources that emit criteria air pollutants, their precursors, and HAP. 

The NEI database includes estimates of annual air pollutant emissions from point and volume 

sources, emission release characteristic data such as emission release height, temperature, and 

velocity, and location latitude/longitude coordinates. We reviewed the NEI datasets, checked 

geographic coordinates, and made changes based on available information. 

The sole remaining facility in this source category is the Doe Run Company in Herculaneum, 

Missouri. The Doe Run facility has been the subject of many compliance and regulatory actions 

by the State of Missouri and by EPA Region 7 due to efforts to comply with the lead National 

Ambient Air Quality Standard (NAAQS). The controls applicable to the facility in order to meet 

the NAAQS are codified in the Lead State Implementation Plan. In 2007 a SIP demonstration 

was conducted which included modeling of facility emissions to determine compliance with the 

SIP. EPA also reviewed the emissions data used for that demonstration to update the risk 

analysis data set. Since many improvements in emissions controls have been implemented from 

2001 through 2007 due to the 2001 SIP and the 2007 SIP revision, EPA determined that more 

recent data would be necessary to conduct an appropriate risk assessment of the current 

emissions impacts. EPA requested emissions and source control information through a section 

114 information collection request (ICR) in October, 2009. The February, 2010 Doe Run ICR 

response included copies of the emissions inventories that were provided to the Missouri 

Department of Natural Resources (MDNR) for the CY 2000 through 2008. 

1.2 Risk Analysis Emissions Data Set

The analysis performed considers HAPs that are regulated by the existing MACT standard, and 

also considers any other HAPs that have the potential to present risk. The risk analysis considers 

both actual emissions of the facility and the emissions that would be allowable under the MACT 

rule. Once the analysis is complete, EPA determines if any further emission reductions are 
Primary Lead Smelting NESHAP Technical Support Document 

3

necessary to assure that an acceptable level of risk is achieved. For the Doe Run facility, we 

determined the actual and allowable emissions as described below. 

1.2.1 Actual Emissions

We reviewed the NEI datasets, checked geographic coordinates, and made changes based on 

available information. We also reviewed the emissions and other data to identify data anomalies 

that could affect risk estimates. Since the 2008 emissions inventory is the most recent emissions 

data source available, and reflects the implementation of the numerous SIP emission reduction 

requirements (as evidenced by the ICR response), EPA determined that the emissions reported 

for the facility in the CY2008 emissions inventory report would be the most representative of 

current facility operations and would also be appropriate for use in the risk analysis. 

The dataset derived from the review of the 2002 and 2005 NEI/NATA data was then updated to 

include the emissions for all sources from the CY2008 emissions inventory report. Any 

differences in the data between the NEI and the CY2008 emission inventory were noted and 

analyzed. If data found in the NEI was not included in the CY2008 emission inventory, but was 

found to be pertinent, then it was included in the data set used for the risk analysis. Any 

discrepancies found between the NEI and the CY2008 emission inventory was discussed with 

the facility. 

One specific change to the dataset derived from the combination of the NEI data and the CY2008 

emission inventory pertained to organic HAP emissions. The 2005 NEI file included several 

sources that emitted trace levels of 25 organic HAP from natural gas and other combustion 

sources primarily through the main stack. The current VOC emission levels as reported in the 

ICR response are well below the level which can be addressed by current controls. In addition, 

the levels are low enough to preclude effectively modeling for risk assessment (i.e. the dispersion 

from the 500 foot stack would effectively put any modeled emissions at zero at receptor sites). 

Therefore, the organic HAP emissions sources were removed from the modeling dataset and not 

considered during the risk analysis. 

The final dataset included emissions of lead compounds and other metal HAP (i.e. antimony, 

arsenic, cadmium, chromium, cobalt, and nickel) which are the HAP currently regulated under 

the MACT standard. 

“Lead compounds” is the primary HAP emitted from the Doe Run facility and accounts for 

approximately 99 percent of the total HAP emitted. Of the lead compound emissions, 

approximately 86 percent is emitted through stacks (point or vertical sources) with the remainder 

being fugitive emissions. The point or vertical sources include stacks that discharge from 

baghouses, heat stacks and roof vents. The MACT emission limit applies to operations that 

discharge through 2 stacks, the main and baghouse #7 stacks which account for 15.1 of the total 

17.9 TPY stack lead compound emissions. Since promulgation of the MACT rule, the facility 
Primary Lead Smelting NESHAP Technical Support Document 

4

has captured and controlled all refining operations with two additional baghouses (baghouse #8 

which vents to a stack and baghouse #9 which vents to a common stack with baghouse #7). 

These emissions are included in the table below. Fugitive sources include material handling and 

plant yard and roadway dust. Table 1.1 summarizes the types and volumes of HAP and the types 

of sources included in the dataset for the Doe Run Company facility. Total actual lead emissions 

including fugitive emissions are 20.7 tons per year (TPY). It should be noted that non-volatile 

metal HAP other than lead are reported by Doe Run based on speciation tests conducted for the 

various sources. 

Table 1.1 - Summary of Doe Run Company Risk Dataset Emission Sources 

 Fugitive Stack Total 

HAP 

Number 

 of Sources TPY 

Number 

 of Sources TPY 

Number 

 of Sources TPY 

Lead 115 2.8053 22* 17.9030 137 20.7083 

Antimony 6 0.0028 4 0.0252 10 0.0280 

Arsenic 10 0.0005 6 0.0210 4 0.0215 

Cadmium 12 0.0296 7 0.0823 19 0.1118 

Chromium 0 0.0000 3 0.0056 3 0.0056 

Cobalt 6 0.0005 6 0.0049 12 0.0054 

Nickel 8 0.0019 7 0.0154 15 0.0172 

*Of the 22 stack sources, 2 are included within the MACT emission limit which account for 17.6 of the 17.9 TPY.

The actual emissions dataset for this facility represents the entire source category. Likewise, all 

HAP emission points for this source are included in the risk analysis dataset; therefore, the 

facility-wide emission dataset for this source category is the same as the risk analysis dataset. 

1.2.2 Allowable Emissions

Allowable emissions are emissions that would be allowed under the current NESHAP for 

primary lead smelters. For the Primary Lead Smelting source category and NESHAP, lead is the 

regulated HAP and other non-volatile metal HAP are regulated using lead as a surrogate. 

Therefore, allowable emissions would only apply for the lead compound emissions. For the Doe 

Run facility, allowable lead compound emissions are summarized in Table 1.2. 

Under the NESHAP, an emission limit of 1.0 pound of lead per ton of lead produced (lb/ton) 

applies to the following nine sources: 

1) Sinter machine 

2) Blast furnace 

3) Dross furnace 

4) Dross furnace charging location 

5) Blast furnace and dross furnace tapping location 

6) Sinter machine charging location 
Primary Lead Smelting NESHAP Technical Support Document 

5

7) Sinter machine discharge end 

8) Sinter crushing and sizing equipment 

9) Sinter machine area 

Applying the allowable emissions rate of 1.0 lb/ton to the Doe Run’s 2008 lead production of 

149,564 tons, the allowable emissions from the above nine sources would be 74.8 TPY. All 

emissions from the source’s nine emission points listed above are captured and controlled by 

baghouses, which vent to the main stack or the furnace area stack. The total allowable emissions 

were prorated between the two stacks based on the ratio of actual emissions reported for the two 

stacks. 

Note that refining operations are not listed above and are not subject to the 1.0 lb/ton limit in the 

original MACT. At the time the NESHAP was promulgated, refining operations were a fugitive 

emissions source, however, these emissions under the current facility configuration are now 

captured, controlled by a baghouse, and vented through two stacks. As the emissions are no 

longer fugitive, and the MACT emission limit does not apply to the operation, we were unable to 

calculate an allowable emission level for refining operations. 

Under the NESHAP, fugitive emissions are governed by work practices, which under §63.1544 

are defined as the measures that will be “put into place to control fugitive dust emissions.” Thus, 

the actual fugitive emissions, which reflect the measures that have been put in place, would be 

equivalent to the allowable emissions. Fugitive emissions levels were taken from Doe Run’s 

2008 Emissions Inventory that is submitted annually to the MDNR. 

Table 1.2 Summary of Actual and Allowable Lead Emissions for the Doe Run Primary Lead 

Smelter, 20081

Emission Point Processes 

Actual 

Emissions 

(TPY) 

Allowable Lead 

Emissions 

(TPY) 

Main Stack (BH # 3, 5, 6) Sintering, blast furnace, dross 

furnace 

13.31 65.8 

Furnace Area (BH # 7) Smelter building 1.81 8.94 

Refining (BH # 8, 9) Refining kettles and building N/A N/A 

Fugitives Roadways, storage piles, 

materials handling and transport

2.85 2.85 

As shown above, we estimate that MACT-allowable emissions from this source category are 

about four times greater than the actual emissions, based on the MACT limit (1 lb/ton) applied to 

2008 production data and compared to 2008 actual emissions. The modeling file for this risk 

analysis can be reviewed in the EXCEL spreadsheet 

“PrimLead_RTR_ModelingFile_102110_2008_DOE_RUN.xls” available in the docket. 
Primary Lead Smelting NESHAP Technical Support Document 

6

References: 

1. Curran, D., Stinson Morrison Hecker, for The Doe Run Company, to Nizich, S., US EPA, 

Response to Section 114 Information Collection Request, February 5, 2010. 
Primary Lead Smelting NESHAP Technical Support Document 

7

2.0 Calculation of Proposed Emission Limits Based on Modeled

Concentrations  

The risk analysis process included modeling of actual and allowable emissions to determine the 

anticipated concentration at individual receptor locations. For this source category, the 

emissions for the lead emissions sources were individually modeled for each receptor location 

and the results were compared to the Primary National Ambient Air Standard (NAAQS) for lead 

(0.15 μg/m3

). If the modeled emissions exceeded the lead NAAQS, those locations were 

considered to be exposed to unacceptable risk. The results indicated multiple locations exceeded 

the level of the NAAQS to various degrees. 

Our modeling results indicated that emissions from the main stack did not exceed NAAQS 

within the 50 km radius modeled. The highest concentration location was a point on the property 

boundary. Emissions contributing to this exceedance were found to be cumulative fugitive dust 

emissions from various emission points. Other emission points that resulted in exceedance of the 

lead NAAQS were the furnace area stack and the Baghouse #9 stack for the refinery building, 

both at various census block locations. 

Each emission point (with fugitive dust emissions being treated as one emission point) were 

analyzed to determine what emission levels would be necessary to reduce risk to an acceptable 

level. EPA determined that if the emissions from each emission point were reduced below the 

NAAQS level based on the worst-case or highest location concentration, then all risk for that 

emission point at any location would be reduced to acceptable levels. Therefore, a roll-back 

calculation was conducted to determine what percentage reduction in concentration was required 

for each of the highest concentration locations. Since the relationship between level of emissions 

and modeled concentrations is linear, a percentage reduction could be applied to the actual 

emissions from the CY 2008 emissions inventory for a given emission point that would reflect 

the same reduction in modeled concentration. 

The reduction necessary to address fugitive dust emissions risk was determined to be 98 percent. 

The reduction necessary to address the furnace area stack emissions was determined to be 52 

percent. 

The refinery emissions are vented through Baghouse #8 and Baghouse #9 stacks, and ten heat 

stacks. For the refinery operation, only one stack (Baghouse #9) showed exceedance of the 

NAAQS. The emission reduction found necessary from Baghouse #9 stack is 66 percent, which 

was applied to the total emissions from all of the refinery operation emissions points. 

Table 2.1 summarizes the calculations and recommended limits for the total facility including 

furnace area stack, fugitive dust, and the refinery operations. Table 2.2 summarizes just the 

refining operation calculation, considering all contributing emission points. 
Primary Lead Smelting NESHAP Technical Support Document 

8

Table 2.1 - Calculations of Emission Limits Based on Modeled ConcentrationsModeled Source

2008 Emissions 

(tpy)

Highest receptor 

location Concentration Roll back %

Emissions after 

rollback (tpy) No

Stacks  - Main 13.31 0.007 0 13.31 No risk impacts within  - Baghouse #7, furnace area 1.81 0.314 52 0.86 At census block #29099 - Baghouse #8 - refinery kettles 2.03 0.079 0 see below Included in refinery ma - Baghouse #9- refinery buiding 0.45 0.352 57 see below Included in refinery maTotal of BHs 7+8+9 4.29 0.745 80 15.12Refinery stacks 2.74 0.4363 66 0.94 BHs #8, #9 and heat sta

calculation

Smelter Fugitives 2.55 6.94 98 0.06 Fume, sinter and concePlantwide Fugitives 0.39 1.063 86 0.06 Roadays, plant yard, reAll Fugitives 2.94 7.289 98 0.061) Emission Limit Ambient lead concentration at property boundary* 0.15 ug/m32) Emissions Cap  Furance Area stack (BH#7) 0.86 TPY Refinery stacks 0.94 TPY* To address 98% reduction needed from fugitive emissions, with receptor location at property boundary.Calculations Roll back % = (Actual concentration - 0.15)/actual concentration

Emissions after rollback = 2008 emissions * (1-(rollback%/100))

RECOMMENDED ACTIONS

All Modeled Sources
Primary Lead Smelting NESHAP Technical Support Document 

9

Table 2.2 - Calculation of Proposed Refinery Operation Emission Limit based on Modeled Concentrations

Modeled Source

Modeled values at the site of max. 

impact for refinery stack sources 

(ug/m3)*

50007 Baghouse #8 Stack 0.070750008 Baghouse #9 Stack 0.315050011 Refinery Kettle Heat Stack 0.001050012 Refinery Kettle Heat Stack 0.001050013 Refinery Kettle Heat Stack 0.001050014 Refinery Kettle Heat Stack 0.001050015 Refinery Kettle Heat Stack 0.001050016 Refinery Kettle Heat Stack 0.001050017 Refinery Kettle Heat Stack 0.001050018 Refinery Kettle Heat Stack 0.0011 Subtotal all refinery stacks 0.4363Ratio of NAAQS to refinery max 0.34 or 0.15/.4364Percent reduction required 0.66 or 1- 0.34TPY emission cap 0.94 or (NAAQS limit * TPY refinery currentlb /ton on rolling avg. 90 days 0.01 or (0.94 *2000 /149,500)

Refinery Maximum Calculation
Primary Lead Smelting NESHAP Technical Support Document 

10

3.0 Estimated Costs of Proposed Revisions to the Primary Lead

Smelting NESHAP

    

With regard to lead emissions, we are proposing to require most of the emission sources at the 

facility to implement all technically feasible controls in order to ensure that the ambient air meets 

the level of the lead NAAQS, which is the level we have determined will ensure an acceptable 

level of risk. EPA has determined that lead compound emissions must be reduced to allow for an 

acceptable level of risk for fugitive dust emissions, emissions from the furnace area stack, and 

the refining operation. As a result, the facility will need to implement emission controls or other 

actions that will reduce lead emissions to an acceptable level and to meet the new emission 

limits/caps in this proposed rule. In addition, in order to demonstrate compliance with these 

limits, additional ambient lead continuous monitoring is being required. 

This section summarizes the impacts analysis conducted on all additional emission control 

options that were considered technologically feasible for achieving all necessary reductions as 

well as those monitoring costs necessary to comply with proposed requirements. 

We note that the same controls for the three emission points to reduce lead emissions are the 

same controls that would reduce risks from cadmium and all other metal HAP; therefore we are 

not proposing additional, or other controls for control of other metal HAP. 

For fugitive dust emissions, which are controlled by work practices, no additional controls were 

evaluated because all reasonable practices are currently being implemented. Therefore, there are 

no additional controls and cost impacts considered for fugitive dust emissions however, based on 

our proposed concentration limit, we have evaluated the costs for ambient monitoring to meet the 

requirement. For the four stack emission points, we considered the upgrading of existing 

baghouses from use of cloth bags to membrane bags and addition of an in-series baghouse 

emission as emission reduction options. 

3.1 Emission Control Costs for Acceptability Reductions

Emissions from the main stack did not trigger unacceptable risk levels however; emission 

reductions were required from the furnace area (baghouse #7), refining kettles (baghouse #8), 

refinery building (baghouse #9) and fugitive dust to meet acceptability requirements. Although 

costs are not considered under section 112(f)(1) (acceptability) in order to meet acceptable risk, 

EPA has estimated the cost impacts for these emission controls for the furnace area and refining 

operation stacks, and has also estimated the costs for the proposed ambient lead monitoring. 

EPA estimates that replacing existing cloth bags in all baghouses will provide an approximately 

95 percent reduction in emissions from the emission points controlled by baghouses. 

Table 3.1 summarizes the costs and cost-effectiveness upgrading existing baghouses from cloth 

bags to membrane bags. Table 3.2 summarizes the costs and cost-effectiveness of adding inseries baghouses. The calculations supporting the costs reflected in the summary are included in 

EXCEL spreadsheet DRAFT ImpactsEst_PrimLeadRTR_122210.xls found in the docket. 
Primary Lead Smelting NESHAP Technical Support Document 

11

3.2 Emission Control Costs for Ample Margin of Safety Reductions

Once we ensure that the risk is acceptable, we then determine whether further reductions are 

appropriate to ensure an ample margin of safety. We investigated available and feasible control 

options that could be implemented by the facility to attain the additional emissions reductions to 

provide an ample margin of safety. 

Because all feasible controls will need to be adopted in order to meet the risk acceptability 

reductions, there are no additional controls to consider for fugitive dust emissions, the furnace 

area stack, and the refinery stacks. For the main stack, additional controls were evaluated and 

considered with regard to risk reduction and cost under the ample margin of safety analysis. 

For the main stack, our risk analysis indicates that the main stack emissions do not result in 

ambient lead levels exceeding the NAAQS based on either actual or allowable emission levels. 

However, we determined that it is technologically feasible to reduce emissions from the main 

stack to a level well below the allowable level of the MACT, since those levels are currently 

being achieved. We evaluated additional controls such as membrane bags or add-on baghouses 

as a means for achieving those reductions and reducing associated risk. We determined that the 

additional controls would not provide an appreciable risk reduction (emission reduction) for the 

associated cost. However, we have determined that emissions allowable under MACT should be 

reduced under the section 112(d)(6) technology review as described in the technology review 

memorandum found in this docket. 

Table 3.3 summarizes the costs and cost-effectiveness of upgrading existing baghouses from 

cloth bags to membrane bags. Table 3.4 summarizes the costs and cost-effectiveness of adding 

an in-series baghouse. The calculations supporting the costs reflected in the summary are 

included in EXCEL spreadsheet DRAFT ImpactsEst_PrimLeadRTR_122210.xls found in the 

docket. 
Primary Lead Smelting NESHAP Technical Support Document 

12

Total Cost 

Investment

Total 

Annualized 

Cost

2008 Baseline 

Pb Emissions 

(tpy)

Emission Reduction 

from upgrade* 

(tpy)

CE 

($/ton)

Furnace area, BH 7 81,548 27,591 1.81 0.95 29,043Refining, BH 8 102,032 17,048 0.45 0.21 81,179Refining BH 9 366,932 60,471 2.03 1.3 45,467

*We estimate removal efficiency for membrane bag update to be between 50 and 70 percent.

Cost of Upgrade to

Membrane Bags

Table 3.1 - Cost Effectiveness of Upgrading Baghouses to Membrane Bags for Baghouses 7, 8 and 9

Impacts

Source

Pb emissions (tpy) 

reported in 2008 

EI

Pb emission reduction 

with additional BH 

assuming 50% RE (tpy)

Pb emission reduction 

with additional BH 

assuming 97% RE (tpy)

Annualized cost of 

adding extra BH's 

($/yr)

Cost effectiveness 

assuming 50% RE 

($/ton)

Cost effectiveness 

assuming 97% RE 

($/ton)

BH 7 1.81 0.9 1.8BH8 0.45 0.2 0.4BH 9 2.03 1.0 2.0Total 4.29 2.1 4.2 $849,750 $396,154 $204,203

1 Reflects costs for pulsejet baghouses2 See DRAFT ImpactsEst_PrimLeadRTR_122210.xls for detail on cost analysis.

RE = Removal efficiency

Table 3.2 - Cost Effectiveness of Adding Additional Baghouses to Control Emissions for Baghouses 7, 8 and 9 1,2

Total Cost 

Investment

Total 

Annualized 

Cost

2008 Baseline 

Pb Emissions 

(tpy)

Emission Reduction 

from upgrade* 

(tpy)

CE 

($/ton)

Main Stack 1,958,851 322,823 13.31 8.0 40,424

*We estimate removal efficiency for membrane bag update to be between 50 and 70 percent.

Cost of Upgrade to

Membrane Bags

Table 3.3 - Cost Effectiveness of Upgrading Baghouses to Membrane Bags for Main Stack

Impacts

Source

Pb emissions (tpy) 

reported in 2008 

EI

Pb emission reduction 

with additional BH 

assuming 50% RE (tpy)

Pb emission reduction 

with additional BH 

assuming 97% RE (tpy)

Annualized cost of 

adding extra BH's 

($/yr)

Cost effectiveness 

assuming 50% RE 

($/ton)

Cost effectivenes

assuming 97% R

($/ton)

Main Stack 13.31 6.7 12.9 $1,529,730 $229,862 $118,485

1 Reflects costs for pulsejet baghouses2 See DRAFT ImpactsEst_PrimLeadRTR_122210.xls for detail on cost analysis.

RE = Removal efficiency

Table 3.4 - Cost Effectiveness of Adding Additional Baghouses to Control Emissions for the Main Stack 1,2
Primary Lead Smelting NESHAP Technical Support Document 

13

3.3 Additional Testing and Monitoring Costs

Based on the elevated risk levels found for the furnace area stack and the refining operation 

stacks, EPA is proposing emission caps for those emission points. To demonstrate compliance 

with the new emission caps and the plant—wide emission limit, EPA is proposing to require 

quarterly stack testing. Although the method for testing is the same as it was under the current 

MACT, the quarterly frequency requirement imposes additional impact with regard to the cost of 

additional testing. 

In addition, the risk analysis results indicate that modeled lead concentrations exceed the 

NAAQS at several of the property boundary receptor locations. Since the impact at these 

locations is driven by fugitive dust emissions, EPA is proposing an ambient lead concentration 

limit at the property boundary. To demonstrate compliance with this limit, EPA is proposing to 

require ambient lead monitoring at four locations that would be most representative of the 

highest modeled emissions of lead. 

The additional monitoring requirements will cause annual costs for the performance of additional 

testing and monitoring. Since EPA assumes that monitoring equipment will be leased and not 

purchased, there are no anticipated capital costs associated with the new requirements. We have 

determined the cost for the additional testing and monitoring to meet these requirements as 

summarized in Table 3.5 below. 

Table 3.5 - Additional Testing and Monitoring Costs 

Type of Testing/Monitoring Notes Cost Annual Cost1

Stack Testing Method 12 $13,000 per test $156,000 

Ambient Lead Monitoring (lab 

analysis) 

Per required monitoring plan $127 per test $185,420 

Ambient Monitoring Equipment Annual Lease $2,500 per unit $10,000 1

 Includes 12 additional stack tests (4 stacks x 3 more tests) and 4 ambient monitors, each tested 365 days per year. 
1 

December 28, 2010 

MEMORANDUM

TO: Docket No.: EPA-HQ-OAR-2004-0305 

FROM: Sharon Nizich, Project Lead 

Risk and Technology Review - National Emission Standards for Hazardous Air 

Pollutants (NESHAP) for Primary Lead Smelting 

SUBJECT: Technology Review: Developments in Practices, Processes, and Control 

Technologies 

The purpose of this memorandum is to present the results of an analysis to identify 

developments in practices, processes, and control technologies for hazardous air pollutants 

(HAP) emission sources for the Primary Lead Smelting source category. This analysis is part of 

EPA’s review efforts in accordance with section 112(d)(6) of the Clean Air Act (CAA). 

1.0 BACKGROUND 

1.1 Requirements of Section 112(d)(6) of the CAA 

Section 112 of the CAA requires EPA to establish technology-based standards for 

sources of HAP. These technology-based standards are often referred to as maximum achievable 

control technology, or MACT, standards. Section 112 also contains provisions requiring EPA to 

revisit these standards. Specifically, paragraph 112(d)(6) section states: 

(6) REVIEW AND REVISION. – The Administrator shall review, and revise as 

necessary (taking into account developments in practices, processes, and control 

technologies), emission standards promulgated under this section no less often 

than every 8 years. 

1.2 Description of Primary Lead Smelting Source Category and NESHAP 

Requirements 

The Primary Lead Smelting source category includes all facilities that smelt lead-bearing 

ore concentrates to produce lead metal using pyrometallugical techniques. The source category 

does not include secondary lead smelters, lead remelters, or lead refiners that are not located at a 

primary lead smelting facility. Lead is used to make various construction and consumer products 

such as batteries, paint, glass, piping, and filler. Lead sulfide (PbS) ore concentrates are the main 

feed material to primary lead smelters. The primary lead smelting process consists of PbS 

concentrate storage and handling, sintering of ore concentrates, sinter crushing and handling, 
2 

smelting of sinter to lead metal, drossing (i.e., removing the solid oxide deposits), refining and 

alloying of lead metal, and smelting of the drosses. 

HAP is emitted from primary lead smelting as process emissions, process fugitive 

emissions, and fugitive dust emissions. Process emissions are associated with the exhaust gases 

from sinter machines and blast and dross furnaces. HAP expected in process emissions are 

metals (mostly lead, but also some arsenic, cadmium, and other metals) and also may include 

organic compounds that result from incomplete combustion of coke and natural gas combustion. 

Process fugitive emissions occur at various points during the smelting process (such as during 

charging and tapping of furnaces) and generally include metal HAP. Fugitive dust emissions 

result from the entrainment of dust due to material handling, vehicle traffic, and wind erosion 

from storage piles. All fugitive dust emissions contain metal HAP. The majority of these 

fugitive emissions are related to concentrate handling, sinter transfer, and sintering operations. 

 The NESHAP for Primary Lead Smelting were promulgated on June 4, 1999 (64 FR 

30194) and codified at 40 CFR part 63, subpart TTT. The Primary Lead Smelting MACT 

standard applies to affected sources of HAP at primary lead smelters. Primary lead smelters are 

defined as “...any facility engaged in the production of lead metal from lead sulfide ore 

concentrates through the use of pyrometallurgical techniques.” At the time of promulgation of 

the Primary Lead Smelting MACT rule, there were three operating lead smelters. Today there is 

one operating facility, The Doe Run Resources Corporation (Doe Run) in Herculaneum, 

Missouri, that is subject to the MACT standard. 

 

 The Primary Lead Smelting MACT standard applies to sinter machines, blast furnaces, 

dross furnaces, process fugitive sources, and fugitive dust sources. Process and process fugitive 

emissions of lead compounds from sinter machines, blast furnaces, and dross furnaces are 

limited to 500 grams (g) of lead emissions per mega gram (Mg) of lead produced (i.e., 500 g/Mg 

of lead produced, or 1.0 lb/ton of lead produced). Process fugitive sources that are subject to the 

MACT standard are dross furnace charging, blast furnace and dross furnace tapping, and the 

sinter machine (charging, discharge end, crushing, and sizing). Process fugitive emissions must 

be captured by a hood and ventilated to a baghouse or equivalent control device. In addition, the 

sinter machine area must be enclosed in a building that is ventilated to a baghouse at a rate that 

maintains a positive in-draft through any doorway opening. The MACT standard also requires 

the use of bag leak detection systems for continuous monitoring of baghouses. For fugitive dust 

sources, the MACT standard requires that the owner or operator prepare and operate at all times 

according to a standard operating procedures (SOP) manual that describes in detail the measures 

used to control fugitive dust emissions from plant roadways, material storage and handling areas, 

sinter machine areas, furnace areas, and refining and casting areas. The work practices outlined 

in the SOP manual developed for compliance with a state implementation plan is considered to 

be compliant with the MACT standard with regard to fugitive emissions work practice controls. 

 Other metal HAP emitted from the primary lead smelting processes (arsenic, cadmium, 

cobalt and nickel) are covered by the MACT standard by the regulation of lead, which is a 

surrogate for all other nonvolatile metal HAP. Lead is not a surrogate for mercury. However, 

mercury emissions are not a concern for this source category because the mercury content of the 

lead sulfide ore and other materials that could introduce mercury into the process is below the 
3 

detection limit. Organic HAP are emitted in very small quantities from the incomplete 

combustion of small amounts of coke in the blast furnace and natural gas combustion sources 

such as space heating and generators. Although they were considered in the development of the 

1999 MACT rule, they were not regulated because they are emitted at a rate so low as to be 

infeasible to reduce. Acid gas HAP were not identified and, therefore, were not regulated in the 

original MACT rule. More recent emissions data indicate that acid gas HAP are not emitted by 

the lead smelting process. 

2.0 DEVELOPMENTS IN PRACTICES, PROCESSES, AND CONTROL 

TECHNOLOGIES 

For the purposes of this technology review, a “development” was considered to be 

any of the following: 

 Add-on control technology or other equipment that was not identified and 

considered during the development of the NESHAP for the source category; 

 Improvement in add-on control technology or other equipment that was identified 

and considered during NESHAP development for the source category that could 

result in significant additional HAP emissions reductions; 

 Work practice or operational procedure that was not identified and considered 

during NESHAP development for the source category; and 

 Process change or pollution prevention alternative that could be broadly applied 

that was not identified and considered during the development of the NESHAP 

for the source category. 

To identify developments in practices, processes, and control technologies, we 

conducted searches of EPA’s RACT/BACT/LAER clearinghouse and the internet for 

information on primary lead smelting. We also reviewed the state permit, state 

implementation plan (SIP) and the Section 114 information collection request (ICR) 

response from the one remaining primary lead smelting facility. The search results are 

summarized below. 

At the time of the MACT rule promulgation, HAP emissions from the primary lead 

smelting source category were primarily lead but also included small amounts of arsenic, 

cadmium, cobalt, and nickel, and low levels of combustion related organics. Emissions 

data from a 2010 ICR response from the only remaining primary lead smelter (1) 

confirmed that, with the exception of the level of emissions, the emissions profile for the 

facility has not changed, with lead accounting for about 99 percent of the HAP emissions. 

Therefore, this technology review focused on developments in practices, processes, and 

control technologies applicable to lead emission sources. 

2.1 Clearinghouse and Internet Searches 

RACT/BACT/LAER Clearinghouse

The terms “RACT”, “BACT”, and “LAER” are acronyms for different program 

requirements under EPA’s New Source Review (NSR) program. Under EPA’s New 
4 

Source Review (NSR) program, if a company is planning to build a new plant or modify 

an existing plant such that air pollution emissions will increase, the company must obtain 

an NSR permit. The NSR permit is a construction permit which requires the company to 

minimize air pollution emissions by changing the process to prevent air pollution and/or 

installing air pollution control equipment. RACT, or Reasonable Available Control 

Technology, is required on sources in areas that are not meeting national ambient air 

quality standards (i.e. non-attainment areas). BACT, or Best Available Control 

Technology, is required on major new or modified sources in attainment areas. LAER, or 

Lowest Achievable Emission Rate, is required on major new or modified sources in nonattainment areas. BACT and LAER (and sometimes RACT) are determined on a caseby-case basis, usually by State or local permitting agencies. EPA established the 

RACT/BACT/LAER Clearinghouse, or RBLC, to provided a central database of air 

pollution technology information (including past BACT and LAER decisions contained 

in NSR permits) to promote the sharing of information among permitting agencies and to 

aid in future case-by-case determinations. However, data in the RBLC are not limited to 

sources subject to RACT, BACT, and LAER requirements. Noteworthy prevention and 

control technology decisions and information are included even if they are not related to 

past RACT, BACT, or LAER decisions. 

The RBLC contains over 5,000 air pollution control permit determinations that 

can help indentify appropriate technologies to mitigate most air pollutant emission 

streams. It was designed to help permit applicants and reviewers to make pollution 

prevention and control technology decisions for stationary air pollution sources, and 

includes data submitted by several U.S. territories and all 50 States on over 200 different 

air pollutants and 1,000 industrial processes. 

 The RBLC was searched for facilities that conduct primary lead smelting as well 

as for facilities in other nonferrous manufacturing industries. No facilities were 

identified during the search and no new control technologies or developments in existing 

control technologies were identified to further reduce emissions from primary lead 

smelting facilities. 

Internet Search

 A general search of the internet was conducted for information on new processes 

and control technologies for primary lead smelting. The search identified one new 

technology: a hydrometallurgical process, which could potentially be used in lieu of 

pyrometallurgical smelting to produce lead metal from lead sulfide ore. The 

hydrometallurgical lead processing technology is under development and uses 

electrolysis and electrowinning to produce lead from lead ore. This technology, however, 

is currently only in demonstration project status and not commercially available. 

Therefore, it is not a proven technology and currently cannot be considered a replacement 

technology for primary lead smelting operations. 

2.2 State SIP and ICR 
5 

 Based on our review of The Doe Run Herculaneum Title V permit, the Missouri SIP for 

lead, and information provided in the Section 114 ICR response from The Doe Run Company, 

we have determined that there have been advances in emission control measures since the 1999 

Primary Lead Smelting MACT standard. The following paragraphs discuss these advances and 

improvements. 

 

The 1999 MACT lead emission limit for primary lead smelting was set at 1 lb/ton. The 

limit is a facility-wide emission limit that applies to the aggregation of emissions discharged 

from the air pollution control devices used to control emissions from the following sources: 

 Sinter machine; 

 Blast furnace; 

 Dross furnace; 

 Dross furnace charging location; 

 Blast furnace and dross furnace tapping location; 

 Sinter machine charging location; 

 Sinter machine discharge end; 

 Sinter crushing and sizing equipment; and 

 Sinter machine area. 

A facility-wide limit format was used because it was consistent with SIPs, the 

commingling of exhaust gases from processes to a single stack made it impossible to set limits 

for individual sources, it gave the facilities more flexibility in complying with the standard, and 

it promoted pollution prevention by giving each facility the ability to meet the emission limit 

through any combination of source reduction and control technology options. 

The 1999 MACT lead limit was set using the lead emission limits from the lead SIPs for 

the states in which primary lead smelting sources were operational at the time of the rulemaking. 

EPA took each of the three lead SIP limits, in lb/day, divided them by the corresponding lead 

production capacity, in tons/day, and calculated a lead emission rate in lb/ton. The results were 

as follows: 

ASARCO - Missouri 1.0 lb/ton 

ASARCO - Montana 1.0 lb/ton 

Doe Run - Missouri 0.84 lb/ton 

The values were ranked and the median value (1.0 lb/ton) was selected as representative 

of the MACT floor. 

Since the MACT standard was promulgated, the industry has undergone significant 

changes. Two of the three facilities have shut down. As discussed above, the only remaining 

primary lead smelting facility is the Doe Run smelter at Herculaneum, Missouri. Because the 

Doe Run facility is located in an area designated as non-attainment for the lead National 

Ambient Air Quality Standard (NAAQS), the facility is subject to control requirements under the 

Missouri SIP for lead. In an effort to meet the lead NAAQS, Missouri revised the lead SIP as it 

applied to the Doe Run facility in 2000, 2002 and 2007, requiring numerous emissions reducing 
6 

measures and improvements to add-on control devices, processes, and work practices. SIP 

requirements are also incorporated into Doe Run’s Title V permit. 

The SIP requirements, implemented after the 1999 MACT standard, were considered in 

our technology review. The SIP requirements, summarized below, are described in detail in the 

2007 revision of SIP prepared by the Missouri DNR (available at 

http://www.dnr.mo.gov/ENV/apcp/docs/2007revision.pdf). The SIP addresses process, process 

fugitives, and fugitive lead emissions and requires enhancements of existing emission control 

technology, adding or upgrading enclosures, process changes and limitations, and work 

practices. 

 Under the SIP, fugitive dust emissions are controlled by comprehensive work practices 

including road watering and automatic sprinklers, using regenerative sweepers to remove dust 

from paved surfaces to reduce emissions from traffic, maintaining a minimum water content for 

ore concentrate and for baghouse dust that is loaded into railcars, and inspecting the siding that 

encloses buildings (followed by prompt repairs if needed). 

 

Our review found that the practices implemented under the SIP to control fugitive dust 

emissions have resulted in reductions in these emissions. As a result of the SIP requirements, we 

find that all feasible practices and controls available for control of fugitive dust emissions in this 

industry have already been implemented. Therefore, EPA did not find further applicable 

practices or controls that should be required under the MACT to reduce fugitive emissions. 

 Baghouses are the most common control devices used to control process and process 

fugitive emissions of lead compounds at the Herculaneum facility with the exception of the 

process emissions from the sinter machine, which are controlled by a combination of devices in 

series: electrostatic precipitator, baghouse, and acid plant (for control of sulfur dioxide). The 

buildings that house the blast furnaces, dross furnaces, and refinery kettles are also exhausted to 

a baghouse. Improvements to existing emission controls required by the SIP include the 

installation of pleated filters to lower the air-to-cloth ratio for baghouses, increased ventilation 

and improved ventilation hoods at the blast furnace, and using reverse flow technology for 

baghouse cleaning. SIP-required measures also included the installation of enclosures for 

unloading ore concentrate, sinter storage, and the sides of the sinter machine (which are 

evacuated to a baghouse). 

 

 Process changes implemented in response to the SIP to reduce emissions include a 

process control system for the injection of air through the blast furnace tuyeres located at the 

bottom of the blast furnace, limitations on individual process and overall plant throughputs, and 

limiting specific operations to only certain times of the day when the impact on ambient air 

concentrations is less. Emissions from malfunctions will be reduced by alarms that sound when 

the baghouse fan malfunctions, an interlock system to restrict air flow into the blast furnace 

when the baghouse is not operating properly, and cameras for the dross and refinery kettles to 

detect kettle failure (i.e., when a plume of smoke is detected from the stack, the kettle burner can 

be immediately shut off and the problem corrected). 

Under the SIP, technological improvements have also been made to the refining 

operations at the Doe Run facility. Under the current MACT, refining operations are not subject 
7 

to the lead emission limit because at the time the MACT standards were developed, emissions 

from refining were considered fugitive in nature. In response to the SIP requirements, the Doe 

Run facility has enclosed the refining and casting operations and now exhausts the emission from 

the refining kettles as well as the refining building to baghouses. 

Recent stack tests show that these improvements have resulted in emissions substantially 

lower than are allowed under the current MACT rule. To assess the impacts of the technological 

improvements, lead emissions data from 2008 were compared with emissions data from 2000. 

Data from 2008 was selected because it reflects the many technological improvements that have 

been implemented at the facility since the MACT rule promulgation. Emissions data from earlier 

years would not account for all of the emission reducing changes that have been implemented at 

the Doe Run facility given that some of the improvements were not implemented until 2007 and 

2008. In 2008, lead emissions from the smelter operations sintering, blast furnace and drossing 

(i.e. from the main stack) were 13.31 TPY and emissions from the baghouse controlling 

emissions from the blast furnace and dross plant building (i.e., baghouse 7) were 1.81 TPY for a 

total of approximately 15.1 TPY. At the 2008 lead production rate of 149,500 tons, the emission 

rate at Doe Run was about 0.2 lb/ton, an 80 percent reduction from the current MACT limit of 1 

lb/ton. 

The 2008 emissions of 13.31 TPY from sintering, blast furnace operations, and drossing 

operations, represent nearly 70 percent of total facility-wide lead emissions and reflect the annual 

rate of emissions achievable as a result of the technological improvements that have been made 

since 1999. EPA believes that the level of emissions in 2008 support the lowering of the MACT 

limit to be consistent with the demonstrated level of performance. 

In order to establish an emission limit that would properly reflect the facility 

performance, EPA used the actual 2008 annual emissions from the sintering, blast furnace and 

drossing operations (i.e. 13.31 TPY) and then accounted for variability using the 95 percent 

confidence upper predictive limit (UPL). The 95 percent confidence UPL for the lead emissions 

is 14.8 tons. The use of the UPL to account for variability in emissions and the emissions data 

used in the calculation is discussed in Attachment 1. 

To estimate the plant wide emission limit that EPA is proposing, the technology-based 

emissions level for sintering, blast furnace and dross furnace operations (i.e., 14.8 TPY) was 

added to the other risk-based emission levels established for the other emission sources at the 

facility. The development of the plant wide emission limit is described in the preamble to the 

proposed rule. 

3.0 CONCLUSION 

 This review identified several developments in practices, controls or processes that have 

been implemented in the primary lead smelting source category since the 1999 MACT 

promulgation. The primary lead smelting source category currently includes one operating 

facility compared to three at the time the MACT rule was promulgated. The one remaining 

facility, The Doe Run Resources Corporation, has implemented numerous work practices to 

control fugitive emissions and additional enclosures and improvements to add-on controls to 

address process and process fugitive emissions since the 1999 MACT. Additionally, refinery 
8 

operation emissions, which were formerly fugitive, are now captured and exhausted through a 

baghouse. 

The improvements identified in this review were all requirements imposed on the Doe 

Run facility through the Missouri Lead SIP in order to comply with the lead NAAQS. As a 

result, current emissions data indicate an approximate 80 percent plant wide reduction in lead 

emissions since the MACT was promulgated. Although these lead emission reductions are not 

the result of the MACT requirements, EPA believes that the current demonstrated emission 

levels represent an achievable performance and that a reduction in the standard is warranted to 

bring the standard in line with actual performance. 

To determine the emissions level on which the new emission limit would be based, EPA 

used the 2008 emissions for the facility as reported in the Section 114 ICR response for the main 

stack emission (which includes the sintering, blast furnace, and drossing operations), and 

considered variability based on recent stack tests. EPA calculated that the new emission limit 

should be based on a 14.8 tons per year contribution from the sintering, blast furnace,and 

drossing operations (i.e. the main stack). This 14.8 tons per year should be included in the 

calculation of the facility-wide lead emission limit taking into consideration any other necessary 

emission reductions resulting from the residual risk analysis being conducted under Section 

112(f)(2) for the source category. 

4.0 REFERENCES 

 1. Letter from Curran, D.Y., Stinson Morrison Hecker LLP to S. Nizich, US Environmental 

Protection Agency, Response from The Doe Run Resources Corporation to EPA’s December 4, 

2009, Section 114 Information Collection Request, February 5, 2010. 
9 

ATTACHMENT 1 

Variability and Upper Predictive Limit Calculation

Main Stack Lead Emissions

In assessing sources’ performance, EPA may consider variability both in identifying 

which performers are “best” and in assessing their level of performance. Brick MACT, 479 F. 

3d at 881-82; see also Mossville Envt’l Action Now v. EPA, 370 F.3d 1232, 1241–42 (D.C. Cir 

2004) (EPA must exercise its judgment, based on an evaluation of the relevant factors and 

available data, to determine the level of emissions control that has been achieved by the best 

performing sources considering these sources’ operating variability). 

Variability in lead producers’ performance has a number of causes. For emissions of lead 

compounds that are controlled by baghouses, the variability is chiefly due to variations in 

performance of the control device for which both run-to-run and test-to-test variability must be 

accounted.1 

In determining a plant-wide emission limit, we used annual emissions discharged from 

the air pollution control devices used to control lead emissions from the Doe Run primary lead 

smelter. For this rule, we used the 2008 emissions reported by Doe Run to the State of 

Missouri. Variability was added only to the main stack emissions as the emission levels for the 

other sources had required risk-based emission levels. 

We assessed variability using a statistical formula designed to estimate an emissions level 

that is equivalent to the source’s performance based on future compliance tests. Specifically, the 

calculated limit is an upper prediction limit (UPL) calculated with the Student’s t-test using the 

TINV function in Microsoft Excel®. The Student’s t-test has also been used in other EPA 

rulemakings (e.g., NESHAP for Portland Cement Manufacturing; NSPS for 

Hospital/Medical/Infectious Waste Incinerators; NESHAP for Industrial, Commercial, and 

Institutional Boilers and Process Heaters) in accounting for variability. A prediction interval for 

a future observation is an interval that will, with a specified degree of confidence, contain the 

next (or some other pre-specified) randomly selected observation from a population. In other 

words, the prediction interval estimates what the upper bound of future values will be, based 

upon present or past samples taken. The UPL consequently represents the value which we can 

expect the mean of future observations (3-run average for lead) to fall below within a specified 

level of confidence, based upon the results of an independent sample from the same population. 

In other words, if we were to randomly select a future test condition from any of these sources 

(i.e., average of 3 runs or 30-day average) we can be 95 percent confident that the reported level 

will fall at or below the UPL value. Use of the UPL is appropriate in this rulemaking because it 

sets a limit any single or future source can meet based on the source’s past performance. 

                                                           

1 Run-to-run variability is essentially within-test variability, and encompasses variability in individual runs 

comprising the compliance test, and includes uncertainties in correlation of monitoring parameters and emissions, 

and imprecision of stack test methods and laboratory analysis. 72 FR at 54877 (Sept. 27, 2007). Test-to-test 

variability results from variability in pollution device control efficiencies over time (depending on many factors, 

including for fabric filters the point in the maintenance cycle in which a fabric filter is tested). Test-to-test 

variability can be termed long-term variability. 72 FR at 54878. 
10 

This formula uses a pooled variance (in the s2

 term) that encompasses all the data-point to 

data-point variability. Where variability was calculated using the UPL statistical approach, we 

used the sample standard deviation calculated from the emissions data distributions for lead. The 

standard deviation is the common measure of the dispersion of the data set around an average. 

We note here that the methodology accounts for both short-term and long-term variability and 

encompasses run-to-run and test-to-test variability. 

We adopted a form of the UPL equation that has been used in more recent rulemakings. 

See 75 FR 54970 (September 9, 2010), 75 FR 32020 (June 4, 2010) and 75 FR 31905 (June 4, 

2010). The UPL used in this proposed rule is calculated by: 

Where: 

x ̄ = 2008 annual emissions 

n = the number of test runs 

m = the number of test runs in the compliance average 

s

2

 = observed variance 

t = student t distribution statistic 

This calculation was performed using the following Excel functions: 

95 percent UPL =  2008 annual emissions + [STDEV(Test Runs) x TINV(2 x probability, n‐1 degrees

of freedom)*SQRT((1/n)+(1/m))], for a one‐tailed t‐value, probability of 0.05,

and sample size of n   

Figure 1 provides the UPL calculation using the recent stack test data for the main stack at the Doe Run

Herculaneum facility.  Figure 2 provides a listing of stack test results.
11 

Figure 1 - UPL Calculations for Main Stack Lead Emission

UPL Pooled Variance=

Runs 2001-2008

1 2.28

2 2.35

3 3.15

4 2.85

5 0.47

6 0.58

7 0.39

8 0.43

9 0.40

ni = number test runs = 9

Total Number of sources = 1

n =Total # test runs = 9

8

This step is for QC only:

means 1.4335

1.4335 13.31 Main Stack Pb emissions (tons/yr) ‐ 2008 EI

Mean =

Pooled Variance = 1.42101

m= number future runs = 3 Method 12 test quarterly (3 runs/test)

Term1 0.4444

Term2 0.6316

Squared root Term2 0.7947

t‐statistic = quantile t‐distribution with df degrees of freedom at .95 confidence level = 1.859548033

UPL  POOLED VARIANCE = 14.78779913

Doe Run Main Stack Pb

Emissions, lb/hr

NOTE: the pvalue for the t-statistic is calculated as: 2*alpha, where 1-alpha is desired confidence, so if 99% confidence is desired then alpha=0.01 and 

2*alpha=2*(0.01)

 2 2

1

1

1

n

i

i

s x X n    

1 1

1 i N n

ij

i j

X x n   

1 1

n m



2 1 1 s n m

      

1

1

N

i

i

df n 

        

df t

2 1 1 s n m

      

1

1 ni

i ik

i k

x x n  

1

N

i

i

n





N

2

,

1 1 Xt s df p n m

       

2

,

1 1 Xt s df p n m

       
12 

Figure 2 - Doe Run Herculaneum Stack Test Data from Section 114 ICR Response

Source Year of Test Run #

Emissions

Tests Results

for Pb (lb/hr)

Production

during

testing (tons

Pb/hr)

Emissions

rate during

testing (lb

Pb/ton Pb

produced)

Main Stack 2001 1 6.07       

      2 4.95

      3 3.13

   2002 1 20.24 8.88 2.28

      2 20.87 8.88 2.35

      3 27.99 8.88 3.15

   2003 1 25.2 8.83 2.85

      2 11.92 25.38 0.47

      3 14.62 25.38 0.58

   2004 1 6.85 17.50 0.39

      2 7.46 17.50 0.43

      3 6.99 17.50 0.40

   2006 1 3.3       

      2 4       

      3 4

   2008 1 10.81       

      2 17.49

      3 19.23