1

MEMORANDUM

To: Chuck French, U.S. Environmental Protection Agency, OAQPS

From: Mike Burr, Donna Lazzari, and Danny Greene, ERG

Date: April 2011

Subject: Draft Summary of the Technology Review for the Secondary Lead Smelting

Source Category

This memorandum summarizes the results of an analysis to identify developments in practices, processes, and control technologies for emissions sources of hazardous air poll utants (HAP) from the Secondary 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). This memorandum is organized as follows:

1.0 Background

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

1.2 Description of the Secondary Lead Smelting Source Category and
Requirements of the Current NESHAP

2.0 Developments in Practices, Processes and Control Technologies

2.1 Stack Emissions

2.2 Fugitive Emissions

3.0 Recommended Revisions Based on Developm ents in Practices, Processes and
Control Technologies

3.1 Stack Emissions

3.2 Fugitive Emissions

4.0 Conclusions

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. Th ese technology

- based standards are often referred to as maximum achievable control technology, or MACT, standards. Section 112 also contains provisions requiring EPA to periodically revisit these standards. Specifically, paragraph 112(d)(6) states:2 (6) REVIEW AND REVISION.

– The Administrator shall 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.

1.2 Descri ption of the Secondary Lead Smelting Source Category and Requirements of the Current NESHAP
The current National Emissions Standards for Hazardous Air Pollutants (NESHAP) for the Secondary Lead Smelting source category was promulgated on June 13, 1997 (62 FR 32216) and codified at 40 CFR part 63, subpart X. As promulgated in 1997, the NESHAP applies to affected sources of HAP emissions at secondary lead smelters. The current NESHAP (40 CFR 63.542) defines “secondary lead smelters” as “ any facility at whic h lead

- bearing scrap material, primarily, but not limited to, lead

- acid batteries, is recycled into elemental lead or lead alloys by smelting .” The secondary lead smelting process consists of : (1) pre

- processing of lead bearing materials, (2) melting lea d metal and reducing lead compounds to lead metal in the smelting furnace, and (3) refining and alloying the lead to customer specifications. The NESHAP for the Secondary Lead Smelting source category does not apply to primary lead smelters, lead
remelter s, or lead refiners.

Today

, there are 14 secondary lead smelting facilit ies that are subject to the NESHAP.
No new secondary lead smelters have been built in the last 20 years, and no new secondary lead smelting facilities are antici pated in the foresee able future, although one facility is currently in the process of expanding their operations.

HAP are emitted from secondary lea d smelting as stack releases (i.e., process emissions,
and process fugitive emissions ) and fugitive dust emissions. Process emissions include exhaust gases from feed dryers and from blast, reverberatory, rotary, and electric furnaces

. The HAP in process emissions are comprised primarily of metals (mostly lead compounds, but also some

arse nic, cadmium, and other metals) and also may include organic compounds that result from incomplete combustion of coke that is charged to the smelting furnaces as a fuel or fluxing agent, combustion of natural gas or other fuels, or combustion of small amou nts of plastics or other materials that get fed into the furnaces along with the lead

- bearing materials. Process fugitive
emissions are released from various sources throughout the smelting process, including smelting furnace charging and tapping points, refining kettles, agglomerating furnace product taps, and drying kiln transition equipment. Process fugitive emissions are comprised primarily of metal
HAP

. Fugitive dust emissions are emissions that are not associated with a specific process or

process fugitive vent or stack. Process fugitive emissions are comprised of metal HAP and result3

from the entrainment of HAP in ambient air due to material handling activities , vehicle traffic,
wind , and other activities.

The current NESHAP applies to process e missions from blast, reverberatory, rotary, and electric smelting furnaces, agglomerating furnaces, and dryers ; process fugitive emissions from smelting furnace charging points, smelting furnace lead and slag taps, refining kettles, agglomerating furnace p roduct taps , and dryer transition equipment ; and fugitive dust emission s from roadways, battery breaking areas, furnace charging and tapping areas, refining and casting areas, and material storage areas

. For process sources, the current NESHAP specifies n umerical
emissions limits for total hydrocarbons (THC) and lead compounds for blast furnaces and collocated blast and reverberatory furnaces. Additionally, emissions limits for lead are specified for reverberatory, electric, and rotary furnaces. Lead com pound emissions from all smelting furnace configurations are limited to an outlet concentration of 2.0 milligrams per dry standard cubic meter (mg/dscm) (0.00087 grains per dry standard cubic foot (gr/dscf)) (40 CFR 63.543(a)). THC emissions from collocat ed blast and reverberatory furnaces are limited to an outlet concentration of 20 parts per million volume (ppmv) (expressed as propane) corrected to 4 percent carbon dioxide (CO 2 ). THC emissions are limited to 360 ppmv (as propane) at 4 percent
CO 2 from e xisting blast furnaces and 70 ppmv (as propane) at 4 percent CO 2 from new blast furnaces (40 CFR 63.543(c)). The current NESHAP does not specify limits for THC emissions from reverberatory furnaces not collocated with blast furnaces, rotary furnaces, or e lectric
furnaces.

The current NESHAP requires that process fugitive emissions sources be equipped with an enclosure hood meeting minimum face velocity requirements or be located in a total enclosure subject to general ventilation that maintains the building a t negative pressure ( 40 CFR 63.543(b ) ). Ventilation air from the enclosure hoods and total enclosures are required to be conveyed to a control device. Lead emissions from these control devices are limited to 2.0 mg/dscm (0.00087 gr/dscf) ( 40 CF R 63.544(c) )

. Lead emissions from all dryer emissions vents and agglomerating furnace vents are limited to 2.0 mg/dscm (0.00087 gr/dscf) ( 40 CFR 63.544(d) ) . The current NESHAP also requires the use of bag leak detection systems for continuous monitoring of baghouses in cases where a high efficiency particulate air (HEPA) filter are not used in series with a baghouse (40 CFR 63.548(c)(9)).

For fugitive dust sources, the current NESHAP requires that facilities develop and operate according to a standard operating procedures (SOP) manual that describes, in detail, the measures used to control fugitive dust emissions from plant roadways, battery breaking areas, furnace areas, refining and casting areas, and material storage and handling areas.4

2.0 DEVELOPMENTS IN PRACTICES, PROCES SES, AND CONTROL TECHNOLOGIES For the purposes of this technology review, a “development” was considered to be a (n):

add

- on control technology or other equipment that was not identified during the development of the current NESHAP fo r the source category;
i mprovement in add

- on control technology or other equipment that was identified and considered during development of the current NESHAP for the source category that could result in significant additional HAP emissions reductions;

w ork practice or operational procedure that was not identified during development of the current NESHAP for the source category; or applicable p rocess change or pollution prevention alternative that was not identified and considered during the development of the current NESHAP for the source category.
We investigated developments in practices, processes, and control technologies for three categories of HAP emissions sources from secondary lead smelters: (1) stack emissions of lead and other metal HAP, (2) stack emissions of organic HAP, and (3) fugitive emissions of lead and other metal HAP. To identify developments, w e conducted searches of EPA’s
RACT/BACT/LAER (Reasonably Achievable Control Technology/Best Available Control Technology/Lowest Achievable Emissions Rate) clearinghouse and the I nternet for information

on secondary lead smelting and similar processes, examined the Section 114 information collection request (ICR) responses from the 14 secondary lead smelting facilities, reviewed technologies e mployed by similar industries, and reviewed new or updated NESHAPs for other source categories. The results of these analyses are presented in the following sections.

2.1 Stack Emissions

The current NESHAP specifies emission s limits for metal HAP ( using lead as a surrogate) and organic compounds (using THC as a surrogate) from stacks. This section of the technology review will focus on developments in practices, processes, and control technologies applicable to emissions of metal HAP and organic compounds fro m stacks.

a. Metal Hap E

missions from Stacks
Based on a review of the ICR responses, the most common control technology employed by the industry to control emissions of metal HAP from stacks is fabric filtration (or baghouses). Several types of baghouses are currently used by the industry, including shaker, pulse jet, and reverse pulse jet bag filters. One facility uses a wet electrostatic precipitator (WESP) downstream of a baghouse to further reduce emissions of metal HAP from stacks. Two other facilities have plans to install similar WESP units. Several facilities also reported using HEPA
filters as an add

- on control downstream of their baghouses. Additionally, some facilities reported using cartridge collectors; however these types of controls are generally suited to reduce5

metal HAP emissions from sources that have lower inlet concentrations and are typically not used to control metal HAP in smelting furnace exhaust.

The first part of our analysis included attempting to determine which control technology (e.g., fabric filter, WESP, HEPA filter , cartridge collectors) achieves the greatest control efficiency for metal HAP. We could not directly calculate control efficiencies due to lack of inlet concentration data; however, we compared the outlet lead concentrations from the different
control te chnologies based on emissions data that we received in the ICR.

As displayed in Figure 2

- 1, the average stack outlet lead concentration from the baghouse and WESP combination was almost 50 times lower than the outlet concentration achieved by using bagho uses alone. HEPA filters used downstream of a baghouse achieved approximately 20 percent lower outlet lead concentrations than baghouses alone. Cartridge collectors appear to achieve outlet lead concentrations approximately three times lower than baghous es; however, as mentioned, cartridge collectors are generally limited to emissions points with lower flow rates and inlet loading concentrations.

Figure 2

- 1. Comparison of Control Device Outlet Lead Concentrations from Different Technologies

.

Based on emissions data received in the ICR, we also compared the relative performance of each baghouse across facilities and attempted to determine the factors that correlate best with
low outlet lead concentrations. Th e factors that we considered include baghouse type ( e.g., shaker, pulse jet, reverse bag pulse), filter material, and age of the unit. Figure 2

- 2 shows the results of these analyses. Based on our analysis, the most significant factor affecting baghouse

p erformance is the age of the unit. We found that units installed prior to 1989 generally had significantly higher outlet lead concentrations than the newer units. Shaker baghouses appear to have higher outlet lead concentrations than those of the pulse je t or reverse bag pulse type. 0.00 0.02 0.04 0.06 0.08 0.10 0.12 0.14 0.16

Fabric Filter HEPA Filter Cartrige collectors WESP Pb Concentration (mg/dscm) Average Outlet Lead Concentration by Control Technology6

Figure 2

- 2. Comparison of Baghouse Outlet Lead Concentrations Based on Type (Upper Left), Filter Media (Upper Right), and Installation Year (Bottom)

. 0.00 0.05 0.10 0.15 0.20 0.25 0.30

Shaker Reverse Air Pulse Pb Concentration (mg/dscm) Average Outlet Lead Concentration from Baghouses by Type

0.00 0.05 0.10 0.15 0.20

Teflon Other Polyester Pb Concentration (mg/dscm) Average Outlet Lead Concentration from Baghouses by

Filter Material

0.00 0.20 0.40 0.60 0.80 1.00 1.20 1.40

1960 1970 1980 1990 2000 2010 2020 Pb Concentration (mg/dscm) Average Outlet Lead Concentrations from Baghouses by

Installation Year7

However, the majority of the older units appear to be shaker types, and thus the age of the baghouse may be the controlling factor. We did not find a significant correlation between the outlet lead concentration and the filtration media used in the baghouses, although one company
in the industry suggested, based on its experience, that Teflon ( polytetrafluoroethylene) bags specifically supplied by Gore

- Tex© performed better than other bag types. The company also suggested that the most critical factors influencing baghouse performan ce are proper installation and maintenance practices. They mentioned specific practices such as ensuring proper installation of the bags and properly sealing all ducts and dust conveyance devices. Additionally, they claim that replacing torn bags, rather than repairing them, can significantly improve baghouse performance.

Based on our analyses, we believe that the most important development in the control of stack emissions of metal HAP from this source category has been improvement in the performance of baghouses throughout the industry. The biggest indicator of such improvements is the level of metal HAP emissions currently being achieved in the industry in relation to the allowable level in the current NESHAP (referred to as “MACT

- allowable”), which is a lead based concentration standard of 2.0 mg/dscm for all stacks. Figure 2

- 3 shows the lead concentrations reported by the industry in the ICR compared to the lead concentration limit in the current NESHAP. As illustrated by Figure 2

- 3, the outlet lead concentrations currently being achieved by the industry are far below, and in most cases orders of magnitude below, the concentration limit specified in the current NESHAP. The average reported stack lead concentration was 0.16 mg/dscm with a median of 0 .04 mg/dscm. This large discrepancy
between actual and MACT

- allowable stack lead concentrations is likely a result of improvements in practices, processes, and control technologies that have significantly improved the performance of baghouses employed by this industry since the promulgation of the current
NESHAP. We also believe that the concentr ation data presented in Figure 2

- 3 clearly show that improvements in baghouse technology and operation have occurred that resulted in the capability of achieving significantly lower stack lead emissions than what is required by the current
NESHAP.

b. Organic HAP and Dioxin and Furan Emissions
Based on our review of the ICR responses, we found that emissions of organic HAP from smelting furnaces vary substantially amon g the different furnace types

. In general, emissions of organic HAP from blast furnaces are much higher than those from other furnace types. Information collected in the ICR indicates that this is likely due to the much lower exit temperature of the blas t furnace exhaust relative to the other furnace types. The majority of facilities that operate blast furnaces use afterburners to control emissions of organic HAP. The exhaust of reverberatory furnaces is sufficiently hot that the use of an afterburner i s generally not8

required to meet the current THC limit. Some facilities that operate both blast and reverberatory furnaces comingle the hotter reverberatory furnace stream with the cooler blast furnace stream to control organics in the blast furnace strea m. We did not identify new control technologies or developments in the mentioned existing control technologies that would achieve reductions in organic HAP emissions beyond the limits established in the current NESHAP.

Figure 2

- 3. Comparison of Stack Lead Concentrations Reported by the Industry with the Current MACT S tandard

. Although dioxin and furan (D/F) emissions limits are not specified in the current NESHAP, we investigated technologies available for prevention and/or control of D/F emissions
fro m the smelting furnaces. Based on data submitted by the industry in the ICR, D/F emissions from blast furnaces are one to three orders of magnitude higher than emissions from reverberatory and electric furnaces. The key conditions typically associated wi th higher D/F emissions, listed in order of relative importance 1 , are:

Poor combustion conditions

, High particulate concentration i n the flue gases of a combustion process

, Increased residence time for particulate in critical temperature window (150

- 450 deg rees C elsius )

, Particulate matter containing metals that can catalyze formation to dioxin

, Waste or fuel that is comprised of complex organic or lignin

- like structure , and

1 Gullett, Brian (EPA) and Seeker, Randy (EER Corporation), Chlorinated Dioxin and Furan Formation Control and Monitoring. Presentation at the Industrial Combustion Coordinated Rulemaking Meeting

. September 17, 1997.

0 0.5 1 1.5 2 2.5 Concentration (mg/dscm)

Individual Stack Test Results



### Reported Stack Lead Concentrations

Reported Lead Concentrations Current MACT9 Sufficient chlorine.
We believe the controlling factor for D/F formation in blas t furnaces is the relatively low exit temperature of the exhaust stream in comparison to other furnace types.

We identified two technologies employed by this source category that have demonstrated effective control of D/F emissions from blast furnaces: ( 1) incineration of the furnace exhaust, and (2) comingling of the blast furnace exhaust with the hotter reverberatory furnace exhaust.
Based on information submitted in the ICR and information in the literature on dioxin destruction efficiency, operating an afterburner at sufficient temperature (approximately 1,600 degrees Fahrenheit) with adequate residence time (approximately 2.0

- 2.5 seconds) can achieve significant reductions in D/F emissions from blast furnaces 2 . Additionally, emissions data submitted in the ICR indicate that D/F emissions from collocated blast and reverberatory furnaces are generally lower than emissions from a blast furnace alone. Average exhaust D/F concentrations of the various furnace type s are summarized in Table 2

- 1.

Table 2

- 1

. Summary of Exhaust D/F Concentrations by Furnace Type.

Furnace Type Average D/F (nanograms/dscm) Reverberatory furnaces not collocated with blast furnaces, and reverberatory furnaces mixed with electric furnaces 0.10

Blast Furnaces 38.83 Collocated Blast and Reverberatory Furnaces 0.19 Rotary Furnaces 0.14

A review of technologies employed by other industries to control D/F emissions concluded that injecting activated carbon into the exhaust stream can also achieve significant reductions of D/F emissions; however, the costs associated with this technology fo r this source category were determined to be high (see Draft Cost Impacts of the Revised NESHAP for the Secondary Lead Smelting Source Category)

. Because the presence of chlorine is necessary for D/F formation, we also examined the potential sources of ch lorine in the feed materials charged to the smelting furnaces. Historically, the plastic battery casings used in the construction of automotive batteries contained polyvinyl chloride (PVC). Although battery casings are no longer made of PVC, the battery casings can sometimes contain small amounts of chlorinated flame retardants. This material may be introduced into the furnace through incomplete separation of the battery casing material from the

2 Ficarella, Domenico and Laforgia, Domenico, Numerical Simulation of Flow

- Field and Dioxins Chemistry for Incineration Plants and Experimental Investigation, Waste Management, 20 (2 000) 27

- 49. http://www.bvsde.paho.org/bvsacd/cd43/antonio.pdf10

lead

- bearing material in the feed preparation process. Ch lorine may also be present in the coke fed to the furnace as a fuel and reducing agent. Moreover, we believe that occasionally some older batteries that still contain PVC casings could be processed.

Based on our review, the main control of D/F emissions o ccurs due to measures initially implemented to control organic HAP emissions ( i.e., incineration and co

- mingling of furnace exhaust streams). We identified one other control technology with the potential to reduce D/F emissions ( i.e., carbon injection); h owever, the costs to apply this technology were determined to be high.

2.2 Fugitive Emissions

As outlined in s ection 1.2 of this memorandum , the pollutants emitted from fugitive
emission s sources in this source category are metal HAP. Therefore, we focused o n identifying advancements in practices, processes, and control technologies related to fugitive emissions of metal HAP. Sources of fugitive emissions at secondary lead smelters include dust from plant roadways, battery breaking operations, material stora ge areas, and process fugitives that are not captured by a control device.

The minimum requirements for control of fugitive emissions in the current NESHAP for the following specified fugitive sources are:

Plant roadways

– must be cleaned twice per day;

Ba ttery breaking area

– partial enclosure of storage piles and wet suppression with twice daily pavement cleaning; Furnace and refining and casting areas

– partial enclosure and pavement cleaning; and Material Storage and Handling Areas

– partial enclosure, wet suppression, and vehicle wash at exits.
Based on our analysis of information received in the ICR, we grouped the facilities into three categories that describe the level of fugitive emissions control implemented. Table 2

- 2 defines these categories and Table 2

- 2 summarizes our categorization for each facility.

Table 2

- 2. Enclosure Category Definitions. Enclosure Category Description

Level 1 Enclosure Facilities described as having Level 1 enclosure meet the enclosure requirements in the current NESHAP. The facilities rely primarily on enclosure hoods to capture process fugitive emissions and partial enclosures with wet suppression for process units and storage areas.

Level 2 Enclosure Facilities described as having Level 2 enclosure generally employ, in addition to enclosure hoods for process fugitive sources, a combination of negative pressure total enclosures and partial enclosures with wet suppression for process units and storage areas.11

Enclosure Category Description

Level 3 Enclosure Facilities described as having Leve l 3 enclosure generally employ, in addition to enclosure hoods for process fugitive sources, negative pressure total enclosures for all process units and storage areas.

Table 2

- 3

. Enclosure Category Assigned to the 14 Secondary Lead Smelting F a cilities.

Facility Enclosure Category
Exide Technologies

– Baton Rouge, LA Level 1
Exide Technologies

– Forest City, MO Level 2
Exide Technologies

– Frisco, TX Level 2
Exide Technologies

– Muncie, IN Level 3
Exide Technologies

– Reading, PA Level 2
Exide Technologies

– Vernon, CA Level 3
Revere Smelting And Refining

– Middletown, NY Level 3

Quemetco Inc.

– Industry, CA Level 3
Quemetco Inc.

– Indianapolis, IN Level 3

Sanders Lead Co.

– Troy, AL Level 1
EnviroFocus Technologies

– Tampa, FL Level 2
Gopher Resources

– Eagan, MN Level 3
Buick Resource Recycling Facility

– Boss, MO Level 1
East Penn Manufacturing

– Lyons, PA Level 3

As displayed in Table 2

- 3, our analysis concludes that 11 of the 14 facilities are controlling fugitive emissions beyond the levels required by the current NESHAP. Additionally, seven of the 14 facilities have placed all of their process areas in total enclosures under negative pressure with ventilation to a control device. Furthermore, an 8 th facility (EnviroFocus Technologies) has a current project to implement level 3 enclosure. Of the seven facilities that are currently level 3 enclosures, several facilities claimed performing additional work practices (beyond the enclosures) that exceed the requirements of the current NESHAP to further limit the formation of fugitive dust in other areas of their facilities. Examples of these work practices
include:

m ore complete vehicle washing inside buildings;

i mproved roadway cleaning techniques and frequency;

p avement of en tire facility grounds;

c leaning of building roofs and exteriors;12 u se of daily ambient monitoring to diagnose plant activities that lead to exceedances of the National Ambient Air Quality Standards (NAAQS) for lead; timely cleaning of accidental releases;
i nspection of outside battery storage areas for broken batteries; and performance of all maintenance activities inside total enclosures operated under negative pressure.
Our analysis of ambient lead concentration data measured near the facilities indicates that facilities with level 3 enclosure that implement the work practices described above are generally achieving much lower lead concentrations near their property boundaries (see Figure 3

- 2). For this reason, we believe that developments in practices, pr ocesses, and control technologies with regard to fugitive emissions of metal HAP have occurred that can result in reduced metal HAP emissions from fugitive sources beyond the standards contained in the current NESHAP.

3.0 RECOMMENDED REVISIONS BASED ON DEVELOP MENTS IN PRACTICES, PROCESSES, AND CONTR OL TECHNOLOGIES Based on the analyses presented above, we are recommending the following revisions to the current NESHAP with regards to stack and fugitive emissions from the Secondary Lead Smelting source category.

3.1 Stack Emissions
As described in section 2.1 of this memorandum, the concentrations of lead in stacks reported by this industry in the ICR are far below the level specified in the current NESHAP, indicating improvements in the control of metal HAP emissions since promulgation of the current NESHAP. Our analysis indicates that this is primarily a result of improved performance of baghouses. Therefore, we recommend revising the current NESHAP to reflect the level of performance currently being achieved by fa cilities that implement well

- performing baghouses to
control emissions of metal HAP from stacks.

When considering the most appropriate form of a revised lead standard for this source category, we considered alternatives to the current form ( i.e.

, outlet lead concentration). However, our analysis indicates that a concentration

- based lead standard continues to be the most appropriate form for this industry. We then attempted to determine the appropriate
reduction to the current lead concentration limit of 2.0 mg/dscm. As outlined in section 2.1, the average stack concentration of lead reported by the industry in the ICR was 0.16 mg/dscm with a median concentration was 0.04 mg/dscm. Over 96 percent of the reported concentrations were
less than hal f the current limit of 2.0 mg/dscm and over 80 percent of the reported concentrations were at least an order of magnitude less than the current limit. Our analyses conclude that advancements in the performance of baghouses appear to be the controlling fac tor for these lower concentrations and that reducing the current lead concentration limit from 2.0 to 0.213

mg/dscm would reflect the level of control achieved in practice by facilities that implement well

performing baghouses.

Figure 3

- 1 compares the lead c oncentrations reported by the industry in the ICR with a potential revised lead concentration limit of 0.2 mg/dscm. Although the majority of stacks reported concentrations well below 0.2 mg/dscm, a limited number of stacks would need improvements, possibl y in the form of improved maintenance practices on their existing baghouses or installation of newer, more efficient units. To provide the facilities flexibility in determining the best approach to meeting a revised concentration limit, we considered prop osing a facility

- wide flow

- weighted average lead concentration limit of 0.2 mg/dscm. For this limit, facilities would assign a weighting factor to each stack lead concentration based on the flow rate of the stack. They would then sum the flow

- weighted co ncentration of all the stacks at their facility to get a facility

- wide flow

- weighted concentration. A limit in this form would reflect the level of metal HAP emissions control being achieved in practice by well performing baghouses while providing flexibi lity to the facilities in determining the most cost

- effective approach to achieving the necessary reductions.

As required under section 112(d)(6), we considered the costs and other impacts associated with revising the lead concentration limit in the mann er described above. As described in the Draft Cost Impacts of the Revised NESHAP for the Secondary Lead Smelting Source Category , we estimate that three baghouses at two facilities would need to be replaced as a result of the revised
limit. The estimated total capital cost is $7.7 million with a total annualized cost of $1.7 million.
We estimate that the revised limit would result in annual reductions of metal HAP of approximately 5.9 tons with co

- reductions in emissions of particulate matter (PM) of

app roximately 56 tons. We do not anticipate additional energy use associated with this revised limit, as only replacement baghouses, as opposed to new additional units, are expected. Furthermore, we do not anticipate any adverse non

- air environmental impacts associated with the implementation of this revised limit.

For these reasons, we are recommending that a flow

- weighted average lead concentration limit of 0.2 mg/dscm be applied to the sum of all stacks at each facility in this source category.
To limit t he potential impacts of any individual stack, we are also recommending that a maximum lead concentration limit of 1.0 mg/dscm be applied to individual stacks in this source category. This is warranted given the fact that, as described above, over 96 perce nt of stack lead concentrations reported in the ICR were less than 1.0 mg/dscm.14

Figure 3

- 1. Comparison of Stack Lead Concentrations Reported by the Industry with a Potential Revised Lead Concentration Limit.

3.2 Fugitive Emissions

As outlined in section 2.2 of this memorandum, several facilities in this source category are currently implementing controls for fugitive emissions of metal HAP that exceed what is required in the current NESHAP. Based on our analyses, we are recommending revising the

current NESHAP to reflect the level of control currently being achieved by the better performing facilities in this source category with regards to fugitive emissions of metal HAP.

Because fugitive emissions cannot be directly captured or measured, the most feasib le limit is a work practice standard. Although lack of direct measurement makes comparisons of the efficiency of different control technologies challenging, analysis of ambient lead monitoring data near the facilities has generally been considered an accu rate indicator of the level of fugitive
emissions of metal HAP. The Draft Residual Risk Assessment for the Secondary Lead Smelting Source Category presents dispersion modeling results for this source category indicating that fugitive emissions are overwhe lmingly the most significant source contributing to ambient lead concentrations near the property boundaries of secondary lead smelting facilities. The same modeling results indicate that fugitive lead emissions from this source category could result in

e xceedances of the lead NAAQS at 12 of the 14 facilities.

We analyzed available ambient monitoring data to determine which facilities were implementing the most effective controls for fugitive emissions of metal HAP. Figure 3

- 2 0 0.5 1 1.5 2 2.5 Concentration (mg/dscm)

Individual Stack Test Results



### Reported Stack Lead Concentrations

Reported Lead Concentrations Potential Revised MACT15

displays the annual average lead concentrations at ambient monitoring locations around facilities based on the enclosure category assigned to the facility in section 2.2 of this memorandum. The figure includes concentration data for 12 of the 14 facilities (monitoring data near Exi de Baton Rouge and Exide Forest City were not available). All data in this figure were taken from http://www.epa.gov/airexplorer/monitor_kml.htm . The most recent year’s monitoring data
availabl e (either 2008 or 2009 for each facility) was selected for each facility. In cases where data were available at multiple monitoring locations around a facility, we chose the monitor with the highest annual lead concentration.

Figure 3

- 2

. Comparison of A n nual Ambient Lead C oncentrations for Each Enclosure Category.

As the figure shows, facilities categorized as level 3 enclosures achieved significantly lower ambient lead concentrations than those classified as level 1 or 2 enclosures. As previously

me ntioned, seven of the 14 facilities are currently classified as level 3 enclosures, with an 8 th facility planning to implement level 3 enclosures in the near future. Of the facilities classified as having level 3 enclosures, four facilities also implement some or all of the additional work practices mentioned in section 2.2 to further prevent the formation of fugitive dust in other areas of their facilities. Based on this analysis, we concluded that level 3 enclosure plus the implementation of additional fugitive control work practices is necessary to achieve ambient lead concentrations below the NAAQS near the fence line of a facility. Because several facilities are already implementing these controls and because we estimate that these controls are neces sary to ensure to ensure ambient lead concentrations below the NAAQS, we recommend revising the current NESHAP to require these controls. 0.00 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60

Level 1 Level 2 Level 3 Concentration (mg/dscm) Annual Ambient Lead Concentrations by Enclosure Category16

As with the revised stack lead concentration limit discussed in section 3.1 of this memorandum, we considered the pote ntial cost impacts of revising the fugitive emissions
standard in the current NESHAP to include the controls mentioned above. As described in the
Draft C ost Impacts of the Revised NESHAP for the Secondary Lead Smelting Source Category

, we estimate that the total capital cost to implement level 3 enclosure and additional fugitive control work practices throughout the industry is approximately $40 million with a total annualized cost of approximately $9.6 million. We estimate reductions in metal HAP emiss ions of 9.5 tons per year resulting from this revised standard with co

- reductions of PM of approximately 104 tons. We do not anticipate any adverse non

- air environmental impacts associated with this recommended standard. However, we do anticipate some ad ditional energy use associated with the operation of the new total enclosure. After consideration of the costs, emissions reductions, and other potential impacts, we believe the revision of the fugitive emissions standard for this source category to inclu de the control measures described in this memorandum is warranted and necessary.

As an alternative to requiring level 3 enclosure and the implementation of an extensive list of fugitive control work practices, we recommend that facilities be allowed to dem onstrate compliance through ambient lead monitoring. If facilities are able to demonstrate ambient lead concentrations near their facility that are below the lead NAAQS using practices other than those specified above, then it can be concluded that they a re achieving a similar level of control as would be achieved by the control measures described in this memorandum. Providing such an alternative would allow the facilities flexibility in determining the most appropriate and cost

effective method of achiev ing the necessary reductions in fugitive emissions of metal HAP.

4.0 CONCLUSIONS This review identified several developments in practices, processes , or control technologies that have been implemented in this source category since promulgation of the
current N ESHAP. Our analysis indicates that several facilities have significantly reduced stack emissions of metal HAP, primarily though improved performance of baghouses. Additionally, several facilities have implemented fugitive emissions control practices that exceed the requirements of the current NESHAP. Based on our review, we conclude that it is feasible and

cost

- effective for facilities to achieve a facility

- wide, flow

- weighted average lead concentration of 0.2 mg/dscm with a limit of 1.0 mg/dscm for any individual stack. We conclude that it is feasible for all facilities to fully enclose all process areas under negative pressure of and implement a prescribed list of work practices to limit fugitive emissions. As an alternative,
facilities could demonstr ate a similar level of control for fugitive emissions by monitoring ambient lead concentrations at or near the facility boundaries to ensure that concentrations remain below the lead NAAQS ( i.e.

, 0. 15 μg/m 3 ). Implementing these controls would achieve17

redu ctions in lead emissions of approximately 13.3 tons with total metal HAP reductions of approximately 15 tons. Additionally, we expect total co

- reductions of PM emissions of approximately 160 tons. We estimate that between 48 and 76 tons of the total PM r eductions will be reductions in particles with diameters less than 2.5 microns (PM 2.5 ), depending on the nature of the particle size distribution of emissions from this source category. For these reasons,
we believe that these controls and measures are co st

- effective measures that reflect achievable performance for this industry.