Primary Lead Processing NESHAP Technical Support Document : Final Rule



## Risk and Technology Review

**National Emission Standards for Hazardous Air Pollutants (NESHAP)**
**for Primary Lead Processing** 

**Technical Support Document : Final Rule** 

**Docket No. EPA** 

**- HQ** 

**- OAR** 

**- 2004** 

**- 0305** 

**November 4 , 2011** Primary Lead Processing NESHAP Technical Support Document : Final Rule

i Table of Contents

1.0 Residual Risk Analysis

– Revisions to the Emissions Dataset from Proposal for the
Primary Lead Processing NESHAP

................................ ................................ .................... 1

1.1 Comparison of Emission Sources

................................ ................................ .................. 2

1.2 Comparison of Emissions

................................ ................................ .............................. 2

2.0 Calculation of Final Risk

- Based Emission Limits Based on Modeled Concen trations

..... 4

3.0 Model to Monitor Comparison

................................ ................................ ........................... 7

4.0 Estimated Costs of Revisions to the Primary Lead Smelting NESHAP

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

4.1 Emission Control Costs for Ample Margin of Safety and Technology Review Analyses

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

4.2 Additional Testing and Monitoring Costs

................................ ................................ .... 12

Tables

Table 1 Comparison of Lead Emissions (TPY) from Proposal and 2009 Doe Run Submitted Modeling Data

Table 2 Calculations of Risk

- Based Emission Limits Based on Modeled Concentrations

Table 3 Remodeling for Final Rule

– Mo del

- to

- Monitor Comparison

Table 4 Estimated Costs for Wet Electrostatic Precipitator Control Technology for Doe Run Company Primary Lead Processing Facility

Table 5 Additional Testing and Monitoring CostsPrimary Lead Processing NESHAP Technical Support Document : Final Rule

1 

### 1.0 Residual Risk Analysis

– Revisions to the Emi ssions Dataset from Proposal for
the Primary Lead Processing NESHAP

On February 17, 2011, the EPA proposed changes to the Primary Lead Smelting NESHAP based on the

results of a residual risk analysis conducted to fulfill Section 112 (f)(2) of the Clean Ai r Act (CAA). In
order to conduct the risk analysis of sources in the Primary Lead Smelting source category, a n emissions
dataset was developed that included estimates of individual hazardous air pollutants ( HAP ) emissions
from each HAP emitting source as w ell as source characteristics. Using t he emissions dataset emissions

were modeled to determine concentrations of lead and other HAP at the modeled receptor locations.
Those concentrations were compared to established risk

- based threshold s for each HAP to e stimate

residual risk s . 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

the docket.

The EPA solicited comment s on the e missions and other data used to conduct the residual risk
assessment and received significant comment s on the data used along with submittal of revised and/or

corrected emissions data , source characteristic information

, and meteorological data. Comment s on the
modeling methodology and parameters were also received along with additional model parameter
information. Based on the comment response, a revised emissions dataset was developed and emissions

were remodeled

.

As part of their comment s , the Doe Run C ompany (Doe Run) provided a modeling file developed by
Shell Engineering which they indicated included the appropriate emissions and source characteristic
information for the facility. The following information was extracted from the Doe Run modeling files :

• For Point sources: Source ID, X Coord. [m], Y Coord. [m], Base elevation [m], Release height
[m], Emission rate [g/s], gas exit temperature [K], gas velocity [m/s], inside diameter [m]

• For Volume sources; Source ID, X Coord. [m], Y Coord. [m], Base elev ation [m], Release height
[m], Emission rate [g/s], side length [m], building height [m], initial lateral dimension [m], initial

vertical dimension [m]

• For Area sources; Source ID, X Coord. [m], Y Coord. [m], Base elevation [m], Release height

[m], Emissio n rate [g/s ·m 2 ], X side length [m], y side length [m], angle from North [deg.], initial

vertical dimension [m].

In addition, Doe Run provided p article size range s and distribution s pro vided hours of operation for

several sources which indicated the distrib ution of the emission rate from the source file over a 24

- hour
period.Primary Lead Processing NESHAP Technical Support Document : Final Rule

2 Because the original emissions file and modeling data did not include particle distribution data or an operations profile, these files were not compared to the original dataset. Below i s a comparison of the
dataset used in the proposal and the dataset used for remodeling exercise.



### 1.1 Comparison of Emission Sources

We compared information on emission sources from the Doe Run submittal against the source

information in the proposal da ta set

. The majority of the sources submitted by Doe Run matched those in
the proposal dataset. The following list itemizes the differences found in the datasets with regard to

sources and level of emissions;

• Baghouse 7 ( S ource ID 50008 ) emissions were acco unted for under Baghouse 9

, which shares a
common stack with Baghouse 7. Emissions were combined in the modeling performed by Doe
Run; however, emission rate estimates for each baghouse were provided in their comments.

• For proposal

, Source ID 50006 was not included in the risk assessment as the facility reported

that it no longer exist ed and that those emissions were now captured and vented through a baghouse . However, the new submission reported this source with 0.0018 tpy emissions.

• Source IDs 20004, 200 04B, 20004C (fume handling) and 60004 (low alpha baghouse) were
shown with emissions totaling 0.2125 ton year and the new submission reported ze ro emissions
from these sources because they are no longer operating the low alpha baghouse and the fume

handlin g is now performed in such a way that fugitive emissions are not generated at those

locations

.

• P lantwide resuspension was characterized with emissions of 0. 31 tpy in the proposal dataset.

This was reported as zero emissions in the new submittal ; however, D oe Run reported individual
haul road segments with a total of 0. 51 tons per year of fugitive dust emissions.



### 1.2 Comparison of Emissions

We used data provided in the Doe Run submittal to develop an emissions profile for modeling.
Specifically, we used the temporal restrictions on operations of some sources to determine operating
hours for each source. Where a specific operating scenario was not listed, we assumed even distribution
over 24 hours for 365 days per year. We used the emission rate provided in g rams per second and
operating hours to calculate the estimated tons per year emissions for each source. We also reviewed the

new stack height data

, which showed an increase in height for the Baghouse 8 and 7/9 stacks to 150 feet

from the 100 feet in the pr oposal dataset. The Doe Run submittal listed the stack height for the main
stack as 330 feet. The proposal dataset listed the stack height for the main as 55 0 feet which is the actual
stack height. However, the Doe Run submittal limited the height for the main stack consistent with

“ Good Engineering Practice ” which is required when modeling for NAAQS compliance demonstration.Primary Lead Processing NESHAP Technical Support Document : Final Rule

3 The difference in total lead emissions in the modeling submitted as a part of Doe Run’s comments was an increase of 11.27 tons per ye ar from the proposal dataset . The stacks , which include the main stack,
Baghouse 8, Baghouse 9 account for an additional 13.49 tons of lead per year

. However, as described
more fully below, the emission rate for the main stack included in Doe Run’s modelin g was not used for

the revised risk assessment.

Lead f ugitive dust emissions decreased by a total of approximately 1.54 tons per year . This included a

65 percent increase in emissions reported for the plantwide resuspension source in the proposal dataset

a nd a n 81 percent decrease from the reported emissions for other fugitive dust emission sources (i.e.,
concentrate, sinter and fume handling). Table 1 below summarizes the change s in lead emissions levels
reflected in the comparison of the proposal dataset (based on 2008 emissions) and the Doe Run

submission (based on 2009 emissions)

.

Table 1 Comparison of Lead Emissions (TPY) from Proposal and 2009 Doe Run Submitted
Modeling Data

New Submittal * Proposal Dataset **

Source ID Name Emissions (tpy) Name Emi ssions (tpy) Comment:

7000#s Haul roads 0. 51 plantwide resuspension 0.31 increase of 65%

30001 main stack *** 68.32 main stack 13.31 increase of 410 %

5 000 8 BH 7 2.46 BH7 1.81 increase of 36%

50007 BH 8 1.17 BH 8 0.45 increase of 160%

50008 BH 9 7.96 BH 9 2.03 increase of 290 %

NA Other stacks 0. 40 Other stacks 0.26 increase of 55%

NA Other fugitive 0. 49 Other fugitive 2.54 decrease of 81 %

Total 81.31 20.71

*Based on 2009 emissions data.

**Based on 2008 emissions data.

***The main stack emiss ion rate (19.53 tpy) included in the new submittal was not included for reasons described below.

The final dataset included emissions of lead compounds and other metal HAP (i.e. antimony, arsenic,
cadmium, chromium, cobalt, and nickel).

The emissions dat aset for this facility represents the entire source category. Likewise, all emission points
located at this facility and that emit HAP are included in the risk analysis dataset; therefore, the facility

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

.

The emission rate for the main stack was revised using the results of a 2009 stack test submitted by Doe

Run rather than the rate provided in the Doe Run modeling run submittal . The lead emission rate for the

main stack included in Doe Run’s modeling was based on an emission factor used since 2004 that wasPrimary Lead Processing NESHAP Technical Support Document : Final Rule

4 not reflective of the emission rate measured during the stack test performed for their 2009 compliance

demonstration. The emission rate of 68.32 tons per year that was modeled for the revised risk

assessment is likely a conservative estimate of annual emissions. This emission rate does not reflect the

fact that some downtime occurs throughout the year during which sources emitting through the main

stack are not operating

.

The emissions and source parameters used in the residual risk modeling conducted for the final rule can

be reviewed in the docket of this rule.



### 2.0 Calculation of Final Risk

- Based Emission Limits Based on Modeled

Concentrations

The final risk analysis model ed actual lead emissions to determine lead 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 th e Primary National

Ambient Air Quality Standard (NAAQS) for lead ( 0.15 μg/m 3 ). If the modeled emission s exceeded the
lead NAAQS, the risk at that location w as considered to be unacceptable. The results indicated multiple

locations exceeded the level of the NAAQ S to various degrees.

M odeling results indicated that t he highest concentration location was a point on the property boundary

. Emissions contributing to this concentration were cumulative stack emissions ( Baghouse 7/9 stack and
Baghouse 8 stack wer e the largest contribut o rs ) and fugitive dust emissions. As in the proposal
modeling, t he emissions from the main stack did not exceed NAAQS within the 50 km radius modeled

area

.

Each emission point (with roadways and all other fugitive dust emissions bei ng treated as one emission
point) was analyzed to d etermine what emission level s would be necessary to reduce risk to an
acceptable level ( i.e., such that modeled emissions met or were below the level of the NAAQS )

. The

EPA assumes that if the highest or w orst

- case concentration at a receptor location resulting from the
emissions from each emission point were reduced to below the NAAQS level, then the risk s for that
emission point at any location would be reduced to an acceptable level. Further, the EPA ass umes that a
reduction in emissions from an emission point will result in a proportionate reduction in the modeled
concentration at a given receptor location. Since the relationship between level of emissions and

modeled concentrations is assumed to be line ar, a percentage reduction applied to an annual emissions

rate for a given emission point would produce the same reduction in modeled concentration s

. A

calculation was made for each emission point to determine what percent reduction in concentration was

re quired for each of the highest concentration location s to meet the NAAQS.

T he risk assessment projected ambient lead concentrations from fugitive dust emissions to be very close
to the NAAQS for lead at the location of maximum impact . W ith respect to fug itive dust emissions, only
minimal (if any) reductions beyond those already in place are needed to ensure lead levels in the air doPrimary Lead Processing NESHAP Technical Support Document : Final Rule

5 not exceed the NAAQS

. The furnace area is vented through Baghouse 7 and exhausts through a stack
shared with Baghouse 9. The refining operations consist of the refining kettles and refining building
which exhaust through Baghouse 8 and Baghouse 9, respectively. Our analysis indicated that the

maximum lead concentration location for the furnace area (Baghouse 7) and refinery ope rations
(Baghouse 8 and 9) overlapped at the same census block. Therefore, their combined concentrations at

that location would be the driver for the reduction from these emission points. The reduction necessary

for the combined furnace area stack and refi nery stack emissions from the emission levels provided by

Doe Run in their comments was determined to be approximately 9 0 percent.

For the combined furnace area and refining operations stacks the total emissions reported w ere 11.5 6

tons per year ; the new lead emission limit for the combined furnace area and refining operations stacks
would be 1.2 tons per year.

Table 2 summarizes the calculations and recommended limits for the furnace area /refinery stack s

.Primary Lead Processing NESHAP Technical Support Document : Final Rule

6 Table 2

- Calculations of Risk

- Based Emission Limits Based on Modeled Concentration s

Modeled Source 2009

Emissions Maximum

Modeled L ead

C oncentration* Rollback to

M eet 0.15μg/m 3 * Estimated

Emissions

A fter R ollback

(tpy) (μg/m 3 ) % (tpy)

Stacks

- Baghouse 8 & 9(refinery) 9.1 1.1 6 87 1.2

- Baghouse 7 (furnace area) 2. 5 0.31 52 1.2

Combined Stacks 11. 6 1.47 90 1.2

FINAL EMISSION LIMIT
Furnace Area and Refinery Stacks 1.2 TPY

Calculations:

Roll back % = (Actual concentration

- 0.15)/actual concentrat ion

Emissions after rollback = 2009 emissions * (1

- (rollback%/100))Primary Lead Processing NESHAP Technical Support Document : Final Rule

7 

### 3 .0 Model to Monitor Comparison

In the proposed rule the EPA compared the maximum modeled estimates of ambient air lead

concentrations with those measured at four monitor s located close to the Doe Run facility in

Herculaneum , Missouri for calendar year 2008. More specifically, the maximum 3

- month rolling
average lead concentrations (for calendar year 2008) calculated from data reported at the Main Street,

Circle Str eet, South Cross, and Church Street monitors were compared to the maximum 3

- month rolling
average lead concentrations at model receptor locations in close proximity to these monitoring sites.

Results of this analysis were presented in the proposal preambl e and indicated that with respect to the

Main Street and Circle Street monitors, AERMOD underestimate d 3

- month maximum lead
concentrations by approximately 2.8

- and 4.2

- fold, respectively. The EPA received comment that the

modeled

- to

- monitored ratio was to o high indicating that the modeled results were not reasonably in
agreement with modeled concentrations. According to commenters, the model

- to

- monitor ratio should

have been less than two in order to demonstrate that the AERMOD estimate s are a reasonable

r epresentation of the measured 3

- month maximum lead concentrations in the ambient air near this
facility.

For the final rule, the facility emissions were re modeled based on revised and new information
submitted through the public comment process. A model

- t o

- monitor comparison was conducted for six
monitor locations close to the facility for the year 2009

. The resulting model

- to

- monitor ratio indicates

that for any monitor analyzed, the maximum model ed concentration is within 50% of the maximum

monitored con centration at the same location which demonstrates a reasonable agreement of the

modeled concentrations with the monitored concentrations at the six monitor locations. Table 3 provides
a summary of the model

- to

- monitor comparison for the remodeling of emis sions data for the final rule

.Primary Lead Processing NESHAP Technical Support Document : Final Rule

8 Table 3 Remodeling for Final Rule

– Model

- to

- Monitor Comparison

Monitor Name Latitude Longitude AE R MOD

Modeled Lead

C oncentration 2
(μg/m 3 ) Maximum

Monitored Lead

Concentration 2
(μg/m 3 ) Max Modeled/

Max Monitored Percent

Difference 3

City Hall/Main St. 4238290 729319 0.776 1.2 6 4

. 67 %

- 3 5

. 33 %

Sherman 4239206 729503 0.19 0.16 118.75% 18.75%

North Cross 4238151 729121 0.34 0.59 57.63%

- 42.37%
High School/Dunklin 4238702 729334 0.343 0.39 87.95%

- 12.05%

Church St. 4237753 729168 0.601 0.45 133.56% 33.56%

Ursuline 1 4235800 729617 0.073 0.08 91.25%

- 8.75%

1 There is no 2009 data for this monitor. The value for "Max Monitored" is from 2010.

2 Maximum 3

- month average

3 Negative value = model underestimationPrimary Lead Processing NESHAP Technical Support Document : Final Rule

9 

### 4.0 Estima ted Costs of Revisions to the Primary Lead Smelting NESHAP

With regard to lead emissions, we are finalizing emission limits that are consistent with the results of our risk and technology reviews of the current NESHAP for primary lead processing

. We fou nd that no emission reductions were required from the main stack to achieve acceptable risk. Under our ample margin of safety technology review analys e s, we evaluated addition controls beyond the existing level of

control for the main stack as well as the refining and furnace area stacks to determine if a reduced

standard was warranted in order to provide an ample margin of safety

, or whether there were developments in practices, processes, or control technologies that warranted a reduced standard

consideri ng cost and technical feasibility

.

Although our analysis indicated that additional controls were not warranted for the main stack to achieve acceptable risk , we are reducing the main stack emission limit under section 112(d)(6) to reflect performance ach ievable from technological improvements. In addition we are increasing the frequency of monitoring stack emission from the current annual emissions testing to quarterly testing. This section, therefore, also includes estimates of the impacts for the additi onal monitoring costs necessary to comply

with final emission limit requirement s

.

In the proposed rule f or the main stack emission point, we considered and rejected the option of upgrading existing controls by adding in

- series baghouses

. During the publi c comment period, commenters suggested that the EPA evaluate wet electrostatic precipitators as polishing control devices in the analysis performed under section 112(d)(6) of the CAA and the ample margin of safety analysis performed under section 112(f) of the CAA. The EPA has determined wet electrostatic precipitator s (WESP) may be technologically feasible for achieving additional emission reductions from the main

stac k, refinery stacks, and furnace area stack , but the technology is not economically feasib le in this

case

. Therefore, we are not requiring a reduced emission standard that reflects the performance of WESP technology for these three stacks. This section summarizes the impacts analysis that was

conducted on adding this additional emission control option to the existing control configuration

.

We note that the controls that reduce lead emissions are the same controls that would reduce emissions

and risks from other metal HAP; therefore we are not proposing additional controls for other metal

HAP. W e further note that the analysis for the ample margin of safety determination and the technology review both evaluated the same technology. This technology has been determined to be cost prohibitive in both analyses.

4

. 1 Emission Control Costs for Ample Ma rgin of Safety and Technology Review Analyses

Once we determine that risk will be reduced to a level that is acceptable, we then determine whether further reductions are appropriate to ensure an ample margin of safety. We investigated available control

opt ions that could be implemented by the facility to attain the additional emissions reductions that would provide an ample margin of safety

.

N o additional controls other than the WESP technology described in public comments were identified to

further contr ol emissions from the furnace area stack or the refinery stacks that are already controlled with baghouses using membrane bags

.Primary Lead Processing NESHAP Technical Support Document : Final Rule

10 For the main stack, our risk analysis indicates that emissions do not result in ambient lead levels exceeding the NAAQS based o n the actual emission levels . However, we determined that it is technologically feasible to reduce emissions from the main stack to a level below the allowable level of the MACT, since those levels are currently being achieved. We evaluated additional cont rols beyond what is already achieved such as a WESP for achieving further reductions and reducing associated risk. The investment required to install a polishing control device after the baghouses ducted to the main stack would approach $100 million dollar s. We determined that the additional controls would not be economically feasible based on 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 t he technology review memorandum found in the docket for this action

. There is no cost associated with the revised main stack emission standard promulgated under section 112(d)(6) as this level of emissions is already achieved . As with the main stack, we ev aluated the cost of installing WESPs on the

stacks for which emission standards are being promulgated under 112(f) during our ample margin of safety and 112(d)(6) technology review analyses. The cost of installing WESPs on Baghouses 7/9 and Baghouse 8 is a pproximately $50 million dollars. This cost is prohibitively high and makes the reductions based on installation of WESPs on these sources economically infeasible . Based on the economic infeasibility of installing additional control devices, reduc tions in the emission standards based on WESP technology were rejected under the 112(f) ample margin of safety analysis and the 112(d)(6) technology review.

Table 4 summarizes the costs and cost

- effectiveness of adding a WESP to the main stack

, the Baghouse

7 & 9 s tack

, and Baghouse 8 stack.Primary Lead Processing NESHAP Technical Support Document : Final Rule

11 Table 4 Estimated Costs for Wet Electrostatic Precipitator Control Technology for Doe Run Company Primary Lead Processing Facility

Cost Efficiency at 95% RE

Source Volumetric Flow (cfm) Total Capital

Investment Total Ann ual Costs ($US) Emissions Reduction (tons) Control Efficiency ($/ton of lead)

Main stack 1,023,723 $ 86,104,296 $ 15,355,845 65 $237,707

BH 7 & 9 * 519,614 $ 44,354,995 $ 7,794,210 9 $901,586

BH 8 76,274 $ 7,638,460 $ 1,144,110 2 $487,582

* Baghouses 7 and 9 are discharged to the same stack. Therefore, costing was based on air flow for both baghousesPrimary Lead Processing NESHAP Technical Support Document : Final Rule

12 4

. 2 Additional Testing and Monitoring Costs

To demonstrate compliance with the new 0.97 lb/ton emission limit, EPA is requiring 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. Quarterly

stack test ing will also be required for the baghouse 7/9 and baghouse 8 stacks.

The add itional testing and monitoring requirements will result in additional cost as summarized in Table

5

.

Table 5

- Additional Testing and Monitoring Costs

Type of Testing/Monitoring Notes Cost Annual Cost

Main Stack Testing 1 Method 12 $13,000 per test $ 39,000

Baghouse 7/9 Stack Testing Method 12 $13,000 per test $52,000

Baghouse 8 Stack Testing Method 12 $13,000 per test $52,000

1 Includes 3 additional stack testsPrimary Lead Processing NESHAP Technical Support Document : Final Rule

Appendix A

Page 1 APPEND IX A

Cost Estimates for West Electrostatic Precipitator Control Technology

For Doe Run Company Primary Lead Processing Facility

Based on

EPA Cost ManualPrimary Lead Processing NESHAP Technical Support Document : Final Rule

Appendix A

Page 1 WESP Cost Estimates

- EPA Cost Manual

DEC

volumetric flow rate A B .67B .57B 5$/CFM

Main Stack 1,023,723 cfm WESP

initial Cost Cost Purchased equipment

cost Direct

Installation

Costs Total Direct

Costs Indirect

Installation

Costs TCI TAC O&M

for 95% efficiency 22.6 $/cfm $32,075,778 $32,575,778 $38,439,418 $25,754,410 $64,193,828 $21,9 10,468 $86,104,296 $15,355,845 $5,118,615

for 90% efficiency 18 $/cfm $25,547,080 $26,047,080 $30,735,554 $20,592,821 $51,328,375 $17,519,266 $68,847,641 $14,332,122 $5,118,615

for 85% efficiency 14.7 $/cfm $20,863,448 $21,363,448 $25,208,869 $16,889,942 $42,098,812 $14,369,055 $56,467,867 $13,308,399 $5,118,615

Baghouse 7 & 9 519,614 cfm

for 95% efficiency 22.6 $/cfm $16,280,794 $16,780,794 $19,801,337 $13,266,896 $33,068,233 $11,286,762 $44,354,995 $7,794,210 $2,598,070

for 90% efficiency 18 $/cfm $12,967,004 $13,467,004 $15,891,065 $10,647,013 $26,538,078 $9,057,907 $35,595,985 $7,274,596 $2,598,070

for 85% efficiency 14.7 $/cfm $10,589,720 $11,089,720 $13,085,870 $8,767,533 $21,853,402 $7,458,946 $29,312,348 $6,754,982 $2,598,070

Baghouse 8 76,2 74 cfm

for 95% efficiency 22.6 $/cfm $2,389,853 $2,889,853 $3,410,027 $2,284,718 $5,694,745 $1,943,715 $7,638,460 $1,144,110 $381,370

for 90% efficiency 18 $/cfm $1,903,423 $2,403,423 $2,836,039 $1,900,146 $4,736,185 $1,616,542 $6,352,728 $1,067,836 $3 81,370

for 85% efficiency 14.7 $/cfm $1,554,462 $2,054,462 $2,424,265 $1,624,258 $4,048,523 $1,381,831 $5,430,354 $991,562 $381,370

W ESP Auxiliary $ 500,000

1998 389.5 Multiplier

2010 540 1.386393

2008 575.4