## DEVELOPMENT OF THE MACT FLOORS AND MACT FOR THE FINAL NESHAP

FOR GOLD MINE ORE PROCESSING AND PRODUCTION

Metals and Minerals Group

Sector Policies and Programs Division

Office of Air Quality Planning and Standards

U.S. Environmental Protection Agency

Research Triangle Park, NC

December 1 6

, 20 10

## 1 Development of the MACT Floors and MACT for the Final NESHAP for Gold Mine Ore

Processing and Production

1. Selection of Affected Source

The Gold Mine Ore Processing and Production source category consists of facilities

engaged in processing gold ore to recover gold using roasters, autoclaves, carbon kilns, melt

furnaces, mercury retorts, electrowinning, and preg tanks. There were approximately 2 1 gold

mine ore processing facilities opera ting these processes in the United States in 2008.

Th e final rule appl ies to each new or existing affected source and specifies maximum

achievable control technology ( MACT ) standards for mercury emissions for the following four

affected sources in the G ol d M ine O re P rocessing and Production source category : ore

pretreatment, carbon processes with mercury retorts, carbon processes without mercury retorts,

and non

- carbon concentrate processes. These affected sources reflect the differences in process

operat ions, the sources of mercury entering the processes, and the nature of the emissions

.

Ore Pretreatment

The ore pretreatment affected source includes roast ing operation s and autoclaves that

pretreat refractory ore, which contains organic carbon and sulfid e mineral grains that prevent the

initial use of cyanide leaching to effectively extract the gold from the ore. The refractory ore is

oxidized in the roaster or autoclave, converting it to an “oxidized” ore, which can then be

effectively leached with cyan ide solution. Mercury enters these processes with the ore.

There are four existing facilities that use ore pretreatment processes, and mercury

emissions data are available for al l four of these facil i ties. The potential for mercury emissions

from this affected source is directly related to the amount of ore processed in the autoclaves and

roasters; consequently, the format selected for the standard for this affected source is pounds of

mercury emissions (lb) per million ton of ore processed (lb/ million ton of ore). In the 2007

- 2009

timeframe , the ore pretreatment sources accounted for approximately 55 percent of the mercury

emissions from the source category.

Carbon Processes with Mercury Retorts

The second affected source is carbon processes with mercury retorts

, which includes

those gold production operations that use carbon to collect (adsorb) the gold and mercury from

solution and the process units that follow (i.e., carbon kilns, pregnant tanks, electrowinning cells,

mercury retorts

, and melt f urnaces) . Mercury emissions are subsequently generated by these

## 2 process units. The primary intermediate product that is common to all of the facilities with these

carbon processes with mercury retorts is the gold

- bearing concentrate, which is the input to

mercury retorts. Further, concentrate is closely related to the final product because it contains

about 60 percent gold, and because of its value, it is carefully weighed and records of the

quantities are kept. The amount of c oncentrate input to the m ercury retort is also required to be

reported under the Nevada Division of Environmental Protection ( NDEP ) program, so we had

comparable and reliable data from the different gold mine facilities. Consequently, we decided

that the most appropriate format o f the emission limit for the carbon processes with mercury

retorts is lb/ton of concentrate processed

.

There are approximately 10 facilities with the carbon processes with mercury retorts , and

we have mercury emissions data for 10 of these facilities. I n the 2007

- 2009 timeframe , the

carbon process es with mercury retorts sources accounted for approximately 44 percent of the

mercury emissions from the source category.

Carbon Processes without Mercury Retorts

The third affected source is carbon processes wi thout mercury retorts

, which includes

those gold production operations that use carbon to collect the gold and mercury from solution

without the use of mercury retorts

. Several facilities have such low concentration s of mercury in

their ore that they do n ot require a mercury retort to remove and recover mercury. In addition,

the average mercury emissions from these types of facilities that do not have mercury retorts are

a factor of 10 less than facilities that do have mercury retorts. For these reasons, the final rule

differentiate s between carbon processes with and without mercury retorts

.

Mercury emissions are subsequently generated by the process units included in this

affected source (i.e., carbon kilns, pregnant tanks, electrowinning cells, and melt furnaces)

.

Similar to the reasons described previously for carbon processes with mercury retorts , the

concentrate is the input to the melt furnace for carbon processes without mercury retorts ; we

decided that the most appropriate format of the emission limit for the carbon processes without

mercury retorts is lb/ton of concentrate processed

.

There are approximately eight facilities with the carbon processes without mercury

retorts , and we have mercury emissions data for two of these facilities. In the 2007

- 2009

timeframe , the carbon process es without mercury retorts sources accounted for approximately

0.19 percent of the mercury emissions from the source category.

## 3 Non

- Carbon Concentrate Processes

Th is a ffected source includes facilities with gold ore processes that do not use carbon or

ore pre

- treatment. These facilities do not have roasters, autoclaves, or carbon kilns and instead

only use mercury retorts and melt furnaces to recover the gold and liberate mercury from the

concentrate. The amount of mercury entering these processes and potential mercury emissions

are directly related to the amount of concentrate processed; consequently, the appropriate format

for the final standard for this affected source is lb/ton of concentrate processed. There ar e about

three gold mine ore processing facilities sources with non

- carbon concentrate affected sources,

and we have mercury emissions data for two of these facilities. In the 2007

- 2009 timeframe , the

non

- carbon concentrate sources accounted for approximat ely 0.98 percent of the mercury

emissions from the source category.

2. Approach for Developing the MACT Floor

Pursuant to Section 112(d) of the Clean Air Act, MACT standards for existing

affected sources must be at least as stringent as the average emiss ions limitation achieved by

sources in the MACT pool ; that is, the best performing 12 percent of existing affected sources

for which the Administrator has data for source categories with 30 or more sources or the best

performing 5 sources for source catego ries with fewer than 30 sources. This level of

minimum stringency is called the MACT floor. For new sources, MACT standards must be at

least as stringent as the control level achieved in practice by the best controlled similar

affected source.

The MAC T floor limits for each of the four affected sources were calculated based on

the performance of the lowest emitting (best performing) sources in each pool of sources with

available data . We ranked all of the sources for which we had valid data representi ng current

performance based on their emissions and identified the lowest emitting of the existing

affected sources, which resulted in 4 facilities with ore pretreat ment processes, 10 facilities

for those with carbon processes with mercury retorts

, 2 facil ities for those with carbon

processes without mercury retorts, and 2 facilities with the non

- carbon concentrate processes.

For new source s, MACT was based on the best performing source for each of the four

aff ected source s

.

The run

- by

- run data and the de tails of the statistical calculations for the MACT floor

analyses are provided in Appendices A through E.

## 4 2.1 Statistical Approach for Existing Sources

To calculate the MACT floor limit for each of the affected sources, we established and

ranked source s’ emissions from lowest to highest. The data on which the limits are based are

expressed in terms of pounds of mercury emitted per unit of mass of input, where millions of

tons of gold mine ore is the input for the ore pretreatment processes and tons of concentrate is the

input for the carbon processes with mercury retorts, carbon processes without mercury retorts,

and the non

- carbon concentrate processes.

T he emissions data for those best performing affected sources were used to determine the

final emis sion limits, with an accounting for variability. 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 under var iable conditions. The

Court has recognized that EPA may consider variability in estimating the degree of emission

reduction achieved by best

- performing sources and in setting MACT floors. See Mossville Envt’l

Action Now v. EPA, 370 F.3d 1232, 1241

– 42 (D.C. Cir 2004) (holding EPA may consider

emission variability in estimating performance achieved by best

- performing sources and may set

the floor at a level that a best

- performing source can expect to meet “every day and under all

operating conditions”).

To c alculate the achieved emission limit, including variability, we used upper prediction

limit (UPL) approach, which is defined by the following equation :

T df T 

## v t x UPL **+ =** 

w here:

UPL = upper prediction limit,

T 

## x = the average total emission rate over the best performing affected sources

,

df 

## t 

## = the 99 th 

## percentile of the t distribution , and

T 

## v = the total variance for the top performing affected sources

.

The degrees of freedom associated with

df 

## t 

## is given by:



# ( **) ∑**  **∑**

**= =**  

## − **=** N

i M

j ij

i 

## n df

1 1 

## 1

## 5 where:

N = number of best performing affected sources (2 to 4 for the four affected sources),

M i 

## = number of mercury emitting processes at each affected source , and

n ij 

## = number of mercury emis sion test r u ns for each process unit.

The average total emission rate (

T 

## x ) is calculated from :



# ∑

**=** 

## = N

i Ti T 

## x N x

1 

## 1



## where:

N

= the number of top N affected sources ( N = 2 to 5),

Ti 

## x = t he total emission rat e of an entire i th affected source

.

To calculate

Ti 

## x :



# ∑

**=** 

## = i M

j ij Ti 

## x x

1



## where:

M i 

## = the number of distinct units within the i th affected source (i.e., we count all the distinct

units in a n affected source , so if a process t ype has two or more units, then each of those

units must be counted),

ij 

## x 

## = the unit average for the j th unit within the i th affected source

.

To calculate

ij 

## x 

## :



# ∑

**=** 

## = ij n

k ijk

ij ij 

## x

n x

1 

## 1

where:

n ij 

## = the number o f runs within the j th unit of the i th affected source

,

x ijk 

## = the observation associated with the k th run within the j th unit and i th affected source

.

T he total variance (

T 

## v ) consists of the following two variance components:

W B T 

## v v v **+ =** 

## 6 The first variance component (

B 

## v ) is simply the variance of

T 

## x ( the average total emission rate

over all affected sources )

. Suppose 2 

## var( )

ij ijk 

## s x **=** is the variance of an individual run i n the j th

unit and i th affected source , then th e variance of the unit average

, ij 

## x 

## in the j th unit and i th

affected source is

ij ij

ij



## n s

x 2



## ) var(

**=**

.

If all units operate independently, then the unit variances, 2

ij 

## s , will be additive. Therefore, based

on the assumption of variance additivity, the variance of the total emission rate of the i th affected

source is



# ∑

**=** 

## = i M

j ij ij

Ti



## n s

x

1 2



## ) var(

,

and the variance of the average total emission rate over all affected sources i s



# ∑ **∑**

**= =**  

## = **=** N

i M

j ij ij

T B i



## n s

N x v

1 1 2

2 

## 1 ) var(

.

The second variance component (

W 

## v ) is the variance of

new T 

## x

, 

## , the total emission rate

from new test runs at a n affected source in the future to determine compliance

. The theoretical

formu lation of

W 

## v based on thes e future runs is :

, , , 2

1 1 1 

## 1 var( ) var( ) var( ) M M m

W T new j new jk new

j j k 

## vx x x

m

**= = =**  

## = = **=** 

# ∑ ∑∑

,

where

, jk new 

## x 

## refers to the k th run of the j th unit in the new affected source , and M is the number

of units in the new affected source

. Also note that t he number of units, M , in the affected source

to be tested in the future is unknown and may vary

.

However, the theoretical formulation informs us how to derive an operational

formula tion of

W 

## v based on the data available f rom the runs already completed from the top N

affected sources :

## 7 2

2

1 11 1 1 

## 1 1 1 var( ) i i M M N m N

W ijk ij

i jk i j 

## v xs N m Nm

**= = = = =**  

##  

**= =**  **   **  

# ∑ ∑∑ ∑∑

Substituting into the equation provided for UPL earlier and rearranging yields:

2

1 1 

# 1 11 i M N

T df ij

i j ij 

# UPL x t s

N Nn m

**= =** 

#  

**= + +**  ** **

** ** 

# ∑∑

The first term of the equation ref ers to the average total emission rate of the top N affected

sources

. The second term accounts for the expected variability in future measurements due to

variations resulting from system operation and measurement activities , and this variability

consists of two components

. The first component accounts for the variability of the average

total emissions of the existing lowest emitting MACT pool sources , and the second component

accounts for the variability of the average of m new test runs based on the obse rved variance of

individual runs within test conditions from the lowest emitting MACT pool sources (the

second component typically accounts for the major portion of the overall variability) . The

variability factor assumes that variability from the individ ual best performing source s are

independent, and thus are additive. This is a reasonable assumption because each individual

best performing source has certain characteristics, such as material inputs, design and

operation, etc.

, that are unique to that pr ocess unit

.

2.2 Statistical Approach for New Sources

MACT for new sources is based on the UPL for the best performing source for each of

the four types of affected sources and is calculated from:

1 1 T df 

## v t x UPL **+ =** 

where:

1 

## x = the average total emission rate of the best performing affected source,

df 

## t 

## = the 99 th 

## percentile of the t distribution with ( n

– 1) degrees of freedom, and

1 T 

## v = the total variance of the best performing source.

The total variance of the best performing source is calculated from the formulas given in Section

2.1, except that in this case, N = 1 and the subscript i is replaced by the subscript 1 :

1 2

1 1

1 1 

## 1 1 M

T j

j j 

## v s

n m

**=** 

##  

**= +  ** 

** ** 

# ∑

,

## 8 where 2

1 j 

## s and

1 j 

## n 

## are the variance and number of runs, respectively, from the j th mercury

emitting unit of the best performing source

, 1 

## M is the number of distinct mercury

- emitting units

in this source, and m is the number of future runs to determine compliance (typically 3).

3

. MACT Floor for Mercury

Most of t he mercury emissions data used in the MACT floor analyses were obtained

from annual testing that was required by the Nevada Division of Environmental Protection

( NDEP ) for 2007 through 2009

. 1



## The NDEP i nvalidated several me rcury emission tests conducted in 2007 and 2008

because of failure s to comply with the federal reference test method , failure to comply with

the established testing protocol , possible sample contamination, etc. See docket item EPA

HQ

- OAR

- 2010

- 0239

- 0061 fo r a complete list and rationale for invalidated tests . As a result,

none of the test data for Barrick Goldstrike’s roasters and autoclaves for 2008 were used in

the analysis. However, 2007 and 2009 data for Goldstrike’s autoclaves and roasters w ere

use d in the analyses. The 2007 and 2008 tests for the mercury retorts at Goldstrike were also

invalidated; however, test data for 200 9 w ere available for the mercury retort s and w ere used

in the analysis for the carbon processes with mercury retorts . Other te sts that were invalidated

included the 2007 tests at Coeur Rochester

, one of the October 2008 test s at Marigold , two of

the August 2007 ore preheater tests at Goldstrike, and one of the February 2010 roaster tests

at Jerritt Canyon

. In addition, we exclud ed data from the October 2009 emission test on one

of the m elt f urnace s for the Cortez Pipeline facility

. The NDEP reported that, for that test, the However, 2010 test data were used for one facility that

installed new mercury emission controls on its roasters and resumed operation in late 200 9

.

The tests generally consist of three runs per test per process at each affected s ource . Most of

the measurements were made using EPA Method 29; however, Method 101A and the Ontario

Hydro method were used in a few cases. There we re cases where 2007 and/or 2008 results

represent emissions before a control device was installed, and 2008 and/or 2009 test results

represent emissions after a mercury emission control device had been installed. In those

cases, we used only the controlled test results to determine the top performing affected

sources . Emissions in lb/hr were multiplied by the number of hours the process operated in

2007 , 2008, or 200 9 and then divided by the process input rate for the year (in tons or million

tons ) to express mercury emissions in lbs per ton (or million tons) of input material.

1 

### A complete listing of the emission test data is provided in Appendix A throug h F of this document

.

## 9 mercury content of the concentrate was only 8 ppm, whereas the content for the December

2009 test was 1,55 7 ppm, and the content in 2007 and 2008 averaged 4,480 ppm and 4,250

ppm , respectively. Based on that information, we concluded that the mercury content was

unusually low for the October test

, and the emissions data would not be representative of

typical operations.

The following paragraphs discuss the results of the MACT floor analyses for the four

affected sources for the Gold Mine Ore Processing and Production source category

. Tables 1

through 4 summarize the results

.

Ore Pretreatment

V alid emissi ons d ata were available for all four o f the facilities with ore pretreatment

processes . As shown in Table 1, the average emissions level achieved by these four facilities

is 84 lb Hg/million tons of ore. The MACT floor based on the UPL is 158 lb Hg/milli on tons

of ore. For new sources, MACT corresponds to 84 lb Hg/million tons of ore. We estimate

that requiring the MACT floor emission limit for th is affected source w ould reduce emissions

of mercury by about 431 pounds per year ( lbs /yr) , a reduction of 3 0 percent from current

levels. In addition, e nergy consumption would increase by about 11,400 megawatt

- hours per

year (or 11.4 gigawatt

- hours per year ) . Solid waste generation and disposal (spent carbon

loaded with mercury) would increase by about 3 tons per year.

Table 1. MACT Floor Results for Ore Pretreatment

Affected Source Average performance (lb Hg /million tons ore)

Goldstrike (Facility A) 45 (14 tests, 42 runs)

Gold Quarry (Facility C) 56 (17 tests, 51 runs)

Jerritt Canyon Mine (Facility E) 71 (7 tests, 21 runs)

Twin Creeks Mine (Facility D) 165 (12 tests, 36 runs)

Summary of Statistical Analysis

Statistic Existing (top 4 ) New

Average (lb/MM tons) 84 45

df 131 42

t 2.36 2.42

Vb 52 65

Vw 935 198

Vt 988 263

99% UPL (lb/MM tons) , MA CT Floor 158 84

## 10 Carbon Processes with Mercury Retorts

Valid emissions data were available for 10 facilities that operate carbon processes with

mercury retort s

. Based on the MACT floor analysis, t he average emissions level achieved by

the best perform ing five sources is 1.1 lb Hg/ton of concentrate. After accounting for the

variability in emissions, t he MACT floor for this affected source is 2.2 lb Hg/ton of

concentrate. For new sources, MACT is 0.8 lb Hg/ton concentrate. We estimate that the

MACT f loor limit for th is affected source w ould reduce emissions by about 899 lbs /yr , a

reduction of 78 percent from current levels.

Table 2. MACT Floor Results for Carbon Processes with Mercury Retorts

Affected Source Average performance (lb Hg /ton concentrate )

Marigold (Facility N) 0.53 (7 tests, 21 runs)

Bald Mountain (Facility J) 0.74 (4 tests, 12 runs)

Ruby Hill (Facility I) 1.06 (4 tests, 11 runs)

Goldstrike (Facility A) 1.47 (18 tests, 54 runs)

Denton

- Rawhide (Facility H) 1.67 (12 tests, 36 runs)

Tw in Creeks (Facility D) 2.20 (31 tests, 93 runs)

Gold Quarry (Facility C) 3.71 (21 tests, 57 runs)

Florida Canyon (Facility G) 8.17 (18 tests, 54 runs)

Jerritt Canyon (Facility E) 14.49 (2 tests, 6 runs)

Lone Tree (Facility B) 20.60 (7 tests, 21 runs)

Summary of Statistical Analysis

Statistic Existing (top 5) New

Average (lb/tons) 1.1 0.53

D f 110 17

t 2.36 2.57

Vb 0.015 0.003 2

Vw 0.20 0.0037

Vt 0.2 2 0.0069

99% UPL (lb/ton) , MACT Floor 2.2 0. 8

Carbon Processes without Mercury Retorts

Val id data were available for two facilities that operate carbon processes without

mercury retorts

. As shown in Table 3, the average emissions level achieved by these two

facilities is 0.078 lb Hg/ton of concentrate. The existing MACT floor based on the UPL is

## 11 0.17 lb Hg/ton of concentrate. For new sources, MACT corresponds to 0.14 lb Hg/ton of

concentrate.

Table 3. MACT Floor Results for Carbon Processes without Mercury Retorts

Affected Source Average performance (lb Hg /ton concentrate)

Round Mountain (Facility M) 0.058 (5 tests, 15 runs)

Cortez (Facility F) 0.098 (13 tests, 39 runs)

Summary of Statistical Analysis

Statistic Existing (top 2) New

Average (lb/ton) 0.078 0.058

df 4 3 12

t 2.42 2.68

Vb 0.00031 0.00045

Vw 0.0010 0.00048

Vt 0.00 13 0.00093

99% UPL (lb/ton) , MACT Floor 0.1 7 0.14

Non

- Carbon Concentrate Processes

For this affected source, valid emissions data were available for two facilities. The

results of the analysis are summarized in Table 4. B ased on the MACT floor analy sis, the

average emissions level achieved by the se two facilities is 0.062 lb Hg/ton of concentrate.

The MACT floor for this affected source is 0.2 Hg/ton of concentrate. For new sources,

MACT is 0. 1 lb Hg/ton concentrate. We estimate that requiring the MACT floor emissions

limit for non

- carbon concentrate processes would reduce emissions by about 14 lbs /yr , a

reduction of 54 percent from current levels.

Table 4 . MACT Floor Results for Non

- Carbon Concentrate Processes

Affected Source Average performan ce (lb Hg /ton concentrate)

Coeur Rochester Mine (Facility K) 0.047 (5 tests, 17 runs)

Midas Operations (Facility L) 0.078 (13 tests, 27 runs)

Summary of Statistical Analysis

Statistic Existing (top 2) New

Average (lb/ton) 0.062 0.047

df 3 9 1 5

t 2. 43 2.6 0

Vb 0.0002 4 0.0002 6

Vw 0.002 6 0.0005 2

Vt 0.0028 0.00077

99% UPL (lb/ton) , MACT Floor 0. 2 0.1

## 12 4 . Beyond the Floor 2



## To evaluate opportunities for emission reductions beyond those that would result from

requiring facilities to meet the MAC T floor emissions limits , we typically identify control

techniques that have the ability to achieve an emissions limit more stringent than the MACT

floor. The following paragraphs summarize the results of th is " beyond

- the

- floor " analysis for

the four affe cted sources for the G old M ine O re P rocessing and P roduction source category.

Ore Pretreatment

Facilities with ore pretreatment processes have installed, or would need to install

,

calomel mercury scrubbers on their roasters and venturi scrubbers and/ may be carbon

adsorbers on their autoclaves, to achieve the MACT floor for ore pretreatment processes. To

achieve further reduction in mercury, one beyond

- the

- floor option is the installation of both a

refrigeration unit and a carbon adsorber on the facilit ie s with autoclaves . This additional

control system would follow the existing venturi scrubbers, and

, because autoclave exhaust is

saturated with water, a refrigeration unit or condenser would be required to remove moisture

that would otherwise adversely af fect the adsorptive ca pacity of the carbon adsorber. We

assumed that the additional control from the carbon adsorber would result in a 70 percent

reduction of mercury emissions. This value was proposed by Newmont Twin Creeks facility

in their Phase 2 app lication to the Nevada Mercury Control Program. We believe that it is an

appropriate estimate of emissions reductions seeing as this control has never been

demonstrated on an autoclave.

The estimated capital cost for the additional controls for the aut oclaves at Twin Creeks

would be $29.3 million, with a total annualized cost of $4.9 million/yr. Based on an

estimated control efficiency of 70 percent, mercury emissions would be reduced by 431

lbs/yr, resulting in an estimated cost effectiveness of $11,3 90/lb. We are incorporating this

beyond

- the

- floor analysis in the final rule.

We estimate the capital cost for the additional controls on the autoclaves at Goldstrike

would be $47,000,000

, with a total annualized cost of $8,200,000/yr

. This option would

reduce m ercury emissions by 10 lbs /yr , resulting in an estimated cost effectiveness of

2 

### Additional details and documentation for the estimates of emissions, emission reductions, and costs are provided

in the rulemaking docket (EPA

- HQ

- OAR

- 2010

- 0239)

.

## 13 $782,409/lb. Because of the high cost effectiveness for addition controls to the autoclaves at

Goldstrike, we are not incorporating this beyond

- the

- floor analysis in t he final rule.

We also identified as a beyond

- the

- floor option the installation of a carbon adsorber on

ore preheater/dryer units. Again, we assumed that the additional control from the carbon

adsorber would result in a 70 percent reduction of mercury em issions on the ore

preheater/dryer units. We believe that this is an appropriate estimate of emissions reductions

because this control has never been demonstrated on these units. We estimate d the capital

cost for the additional controls as $2,962,000

, wi th a total annualized cost of $1,622,000/yr.

Based on an estimated control efficiency of 70 percent, m ercury emissions would be reduced

by 118 lbs /yr , resulting in an estimated cost effectiveness of $13,784/lb

.

Another assumption used in the beyond

- the

- floor calculations was th at one facility

,

which h as both roasters and autoclaves

, would operat e only their roasters. With these

additional control s

, the average emissions level achieved by these sources facilities would be

80 lb/million tons of ore. We estimate that requiring the MACT floor emissions limit and the

beyond

- the

- floor options for ore pretreatment processes results in a total emissions reductions

of 548 lbs/yr, a reduction of 38 percent from current levels. Applying the UPL formula to

account for variability, the resulting beyond

- the

- floor emissions limit would be 127 lb/million

tons of ore . Table 5 summarizes the beyond

- the

- floor analysis for ore pretreatment processes

.

This emission limit was incorporated in the final rule.

We also eval uated a beyond

- the

- floor option for the new source standard. The best

performing similar source for the ore pretreatment affected source is the Goldstrike facility.

We identified as a beyond

- the

- floor option the installation of a carbon adsorber on the

a utoclaves and on ore preheater units at this facility. We estimated the capital cost for the

additional controls as $48,100,000, with a total annualized cost of $ 9,419,000 /yr. Based on

an estimated control efficiency of 70 percent for the controls on the autoclaves and the ore

preheaters, mercury emissions would be reduced by 44.6 lbs/yr, resulting in an estimated cost

effectiveness of $211,188/lb. Because of the high cost effectiveness values, the beyond

- the

floor anyslsysis for new sources in the ore p retreatment affected source were not adopted in

the final rule.

## 14 Table 5

. Beyond the Floor Results for Ore Pretreatment

Affected Source Average performance

(lb Hg/million tons ore)

Gold Quarry (Facility C) (70% reduction) 37

Twin Creeks (Facility D) ( 70% reduction) 49

Jerritt Canyon (Facility E) (70% reduction) 58

Goldstrike (Facility A) (70% reduction) 80

Summary of Statistical Analysis

Statistic

Average achieved by all (lb/MM tons) 80

df 123

t 2.36

Vb 30

Vw 369

Vt 399

Affected Sourc e 99% UPL (lb/MM tons) 127

Other Affected Sources

For two of the other affected sources (carbon processes with mercury retorts and non

carbon concentrate processes), existing sources are equipped with efficient mercury emission

controls, and it is dif ficult to identify a technology that might be applied to achieve further

reductions in emissions , especially considering the very low mercury concentrations after the

MACT floor level of control and the difficulty in obtaining efficient additional percent

reductions for low concentration streams. For the beyond

- the

- floor analysis, we assumed that

a second carbon adsorption system could be installed in series with the first or existing

adsorber and would get an additional reduction of 90 percent. (We ackno wledge that there is

significant uncertainty in the additional reduction s the redundant control system might

achieve.) For carbon processes with mercury retorts, t he capital cost for the additional control

was estimated to be $3 million

, with a total annu alized cost of $1. 3 million/ yr . The emission s

reduction s for this control option would be 9 lbs /yr , resulting in an estimated cost

effectiveness of $150,275/ lb

. For non

- carbon concentrate processes, w e estimated the capital

cost for the additional adsorb er to be $0. 4 million , with a total annualized cost of

$ 191,000 /year. The mercury e missions reductions that would be achieved by this option

would be 0.13 lb/year , resulting in an estimated cost effectiveness of $1,400,000/ lb

. Because

of the uncertaintie s in the emissions reductions that could be achieved, and the high cost

effectiveness values, beyond

- the

- floor limits for these three types of affected sources were not

## 15 adopted in the final rule.

For a beyond

- the

- floor analysis for carbon processes withou t mercury retorts

, we

estimated the costs and reductions for installing a carbon adsorber to a unit at Round

Mountain that is currently uncontrolled. T he capital cost for a carbon adsorber was estimated

to be $ 0.2 million with a total annualized cost of $ 72,000 /yr . The mercury emission s

reduction associated with this option would be 1.6 lbs /yr, resulting in an estimated cost

effectiveness of $44,000/lb

. We do not believe that the small emission reduction that this

control option would achieve is justifie d in light of its cost. We therefore decided not to go

beyond

- the

- floor.

4. Summary of Final Emission Standards

Table 6 summarizes the mercury emission limits included in the final Gold Mine Ore

Processing and Production Area Source NESHAP

.

Table 6 . Summary of Final Mercury Emission Limits

Affected Source Hg Emission Limit s

Units Existing

Source s New

Source s

Ore pretreatment processes 127 84 lb/million ton s of ore

Carbon processes with mercury retorts 2.2 0.8 lb/ton of concentrate

Carbon processes without mercury retorts 0.17 0.14 lb/ton of concentrate

Non

- carbon concentrate processes 0.2 0.1 lb/ton of concentrate

## 16 Appendix A. Mercury Emissions Data for the Ore Pretreatment Affected Source (lb/ton of ore)

Facility Unit Run 1

(lb/ton) Run 2

(lb/ton) Run 3

(lb/ton) Unit sum

(lb/ton) Unit

average

(lb/ton) Facility

total

(lb/ton) Unit

variance No. of

runs per

unit DF (n

- 1)

per unit Variance

of unit

average Facility

variance Vw (m =

3 per

unit) Facility

Vw

Gold Quarry Roaster/Calcine

quen ch 1.35E

- 05 9.56E

- 06 1.37E

- 05

Gold Quarry Roaster/Calcine

quench 1.05E

- 05 1.33E

- 05 1.69E

- 05

Gold Quarry Roaster/Calcine

quench 8.45E

- 06 1.05E

- 05 9.66E

- 06 1.06E

- 04 1.18E

- 05 7.33E

- 12 9 8 8.14E

- 13 2.44E

- 12

Gold Quarry Roaster Ore

Preheater 1.27E

- 05 5.41E

- 06 4.53E

- 06

Gold Quarry Roaster Ore

Preheater 2.63E

- 05 2.50E

- 05 1.54E

- 04

Gold Quarry Roaster Ore

Preheater 8.18E

- 06 3.48E

- 06 3.03E

- 06 2.43E

- 04 2.70E

- 05 2.35E

- 09 9 8 2. 62E

- 10 7.85E

- 10

Gold Quarry Roaster 8.99E

- 07 6.97E

- 07 7.87E

- 07

Gold Quarry Roaster 1.27E

- 06 1.61E

- 06 6.19E

- 07

Gold Quarry Roaster 4.92E

- 07 2.75E

- 07 3.56E

- 07 7.00E

- 06 7.78E

- 07 1.86E

- 13 9 8 2.07E

- 14 6.21E

- 14

Gold Quarry Roaster Ore

Grinder 1.66E

- 06 2.06E

- 06 1.48E

- 06

Gold Quarry Roaster Ore

Grinder 1.50E

- 06 4.82E

- 06 1.75E

- 06 1.33E

- 05 2.21E

- 06 1.67E

- 12 6 5 2.79E

- 13 5.58E

- 13

Gold Quarry Roaster/Calcine

quench 1.67E

- 05 1.36E

- 05 9.55 E

- 06

Gold Quarry Roaster/Calcine

quench 1.27E

- 05 1.46E

- 05 2.11E

- 05

Gold Quarry Roaster/Calcine

quench 1.03E

- 05 1.31E

- 05 1.32E

- 05 1.25E

- 04 1.39E

- 05 5.56E

- 05 1.19E

- 11 9 8 1.32E

- 12 2.64E

- 10 3.96E

- 12 7.92E

- 10

Goldstri ke Roaster Ore

Preheater 3.23E

- 07 5.03E

- 07 3.60E

- 07

Goldstrike Roaster Ore

Preheater 8.61E

- 07 5.96E

- 07 5.17E

- 07

Goldstrike Roaster Ore

Preheater 1.79E

- 06 1.39E

- 06 2.65E

- 07

Goldstrike Roaster Or e

Preheater 2.19E

- 06 1.13E

- 06 2.65E

- 07 1.02E

- 05 8.48E

- 07 4.12E

- 13 12 11 3.43E

- 14 1.37E

- 13

Goldstrike Roaster Ore

Preheater 8.68E

- 06 4.71E

- 06 1.71E

- 06

Goldstrike Roaster Ore

Preheater 2.36E

- 05 5.05E

- 06 7.86E

- 07

Goldstrike Roaster Ore

Preheater 8.52E

- 07 8.52E

- 07 3.93E

- 07

Goldstrike Roaster Ore

Preheater 1.64E

- 06 8.52E

- 07 3.93E

- 07 4.95E

- 05 4.12E

- 06 4.40E

- 11 12 11 3.67E

- 12 1.47E

- 11

## 17 Facility Unit Run 1

(lb/ton) Run 2

(lb/ton) Run 3

(lb/ton) Unit sum

(lb/ton) Unit

average

(lb/ton) Facility

total

(lb/ton) Unit

variance No. of

runs per

unit DF (n

- 1)

per unit Variance

of unit

average Facility

variance Vw (m =

3 per

unit) Facility

Vw

Goldstrike Roaster 7.25E

- 05 5.71E

- 05 5.26E

- 05

Goldstrike Roaster 1.25E

- 05 1.25E

- 05 1.71E

- 05

Goldstrike Roaster 1.95E

- 05 1.73E

- 05 1.31E

- 05 2.74E

- 04 3.05E

- 05 5.47E

- 10 9 8 6.08E

- 11 1.82E

- 10

Goldstrike Roaster/Calcine

quench 4.35E

- 06 2.96E

- 06 2.87E

- 06 1.02E

- 05 3.39 E

- 06 6.86E

- 13 3 2 2.29E

- 13 2.29E

- 13

Goldstrike Roaster/Calcine

quench 3.55E

- 06 3.76E

- 06 3.32E

- 06 1.06E

- 05 3.54E

- 06 4.72E

- 14 3 2 1.57E

- 14 1.57E

- 14

Goldstrike Autoclave 2.59E

- 07 4.01E

- 07 4.70E

- 07 1.13E

- 06 3.77E

- 07 1.16E

- 14 3 2 3.87E

- 15 3.87 E

- 15

Goldstrike Autoclave 6.57E

- 07 7.71E

- 07 5.50E

- 07 1.98E

- 06 6.59E

- 07 1.23E

- 14 3 2 4.09E

- 15 4.09E

- 15

Goldstrike Autoclave 1.42E

- 06 1.65E

- 07 1.81E

- 07 1.77E

- 06 5.90E

- 07 5.21E

- 13 3 2 1.74E

- 13 1.74E

- 13

Goldstrike Autoclave 1.42E

- 06 8.32E

- 07 4 .62E

- 07 2.71E

- 06 9.03E

- 07 4.49E

- 05 2.32E

- 13 3 2 7.72E

- 14 6.50E

- 11 7.72E

- 14 1.98E

- 10

Jerritt

Canyon Ore dryer 1.35E

- 05 2.86E

- 05 1.92E

- 05

Jerritt

Canyon Ore dryer 3.82E

- 06 3.24E

- 05 1.14E

- 05 1.09E

- 04 1.82E

- 05 1.17E

- 10 6 5 1.95E

- 11 3.90E

- 11

Jerritt

Canyon Roaster 4.42E

- 05 4.47E

- 05 5.14E

- 05

Jerritt

Canyon Roaster 4.48E

- 05 2.07E

- 05 2.99E

- 05

Jerritt

Canyon Roaster 7.01E

- 06 7.92E

- 06 8.36E

- 06 2.59E

- 04 2.88E

- 05 3.31E

- 10 9 8 3.68E

- 11 1.1 0E

- 10

Jerritt

Canyon Roaster 5.50E

- 05 4.65E

- 05 2.82E

- 05

Jerritt

Canyon Roaster 5.80E

- 06 4.30E

- 06 4.65E

- 06 1.44E

- 04 2.41E

- 05 7.10E

- 05 5.16E

- 10 6 5 8.60E

- 11 1.42E

- 10 1.72E

- 10 3.21E

- 10

Twin Creeks Autoclave 5.52E

- 05 1.45E

- 04 1.02E

- 04

Twin Creeks Autoclave 7.82E

- 05 2.59E

- 04 2.90E

- 05

Twin Creeks Autoclave 2.36E

- 04 1.17E

- 04 1.08E

- 04

Twin Creeks Autoclave 2.13E

- 04 1.33E

- 04 1.10E

- 04

Twin Creeks Autocl ave 9.97E

- 05 1.97E

- 04 2.66E

- 04

Twin Creeks Autoclave 1.06E

- 04 6.95E

- 05 6.21E

- 05

Twin Creeks Autoclave 8.65E

- 06 8.07E

- 06 7.63E

- 06 2.41E

- 03 1.15E

- 04 6.39E

- 09 21 20 3.04E

- 10 2.13E

- 09

Twin Creeks Autoclave 1. 14E

- 04 5.47E

- 05 5.33E

- 05

Twin Creeks Autoclave 8.67E

- 05 4.98E

- 05 3.45E

- 05

Twin Creeks Autoclave 4.87E

- 05 9.07E

- 05 7.96E

- 05

Twin Creeks Autoclave 3.53E

- 05 2.50E

- 05 2.12E

- 05

Twin Creeks Autoclave 2.04E

- 05 1.91E

- 05 1.96E

- 05 7.53E

- 04 5.02E

- 05 1.65E

- 04 9.06E

- 10 15 14 6.04E

- 11 3.65E

- 10 3.02E

- 10 2.43E

- 09

Average

of top 4: 8.41E

- 05 t DF: 131 Vb: 5.22E

- 11 Vw

(unpoole

d): 9.35E

- 10

t(.99): 2.36

## 18 Appendix B . Mercury Emissions Data for the Carbon Processes with Mercury Retorts Affected Source (lb/ton concentrate)

Facility Unit Run 1

(lb/ton) Run 2

(lb/ton) Run 3

(lb/ton) Unit sum

(lb/ton) Unit

average

(lb/ton) F acility

total

(lb/ton) Unit

variance No. of

runs

per

unit DF

(n

- 1)

per

unit Variance

of unit

average Facility

variance Vw (m = 3

per unit) Facility

Vw

Marigold EW, P/B 3.68E

- 01 5.43E

- 01 4.32E

- 01 1.34E+00 4.48E

- 01 7.86E

- 03 3 2 2.62E

- 03 2.62E

- 03

Mar igold Retort 7.72E

- 02 1.14E

- 01 9.07E

- 02

Marigold Retort 2.48E

- 03 1.14E

- 02 1.37E

- 03 2.97E

- 01 4.95E

- 02 2.52E

- 03 6 5 4.20E

- 04 8.41E

- 04

Marigold Furnace 8.49E

- 02 4.11E

- 02 2.52E

- 02

Marigold Melt Furnace 1.00E

- 02 1.09E

- 02 1.74E

- 02 1.90E

- 01 3.16E

- 02 8.13E

- 04 6 5 1.36E

- 04 2.71E

- 04

Marigold Carbon Kiln 7.52E

- 03 6.29E

- 03 6.99E

- 03

Marigold Carbon Kiln 7.36E

- 04 2.45E

- 04 3.93E

- 04 2.22E

- 02 3.69E

- 03 5.33E

- 01 1.27E

- 05 6 5 2.12E

- 06 3.18E

- 03 4.25E

- 06 3.74E

- 03

Bald

Mountain Carbon Kiln 2.37E

- 02 1.61E

- 02 1.82E

- 02 5.80E

- 02 1.93E

- 02 1.55E

- 05 3 2 5.17E

- 06 5.17E

- 06

Bald

Mountain EW, Barren

Tank 7.41E

- 01 1.76E

- 01 1.08E+00 2.00E+00 6.66E

- 01 2.10E

- 01 3 2 6.99E

- 02 6.99E

- 02

Bald

Mountain Melt Fu rnace 7.09E

- 02 3.63E

- 02 4.76E

- 02 1.55E

- 01 5.16E

- 02 3.11E

- 04 3 2 1.04E

- 04 1.04E

- 04

Bald

Mountain Retort 1.11E

- 03 1.09E

- 03 4.79E

- 04 2.68E

- 03 8.94E

- 04 7.38E

- 01 1.30E

- 07 3 2 4.32E

- 08 7.00E

- 02 4.32E

- 08 7.00E

- 02

Ruby Hill Carbon Kiln 2.30E

- 01 2.16E

- 01 8. 08E

- 02 5.26E

- 01 1.75E

- 01 6.77E

- 03 3 2 2.26E

- 03 2.26E

- 03

Ruby Hill EW, P/B 1.51E+00 5.45E

- 01 4.97E

- 01 2.55E+00 8.49E

- 01 3.24E

- 01 3 2 1.08E

- 01 1.08E

- 01

Ruby Hill Melt Furnace 3.02E

- 02 3.63E

- 02 6.65E

- 02 3.33E

- 02 1.83E

- 05 2 1 9.13E

- 06 6.09E

- 06

Ruby Hill Retort 1.30E

- 04 1.30E

- 04 1.14E

- 04 3.73E

- 04 1.24E

- 04 1.06E+00 8.79E

- 11 3 2 2.93E

- 11 1.10E

- 01 2.93E

- 11 1.10E

- 01

Goldstrike Carbon Kiln 5.45E+00 9.68E

- 01 5.60E

- 01

Goldstrike Carbon Kiln 4.27E

- 01 6.21E

- 01 4.20E

- 01

Goldstrike Carbon Kiln 1.28E+00 1.31E+00 1.57E+00

Goldstrike Carbon Kiln 1.40E+00 1.46E+00 1.35E+00

Goldstrike Carbon Kiln 6.41E

- 01 9.07E

- 01 4.05E

- 01

Goldstrike Carbon Kiln 2.39E

- 02 3.23E

- 02 3.77E

- 02 1.89E+01 1.05E+00 1.47E+00 18 17 8.18E

- 02 4.91E

- 01

Goldstrike Electrowinning 1.58E

- 01 1.80E

- 01 2.02E

- 01

Goldstrike Electrowinning 2.74E

- 01 3.93E

- 01 2.25E

- 01

Goldstrike Electrowinning 1.0 6E

- 01 7.07E

- 02 1.63E

- 01 1.77E+00 1.97E

- 01 9.04E

- 03 9 8 1.00E

- 03 3.01E

- 03

Goldstrike Melt Furnace 2.93E

- 02 7.35E

- 02 2.35E

- 02

Goldstrike Melt Furnace

Goldstrike Melt Furnace 4.56E

- 02 1.28E

- 01 2.10E

- 01 5. 10E

- 01 8.50E

- 02 5.21E

- 03 6 5 8.68E

- 04 1.74E

- 03

Goldstrike Preg Tank 2.07E

- 02 1.43E

- 02 7.33E

- 03

Goldstrike Preg Tank 2.78E

- 03 3.18E

- 03 4.04E

- 03 5.23E

- 02 8.72E

- 03 5.28E

- 05 6 5 8.79E

- 06 1.76E

- 05

Goldstrike Preg Tank 3.97E

- 03 1.33E

- 02 1.19E

- 02

Goldstrike Preg Tank 3.18E

- 03 1.99E

- 03 2.19E

- 03 3.66E

- 02 6.10E

- 03 2.63E

- 05 6 5 4.39E

- 06 8.77E

- 06

Goldstrike Retort

Goldstrike Retort

Goldstrike Retort

## 19 Facility Unit Run 1

(lb/ton) Run 2

(lb/ton) Run 3

(lb/ton) Unit sum

(lb/ton) Unit

average

(lb/ton) F acility

total

(lb/ton) Unit

variance No. of

runs

per

unit DF

(n

- 1)

per

unit Variance

of unit

average Facility

variance Vw (m = 3

per unit) Facility

Vw

Goldstrike Retort

Goldstrike Retort 5.91E

- 02 4.77E

- 02 3.29E

- 02 1.40E

- 01 4.65E

- 02 1.73E

- 04 3 2 5.76E

- 05 5.76E

- 05

Goldstrike Retort

Goldstrike Retort

Goldstrike Retort

Goldstrike Retort 3.00E

- 02 1.52E

- 02 1.23E

- 02 5.75E

- 02 1.92E

- 02 8.94E

- 05 3 2 2.98E

- 05 2.98E

- 05

Goldstrike Retort

Goldstrike Retort

Goldstrike Retort

Goldstrike Retort

Goldstrike Retort 5.85E

- 02 6.70E

- 02 6.34E

- 02 1.89E

- 01 6.29E

- 02 1.47E+00 1.84E

- 05 3 2 6.13E

- 06 8.38E

- 02 6.13E

- 06 4.95E

- 01

Denton

Rawhide Carbon Kiln 3.16E

- 03 3.47E

- 03 1.66E

- 02

Denton

Rawhide Carbon Kiln 1.15E

- 02 6.48E

- 03 2.07E

- 03

Denton

Rawhide Carbon Kiln 2.50E

- 01 1.45E

- 01 1.28E

- 01 5.67E

- 01 6.30E

- 02 8.10E

- 03 9 8 9.00E

- 04 2.70E

- 03

Denton

Rawhide Electrowinning 6.46E

- 04 2.43E

- 04 6.39E

- 03

Denton

Rawhide Electrowinning 1.40E

- 02 2.62E

- 03 3.25E

- 03

Denton

Rawhide Electrowinning 9.14E

- 03 6.49E

- 02 1.27E

- 01 2.29E

- 01 2.54E

- 02 1.87E

- 03 9 8 2.08E

- 04 6.24E

- 04

Denton

Rawhide Melt Furnace 3.64E+00 1.56E+0 0 1.19E+00

Denton

Rawhide Melt Furnace 8.90E

- 01 1.85E+00 1.48E+00

Denton

Rawhide Melt Furnace 7.84E

- 01 2.34E+00 3.23E

- 01 1.41E+01 1.56E+00 9.69E

- 01 9 8 1.08E

- 01 3.23E

- 01

Denton

Rawhide Retort 5.84E

- 05 6.33E

- 05 7.17E

- 05

Denton

Rawhide Retort 4.59E

- 05 1.50E

- 05 1.40E

- 05

Denton

Rawhide Retort 6.24E

- 02 4.38E

- 02 7.62E

- 02 1.83E

- 01 2.03E

- 02 1.67E+00 9.89E

- 04 9 8 1.10E

- 04 1.09E

- 01 3.30E

- 04 3.27E

- 01

Average of

top 5: 1.09E+00 tDF: 110 Vb: 1.50E

- 02 Vw

(unpooled): 2.01E

- 01

t(.99): 2.36

Twin Creeks Electrowinning 2.29E

- 02 1.21E

- 01 4.91E

- 01

Twin Creeks Electrowinning 1.74E+00 1.06E+00 1.18 E+00

Twin Creeks Electrowinning 6.73E

- 02 4.31E

- 02 3.46E

- 02 4.75E+00 5.28E

- 01 4.10E

- 01 9 8 4.55E

- 02 1.37E

- 01

## 20 Facility Unit Run 1

(lb/ton) Run 2

(lb/ton) Run 3

(lb/ton) Unit sum

(lb/ton) Unit

average

(lb/ton) F acility

total

(lb/ton) Unit

variance No. of

runs

per

unit DF

(n

- 1)

per

unit Variance

of unit

average Facility

variance Vw (m = 3

per unit) Facility

Vw

Twin Creeks Melt Furnace 2

(new) 4.20E

- 01 1.20E

- 01 2.89E

- 01

Twin Creeks Melt Furnace 2

(new) 4.85E

- 01 1.38E

- 01 3.90E

- 01

Twin Creeks Melt Furnace 2

(new) 6.60E

- 02 1.86E

- 02 4.80E

- 02

Twin Creeks Melt Furnace 2

(new) 1.77E

- 04 2.48E

- 04 6.84E

- 04 1.98E+00 1.65E

- 01 3.29E

- 02 12 11 2.74E

- 03 1.10E

- 02

Twin Creeks Mel t Furnace 1

(old) 1.04E+00 4.20E

- 01 6.54E

- 01

Twin Creeks Melt Furnace 1

(old) 2.19E+00 8.51E

- 01 9.32E

- 01

Twin Creeks Melt Furnace 1

(old) 2.15E

- 02 6.39E

- 02 9.35E

- 02

Twin Creeks Melt Furnace 1

( old) 7.79E

- 02 4.07E

- 02 2.67E

- 02

Twin Creeks Melt Furnace 1

(old) 5.36E

- 04 4.56E

- 04 4.88E

- 04 6.42E+00 4.28E

- 01 3.84E

- 01 15 14 2.56E

- 02 1.28E

- 01

Twin Creeks Carbon Kiln 2.19E

- 01 2.30E

- 02 9.55E

- 02

Twin Creeks C arbon Kiln 2.80E

- 01 1.07E

- 01 9.08E

- 02

Twin Creeks Carbon Kiln 4.76E

- 02 8.89E

- 02 8.76E

- 02 1.04E+00 1.16E

- 01 6.70E

- 03 9 8 7.44E

- 04 2.23E

- 03

Twin Creeks Preg Tank 2.12E+00 1.91E+00 3.64E

- 01

Twin Creeks Preg Tan k 8.16E

- 01 1.74E+00 7.75E

- 01

Twin Creeks Preg Tank 2.57E

- 01 2.58E

- 01 3.22E

- 01 8.56E+00 9.52E

- 01 5.83E

- 01 9 8 6.48E

- 02 1.94E

- 01

Twin Creeks Retort 8.80E

- 06 7.63E

- 06 6.72E

- 06 2.32E

- 05 7.72E

- 06 1.09E

- 12 3 2 3.63E

- 13 3.63E

- 13

Twin Creeks Retort 8.13E

- 04 1.19E

- 03 2.39E

- 03

Twin Creeks Retort 4.18E

- 03 4.99E

- 03 1.04E

- 02

Twin Creeks Retort 2.57E

- 03 6.68E

- 04 1.08E

- 03 2.82E

- 02 3.14E

- 03 9.63E

- 06 9 8 1.07E

- 06 3.21E

- 06

Twin Creeks Retort 3.51E

- 04 1.34E

- 03 1.38E

- 03

Twin Creeks Retort 1.56E

- 03 5.66E

- 03 2.78E

- 03

Twin Creeks Retort 5.07E

- 04 2.54E

- 03 5.07E

- 04 1.66E

- 02 1.85E

- 03 2.79E

- 06 9 8 3.10E

- 07 9.29E

- 07

Twin Creeks Retort 7.58E

- 04 2.96E

- 03 5 .40E

- 03

Twin Creeks Retort 7.54E

- 05 2.46E

- 04 3.09E

- 04

Twin Creeks Retort 4.75E

- 04 3.43E

- 03 4.05E

- 03 1.77E

- 02 1.97E

- 03 4.03E

- 06 9 8 4.48E

- 07 1.34E

- 06

Twin Creeks Retort 2.17E

- 05 5.49E

- 03 2.06E

- 03

Twin Creeks Retort 6.50E

- 04 4.77E

- 04 1.73E

- 04

Twin Creeks Retort 1.17E

- 04 2.75E

- 04 4.95E

- 04 9.77E

- 03 1.09E

- 03 2.20E+00 3.11E

- 06 9 8 3.45E

- 07 1.39E

- 01 1.04E

- 06 4.72E

- 01

Gold Quarry Carbon Kiln 3.46E+00 3.60E+00 3.93E+00

Gold Quarry Carbon Kiln 7.47E

- 01 3.88E

- 01 5.59E

- 01

Gold Quarry Carbon Kiln 1.29E+00 1.21E+00 1.41E+00 1.66E+01 1.84E+00 1.99E+00 9 8 2.21E

- 01 6.63E

- 01

Gold Quarry Electrowinning 4.54E

- 02 4.24E

- 02 4.64E

- 02

## 21 Facility Unit Run 1

(lb/ton) Run 2

(lb/ton) Run 3

(lb/ton) Unit sum

(lb/ton) Unit

average

(lb/ton) F acility

total

(lb/ton) Unit

variance No. of

runs

per

unit DF

(n

- 1)

per

unit Variance

of unit

average Facility

variance Vw (m = 3

per unit) Facility

Vw

Gold Quarry Electrowinning 7.32E

- 02 6.70E

- 02 5.94E

- 02

Gold Quarry Electrowinning 4.48E

- 01 4.25E

- 01 8.46E

- 02 1.29E+00 1.44E

- 01 2.78E

- 02 9 8 3.09E

- 03 9.28E

- 03

Gold Quarry Preg Tank 2.30E

- 01 2.44E

- 01 3.71E

- 01

Gold Quarry Preg Tank 3.36E

- 01 6.10E

- 02 1.29E+00

Gold Quarry Preg Tank 3.82E

- 03 2.38E

- 01 5.42E

- 01

Gold Quarry Preg Tank 3.06E

- 01 3.71E

- 02 9.78E

- 02 3.76E+00 3.13E

- 01 1.19E

- 01 12 11 9.91E

- 03 3.96E

- 02

Gold Quarry Melt Furnace 2.35E+00 5.33E

- 01 1.25E+00

Gold Quarry Melt Furnace 2.59E

- 02 6.61E

- 03 1.81E

- 01

Gold Quarry Melt Furnace 4.76E

- 01 1.05E+00 2.90E+00 8.77E+00 9.75E

- 01 1.07E+00 9 8 1.19E

- 01 3.58E

- 01

Gold Quarry Retort

Gold Quarry Retort 3.73E

- 02 8.17E

- 02 4.26E

- 02

Gold Quarry Retort 1.30E

- 01 9.79E

- 02 8.90E

- 02

Gold Quarry Retort 1.67E

- 01 1.80E

- 01 1.32E

- 01

Gold Qua rry Retort 1.66E

- 01 1.72E

- 01 9.52E

- 02 9.11E

- 01 1.52E

- 01 1.04E

- 03 6 5 1.74E

- 04 3.48E

- 04

Gold Quarry Carbon Kiln 9.23E

- 01 5.95E

- 01 4.94E

- 01

Gold Quarry Carbon Kiln 5.56E

- 02 6.25E

- 02 7.94E

- 02

Gold Quarry Carbon Kiln 1.42E

- 01 1.41E

- 01 1.72E

- 01

Gold Quarry Carbon Kiln 1.60E

- 01 3.19E

- 01 2.96E

- 01 3.44E+00 2.87E

- 01 3.71E+00 6.93E

- 02 12 11 5.77E

- 03 3.59E

- 01 2.31E

- 02 1.09E+00

Florida

Canyon Carbon Kiln 1.03E+00 5.52E

- 01 6.71E

- 01

Florida

Canyon Carbon Kiln 1.30E+01 2.03E+01 2.00E+01

Florida

Canyon Carbon Kiln 3.87E+00 4.24E+00 1.78E+01

Florida

Canyon Carbon Kiln 3.23E+00 1.51E+00 3.83E+00 9.00E+01 7.50E+00 6.22E+01 12 11 5.18E+00 2.07E+01

Florida

Canyon Melt Furnace 3.17E

- 01 8.30E

- 03 1.71E

- 02

Florida

Canyon Melt Furnace 1.45E

- 02 2.01E

- 02 5.11E

- 02

Florida

Canyon Melt Furnace 5.76E

- 03 8.07E

- 03 9.51E

- 03 4.52E

- 01 5.02E

- 02 1.02E

- 02 9 8 1.13E

- 03 3.40E

- 03

Florida

Canyon Electrowinning 2.68E

- 01 1.42E

- 01 6.00E

- 01

Florida

Canyon Electrowinning 1.03E+00 1.47E

- 01 8.14E

- 01

Florida

Canyon Electrowinning 1.38E

- 01 6.95E

- 01 1.09E+00 4.92E+00 5.47E

- 01 1.49E

- 01 9 8 1.66E

- 02 4.97E

- 02

Florida

Canyon Electrowinning 1.03E

- 01 1.03E

- 01 7.10E

- 02

Florida

Canyon Electrowinning 7.60E

- 02 3.41E

- 02 4.57E

- 02

## 22 Facility Unit Run 1

(lb/ton) Run 2

(lb/ton) Run 3

(lb/ton) Unit sum

(lb/ton) Unit

average

(lb/ton) F acility

total

(lb/ton) Unit

variance No. of

runs

per

unit DF

(n

- 1)

per

unit Variance

of unit

average Facility

variance Vw (m = 3

per unit) Facility

Vw

Florida

Canyon Electrowinning 7.72E

- 02 7.72E

- 02 1.70E

- 02 6 .03E

- 01 6.70E

- 02 8.59E

- 04 9 8 9.55E

- 05 2.86E

- 04

Florida

Canyon Retort 2.63E

- 03 1.25E

- 03 2.90E

- 04

Florida

Canyon Retort 2.30E

- 06 1.53E

- 06 1.67E

- 06 4.17E

- 03 6.95E

- 04 1.13E

- 06 6 5 1.88E

- 07 3.76E

- 07

Florida

Canyon Retort 6 .89E

- 05 5.35E

- 05 6.17E

- 05

Florida

Canyon Retort 3.08E

- 05 1.65E

- 05 1.34E

- 05

Florida

Canyon Retort 5.07E

- 05 3.68E

- 06 4.82E

- 05 3.47E

- 04 3.86E

- 05 8.17E+00 5.39E

- 10 9 8 5.99E

- 11 5.20E+00 1.80E

- 10 2.08E+01

Jerritt Can yon Carbon Kiln 5.10E+00 2.23E+00 1.60E+00 8.93E+00 2.98E+00 3.48E+00 3 2 1.16E+00 1.16E+00

Jerritt Canyon Melt Furnace 3.82E

- 01 1.65E+01 1.76E+01 3.45E+01 1.15E+01 1.45E+01 9.32E+01 3 2 3.11E+01 3.22E+01 3.11E+01 3.22E+01

Lone Tree Electrowinni ng 1.39E+00 7.68E

- 01 1.16E+00

Lone Tree Electrowinning 7.02E

- 01 6.11E+00 7.76E

- 01 1.09E+01 1.82E+00 4.50E+00 6 5 7.50E

- 01 1.50E+00

Lone Tree Elecrowinning 1.92E

- 01 7.15E+00 7.82E

- 02

Lone Tree Electrowinni ng 6.18E+00 2.53E

- 01 1.03E

- 01 1.40E+01 2.33E+00 1.14E+01 6 5 1.90E+00 3.80E+00

Lone Tree Electrowinning 2.67E+00 1.30E+00 5.00E

- 01 4.47E+00 1.49E+00 1.20E+00 3 2 4.01E

- 01 4.01E

- 01

Lone Tree Preg Tank 1.97E+00 3.29E+00 1.72E+01

Lone Tree Preg Tank 9.17E+00 2.14E+01 3.68E+01 8.98E+01 1.50E+01 2.06E+01 1.72E+02 6 5 2.87E+01 3.18E+01 5.74E+01 6.31E+01

## 23 Appendix C . Mercury Emissions Data for the Carbon Processes without Mercury Retorts Affected Source (lb/ton concentrate)

Facility Process type Run 1

(lb/ton) Run 2

(lb/ton) Run 3

(lb/ton) Unit sum

(lb/ton) Unit

average

(lb/ton) Facility

total

(lb/ton) Unit var No. of runs

per unit DF (n

- 1)

per unit Var of unit

average Facility var Vw (m = 3

per unit) Facility Vw

Round Moun tain Electrowinning 1.82E

- 02 7.93E

- 02 1.90E

- 02 1.16E

- 01 3.88E

- 02 1.23E

- 03 3 2 4.09E

- 04 4.09E

- 04

Round Mountain Melt Furnace 1.49E

- 04 1.80E

- 03 1.77E

- 03

Round Mountain Melt Furnace 3.49E

- 02 9.59E

- 03 1.85E

- 02 6.67E

- 02 1.11E

- 02 1. 83E

- 04 6 5 3.05E

- 05 6.10E

- 05

Round Mountain Carbon Kiln 2.57E

- 03 2.86E

- 03 1.56E

- 03

Round Mountain Carbon Kiln 1.52E

- 02 1.02E

- 02 1.59E

- 02 4.83E

- 02 8.05E

- 03 0.058 4.33E

- 05 6 5 7.22E

- 06 4.47E

- 04 1.44E

- 05 4.85E

- 04

Cortez Pipeline Car bon Kiln 1.12E

- 03 6.42E

- 04 2.94E

- 03

Cortez Pipeline Carbon Kiln 2.59E

- 03 1.76E

- 03 1.12E

- 03 1.02E

- 02 1.70E

- 03 8.27E

- 07 6 5 1.38E

- 07 2.76E

- 07

Cortez Pipeline Carbon Kiln 1.26E

- 02 9.36E

- 03 3.67E

- 03

Cortez Pipel ine Carbon Kiln 6.13E

- 04 2.64E

- 04 2.52E

- 04 2.67E

- 02 4.45E

- 03 2.81E

- 05 6 5 4.68E

- 06 9.36E

- 06

Cortez Pipeline Electrowinning 2.58E

- 02 1.92E

- 02 2.99E

- 02

Cortez Pipeline Electro Winning

System 1.41E

- 02 3.58E

- 03 8.79E

- 03 1.01E

- 01 1.6 9E

- 02 1.01E

- 04 6 5 1.68E

- 05 3.36E

- 05

Cortez Pipeline Electrowinning 1.40E

- 02 3.55E

- 03 6.32E

- 03

Cortez Pipeline Electro Winning

System 5.30E

- 03 5.62E

- 03 2.49E

- 03 3.73E

- 02 6.21E

- 03 1.66E

- 05 6 5 2.77E

- 06 5.53E

- 06

Cortez Pipe line Preg Tank 1.01E

- 01 1.61E

- 01 8.80E

- 02

Cortez Pipeline Pregnant and Barren

Tanks 3.25E

- 03 2.44E

- 03 2.50E

- 03 3.58E

- 01 5.96E

- 02 4.50E

- 03 6 5 7.50E

- 04 1.50E

- 03

Cortez Pipeline Melt Furnace 2.67E

- 03 1.21E

- 03 1.84E

- 03 5.72E

- 03 1.9 1E

- 03 5.37E

- 07 3 2 1.79E

- 07 1.79E

- 07

Cortez Pipeline Melt Furnace 1.43E

- 04 1.79E

- 04 1.35E

- 04 4.57E

- 04 1.52E

- 04 5.53E

- 10 3 2 1.84E

- 10 1.84E

- 10

Cortez Pipeline Fusion furnace 5.23E

- 03 1.37E

- 02 2.32E

- 03 2.13E

- 02 7.09E

- 03 0.098 3.52E

- 05 3 2 1.17E

- 05 7.86E

- 04 1.17E

- 05 1.56E

- 03

Average of

top 2: 0.078 tDF: 43 Vb: 3.08E

- 04 Vw

(unpooled): 1.02E

- 03

t(.99): 2.42

## 24 Appendix D . Mercury Emissions Data for the Non

- Carbon Concentrate Affected Source (lb/ton concentrate)

Facility Unit Run 1

(lb/ton) Run 2

(lb/ton) Run 3

(lb/ton) Run 4

(lb/ton) Run 5

(lb/ton) Unit

sum

(lb/ton) Unit

average

(lb/ton) Facility

total

(lb/ton) Unit

variance No. of

runs per

unit DF (n

- 1)

per unit Varianc

e of unit

average Facility

variance Vw (m =

3 per

unit) Facility

Vw

Coeur

Rochester Refinery

Furnace 5.96E

- 02 1.17E

- 01 2.28E

- 02

Coeur

Rochester Refinery

Furnace 2.47E

- 02 1.20E

- 02 2.94E

- 02 2.66E

- 01 4.43E

- 02 1.53E

- 03 6 5 2.55E

- 0 4 5.10E

- 04

Coeur

Rochester Retorts #1 & #2 3.41E

- 03 3.45E

- 03 9.24E

- 05 2.31E

- 03 1.95E

- 03

Coeur

Rochester Retorts #1 & #2 2.93E

- 04 1.53E

- 02 4.20E

- 03

Coeur

Rochester Retorts #1 & #2 4.17E

- 05 1.84E

- 04 5.39E

- 05 3.13E

- 02 2.84E

- 03 0.047 1.96E

- 05 11 10 1.78E

- 06 2.57E

- 04 6.52E

- 06 5.17E

- 04

Midas

Operations Refinery

Furnace 1 & 2 1.60E

- 02 2.63E

- 02 4.55E

- 02

Midas

Operations Refinery

Furnace 1 & 2 1.73E

- 01 2.17E

- 01 4.41E

- 02

Midas

Operations Refinery

Furnace 1 & 2 1.10E

- 02 2.89E

- 02 1.73E

- 02 5.79E

- 01 6.43E

- 02 5.74E

- 03 9 8 6.38E

- 04 1.91E

- 03

Midas

Operations Retort A 2.32E

- 03 1.79E

- 03 1.46E

- 03

Midas

Operations Retort A 1.25E

- 03 6.01 E

- 02 3.41E

- 02

Midas

Operations Retort A 4.07E

- 05 3.18E

- 05 3.72E

- 05 1.01E

- 01 1.12E

- 02 4.56E

- 04 9 8 5.07E

- 05 1.52E

- 04

Midas

Operations Retort B 2.78E

- 04 1.07E

- 05 7.36E

- 06

Midas

Operations Retort B 4.22E

- 03 4.48E

- 03 5.66E

- 03

Midas

Operations Retort B 9.51E

- 04 1.45E

- 03 1.02E

- 03 1.81E

- 02 2.01E

- 03 0.078 4.72E

- 06 9 8 5.24E

- 07 6.89E

- 04 1.57E

- 06 2.07E

- 03

Average

of top 2: 6.23 E

- 02 1.55E

- 03 t DF: 39 Vb: 2.37E

- 04 Vw

(unpoole

d): 2.58E

- 03

t(.99): 2.43

## 25 Appendix E

. New Source MACT Floors

Ore Pretreatment Processes

Facility Unit Run 1

(lb/ton) Run 2

(lb/ton) Run 3

(lb/ton) Unit

sum

(lb/ton) Unit

av erage

(lb/ton) Facility

total

(lb/ton) Unit

variance No. of

runs per

unit DF

(n

- 1)

per

unit Variance

of unit

average Facility

variance Vw (m = 3

per unit) Facility

Vw

Goldstrike Roaster Ore Preheater 3.23E

- 07 5.03E

- 07 3.60E

- 07

Golds trike Roaster Ore Preheater 8.61E

- 07 5.96E

- 07 5.17E

- 07

Goldstrike Roaster Ore Preheater 1.79E

- 06 1.39E

- 06 2.65E

- 07

Goldstrike Roaster Ore Preheater 2.19E

- 06 1.13E

- 06 2.65E

- 07 1.02E

- 05 8.48E

- 07 4.12E

- 13 12 11 3.43 E

- 14 1.37E

- 13

Goldstrike Roaster Ore Preheater 8.68E

- 06 4.71E

- 06 1.71E

- 06

Goldstrike Roaster Ore Preheater 2.36E

- 05 5.05E

- 06 7.86E

- 07

Goldstrike Roaster Ore Preheater 8.52E

- 07 8.52E

- 07 3.93E

- 07

Goldstrike Roaster Ore Preheater 1.64E

- 06 8.52E

- 07 3.93E

- 07 4.95E

- 05 4.12E

- 06 4.40E

- 11 12 11 3.67E

- 12 1.47E

- 11

Goldstrike Roaster 7.25E

- 05 5.71E

- 05 5.26E

- 05

Goldstrike Roaster 1.25E

- 05 1.25E

- 05 1.71E

- 05

Goldstrike Roaster 1.95E

- 05 1.73E

- 05 1.31E

- 05 2.74E

- 04 3.05E

- 05 5.47E

- 10 9 8 6.08E

- 11 1.82E

- 10

Goldstrike Roaster/Calcine quench 4.35E

- 06 2.96E

- 06 2.87E

- 06 1.02E

- 05 3.39E

- 06 6.86E

- 13 3 2 2.29E

- 13 2.29E

- 13

Goldstrike Roaster/Calcine quench 3 .55E

- 06 3.76E

- 06 3.32E

- 06 1.06E

- 05 3.54E

- 06 4.72E

- 14 3 2 1.57E

- 14 1.57E

- 14

Goldstrike Autoclave 2.59E

- 07 4.01E

- 07 4.70E

- 07 1.13E

- 06 3.77E

- 07 1.16E

- 14 3 2 3.87E

- 15 3.87E

- 15

Goldstrike Autoclave 6.57E

- 07 7.71E

- 07 5.50E

- 07 1.98E

- 06 6.59E

- 07 1. 23E

- 14 3 2 4.09E

- 15 4.09E

- 15

Goldstrike Autoclave 1.42E

- 06 1.65E

- 07 1.81E

- 07 1.77E

- 06 5.90E

- 07 5.21E

- 13 3 2 1.74E

- 13 1.74E

- 13

Goldstrike Autoclave 1.42E

- 06 8.32E

- 07 4.62E

- 07 2.71E

- 06 9.03E

- 07 4.49E

- 05 2.32E

- 13 3 2 7.72E

- 14 6.50E

- 11 7.72E

- 14 1.9 8E

- 10

Average = 4.49E

- 05

DF = 42

t = 2.42

Vb = 6.50E

- 11

Vw = 1.98E

- 10

Vt = 2.63E

- 10

Facility

99% UPL

= 8.41E

- 05

## 26 Carbon Processes with Mercury Retorts

Facility Unit Run 1

(lb/ton) Run 2

(lb/ton) Run 3

(lb/ton) Unit sum

(lb/ton) Unit

average

(lb/ton) Facility

total

(lb/ton) Unit

variance No. of

runs per

unit DF

(n

- 1)

per

unit Variance

of unit

average Facility

variance Vw (m = 3

per unit) Facility

Vw

Marigold EW, P/B 3.68E

- 01 5.43E

- 01 4.32E

- 01 1.34E+00 4.48E

- 01 7.86E

- 03 3 2 2.62E

- 03 2.62E

- 03

Marigold Retort 7.72E

- 02 1.14E

- 01 9.07E

- 02

Mar igold Retort 2.48E

- 03 1.14E

- 02 1.37E

- 03 2.97E

- 01 4.95E

- 02 2.52E

- 03 6 5 4.20E

- 04 8.41E

- 04

Marigold Furnace 8.49E

- 02 4.11E

- 02 2.52E

- 02

Marigold Melt Furnace 1.00E

- 02 1.09E

- 02 1.74E

- 02 1.90E

- 01 3.16E

- 02 8.13E

- 04 6 5 1.36E

- 04 2 .71E

- 04

Marigold Carbon Kiln 7.52E

- 03 6.29E

- 03 6.99E

- 03

Marigold Carbon Kiln 7.36E

- 04 2.45E

- 04 3.93E

- 04 2.22E

- 02 3.69E

- 03 5.33E

- 01 1.27E

- 05 6 5 2.12E

- 06 3.18E

- 03 4.25E

- 06 3.74E

- 03

Average = 5.33E

- 01

DF = 17

t = 2.57

Vb = 3.18E

- 03

Vw = 3.74E

- 03

Vt = 6.92E

- 03

Facility 99%

UPL = 7.46E

- 01

Carbon Pr ocesses without Mercury Retorts

Facility Unit Run 1

(lb/ton) Run 2

(lb/ton) Run 3

(lb/ton) Unit

sum

(lb/ton) Unit

average

(lb/ton) Facility

total

(lb/ton) Unit

variance No. of

runs

per

unit DF (n

1) per

unit Variance

of unit

average Facility

variance Vw (m = 3

per unit) Facility

Vw

Round Mountain Electrowinning 1.82E

- 02 7.93E

- 02 1.90E

- 02 1.16E

- 01 3.88E

- 02 1.23E

- 03 3 2 4.09E

- 04 4.09E

- 04

Round Mountain Melt Furnace 1.49E

- 04 1.80E

- 03 1.77E

- 03

Round Mountain Melt Furnace 3.49E

- 02 9.59E

- 03 1.85E

- 02 6.67E

- 02 1.11E

- 02 1.83E

- 04 6 5 3.05E

- 05 6.10E

- 05

Round Mountain Carbon Kiln 2.57E

- 03 2.86E

- 03 1.56E

- 03

Round Mountain Carbon Kiln 1.52E

- 02 1.02E

- 02 1.59E

- 02 4.83E

- 02 8.05E

- 03 0.058 4.33E

- 05 6 5 7.22E

- 06 4.47E

- 0 4 1.44E

- 05 4.85E

- 04

Average = 5.80E

- 02

DF = 12

t = 2.68

Vb = 4.47E

- 04

Vw = 4.85E

- 04

Vt = 9.32 E

- 04

Facility

99% UPL = 1.40E

- 01

## 27 Non

- Carbon Concentrate

Facility Unit Run 1

(lb/ton) Run 2

(lb/ton) Run 3

(lb/ton) Run 4

(lb/ton) Run 5

(lb/ton) Unit

sum

(lb/ton) Unit

average

(lb/ton) Facility

total

(lb/ton) Unit

variance No. of

runs

per

unit DF

(n

- 1)

per

unit Variance

of unit

average Facility

variance Vw

(m = 3

per

unit) Facility

Vw

Coeur

Rochester

Mine Refinery

Furnace 5.96E

- 02 1.17E

- 01 2.28E

- 02

Coeur

Rochester

Mine Refinery

Furnace 2.47E

- 02 1 .20E

- 02 2.94E

- 02 2.66E

- 01 4.43E

- 02 1.53E

- 03 6 5 2.55E

- 04 5.10E

- 04

Coeur

Rochester

Mine Retorts

#1 & #2 3.41E

- 03 3.45E

- 03 9.24E

- 05 2.31E

- 03 1.95E

- 03

Coeur

Rochester

Mine Retorts

#1 & #2 2.93E

- 04 1.53E

- 02 4.20E

- 03

Coeur

Rochester

Mine Retort 4.17E

- 05 1.84E

- 04 5.39E

- 05 3.13E

- 02 2.84E

- 03 4.71E

- 02 1.96E

- 05 11 10 1.78E

- 06 2.57E

- 04 6.52E

- 06 5.17E

- 04

Average

= 4.71E

- 02

DF = 15

t = 2.60

Vb = 2.57E

- 04

Vw = 5.17E

- 04

Vt = 7.74E

- 04

Facility

99%

UPL = 1.19E

- 01

## 28 Appendix F

. Beyond the Floor

– Ore Pretreatment

Facility Unit Run 1

(lb/ton) Run 2

(lb/ton) Run 3

(lb/ton) Unit sum

(lb/ton) Unit

average

(lb/ton) Facility

total

(lb/ton) Unit

variance No. of

runs per

unit DF

(n

- 1)

per

unit Variance

of unit

average Facility

variance Vw (m =

3 per

unit) F acility

Vw

Gold

Quarry Roaster/Calcine

quench 1.35E

- 05 9.56E

- 06 1.37E

- 05

Gold

Quarry Roaster/Calcine

quench 1.05E

- 05 1.33E

- 05 1.69E

- 05

Gold

Quarry Roaster/Calcine

quench 8.45E

- 06 1.05E

- 05 9.66E

- 06 1.06E

- 04 1.18E

- 0 5 7.33E

- 12 9 8 8.14E

- 13 2.44E

- 12

Gold

Quarry Roaster Ore

Preheater 3.81E

- 06 1.62E

- 06 1.36E

- 06

Gold

Quarry Roaster Ore

Preheater 7.90E

- 06 7.51E

- 06 4.63E

- 05

Gold

Quarry Roaster Ore

Preheater 2.45E

- 06 1.04E

- 06 9.09E

- 07 7.29E

- 05 8.10E

- 06 2.12E

- 10 9 8 2.35E

- 11 7.06E

- 11

Gold

Quarry Roaster 8.99E

- 07 6.97E

- 07 7.87E

- 07

Gold

Quarry Roaster 1.27E

- 06 1.61E

- 06 6.19E

- 07

Gold

Quarry Roaster 4.92E

- 07 2.75E

- 07 3.56E

- 07 7.00E

- 06 7.78E

- 07 1.86E

- 13 9 8 2.07E

- 14 6.21E

- 14

Gold

Quarry Roaster Ore

Grinder 1.66E

- 06 2.06E

- 06 1.48E

- 06

Gold

Quarry Roaster Ore

Grinder 1.50E

- 06 4.82E

- 06 1.75E

- 06 1.33E

- 05 2.21E

- 06 1.67E

- 12 6 5 2.79E

- 13 5.58E

- 13

Gold

Quarry R oaster/Calcine

quench 1.67E

- 05 1.36E

- 05 9.55E

- 06

Gold

Quarry Roaster/Calcine

quench 1.27E

- 05 1.46E

- 05 2.11E

- 05

Gold

Quarry Roaster/Calcine

quench 1.03E

- 05 1.31E

- 05 1.32E

- 05 1.25E

- 04 1.39E

- 05 3.68E

- 05 1.19E

- 11 9 8 1 .32E

- 12 2.60E

- 11 3.96E

- 12 7.77E

- 11

Goldstrike Roaster Ore

Preheater 1.82E

- 07 2.84E

- 07 2.03E

- 07

Goldstrike Roaster Ore

Preheater 5.58E

- 07 3.86E

- 07 3.35E

- 07

Goldstrike Roaster Ore

Preheater 1.16E

- 06 9.01E

- 07 1.72E

- 0 7

Goldstrike Roaster Ore

Preheater 1.42E

- 06 7.29E

- 07 1.72E

- 07 6.49E

- 06 5.41E

- 07 1.78E

- 13 12 11 1.48E

- 14 5.94E

- 14

Goldstrike Roaster Ore

Preheater 4.90E

- 06 2.66E

- 06 9.66E

- 07

Goldstrike Roaster Ore

Preheater 1 .53E

- 05 3.27E

- 06 5.09E

- 07

Goldstrike Roaster Ore

Preheater 5.52E

- 07 5.52E

- 07 2.55E

- 07

Goldstrike Roaster Ore

Preheater 1.06E

- 06 5.52E

- 07 2.55E

- 07 3.08E

- 05 2.57E

- 06 1.81E

- 11 12 11 1.51E

- 12 6.04E

- 12

## 29 Facility Unit Run 1

(lb/ton) Run 2

(lb/ton) Run 3

(lb/ton) Unit sum

(lb/ton) Unit

average

(lb/ton) Facility

total

(lb/ton) Unit

variance No. of

runs per

unit DF

(n

- 1)

per

unit Variance

of unit

average Facility

variance Vw (m =

3 per

unit) F acility

Vw

Goldstrike Roaster 1.56E

- 04 1.23E

- 04 1.14E

- 04

Goldstrike Roaster 2.70E

- 05 2.70E

- 05 3.70E

- 05

Goldstrike Roaster 3.67E

- 05 3.26E

- 05 2.47E

- 05 5.78E

- 04 6.42E

- 05 2.65E

- 09 9 8 2.95E

- 10 8.85E

- 10

Goldstrike Roaster/Calcine

que nch 8.18E

- 06 5.56E

- 06 5.40E

- 06 1.91E

- 05 6.38E

- 06 2.43E

- 12 3 2 8.09E

- 13 8.09E

- 13

Goldstrike Roaster/Calcine

quench 6.67E

- 06 7.07E

- 06 6.25E

- 06 2.00E

- 05 6.66E

- 06 8.04E

- 05 1.67E

- 13 3 2 5.57E

- 14 2.97E

- 10 5.57E

- 14 8.92E

- 10

Jerritt

Canyon Ore dryer 4.06 E

- 06 8.58E

- 06 5.77E

- 06

Jerritt

Canyon Ore dryer 1.15E

- 06 9.71E

- 06 3.42E

- 06 3.27E

- 05 5.45E

- 06 1.05E

- 11 6 5 1.76E

- 12 3.51E

- 12

Jerritt

Canyon Roaster 4.42E

- 05 4.47E

- 05 5.14E

- 05

Jerritt

Canyon Roaster 4.48E

- 05 2.07E

- 05 2.99E

- 05

Jerritt

Canyon Roaster 7.01E

- 06 7.92E

- 06 8.36E

- 06 2.59E

- 04 2.88E

- 05 3.31E

- 10 9 8 3.68E

- 11 1.10E

- 10

Jerritt

Canyon Roaster 5.50E

- 05 4.65E

- 05 2.82E

- 05

Jerritt

Canyon Roaster 5.80E

- 06 4. 30E

- 06 4.65E

- 06 1.44E

- 04 2.41E

- 05 5.83E

- 05 5.16E

- 10 6 5 8.60E

- 11 1.25E

- 10 1.72E

- 10 2.86E

- 10

Twin

Creeks Autoclave 1.66E

- 05 4.34E

- 05 3.06E

- 05

Twin

Creeks Autoclave 2.35E

- 05 7.76E

- 05 8.70E

- 06

Twin

Creeks Autoclave 7.07E

- 05 3.51E

- 05 3.25E

- 05

Twin

Creeks Autoclave 6.40E

- 05 3.99E

- 05 3.29E

- 05

Twin

Creeks Autoclave 2.99E

- 05 5.92E

- 05 7.98E

- 05

Twin

Creeks Autoclave 3.18E

- 05 2.09E

- 05 1.86E

- 05

Twin

Creeks Autoclave 2.59E

- 06 2.42E

- 06 2.29E

- 06 7.23E

- 04 3.44E

- 05 5.75E

- 10 21 20 2.74E

- 11 1.92E

- 10

Twin

Creeks Autoclave 3.42E

- 05 1.64E

- 05 1.60E

- 05

Twin

Creeks Autoclave 2.60E

- 05 1.49E

- 05 1.04E

- 05

Twin

Creeks Autoclave 1.46E

- 05 2.72E

- 05 2.39E

- 05

Twin

Creeks Autoclave 1.06E

- 05 7.50E

- 06 6.36E

- 06

Twin

Creeks Autoclave 6.12E

- 06 5.74E

- 06 5.88E

- 06 2.26E

- 04 1.51E

- 05 4.95E

- 05 8.16E

- 11 15 14 5.44E

- 12 3.28E

- 11 2.72 E

- 11 2.19E

- 10

## 30 Facility Unit Run 1

(lb/ton) Run 2

(lb/ton) Run 3

(lb/ton) Unit sum

(lb/ton) Unit

average

(lb/ton) Facility

total

(lb/ton) Unit

variance No. of

runs per

unit DF

(n

- 1)

per

unit Variance

of unit

average Facility

variance Vw (m =

3 per

unit) F acility

Vw

Average

of top 5: 5.62E

- 05 t DF: 123 Vb: 3.00E

11 Vw

(unpooled

): 3.69E

- 10

56 t(.99): 2.36