# Evaluation of Mercury Emissions from U.S. Gold Mining Operations August 2007

Prepared for:

U.S. Environmental Protection Agency

Office of Air Quality Planning and Standards

Research Triangle Park, NC 27711

Prepared by:

RTI International

3040 Cornwallis Road

Research Triangle Park, NC 27709

EPA Contract No. EP-D-06-118

Work Assignment No. 1-20Table of Contents

i Table of Contents

Section Page

Acronyms ...................................................................................................................... .............v

1.0 Introduction .............................................................................................................. ......1

2.0 Background Information ................................................................................................2 2.1 History of Gold Mining in the U.S. ..................................................................2 2.2 General Gold Mining Methods ..........................................................................2

2.3 Production Amounts and Prices .........................................................................3 2.4 Gold Mining Processes Currently Used in the U.S............................................5 2.4.1 Extraction, Crushing, and Milling .........................................................5 2.4.2 Roasting and Autoclaving ......................................................................6 2.4.3 Leaching .................................................................................................6 2.4.4 Carbon Stripping and Regeneration .......................................................6 2.4.5 Recovery from Solution .........................................................................7 2.4.6 Retorting and Smelting ..........................................................................7

3.0 U.S. Gold Mining Industry Survey ................................................................................8 3.1 Description of Industry Survey ..........................................................................8 3.2 Summary of Survey Respondents ......................................................................9 3.3 Survey Characterization of Current Gold Mining Industry .............................10

4.0 Mercury Emissions from Gold Mines ..........................................................................13 4.1 Gold Mining Mercury Emi ssions from Industry Surveys ................................13 4.1.1 Facility Total Mercury Emissions ........................................................13 4.1.2 Thermal Process Mercury Emissions ...................................................13 4.1.3 Thermal Process Mercury Emissions Controls ....................................15 4.2 Gold Mining Mercury Emissions from the TRI ..............................................17 4.3 Gold Mining Mercury Emissions from the NEI ..............................................20 4.4 Comparison of Gold Mining Mercury Emissions ............................................20 4.5 Uncertainty and Biases in Me rcury Emissions Estimates ..............................21

5.0 Nevada Mercury Control Program ...............................................................................24

6.0 References ................................................................................................................ ....25

Appendix A .................................................................................................................... ....... A-1

Appendix B .................................................................................................................... ........B-1Table of Contents

ii List of Figures

1 United States gold production and price of gold, 1907 to 2005 ....................................4 2 United States gold production, 2001 to 2005 .................................................................5 3 Currently operating U.S. gold mines processing mercury-containing ores .................12 4 Mercury emissions from metals mining in the United States, 1998-2005 based on the Toxics Release Inventory ........................................................................19

List of Tables

1 Summary of the Type of Mercury Emi ssions Information Received in the Responses to the Questionnaires ....................................................................................9 2 Summary of Production and Mercury Em issions from Gold Mining Facilities in the United States, 2004/2005 Timeframe ................................................................10 3 Tons of Ore Processed by Process Type, 2004/2005 Timeframe ................................11 4 Summary of Facility-Total Mercury Emissions in the 2004/2005 Timeframe ............14 5 Summary of Mercury Emissions by Th ermal Process (2004/2005 Timeframe) .........14 6 Summary of Thermal Process Units and Controls Used by Gold Mines in the United States, 2004/2005 Timeframe ................................................................15 7 Summary of Gold Mining Facilities Using Autoclaves in the United States ..............16 8 Summary of Gold Mining Facilities Using Roasters in the United States ..................16 9 Summary of Gold Mining Faciliti es Using Carbon Regeneration Kilns

in the United States ......................................................................................................18 10 Comparison of Mercury Emi ssion Estimates by Facility ............................................22 B-1 Summary of Responses to NDEP and U. S. EPA Gold Mines Questionnaire ..........B-3 B-2 Summary of Controls Used at Top Five Mercury Emitting Gold Mines

in the United States ...................................................................................................B-5 B-3 Summary of Gold Mining Facilities Using Electrowinning in the United States ......B-6 B-4 Summary of Gold Mining Facilities Using Retorts in the United States ..................B-7 B-5 Summary of Gold Mining Facilities Using Smelting in the United States ...............B-9 B-6 Summary of Gold Mining Facil ities Using Other Thermal Processes

in the United States ..................................................................................................B-11Acronyms

iii Acronyms

CAA Clean Air Act

CAAA Clean Air Act Amendments

CalEPA California EPA EPA U.S. Environmental Protection Agency GIS geographic information systems HAPs hazardous air pollutants NEI National Emission Inventory

NDEP Nevada Division of Environmental Protection NMA Nevada Mining Association NMCP Nevada Mercury Control Program NvMACT Nevada Maximum Achievable Control Technology OAQPS Office of Air Qualit y Planning and Standards OPTC Operating Permit to Construct ppmw parts per million by weight TRI Toxics Release Inventory VMRP Voluntary Merc ury Reduction ProgramAcronyms

ivSection 1.0 Introduction

1 

# 1.0 Introduction

The purpose of the report is to present recent data collected regard ing mercury emission estimates from gold (and silver) mining operations in the United States (U.S.). In this report we refer to these mining operations as gold mining operations because we did not identify any mines that produce only silver. That is, there are no silver mines th at do not also produce gold. We acknowledge, however, that many of these “gold” mining operations also produce a significant quantity of silver; they may also produce mercury, copper, and other metal products. Nonetheless, in this report, gold mining operation s (or gold mines) refer to all mining operations that produce gold; mining operations that produce bot h gold and silver are c onsidered a subset of gold mines.

Because gold and mercury belts can often be found in close proximity, gold ores commonly contain mercury in the form of mercury sulfide. The mercury concentrations in gold ores varies substantially, from less than 0.1 pa rts per million by weight (ppmw) to 100 ppmw (or 0.01 weight %) (Jones and Miller 2005). During gold production, me rcury can be liberated from the ore. Therefore, gold production processes are potentially significan t sources of mercury emissions to the atmosphere. The potential for mercury emissions from gold mining activities is dependent on the concentration of mercury in the ores along with other fact ors such as type of processes used, control technol ogies present, and pollution pr evention measures applied.

In addition to mercury being present in the ores, mercury was historically used intentionally to extract gold from ores in the U.S., through a process known as mercury amalgamation. This amalgamation method is still common among artisanal miners in many developing counties in South America, Africa and Asia. However, available information indicates that this amalgamation process was larg ely phased out in the U.S. decades ago and is essentially nonexistent in the U.S. today. Theref ore, amalgamation is not covered in this report

other than some historical inform ation presented in the Section 2.

Section 2 of this report provides back ground information on the history of gold production in the U.S. and an overview of the various gold mining proces s operations that are currently used at active U.S. gold mines. As se en in Section 2, the State of Nevada currently dominates the total gold production. Consequently, this report of ten compares and contrasts the gold production and mercury emissions from gold mining activities for the Nevada gold mines and all other (non-Nevada) gold mine s. Section 3 of this report provides a description of the

information collection activ ities conducted to obtain informa tion about current U.S. gold mining operations and their estimated mercury emissions , and it summarizes basic information obtained about the U.S. gold mines. Section 4 summari zes the mercury emission estimates provided in response to the information collection requests a nd compares these emission estimates with other estimates of U.S. gold mining mercury emissions . Finally, Section 5 pr ovides a brief summary on the State of Nevada’s Mercury Control Prog ram implemented to reduce mercury emissions from Nevada gold (and silver) mines.Section 2.0 Background Information

2 

# 2.0 Background Information

This section provides historical backgr ound of U.S. gold mining activities as well as a description of the primary gold pr oduction processes that are curren tly used at U.S. gold mines.



### 2.1 History of Gold Mining in the U.S.

The first documented gold mining in the United States occurred in North Carolina during the early 19 th century, after gold was discovered in 1799 at what would become Reed Gold Mine (North Carolina Office of Archives and Histor y 2006). By the late 1820s and early 1830s, Georgia, Alabama, Tennessee, and Virginia had also become significant gold producers. With the discovery of gold in California in 1848 and th e subsequent gold rush, the bulk of gold mining activity began to shift to the Western states. At the beginning of the 20 th century, there were approximately 4,000 gold mines operating in the Un ited States, a number which remained fairly stable until the Depression, at which time many small mines were opened in response to a spike in the price of gold; by 1934 and 1935 the number of mines had reached over 12,000. However, the majority of gold mines were shut down severa l years later in 1942, in order to focus labor on the war effort. After the war, relatively few mines reopened, and until 1970 only two new large mines were developed (Butterman and Amey 2005) . As of 2005, there were about 19 companies in the U.S. producing gold, with a total of roughly 40 operating mines (NMA 2006).



### 2.2 General Gold Mining Methods

Gold mines typically fall into one of two cat egories: placer mines or lode mines. In placer mining, gold is extracted from alluvial de posits of sand and gravel in which it is concentrated using various mechanical and hydr aulic techniques (Butterman and Amey 2005). In the early years of mining in the United States , the majority of gold recovered was from placer mines through the use of methods such as grav ity separation and amalgamation with mercury. By the 1860s, lode mines (surface or underground mines), also known as hard rock mines, had also become a significant source of gold. Du ring this time period, mercury amalgamation was used to extract gold from the pulverized ore af ter it was removed from the lode mines; the process of cyanidation, also used to chemically recover gold from the or es, was introduced in around 1890. With the advent of cyanidation, it became possible to extract a higher percentage of gold from the ore, thus making it economically feasible to mine lo wer-grade ores. The development of the flotation process, which be gan to see widespread use around the 1930s, also improved the efficiency with wh ich gold could be extracted.

In 1986, the last year for which complete da ta were reported on amalgamation, less than 1 percent of all lode gold was produced using th is process. By the early 1990s, the use of mercury amalgamation was largel y phased out in the United Stat es; in 1991, cyanidation and direct processing (i.e. smelting) were used to process 99 percent of all gold produced (U.S. EPA 1994). Based on information reviewed for this re port, no gold production companies in the U.S. currently use the mercury amalgama tion process to produce gold. In contrast to the early years of mining in the United States, 72 percent of the gold mined between 1900 and 1998 originated from precious metal lodes; 14 percent came from placer deposits and 14 percent was recovered as a byproduct of base-metal mining. Currentl y, 93 percent of gold produced in the UnitedSection 2.0 Background Information

3 States is derived from precious metal mines, w ith 6 percent coming from base-metal mining and just 1 percent from placer mines (Butterman and Amey 2005).



### 2.3 Production Amounts and Prices

Since gold mining began over two hundred year s ago in the United States, approximately 15,200 tons of gold has been produced. Ninety percent of this has originated from seven states: Nevada, California, South Dakota, Colorado, Al aska, Utah, and Montana. The remaining 10 percent of the country’s cumula tive gold production was mined in 17 other states, for a total of 24 gold producing states. Nearly all of South Dakota’s gold production came from Homestake Mine, the longest operating mine in the United St ates, with 1,240 tons of gold produced between 1876 and 2001 (Butterman and Amey 2005).

From the beginning of the 20 th century to around 1920, gold production in the United States ranged between 100 and 150 tons per year . As seen in Figure 1, production then dropped to about 70 tons per year and then briefly spik ed back up to around 150 tons per year an in the late 1930s and early 1940s as a re sult of the opening of many sma ll mines to provide jobs during the Depression (Butterman and Amey 2005). With the advent of World War II, gold production declined sharply and continued to decline stead ily until it reached around 30 tons per year in 1979 and 1980. Around 1980, a combination of fact ors, including strong demand and high prices led to a sharp in crease in gold production. At this time , the cyanide heap leaching process was becoming a primary means for gold extraction. Because the unit cost of gold production is largely dependent on the grade of the ore and the efficiency with which the gold can be extracted, the development of processes which im prove efficiency of removal, such as heap leaching, allow for lower-grade ores to be mined w ithout an increase in cost. By the late 1990s, yearly gold production in the United States r eached over 350 tons (Butterman and Amey 2005); of this amount, over 250 tons, or approximately 70 percent, came from mi nes in Nevada (Figure 1) (Nevada Division of Minerals 2006). At the beginning of the 21 st century, gold production in the U.S. began to decline, while prices rose (Figures 2 and 3). In 2005, the United States produced about 262 tons of gold, with 217 tons (83 percent) coming from Nevada (NMA 2006); at this time, there were about 19 companies producing gold in the United States. The two companies with the greatest production were Barrick Gold Corporation and Newmont Mining Corporation, which contributed approximately 66 percent of the total gol d produced in the U.S. (NMA 2006). As of 2001, the top 5 gold producing ope rations in the country (shown in Table 1)

were all in Nevada.

As seen in Figure 1, the gold mining industr y is a fairly dynamic one with new mines coming on line and old ones being retired. The ne xt few years are expected to continue this trend. The richest production rese rves occur in an area known as the Carlin Trend in Nevada. Development of the Carlin Trend has catapulted Ne vada to the top gold mining spot in the U.S. This is due in part to the ric hness of the trend and also due to advances in technology that allow for development of reserves hitherto considered uneconomic to develop. Mining reports give the Carlin Trend a continued life of about 7-8 years. In the face of declini ng Carlin Trend reserves, the mining industry has understandably been casting fu rther afield in search of new reserves. It appears that their efforts have been successful – the Cortez Trend (also in Nevada) is expected to be almost as productive as the Carlin Tre nd. Already, mines are coming online (e.g., Golden Phoenix) and others ar e being permitted.Section 2.0 Background Information

4 0 50 100 150 200 250 300 350 40019071912191719221927193219371942194719521957196219671972197719821987199219972002

YearU.S. gold production (metric tons)

0 100 200 300 400 500 600 700Price ($) per ounce gold U.S. gold production

NV gold production

Price

Figure 1. United States gold production and price of gold, 1907 to 2005 (Nevada Division of Minerals 2006 and Butterman and Amey 2005).Section 2.0 Background Information

5 0 50 100 150 200 250 300 350

2001 2002 2003 2004 2005

YearU.S. gold production (metric tons)

0 50 100 150 200 250 300 350 400 450Average price ($) per ounce

Total

Nevada

Non-Nevada

Price per ounce

Figure 2. United States gold production and pr ice of gold, 2001 to 2005 (NMA 2006 and Nevada Division of Minerals 2006).



### 2.4 Gold Mining Processes Currently Used in the U.S.

This section describes current gold mining pr ocesses and their poten tial to emit mercury.

2.4.1 Extraction, Crushing, and Milling

The first step in the gold production process is the removal of gold-containing ores from the earth. In both surface and underground lode mining, the extraction of ores is typically accomplished through calculated blasting and dril ling, as well as through the use of earthmoving machinery. Placer mines, though currently far less common as gold sources in the U.S., rely on a

combination of traditional land excavation t echniques and hydraulic equipment, including dredges and high-pressure water nozzles. Afte r the ore has been removed from the ground, jaw and cone crushers are used to reduce the large pieces of ore in size; mills are used next to grind ore particles to an even smaller, consistent size (Butterman and Amey 2005). Crushing and milling do not represent a significant source for mercury emissions because neither chemical

reactions nor heat treatments occu r in these processes (U.S. EPA 2001b).Section 2.0 Background Information

6 2.4.2 Roasting and Autoclaving

If the process of cyanide leaching can extract 88 percent or more of the gold contained in a milled ore with no further proce ssing, the ore is referred to as am enable, and if not, the ore is described as refractory (Butterman and Amey 2005) . Factors such as the presence of organic carbon and sulfide mineral grains in refractory ores inhibit the efficiency of gold recovery during cyanide leaching; both ore roas ters and autoclaves are used to oxidize and remove these components. An ore roaster is an industrial fu rnace in which milled ore is mixed with coal or

other fuel material and combus ted across a fluidized bed. Duri ng roasting, mercury sulfide is converted to elemental mercury and sulfur dioxi de (U.S. EPA 2001b). The elemental mercury is emitted in vapor form with the roaster off gas, which is typically vented to air pollution control devices such as sulfur dioxide scrubbers, baghou ses, and electrostatic pr ecipitators; however, removal efficiencies for elemental mercury vapor are low for these devices (e.g., SO2 scrubbers provide an average mercury removal of only about 25 percent from roasters based on available data) (U.S. EPA 2001a).

Autoclaving involves pumping a slurry of mille d ore, water, and sulfuric acid into a vessel which is highly pressurized with oxygen and h eated to 350 to 430o F. The result of this process is that at least 95 percen t of sulfide minerals in the ore are oxidized to sulfates. During autoclaving, mercury sulfide co mbines with oxygen to form me rcury sulfate (HgSO4), which dissociates to some degree in the slurry. Consequently, the mercury present in gaseous emissions from the autoclave is typically Hg2+ a nd can be effectively cont rolled using a venturi scrubber system (U.S. EPA 2001b). As described in Section 3, three facilities in U.S. use autoclaves, and all three of these facilities are located in Nevada.

2.4.3 Leaching

Leaching generally takes place either directly after milling or after roasting and/or autoclaving. In heap leaching, or e is stacked on a large impervious pad that drains to a collection pond; an alkaline cyanide solution is dispersed over the ore and percol ates through the heap, which can range in size from less than 50,000 tons to greater than 300,000 tons. As the cyanide comes into contact with the gold contained in th e ore, a gold-cyanide solution is formed, which seeps down to the liner and flows out to the co llection pond. During this process, mercury may be leached into the gold-cyanide solution; th e amount of mercury leached is dependent on the concentration of the cyanide solution as well as th e presence or absence of additives designed to suppress mercury dissolution. The solution c ontaining the precious me tals is called the “pregnant” cyanide solution. Regional testing pe rformed in Nevada has indicated that around 20 percent of the mercury in the ore is leached along with the go ld (U.S. EPA 2001b). However, despite the potential for mercury to leach along with the gold, heap leaching does not represent a significant source for mercury emissions, because the mercury remains in either solid or liquid form during the process (U.S. EPA 2001b).

2.4.4 Carbon Stripping and Regeneration

After leaching, the gold complexes in the pr egnant cyanide solution are concentrated through adsorption onto activated carbon; if merc ury is present in the gold-cyanide solution, it too is adsorbed onto the carbon. The adsorbed go ld and mercury are then stripped from the carbon through desorption under pressurized or atmospheric conditions, typically using a heated caustic cyanide solution, resulting in a more concentrated gol d-containing solution. Before reuseSection 2.0 Background Information

7 in the adsorption-desorption proce ss, the carbon is regenerated in a rotary kiln. As the carbon is heated, mercury which remained on the carbon afte r stripping is released as elemental mercury vapor and vented, along with st eam and carbon monoxide, to pollution control devices or directly to the atmosphere. Carbon adsorption filters ar e the only mercury-specific control device used on for carbon regeneration rotary kilns at mines in the United States; particulate control devices are ineffective in controlling elemen tal mercury vapor (U.S. EPA 2001b).

The carbon adsorption filters used to cont rol mercury emissions from the carbon regeneration system or any othe r gold mining process must be pe riodically replaced. The spent carbon filters may be landfilled or the carbon in the f ilters may, in turn, be regenerated, typically by sending the filters to an off-site carbon rege nerator. Unless the off-site regenerator has mercury controls, this practice will simply de lay and shift the mercur y emissions; it will not result in true mercury reductions. Therefor e, the disposition of th e carbon used in carbon adsorption control systems is important to co nsider when evaluating the ultimate mercury reduction achieved by the carbon adsorption control system.

2.4.5 Recovery from Solution

Gold is recovered from solution in one of two ways: electrowinning or precipitation with zinc powder. Separation of gold through elec trowinning is achieved by using an electric potential to plate the gold (and ot her metals present) in solution onto a cathode; steel wool is typically used as the plating surface because of the large surface area it provides for gold deposition. During electrowinni ng, elemental mercury can vaporize and escape from the cell with the other gases produced in the process; ca rbon adsorption filters are effective in controlling these mercury emissions. Zinc powder can also be used to recover gold from solution because zinc has a higher affinity for cyan ide ions than does gold or other metals. Therefore, when zinc powder is added to the cyanide so lution, the zinc dissolves and th e other metals precipitate out and are extracted by filtration. Because zinc prec ipitation typically takes place within a closed cell, mercury emissions from this process are limited (U.S. EPA 2001b).

2.4.6 Retorting and Smelting

After the separation of gold from solution by electrowinning or prec ipitation, gold must be extracted from other remaining metals. This is accomplished through retorting and then smelting. A retort heats the gold and other meta ls under a vacuum for 12 to 24 hours at 600°C to 700°C; around 99 percent of the mercury is removed. The majority of this mercury is condensed and collected, but a small percentage is emitted as vapor with the off-gas, which is typically controlled by a carbon adsorption filter where 95% control efficiency can be expected (U.S. EPA 2001b). Smelting is the last step in gold production before the gold is sent to a refinery. The gold, along with a material with reducing potential known as flux, is heated to around 1500°C, at which time most of the remaining mercury is volat ilized as elemental mercury. Emissions from the smelting furnace are typically vented through a fume hood; venturi scrubbers have been applied to reduce mercury emissions from these furnaces (U.S. EPA 2001b).Section 3.0 U.S. Gold Mining Industry Survey

8 

# 3.0 U.S. Gold Mining Industry Survey

The U.S. EPA’s Office of Air Quality Pla nning and Standards (OAQPS) and State of

Nevada’s Division of Environmental Protecti on (NDEP) coordinated efforts to develop questionnaires designed to gather information on mercury emissions and controls from gold and silver production facilities in the U.S. The NDE P administered the survey questionnaires to all gold and silver production facilities in Neva da, and the EPA administered the survey questionnaire to additional gold and silver produc tion facilities in the United States but not in Nevada. Responses to both of these survey questionnaires were compiled. This section describes the survey and summarizes general facility information and production data obtained from the survey responses. Section 4 summarizes the specific mercury emissions data reported in the survey responses. As described in the introduction, we generally refer to the gold and silver mines collectively as simply gold mine s because all of the respondents produce gold and no respondents produce only silver. Therefore, mines that produ ce silver are a fully included subset of gold mines. Also as described in Section 2.3, the gold mining industry is a fairly dynamic one with new mines coming on line and ol d ones being retired. Therefore, it is important to understand that the i ndustry survey presented here is merely a snapshot of the industry in the 2004/2005 time-frame, and the co mplexion of the industry may be significantly different in 10 years.



### 3.1 Description of Industry Survey

Representatives from the U.S. EPA (inc luding OAQPS, Region 9 and Region 10), the NDEP, and industry representatives collaborated in developing a questionnaire to gather information about mercury emissions from preciou s metals mining in general, and gold mining in specific. The questionnaire focused on collecting mercury air emissions data from thermal operations used to process gold ore. The ques tionnaires included questio ns about amount of ore processed, mercury content in the ore, types of processes used, control technologies applied, and pollution prevention measures used. The questio nnaire was divided into three sections: a general facility information section; a series of tables specific to thermal gold mining processes; and a series of tables specific to mercury emission controls. If a facility did not use thermal processes, then only the general information was requested. Add itionally, in the EPA version of the questionnaire only general information was requested from facilities that processed gold ore that contained 0.1 milligram per kilogram (mg/ kg) regardless of whether or not thermal processes were used.

The NDEP finalized its questionnaire in January 2006, which was intended for mining

facilities located within the State of Nevada. The Nevada questionnaire is available on the

internet at: http://ndep.nv.gov/mercury/mercury_air.htm . The Nevada questi onnaire was sent to all silver and gold mining production companies with operations in the State of Nevada, and requested data specific to thei r Nevada precious metal mining ope rations. Fifty-one facilities completed and returned the Nevada survey questionnaire.

The U.S. EPA administered a very simila r questionnaire in early 2006. This second questionnaire was intended for gold mining operations located in the U.S., but that were outside of the State of Nevada. The U.S. EPA questionnai re is shown in Appendix 1 of this report. In April 2006, the U.S. EPA sent this questionnaire to seven gold producing companies in theSection 3.0 U.S. Gold Mining Industry Survey

9 United States that operate mines located out side of Nevada. One company operated two facilities outside of Nevada; the other companies e ither had only one operating facility outside of Nevada or no longer operated a mining facility outside of Nevada.



### 3.2 Summary of Survey Respondents

Fifty-one gold mining facilities in Nevada and 8 gold mining facilities outside Nevada responded to the survey. The non-Nevada facili ties were located in Alaska, California, Colorado, Montana, and Washington. Nearly half of the respondi ng facilities in Nevada were

subsidiaries of either Newmont Mining Corporation or Barrick Gold Corporation; fourteen belonged to Newmont and nine to Barrick. Twenty -four of the Nevada f acilities are currently mining or processing ore, while six of the eight facilities that responded to the survey from the

rest of the United States are cu rrently operating. In addition, thr ee facilities (two in Nevada and one in Washington) indicated th at mining operations would begin or resume in the future. Table 1 provides the number of respondents for some of the ke y questions in the survey.

Note that mercury emissions were requested in two sections of the questionnaire. First, facilities were requested to report their total fa cility-wide mercury air emissions. For facilities with thermal operations, mercury emission estimat es were also requested individually for each thermal process unit. For the EPA version of the survey, individual thermal process unit data were not requested for facilities that had low me rcury content. A total of 24 facilities reported either total facility mercury emissions, process- specific mercury emissions , or both. Eighteen of

these facilities are located in Nevada and six f acilities are located in ot her states. As shown in Table 1, nineteen facilities reported estimates fo r total mercury emissions (14 Nevada facilities and 5 non-Nevada facilities). Nineteen faciliti es reported mercury emissions by thermal process unit; seventeen of these facilities were in Neva da and two were outside of Nevada. Fourteenfacilities provided mercury emissions estimates on both a facility-total basis and thermal processspecific basis. More details re garding the reported quantity of mercury emissions are provided in

Section 4.

Table 1. Summary of the Type of Mercury Emissions Information Received in the Responses to the Questionnaires.

Description Nevada U.S. EPA Total
Number of facilities respon ding to survey 51 8 59
Number of facilities currently operating 24 6 30
Number of facilities pr oducing gold 20 7 27
Number of facilities prod ucing silver 17 7 24

Number of facilities producing mercury by -product 13 1 14
Number of facilities proc essing mercury-containing

ore 25 3 28

Number of facilities with or e mercury concentrations of 0.1 mg/kg or greater 18 2 20

Number of facilities reporting thermal pr ocesses 20 4 24

Number of facilit ies reporting facility-wide mercury

emissions 14 5 19

Number of facilitie s reporting process-specific mercury

emissions 17 2 19

Number of facilities repo rting both facility-wide and process-specific mercury emissions 13 1 14Section 3.0 U.S. Gold Mining Industry Survey

10 

### 3.3 Survey Characterization of Cu rrent Gold Mining Industry

Table 2 shows the processing and production qu antities for Nevada gold mines compared to non-Nevada gold mines. Most survey responden ts reported data for 2004 but some facilities provided data for 2005. Therefore, the survey data are reported for “the 2004/2005 timeframe.” Nevada facilities produced a total of 7,004,270 ounces of gold and 10,532,992 ounces of silver annually in the 2004/2005 time frame; mines outside of Nevada produced 944,561 ounces of gold and 9,418,246 ounces of silver. Based on thes e results, Nevada mine s represent almost 90 percent of the U.S. gold production and approximate ly 50 percent of the U.S. silver production. The top gold producer in Neva da was Barrick Goldstrike Mines, which produced 1,942,660 ounces of gold in 2005, more than twice the go ld produced from all Non-Nevada facilities combined. Detailed facility-s pecific information on gold, silv er, and mercury production and on mercury emissions based on the questionnair e responses is provided in Appendix 2.

Table 2. Summary of Production and Mercury Em issions from Gold Mining Facilities in the United State, 2004/2005 Timeframe.

Nevada Non-Nevada Total

Tons ore processed (all facilities) 185,132,897 48,308,714 233,441,611
Ounces gold produced 7,004,270 944,561 7,948,831
Ounces silver produced 10,532,992 9,418,246 19,951,238
Pounds elemental mercury produced 202,954 0 202,954
Pounds calomel produced 33,497 0 33,497

In extracting this gold, seventeen Neva da facilities reported processing 185,132,897 tons of ore in 2004/2005 timeframe, while seven non-Neva da facilities processed 48,308,714 tons.Additional ore processing information is summarized in Table 3. In the EPA survey (nonNevada mines), only facilities processing ore with mercury concentrations greater than or equal to 0.1 milligram mercury per kilogram ore (0.1 mg /kg) were asked to report amounts of ore processed by process type (e.g. au toclaving, roasting, heap leaching, etc.). As such, only two of six operating non-Nevada faciliti es reported totals for ore pr ocessing by process type (i.e. autoclaving, roasting, heap leaching, etc.), wherea s fifteen of the seventeen Nevada facilities reported the process-specific ore processing info rmation. Upon initial cal culations, the reported amount of total ore processed by these fac ilities was 140,625,427 tons in Nevada and 4,503,764 tons outside of Nevada; the calcu lated amount of total ore processed by these facilities (that is, the sum of the amounts processed for each process type) was 174,405,287 tons in Nevada and 4,503,764 tons in Non-Nevada states. The reporte d and calculated totals matched for the NonNevada facilities, but the cal culated amount of total or pr ocessed for Nevada mines was significantly higher than the total reported by these facilities. It was appa rent that one facility, Round Mountain Gold Corporation – Smoky Valley Common Operations, reported a quantity of total ore processed (7,801,552 tons) that was lo wer than the amount reported as being heap leached (52,641,580 tons). Given that the total or e processed should include the quantity of ore that was heap leached, it was assumed that one of these numbers was reported incorrectly. Based on the amount of gold produced at this facility, it was concluded that the total quantity of ore processed had been reported incorrectly. Ther efore, the total quantit y of ore processed wasSection 3.0 U.S. Gold Mining Industry Survey

11 assumed to be equal to the sum of ore heap leached and carbon in leach of milled ore. After this correction, the reported amount of total ore pro cessed by Nevada facilities reporting processspecific data was 183,672,254 tons; this figure better corresponded w ith the calculated amount of total ore processed by these faci lities (174,405,287 tons) than did the total before the correction. The remaining difference between the reported a nd calculated amounts of to tal ore processed is likely a result of severa l facilities using processes other th an roasting, autoclaving, and heap leaching to process ore.

Table 3. Tons of Ore Processed by Process Type, 2004/2005 Timeframe.

Nevada Non-Nevada Total

All facilities

Tons ore processed 185,132,897 48,308,714 233,441,611

Facilities reporting amounts by process

Tons ore processed 183,672,254 4,503,764 188,176,018

Tons ore roasted 10,135,483 0 10,135,483

Tons ore autoclaved 11,356,265 0 11,356,265

Tons heap leaching 141,423,965 4,225,516 145,649,481

Tons carbon in leach of milled ore 11,489,574 278,248 11,767,822

Tons other ore processed 9,266,967 0 9,266,967

Of the ore processed in Nevada, 10,135,483 t ons were autoclaved and 11,356,265 tons were roasted; no autoclaving or roasting was re ported at non-Nevada f acilities. In Nevada, 141,423,965 tons of ore were heap leached, while facilities outside of Nevada processed 4,225,516 tons of gold through heap leaching. In a ddition to heap leaching, Nevada facilities used carbon in leach to extract gold from 11,489,574 tons of milled ore and 21,501,656 tons of roasted/autoclaved ore. Only one non-Nevada f acility used the carbon in leach process for gold extraction, with 278,248 tons of mille d ore processed in this way.

Twenty-two of the twenty-four currently operati ng facilities in Nevada process ores that contain mercury; eighteen of these have ores w ith mercury concentrations greater than 0.1 mg/kg (Figure 3). Three currently opera ting non-Nevada facilities pro cess mercury containing ores, and both locations have mercury concentrations grea ter than 0.1 mg/kg in the ore. Nevada mines reported producing 202,954 pounds of elemental mercury and an additional 33,497 pounds of calomel (mercury chloride) in 2004/ 2005; facilities in the rest of the United States did not report any mercury production. (Note: one of th e two non-Nevada mines that have mercury containing ores did indicate that they produce mercury, but they did not report a mercury production quantity. Mines that do not produce mercury product are expected to have higher mercury emissions than those that recovery mercury, all other va riables being equal).Section 3.0 U.S. Gold Mining Industry Survey

12 Figure 3. Currently operating U.S. gold mine s processing mercury-containing ores

Number of currentl y operatin g US g old mines processing mercury-containing ores

NV, >0.1 mg/kg

mercury

18 Non-NV, >0.1
mg/kg mercury

3 NV, ≤ 0.1 mg/kg

mercury

4Section 4.0 Mercury Emissions from Gold Mines

13 

# 4.0 Mercury Emissions from Gold Mines

This section presents data on mercury emi ssions from gold mines. Mercury emissions reported in response to the industr y survey are first presented, a nd then they are compared to mercury emissions reported in the Toxics Rele ase Inventory (TRI) and the National Emissions Inventory (NEI).



### 4.1 Gold Mining Mercury Emissi ons from Industry Surveys

In the EPA and Nevada questionnaires, facil ities were requested to report their total mercury air emissions on a facility-wide basis a nd, for facilities with thermal operations, their mercury emissions for each thermal process unit. Respondents to the industry survey did not, as a rule, provide information on how these emissi on estimates were developed. Additionally, some respondents did not report any mercury em issions even though they did report processing mercury-containing ore. Therefore, the inform ation provided were generally inadequate to characterize the uncertainty in the mercury emissi ons reported. The mercury emission values as reported are provided in the follo wing subsections. Additional discussion of the uncertainties and potential biases in the reported mercury emission estimates are provided in Section 4.5.

4.1.1 Facility Total Mercury Emissions

Table 4 summarizes the reported mercury em issions from the gold and silver mines responding to the industry survey. Based on th e industry survey res ponses, Nevada gold and silver mines produce approximately 90 percent of the gold, but release approximately 99 percent of the mercury emissions from the U.S. gold a nd silver mines. The annual mercury emissions

for all facilities in Nevada in the 2004/2005 tim eframe were 4,487 pounds per year. Almost half of Nevada’s mining mercury emissions came from just one facility, Barrick Gold Corporation’s Goldstrike Mines, which emitted an estimated 2,175 pounds of mercury in 2005. The vast majority of Nevada’s remaining mining mercury em issions came from four facilities: Newmont Mining Corporation’s Gold Quarry Operations ; Newmont Mining Corporation’s Twin Creeks Mine; Barrick Gold Corporation and Kennecott Minerals, Inc.’s Cortez Gold Mine; and Queenstake Resources Ltd.’s Jerritt Canyon Mine (Table 4). Five gold and silver mining facilities from the rest of the United States pr ovided total mercury emissions estimates for the 2004/2005 timeframe; these emissions totaled 41.1 lb s, less than one percent of the emissions

from the Nevada mines.

4.1.2 Thermal Process Mercury Emissions

Gold mining facilities that had thermal proc ess units were requested to estimate their mercury emissions on a process-specific basis for each thermal process unit. The number of facilities reporting thermal processes and the tota l mercury emissions by pr ocess type as reported by the survey respondents are summarized in Table 5. Of the facilities cu rrently operating in the United States that reported using thermal proces ses, twenty were in Nevada and four were

outside the state of Nevada. Se venteen Nevada facilities repo rted mercury emissions for the 2004/2005 timeframe by thermal process unit (of the 20 Nevada facilities reporting to operate thermal process units). Mercury emissions from Nevada’s thermal process units were reported to be 4,176.3 pounds per year. Autoclaves, roaste rs, and carbon regeneration kilns wereSection 4.0 Mercury Emissions from Gold Mines

14 responsible for 90 percent of these emissions , with 3,760.5 pounds of mercury released from these sources. Only two non-Nevada facilities reported emissions by thermal process unit (of the 4 non-Nevada facilities reporting to operate thermal process units ), although a third facility, Apollo Gold’s Montana Tunnels, provided inform ation regarding emissions from its refinery

furnace. No autoclaves or roasters were used by non-Nevada facilities, so these significant thermal processes are not present at non-Nevada mines. Non-Nevada mines reported minimal mercury emissions from thermal processes (0.6 pounds in 2004/2005). Howe ver, it is important

to note that not all of the non-Nevada mines w ith thermal processes reported mercury emissions, and that we could not verify the basis of th e mercury emissions for most of the non-Nevada

mines.

Table 4. Summary of Facility-Total Mercu ry Emissions in the 2004/2005 Timeframe.

Parent company Facility name Quantity of
Ore

Processed

(tons/yr) Quantity
of Gold

Produced

(oz/yr) Total Mercury

Emissions

(lbs/yr) % of Total Mercury

Emissions

Nevada Gold and Silver Mines

Barrick Goldstrike Mines 12,809,234 1,942,660 2,174.6 48.0
Newmont Gold Quarry Operat ions 22,090,847 872,945 658.8 14.5
Newmont Twin Creeks Mine 7,123,665 1,123,755 563.0 12.4
Barrick/Kennecott* Cortez Gold Mines 41,603,701 999,961 492.0 10.9
Queenstake Jerritt Canyon Mine 1,305,833 242,912 461.0 10.2
Other Nevada mines 100,199,617 1,822,037 137.6 3.0
Subtotal: Nevada mines 185, 132,897 7,004,270 4,487.0 99.1

Non-Nevada Gold and Silver Mines

All non-Nevada mines 43,308,714 944,561 41.1 0.9
Nationwide Total Based on Survey Re sponses 228,441,611 7, 948,831 4,528.1 100.0

* Barrick 60%, Kennecott 40%

Table 5. Summary of Mercury Emissions by Thermal Process (2004/2005 Timeframe).

Process # NV facilities NV Mercury Emissions (lbs) # Non-NV
facilities Non-NV Mercury Emissions (lbs)
Autoclaving 3 899.4 0 0.0
Roasting 3 1247.9 0 0.0
Carbon regeneration kiln 12 1613.2 3 0.1
Electrowinning 13 80.7 3 0.0
Retorting 13 18.7 0 0.0
Smelting furnace 16 134.9 2 0.4
Other thermal processes 35 181.6 2 0.0

Total 4176.3 0.6Section 4.0 Mercury Emissions from Gold Mines

15 4.1.3 Thermal Process Mercury Emission Controls

Table 6 provides an overview of the types of c ontrols that have been applied to each type of thermal processes. As seen in Table 6, ther mal process units are used predominately at the Nevada mines. Additionally, air emission controls (and specifically mercury air emission controls) are used predominately at the Nevada mines. Due to their significance to the total annual mercury emissions, process-specific cont rols and estimated mercury emissions are provided for autoclaves, roasters, and carbon regeneration kilns in Tables 7 through 9, respectively.

As seen in Table 7, three Nevada facilitie s used autoclaving, w ith a total of nine

autoclaves used in the state. No non-Nevada mine s used autoclaves. Each of the nine autoclaves was attached to a wet scrubber, with one unit al so attached to an off-gas quencher. Total mercury emissions from these units were 899.4 pounds.

Table 6. Summary of Thermal Process Units and Controls Used by Gold Mines in the United States, 2004/2005 Timeframe.

Process # NV
facilities # NV

units NV controls # NonNV
facilities # NonNV

units Non-NV

controls

Autoclave 3 9 Off-gas quencher

Wet scrubber 0 0 Not applicable

Roaster 3 8 Condenser Electrostatic precipitator
Fabric filter Off-gas quencher

Wet scrubber 0 0 Not applicable

Carbon regeneration

kiln 12 16 Carbon adsorption unit
Condenser

Wet scrubber 3 3 Wet scrubber

Electrowinning 13 13 Carbon adsorption unit

Wet scrubber 3 6 Wet scrubber

Retort 13 28 Carbon adsorption unit
Condenser Cyclone
Fabric filter

Mist eliminator

Wet scrubber 0 0 Not applicable

Smelting
furnace 16 23 Carbon adsorption unit Electrostatic precipitator
Fabric filter

Wet scrubber 2 2 Wet scrubber

Other thermal

process 13 127 Carbon adsorption unit
Fabric filter

Wet scrubber 2 2 Fabric filterSection 4.0 Mercury Emissions from Gold Mines

16 Table 7. Summary of Gold Mining Faciliti es Using Autoclaves in the United States.

Parent

company Facility name State Total ore processed by facility (tons) Unit

ID Control technologies Estimated mercury
emissions from unit (pounds)

Newmont Lone Tree Mine NV 6,068,995 01 Wet scrubber (1993)*
Off-gas quencher (2002) No data

Newmont Twin Creeks Mine NV 7,123,665 01 Wet scrubber (1996) 286

Newmont Twin Creeks Mine NV 7,123,665 02 Wet scrubber (1996) 64.93

Barrick Goldstrike Mines NV 12,809,234 01 Wet scrubber (1990) 70.7

Barrick Goldstrike Mines NV 12,809,234 02 Wet scrubber (1992) 97.05

Barrick Goldstrike Mines NV 12,809,234 03 Wet scrubber (1992) 97.05

Barrick Goldstrike Mines NV 12,809,234 04 Wet scrubber (1993) 95.2

Barrick Goldstrike Mines NV 12,809,234 05 Wet scrubber (1993) 94.25

Barrick Goldstrike Mines NV 12,809,234 06 Wet scrubber (1993) 94.25

Total >899.4 * Dates in parentheses indicate the year control unit was installed.

Three Nevada facilities used roasting, with eigh t roaster units releasing 1,247.9 pounds of mercury (see Table 8). Seven of the roaster units were connected to a we t scrubber, with four units also connected to an off-gas quencher. Two units, including the on e unit not controlled by a wet scrubber, were controlled with a fabric filt er; electrostatic precipitators were also used on

two units. No non-Nevada mines used roasters.

Table 8. Summary of Gold Mining Faciliti es Using Roasters in the United States.

Parent

company Facility name State Total ore processed by facility (tons) Unit

ID Control technologies Estimated

mercury emissions
from unit (pounds)
Barrick Goldstrike Mines NV 12,809,234 01 Wet scrubber (1999)* Electrostatic precipitator (1999) Off-gas quencher (1999) Condenser (1999) 520.5

Queenstake Jerritt Canyon Mine NV 1,305,833 01 Wet scrubber (1999) Hypochlorite scrubber (2001) Off-gas quencher 320.5

Queenstake Jerritt Canyon Mine NV 1,305,833 02 Wet scrubber (1999) Hypochlorite scrubber (2001) Off-gas quencher 138.31

Newmont Gold Quarry Operations NV 22,090,847 01 Fabric filter (1994) 0.63

Newmont Gold Quarry Operations NV 22,090,847 02 Fabric filter (1994) Wet scrubber (1994) 267.05

Newmont Gold Quarry Operations NV 22,090,847 03 Wet scrubber (1994) Electrostatic precipitator (1994) Off-gas quencher 0.75

Newmont Gold Quarry Operations NV 22,090,847 04 Wet scrubber (1994) 0.065

Newmont Gold Quarry Operations NV 22,090,847 05 Wet scrubber (1994) 0.065

Total 1,247.9
* Dates in parentheses indicate the year control unit was installed.Section 4.0 Mercury Emissions from Gold Mines

17 As seen in Table 9, twelve Nevada facilities and three non-Nevada facilities used carbon regeneration kilns, with a total of 19 un its emitting an estimated 1613.3 pounds of mercury.

Twelve units were connected to a wet scrubber to control emissions, with four of these units also using a carbon adsorption unit and one of the units using a hypochlorite scrubber (to enhance mercury control). An additional unit used a ca rbon absorption system alone. One unit using both a wet scrubber and a carbon absorption unit was also connected to a condenser. The remaining six units used no controls.

Thirteen Nevada facilities used electrowinni ng, with thirteen units emitting an estimated 80.7 pounds of mercury; one of these units had a wet scrubber, one had a carbon adsorption unit, and one had both, with rest of th e units uncontrolled. Three facil ities outside of Nevada had six electrowinning units, but no mercur y emissions were reported from them; one of these units was

controlled with a wet scrubber. Thirteen Nevada gold mines used retorting, with 28 retort units emitting an estimated 18.7 pounds of mercury; ever y unit was connected to at least one control device, with carbon adsorption units, condensers, cyclones, fabric fi lters, mist eliminators, and wet scrubbers being used. No facilities outside of Nevada reported using retorts.

Sixteen Nevada mines reported having smelting furnaces, with a total of 23 such furnaces emitting an estimated total of 134.9 pounds of mercur y. Twenty of the furnaces were connected to at least one control, with f ourteen connected to a fabric filt er and seven connected to a wet scrubber; four units also used electrostatic precipitators and on e used carbon adsorption unit.

Two non-Nevada facilities also used one smelti ng furnace each, but only reported a total of 0.44 pounds of mercury emissions; one unit was conne cted to a wet scrubber and one unit had no

control device. Thirteen Neva da facilities reported using a thermal process other than the primary processes listed above, with 127 such units emitting an estimated 181.6 pounds of mercury. The two non-Nevada units using other th ermal processes reported negligible emissions (0.02 pounds) from their two units.



### 4.2 Gold Mining Mercury Emissions from the TRI

The TRI provides yearly estimates of toxic releases into the environment from 1998 to 2005; data from the TRI was extracted using the ba sic TRI Explorer queries. The TRI Explorer includes a query function for predefined industria l sectors. One of the predefined industry sectors is “metal mining” as designated by gene ral standard industrial cl assification (SIC) code of 10. Facility specific data were extracted for the metal mi ning industry (SIC code = 10) for the inventory years of 1998 through 2005. Each fac ility was designated as either a “Nevada gold mining” facility, a “non-Nevada gold mining” facili ty, or an “other metal mining” facility. The “mercury emissions” presented in this section are the sum of the reported on-site air emissions of both mercury and mercury compounds. The results of the TRI data analys is are presented in Figure 4.Section 4.0 Mercury Emissions from Gold Mines

18 Table 9. Summary of Gold Mining Facilities Using Carbon Regeneration Kilns in the

United States.

Parent

company Facility name State Total ore processed by facility

(tons) Unit

ID Control technologies Estimated

mercury emissions
from unit (pounds)
Newmont Lone Tree Mine NV 6,068,995 01 None No data

Newmont Lone Tree Mine NV 6,068,995 02 Wet scrubber (1992)* No data

Florida Canyon/ Jipangu

International Florida Canyon Mine NV 6,256,953 01 None No data

Newmont Battle Mountain Gold,

Reona and Phoenix Projects NV 1,940,439 01 Wet scrubber (2005) No data

Kinross/

Barrick Round Mountain Gold, Smoky Valley Common Operation NV 7,801,552 01 None 13.6

Barrick/

Kennecott Cortez Gold Mines Mill #2 (Pipeline Mill) NV 41,603,701 01 Wet scrubber (2005) 230

Barrick/

Kennecott Cortez Gold Mines Mill #2 (Pipeline Mill) NV 41,603,701 02 Wet scrubber (2005) 231

Golden

Phoenix Mineral Ridge Mine NV 280,000 01 No data No data

Barrick Homestake Mining, Ruby Hill Mine NV 0 01 Wet scrubber (1997) No data

Newmont Twin Creeks Mine NV 7,123,665 02 Wet scrubber No data

Newmont Twin Creeks Mine NV 7,123,665 01 Wet scrubber (1987/1996) Hypochlorite scrubber (2003) 21.78

Barrick Goldstrike Mines NV 12,809,234 01 Wet scrubber (1998/1999) Carbon adsorption unit (1998/1999) Condenser (1999) 1064

Queenstake Jerritt Canyon Mine NV 1,305,833 01 Wet scrubber (2002) Carbon adsorption unit (2002) 0.26

Newmont Gold Quarry Operations NV 22,090,847 01 Wet scrubber (1989) Carbon adsorption unit (1989) 38.54

Newmont Gold Quarry Operations NV 22,090,847 02 Wet scrubber (1993) Carbon adsorption unit (1993) 5.98

Barrick/

Placer Dome Bald Mountain Mine (including Mooney Basin) NV 2,225,405 01 Carbon adsor ption unit (2004) 8.06

Barrick Golden Sunlight Mines MT 2,600,000 01 Wet scrubber 0.12

Kinross Echo Bay Minerals,

Kettle River Operations WA 278,248 01 None No data

Western
Goldfields Western Mesquite

Mine CA 4,225,516 01 None No data

Total >1,613.3

* Dates in parentheses indicate the year control unit was installed. Two dates in parentheses indicate the years

control unit was installed/rebuilt.Section 4.0 Mercury Emissions from Gold Mines

19 0 2000 4000 6000 8000 10000 12000 14000 16000

1998 1999 2000 2001 2002 2003 2004 2005

YearTotal air emissions of mercury (lbs) Total U.S. metal mining

Nevada gold mining

Non-Nevada gold mining

Other metal mining

Jerritt Canyon Mine

Barrick Goldstrike Mines

Figure 4. Mercury emissions from metals mini ng in the United States, 1998-2005 based on the Toxics Release Inventory.

As seen in Figure 4, TRI’s on-site air emi ssions of mercury from gold mines steadily decreased from 1998 to 2005, dropping from 13,612 pounds in 1998 to about 4,908 pounds in 2005. The majority of this decrease is attribut able to emission reducti on activities conducted at gold mines in the state of Nevada. The Nevada gold mines decreased their mercury emissions from 13,576 pounds in 1998 to about 4,681 pounds in 2005. Gold mines in the rest of the United States had some decrease in reported on-site ai r emissions during this time, with total on-site mercury air emissions of 271 pounds in 1998 an d 71 pounds in 2005. As mercury emissions decreased more rapidly within Nevada than in ot her states, the percentage of total metal mining mercury emissions in the US that is attributab le to Nevada gold mines decreased from 99.7% in

1998 to about 95% in 2005.

Between 1998 and 2001, Jerritt Canyon Mine, ow ned by Queenstake Resources USA, Inc., emitted approximately 4 tons per year (tpy) of mercury, well over 50 percent of total mercury emissions from the U.S. metal mining industry. With the installation of mercury emission control systems in 2001 and 2002, emissi ons from Jerritt Canyon dropped to just over 790 pounds in 2003 or about 15 percent of total U.S. metal mining mercury emissions. As seen in Figure 4, the total metal mining industry emi ssions mirror the emissions reductions achieved by Jerritt Canyon. When Jerritt Canyon’s me rcury emissions plunged in 2003, Barrick Goldstrike Mines became the highest emitting facili ty. As detailed in Table 8 in Section 4.1.3, Barrick had installed mercury controls in 1998 and 1999. Therefore, mercury emissions fromSection 4.0 Mercury Emissions from Gold Mines

20 Barrick were relatively stable at approxi mately 1,500 pounds per year between 1998 and 2003. In 2004, Goldstrike’s mercury emissions increased to 2,205 pounds, presumably due to changes in production level and/or mercury content in the ore; these emi ssions represented 43 percent of all mercury air emissions from the U.S. gold mi ning industry. In 2005, Goldstrike’s emissions decreased to 1701 pounds, representing 35 percent of all mercury air emissions from the gold mining in the United States.



### 4.3 Gold Mining Mercury Emissions from the NEI

Unlike the TRI which provides yearly data, the NEI only provides a snapshot of the emissions once every three years. The most recent inventory year for which NEI data are

available is 2002. Data from the 2002 Nationa l Emissions Inventory corresponds reasonably

well to data from the 2002 Toxics Release Inventor y, with one exception. In the 2002 TRI, total mercury emissions from Barrick Goldstrike Mines are reported as 1,300 pounds, while the 2002 NEI reported 5,920 pounds of mercury emissions from Barrick Goldstrike Mines. Consequently, the 2002 NEI’s total reported mercury emissions from gold mines reported were 13,010 pounds, 4,140 pounds more than the 2002 TRI mercury emissions value of 8,870 pounds.



### 4.4 Comparison of Reported Gold Mining Mercury Emissions

Table 10 provides a comparison of the mercury emissions from the EPA/NDEP survey (2004/2005 timeframe), the 2004 TRI, and the 2002 NE I for gold mining facilities. A seen in Table 1, the 2002 NEI provides much higher mercur y emissions for Barrick Goldstrike Mines and the Jerritt Canyon Mine. The higher mercury emissions estimate in the 2002 NEI for the Jerritt Canyon Mine agrees reasonable well with the 2002 TRI data, and the difference between

the 2002 NEI and the other estimates are due to the emissions reductions achieved by Jerritt Canyon Mine through the application of mercury emission control syst ems. It is unclear why the 2002 NEI mercury emission estimate for Barrick Goldstrike Mines is so much higher than the 2004 TRI or NDEP survey estimates, especially noting the increase in emissions from the

Barrick Goldstrike Mines between 2002 and 2004 as seen in Figure 4.

The NDEP survey identifies Newmont’s Gold Quarry Operations as a significant mercury emissions producer; mercury emissions from these operations appear to be reported in the 2004 TRI and 2002 NEI under “South Operations” and “North Operations.” Even so, the NDEP mercury emission estimate for the Gold Quarry Operations a factor of two higher than the emissions reported in the 2004 TRI and almost 20 percent higher than the 2002 NEI estimate.

On the other hand, the NDEP survey showed si gnificantly lower mercury emissions from

the Barrick/Kennecott Cortez Gold Mines than were reported in the TRI or NEI. The mercury emission estimate provided for the Cortez Gold Mines was specifically reported to be for 2004, so this discrepancy cannot be attributed to mercury emission reduction achieved by the

installation of wet scrubber c ontrol systems on their carbon re generation kilns in 2005.

There is one non-Nevada gold mine, CR Bri ggs in California, that reported 62.5 pounds per year of mercury emissions in both the 2004 TRI and the 2002 NEI. This facility did not receive the EPA questionnaire, so the EPA/ NDEP survey results do not include mercury emissions from this mine. While the NDEP questi onnaire was sent to all Nevada mines, the EPA questionnaire was only sent to a handful of mine s and is therefore only a survey of non-NevadaSection 4.0 Mercury Emissions from Gold Mines

21 mines. Additional discussion of the uncertainties and biases of the survey results are discussed

in the next section.



### 4.5 Uncertainty and Biases in Mercury Emissions Estimates

As mentioned previously, there are a few co mpanies and facilities in the U.S. that produce gold and/or silver to which EPA did not send a questionnaire. For example, based on the 2004 TRI, there are 3 gold and/or silver producti on facilities that report ed mercury releases. However, two of these facilities reported 0 poun ds air emissions in the 2004 TRI and the third facility (CR Briggs, California) reported mercury air emissions of 62.5 pounds. Based on

information received from a technical contact at CR Briggs, the facility operated from 1996 to 2004 and is now in the reclamation phase. For 2005, this facility had estimated emissions of about 29 pounds. Thus, based on information in the TRI and other available information (e.g., from states), it appears that the questionnair es were sent to all significant gold producing operations, covering over 99 percent of total current mercury emi ssions from gold mines in the U.S.. Nonetheless, the lack of complete cove rage of all non-Nevada gold mines does create a negative bias to the nationwide mercury emission estimates.

Additionally, the lack of repor ting of mercury emissions from gold mines that process mercury-containing ore, especially those that have thermal process units (as was the case for some non-Nevada mines), is expected to create a small negative bias. For one non-Nevada facility that did provide information on how they derived their mercury emissions, we considered the approach to be technically flawed. For this facility (Kinross – Fort Knox Mine), the reported mercury emissions per ton of gold produced was orders of magnitude lower than any other facility. Although they suggest that their TRI reported value is based on an assumption of 100 percent mercury emissions, we believe the reported 2004/2005 TRI values are much more realistic. Nonetheless, even though we believe the mercury emissi ons reported by this factility in the EPA survey may be orders of magnitude too low, using a high-end emission estimate for this facility does not significantly alter the nationw ide mercury emissions. Therefore, although there appears to be high uncertainty or bias for the emissions from the non-Nevada mines, the emissions from these facilities still appears to make little impact on the nationwide estimates for gold mining mercury emissions. These findings are consistent with the lower mercury content in the gold ores and the lack of autoclaves and roasters (primary emi ssion sources) at the nonNevada gold mines.

In addition to the bias discussed regardi ng non-Nevada gold mines, there is also a negative bias in the survey results caused by Nevada facilities not reporting their mercury emissions. Most notably, the Newmont Lone Tr ee Mine, which operates an autoclave and two carbon regeneration units, did not provide any me rcury emission estimates. The TRI and NEI suggest nominal mercury emissions from this mine. However, this mine has mercury in its ore, produces a significant amount of go ld, and has several thermal proc essing units, one of which is uncontrolled. As such, this mine is expected to have appreciable mercury emissions and the lack of mercury estimates for this mine creates a ne gative bias in the reported mercury emissions.Section 4.0 Mercury Emissions from Gold Mines

22 Table 10. Comparison of Mercury Emission Estimates by Facility.

Parent company Facility name State 2004/2005
EPA/NDEP

Survey (lbs/year) 2002 NEI (lbs/year) 2004 TRI

mercury emissions (lbs/year) 2005 TRI

mercury emissions (lbs/year)

Barrick Goldstrike Mines NV 2174.6 5919.97 2205.24 1701

Barrick / Kennecott Cortez Gold Mines Mill #2 (Pipeline Mill) NV 492 1052.9506 1342.6 851.5

Newmont South Operations Area NV - 507.998 262 690

Newmont Gold Quarry Operations NV 658.8 - - -

Newmont Twin Creeks Mine NV 563 524.001 327 592

Queenstake Jerritt Canyon NV 461 4737.99953 461.78 381.46

Glamis Glamis Marigold Mine NV - 0.9 184.9 327.6

Barrick / Placer

Dome Bald Mountain Mine (including Mooney Basin) NV 53.25 0.3 51.8 83.5

CR Briggs Corp CA Not surveyed 62.5 62.5 28.85465 Anglogold Ashanti / Golden Cycle Cripple Creek & Victor Gold Mining Company CO 34.3 37 34.3 34.3

Golden Phoenix Mineral Ridge Mine NV 33 - - -

Kinross / Barrick Round Mountain Gold - Smoky Valley Common Operation NV 22. 6 0.6 0.12 23.3

Barrick Placer Turquoise Ridge Inc. NV - - 23.1 0.2

Newmont North Operations Area NV - 22.4 23.1 18.7

Newmont Midas Operations NV 12.97 - - -

Coeur d'Alene Coeur Rochester, Inc. NV 4.9 - 7.5 8

Kennecott/ Hecla Kennecott Greens Creek Mining Company AK 5.43 - 6.05 5.43 Florida Canyon / Jipangu Florida Canyon Mine NV 5.52 1.79 1.491 0.07

Newmont Lone Tree Mine NV - 9 4 2

Barrick Ruby Hill Mine NV 3 0.4 0 0

GoldSprings Plum Mining Company LLC NV 1.89 - - -

Barrick Golden Sunlight Mines, Inc. MT 0.12 0.1 0.4 1.7

Western Goldfields Mesquite Mine CA 1.2 - - -

Newmont McCoy/Cove Mine NV 0.5 - 0.5 -

Kinross Fort Knox Mine AK 0.0000111 113 0.12 0.13 Kennecott Barneys Canyon Mining Co UT Not surveyed 0.09 0.05 0.003 Homestake Mining Company CA Not surveyed 16.9033161 - -

Newmont Trenton Canyon Project NV - 1 0 - Viceroy Gold Corp Castle Mountain CA Not surveyed 0.575786 0 -

Ken Snyder Mine NV Not surveyed 0.2 - -

Newmont Rain Mill Mine NV - 0.2 0 -

Glamis Rand Mine CA Not surveyed 0.1 0 - Nevada mercury

emissions 4487.0 12779.7 4895.1 4679.3 Non-Nevada mercury

emissions 41.1 230.3 103.4 70.4 Total U.S. mercury

emissions 4528.1 13010.0 4998.6 4749.7
* Kennecott 70%, Hecla 30%Section 4.0 Mercury Emissions from Gold Mines

23 It is important to note that there is cons iderable uncertainty when estimating mercury emissions from gold mines. Until recently, few s ources actually tested their process emissions for mercury. Without specific data, some facilit ies assumed 100 percent of the mercury in the process ore was emitted, while others assumed little, if any, of the mercury was emitted. Consequently, both under- and over-reporting of me rcury emissions have been documented in recent years. As of August 2007, several facili ties have revised the estimates of mercury emissions that were submitted for the TRI between 2001 and 2005. The 2004 estimated mercury emissions from one facility were revised fr om 6.6 pounds to 184.9 pounds; another facility revised its mercury emissions reported in th e 2004 TRI from 121 pounds (based on 100 percent emissions) to 0.12 pounds, after performing emissions testing of several key process units. From 2001 to 2004, the net effect of all revisions was an increase in total mercury emissions each year. The largest increase due to revision was 166.9 pounds for 2003’s reported mercury emissions.

There remains a significant lack of emissions test data from a variety of gold mining processes. While stack test data are becoming ava ilable from thermal processes as a result of the Nevada Mercury Control Program (described in the Section 5), fugitive emission sources are

more difficult to characterize. There is incr edible uncertainty rega rding the significance of fugitive sources, such as grinding and milling ope rations, heap leaching, and tailing ponds, on a facility’s overall mercury emissions. Due to the large quantity of ore processed, the relatively low and variable concentrations of mercury in the ore, it is difficult to accurately account for all the mercury contained in the processed ore. Wh en facilities perform emissions testing on their process stacks, they often use these data estimate their mercury emissions. While these test data improve the emission estimate for the tested pr ocess, there is a potential to underestimate mercury emissions if the test data are used as the only emissions from the mining operations, thereby neglecting to include inventory es timates for the fugitive emission sources.Section 5.0 Nevada Mercury Control Program

24 

# 5.0 Nevada Mercury Control Program

In the 1998-99 timeframe, gold production facil ities were identified by U.S. EPA and the State of Nevada as significant sources of mercury emissions. As previously described, most of the emissions were coming from five facilities in Nevada. The Nevada DEP and U.S. EPA (and other stakeholders) immediately started to addr ess this issue and explore options to reduce

emissions. These efforts lead to establis hing the Voluntary Merc ury Reduction Program (VMRP) in June 2002 with the goal to achieve significant, permanent and rapid reductions in mercury air emissions from precious metal proce ssing operations. As seen by the reported TRI emissions, mercury emission reductions were qui ckly achieved by adding emission controls to thermal units that emit mercury. The VMRP re sulted in over 75 percent reduction in mercury emissions from these gold producti on facilities (NV DEP, 2006).

Even though the VMRP proved to be succe ssful, the NDEP decided to convert the VMRP into a mandatory program, called the Ne vada Mercury Control Program (NMCP). The NMCP is a State mandatory regulatory Program that supersedes and replaces the VMRP. The NMCP was adopted March 8, 2006 and made effective May 4, 2006. The Program achieves mercury reduction via add-on control techno logies by implementing Nevada Maximum Achievable Control Technology (or “NvMACT”). The NvMACT is “...a standard, method of control or any other limitation whic h is applied to an existing, new or modified thermal unit that emits mercury” (NDEP, 2006).

The “starting point” or “baseline” for Nv MACT is the “Presumptive NvMACT.” The Presumptive NvMACT “...is technologies to c ontrol mercury emissions which have been implemented before May 4, 2006 and associated with Tier-1 units.” Tier-1 units are the units

that were included in the VMRP. NvMACT is based on each discrete thermal mercury emission unit at a facility (NDEP, 2006).

For new/modified emission units, NvMACT is at minimum the emission control that is achieved in practice by the best controlled similar emission unit within the precious metals mining industry. A determination of similar emi ssion units may take into account ore mercury concentration, size of process units and other relevant factors. NDEP will use the principles of MACT consistent with Section 112(d) of the Federal Clean Air Act of 1990 in establishing NvMACT (NDEP, 2006).

Pursuant to the Nevada regulations (NAC 445B.3625), owners or operators that operate, construct or modify a thermal unit that emits mercury must apply for, and obtain, a Mercury Operating Permit to Construct (Mercury OPTC) to apply the NvMACT. Construction of a new or modified thermal unit that emits mercury requi res a permit before construction begins. Those emission units subject to NvMACT must install controls no later than 24 months after final Phase-2 permit issuance, unless deferred 48 mo nths with the Director designated Early Reduction Credit (NDEP, 2006). More informati on on the NV program is available in a paper

titled: “ Nevada Mercury Control Program (NMCP) , Overview and Guidance, July 2006 ”, which

is available at: http://ndep.nv.gov/bapc/downloa d/mercury/white_sheet.pdf . Additional information, including the detaile d regulation, is available at: http://ndep.nv.gov/mercury/index.htm

.Section 6.0 References

25 

# 6.0 References

Butterman, W.C. and Earle B. Amey III, 2005. Mineral Commodity Profiles – Gold. U.S. Geological Survey.

Jones, Greg and Glenn Miller, 2005. Mercury and Modern Gold Mining in Nevada. U.S. Environmental Protection Agency.

NMA 2006, National Mining Association. 2005 Statistics. Available at: http://www.nma.org/statis tics/pub_gold_silver.asp

NV Division of Minerals, Commi ssion on Mineral Resources, 2006. “Nevada Gold and Silver Prices, Productions, and Value. ” December 2006. Available at: http://minerals.state.nv. us/programs/min_AUAG.htm

.

NV DEP, 2006. “Nevada Mercury Control Prog ram (NMCP), Overview and Guidance”. Nevada Department of Environmental Protec tion (NV DEP). July 2006. Available at: http://ndep.nv.gov/bapc/downl oad/mercury/white_sheet.pdf

.

U.S. Environmental Protection Agency, 1994. Technical Resource Document: Extraction and Beneficiation of Ores and Minerals: Volume 2: Gold

. Office of Solid Waste.

U.S. Environmental Protection Agency, 2001a. Mercury Mass Balance and Emissions Factor Estimates for Gold Ore Processing Facilities. Region 9.

U.S. Environmental Protection Agency, 2001b. Process Descriptions and Material Flows for Gold Ore Processing Facilities. Region 9.Section 6.0 References

26Appendix A U.S. EPA Questionnaire

A-1 

# Appendix A

U.S. EPA Questionnaire

Appendix A contains a copy of th e mercury air emissions questionn aire sent to United States precious metal mines outside the state of Nevada by the U.S. EPA. The questionnaire sent to Nevada gold and silver mines by the NDE P is available on the internet at: http://ndep.nv.gov/mercury/mercury_air.htm

.Appendix A U.S. EPA Questionnaire

A-2Appendix A U.S. EPA Questionnaire

A-3 PRECIOUS METALS MINING

MERCURY AIR EMISSIONS QUESTIONNAIRE

(for facilities outside Nevada)

1. Instructions:

We request that this ques tionnaire is completed for ope rations that comprise the "Primary Extraction and Processing of Gold and Silver” industry at your facility. This industry includes all facil ities and processes that are part of primary extraction, processing, and production of gold and silver, a nd the production of particular by-products (such as mercury), including, but not limited to, grinding, leach ing, roasting, autoclavi ng, carbon stripping, carbon regeneration, electrowinning, retorting, smelting a nd waste disposal. The subject operations are generally conducted under Sta ndard Industrial Classificati on (SIC) Codes 1041 and 1042, Gold

and Silver Ores or under North American I ndustry Classification Sy stem (NAICS) Codes 212221 and 212222. We are seeking the information re quested by this questionnaire pursuant to

section 114 of the Clean Air Act.

We are requesting information regarding mercury air emissions from your primary extraction and processing operations, the use of air pollution control (A PC) devices in those operations, and their effectivene ss in reducing mercury emissions. The information requested is described in Sections 2 through 10 of this questionnaire and the Annexes.

Please satisfy this request as completely as possible from existing information . No additional monitoring or emission testing is required by your comp any to respond to this request

.Appendix A U.S. EPA Questionnaire

A-4 If you have any questions regarding this request, please contact me at phone number: 919-541-7912, or by e-mail at e-mail ad dress: french.chuck@epa.gov

Please return this questionnaire along with any additional relevant information to me by June 16, 2006 by e-mail, or by regular mail to the mailing address shown below.

Thank You.

Mr. Chuck French

Environmental Scientist Metals and Minerals Group U.S. Environmental Protection Agency (EPA)

Mailing Address for Responses:

Mr. Chuck French

Environmental Scientist U.S. EPA, Office of Air Quality 109 TW Alexander Drive (D243-02) Research Triangle Park, NC 27711Appendix A U.S. EPA Questionnaire

A-5 2. Facility General Information:

a. Plant-specific facility name:

b. Mailing address:

c. Street address or physical location of facility:

d. Longitude and latitude (or UTM coordina tes) for primary processing/refinery

area:

e. Names and telephone numbers of contact persons who are able to answer technical questions about this questionnaire:

f. Are you a subsidiary or affiliate of another company or other organization? If yes, please provide the name of parent company and/or other organization.

3. Facility Operation Information:

a. Total tons of ore processed in 2005 (or most recent year for which data are available, such as 2004):

Tons of Ore Processed = _________ for year: __________

b. Total quantity (ounces) of precious metals produced in 2005 (or most recent year for which data are available, such as 2004):

i. Ounces of Gold = _________ for year: _________

ii. Ounces of Silver = ________ for year: _________

iii. Other: _________________ for year: _________

c. Does the facility process ore containing mercury at concentrations of 0.1 milligram mercury per kilogram ore (0.1 mg/kg) or higher? If no, please provide ore characterization data or other evidence supporti ng this answer. If the answer is “no” andAppendix A U.S. EPA Questionnaire

A-6 adequate supporting evidence is provided, then you do not need to complete the remaining questions in section 3, and you do not need to complete the questions in sections 4, 6, 7, 10 or the Annexes. Howe ver, please complete the questions in section 2, 5, 8, and 9, to the extent feasible given ava ilable information. On the other hand, if the answer to this question (3c) is “yes” or “ unknown”, please complete the questions in all sections of the questionnaire, as appropria te and applicable to your facility.

____________________________________________________________________

____________________________________________________________________

__________________________________

d. Does the facility use thermal operations in its precious metals processing? (Note: Thermal operations include: pre-dryers, drying, roasting, autoclaving, electrowinning, retorting, smelting, carbon regeneration k ilns, drying, and any other processes that involve units with the potential to emit mercur y generated by direct or indirect sources of heat energy.) If yes, proceed to Question 3e and complete the remaining questions 3e to 10 and the Annexes, as applicable for your fac ility. If no, please provide explanation of plant precious metals processing operations with a flow diagram and basis for determination that no thermal processes are used. If the answer is “no” to this question, you can skip questions 4, 6, 7 and 10 and th e Annexes, but please complete the remaining questions in sections 3, 5, 8 and 9, as applicable for your facility.

e. Please provide a flow diagram and description of the precious metals processing operations at your facility, with identification on the diagram of where mercury is expected to be present. Include a descripti on of how mercury is t ypically liberated from the ore and its flow for eventual recovery , release to the atmosphere or deposition in tailings or waste streams.Appendix A U.S. EPA Questionnaire

A-7 f. If roasting is utilized, total tons of ore roasted in 2005 (or most recent year for which data are available, such as 2004):

Tons of Ore Roasted = _________ for year __________

g. If autoclaving is utilized, total tons of ore autoclaved in 2005 (or most recent year for which data are available, such as 2004):

Tons of Ore Autoclaved = _________ for year __________

h. Please provide the total tons of ore processed that are subject to cyanide leaching (provide quantity by the following categories):

i. heap leaching: ______ tons for year ______

ii. carbon in leach of milled ore: ______ tons for year ______

iii. carbon in leach of roasted or autoclaved ore: ____ tons for year: _____

i. Do you produce mercury as a product or byproduct? If yes, please provide amount (pounds) of mercury produced in 2005 (or most recent year for which data are available) by type of product/byproduct produced:

i.

_______ pounds elemental mercury produced, for year: ____

ii.

_______ pounds calomel produced, for year: _______.Appendix A U.S. EPA Questionnaire

A-8 4. Emission Unit Identification:

For each thermal operation emission unit with the potential to emit mercury, please complete the questions in Annexes 1 to 7, as applicable and appropriate for your facility.

See Annexes 1 to 7.

5. Estimated Total Mercury Emissions From the Facility :

a. Please provide an estimate of the total actual mercury air emissions (in pounds) released from the entire facility (including fugitive em issions) for year 2005 (or most recent year for which data are available) and a description of the basis of such estimate. Please use the following hierarchy of data, for reporting such estimate:

• Direct testing and measurement.

• Based on engineering calculations that take into account the average mercury content of the ore processed, the amount of ore processed and the potential for mercury releases from the specific processes utilized to recover gold.

Total estimated mercury emissions = _____ pounds, for year: ____

b. If ambient mercury monitoring has been conducted at the facility, please attach information regarding the monitoring program (number, placement, sampling duration, collection method of monitors) and the monitoring results.

c. If any studies have been conducted to assess fugitive mercury emissions from various process units (including heap leach pads, carbon in leach tanks, and tailings ponds), please attach information regarding the pr ocesses evaluated, the methods used, and results of each study performed.Appendix A U.S. EPA Questionnaire

A-9 6. Mercury Emissions Control Information as of 2005 (or most recent year for which data are available):

For each air emissions control device that ha s some effect on mercury emissions, please complete the questions in Annexes 8 to 12, as applicable and appropriate for your facility. See Annexes 8 to 12. Also, pleas e describe any additional control measures, improved work place practices, pollution prev ention measures, or other actions being implemented at the time.

7. Modifications to Existing Mercury Controls and Additional Controls:

Please describe any post-2005 modifications to ex isting mercury controls, additional control measures, improved work place practices, pollution prevention measures, or other actions, if any, that have been installed or implemented post-2005 or are planned by the facility to be installed or implemented within the next 24 months to further reduce mercury emissions:

_____________________________________________________________________________

_____________________________________________________________________________

______________________Appendix A U.S. EPA Questionnaire

A-10 8. Process Changes and Future Operations :

a. Please describe any process or equipment ch anges implemented post- 2005, or planned for future years, that could significantly increase the potential for mercury emissions (for example, installing a roaster, carbon kiln, or other thermal process, or processing different ores that have higher mercury content):

______________________________________________________________________________

______________________________________________________________________________

________________________

b. Please describe your facility’s expect ed number of future years of operation:

______________________________________________________________________________

__________________________________________

9. Permit Conditions and other Commitments/Agreements:

Please provide a summary of air emission permit conditions or provide a copy of your air permit. Also, please provide a summary of any voluntary agreements/commitments, especially with regard to pollution prevention measures, control equipment and emissions levels, and compliance

schedules:

______________________________________________________________________________

______________________________________________________________________________

______________________

10. Mercury Control Device Cost Information : Please complete Annex 13, as applicable and appropriate for your facility.Appendix A U.S. EPA Questionnaire

A-11 ANNEX 1. AUTOCLAVING

1. Please provide an identification of each such unit, including a process description and the mechanism by which mercury emissions are released. (Note: if facility has more than 1 autoclave, copy this Annex 1 and complete a separate copy for each such unit.)

Autoclaving process description:

______________________________________________________________

_____________________________________________________________________

_______________________________________________________

2. Please provide the following information a bout the process described in Item 1:

a. Process capacity: tons ore per hour

b. Annual hours this process was operated in 2005 (or most recent year for which data are available): hours for year _____

c. Typical process operating temperature: oF

3. Provide an estimate of the actual mercury ai r emissions released from this unit for 2005 (or most recent year for which data are ava ilable) and the basis of such estimate, in accordance with the following hierarchy of data:

a. Direct testing and measurement.

b. Based on engineering calculations that take into account the average mercury content of the ore processed, the amount of ore processed and the potential for mercury releases from the specific processes utilized to recover gold.

Estimated mercury emissions from autoclave = _____ pounds for year ____

Basis of estimate:

____________________________________________________________________

____________________________________________________________________

________________________________________________Appendix A U.S. EPA Questionnaire

A-12 4. Circle the code numbers for the type of ai r pollution control (APC) devices and the type of fume capture systems used:

APC device: Fume capture system:

0 No device is used 0 None

1 Fabric/cartridge filter 1 Side-draft or canopy hood

2 Wet scrubber 2 Close-fitting hood or direct process vent

3 Off-gas quencher 3 Other: ________________

4 Electrostatic precipitator

5 Carbon adsorption unit

6 Other: ______________

5. Provide exit exhaust vent (or stack) parameters (for gaseous streams):

height: __________________ feet

diameter: ________________ feet

flow rate: ________________ acfm (actual cubic feet per minute)

temperature: ______________ E F

6. Describe any work practices or other measures that pr event mercury emissions from autoclaving operations.

___________________________________________________________

_____________________________________________________

7. Have tests been conducted for mercury ai r emissions on these autoclaving operations?

0 No

1 Yes [ Enclose summary measurement data, including data on mercury speciation, if available, the test methods used, information on actual production or processing rates and on process conditions at the time the measurements were made, and a statement that any APC devices (if present) were operating normally duri ng the test, or if not, what the abnormal operating conditions were. ]

8. Additional comments and information:

________________________________________________________________________

______________________________________________Appendix A U.S. EPA Questionnaire

A-13 ANNEX 2. ROASTING OPERATIONS

1. Please provide an identification of each such unit, including a process description and the mechanism by which mercury emissions are released. (Note: if facility has more than 1 roasting operation, copy this Annex 2 and complete a separate copy).

Description:

______________________________________________________________

_____________________________________________________________________

_______________________________________________________

2. Please provide the following information a bout the process described in Item 1:

a. Process capacity: tons ore per hour

b. Annual hours this process was operated in 2005 (or most recent year for which data are available): hours for year: _____

c. Typical process operating temperature: oF

d. Type of fuel used:

.

3. Provide an estimate of the actual mercury ai r emissions released from this unit for 2005 (or most recent year for which data are ava ilable) and the basis of such estimate, in accordance with the following hierarchy of data:

• Direct testing and measurement.

• Based on engineering calculations that take into account the average mercury content of the ore processed, the amount of ore processed and the potential for mercury releases from the specific processes utilized to recover gold.

Estimated mercury emissions from roaster = ______ pounds for year: _____.

Basis of estimate: ________________________________________

________________________________________________________________________

________________________________________________Appendix A U.S. EPA Questionnaire

A-14 4. Circle the code numbers for the type of ai r pollution control (APC) device and the type of fume capture system used:

APC device: Fume capture system:

0 No device is used 0 None

1 Fabric/cartridge filter 1 Side-draft or canopy hood

2 Wet scrubber 2 Close-fitting hood or direct process vent

3 Off-gas quencher 3 Other: ________________

4 Electrostatic precipitator

5 Carbon adsorption unit

6 Other: ______________

5. Provide exit exhaust vent (or stack) parameters (for gaseous streams):

height: __________________ feet

diameter: ________________ feet

flow rate: ________________ acfm (actual cubic feet per minute)

temperature: ______________ E F

6. Describe any work practices or other measures that preven t mercury emissions from this roasting operation:

________________________________________________________________________

______________________________________________

7. Have tests been conducted for mercury ai r emissions on these roasting operations?

0 No

1 Yes [ Enclose summary measurement data, including data on mercury speciation, if available, the test methods used, information on actual production or processing rates and on process conditions at the time the measurements were made, and a statement that any APC devices (if present) were operating normally duri ng the test, or if not, what the abnormal operating conditions were. ]

8. Additional comments and information:

________________________________________________________________________

________________________________________________________________________

___________________________________Appendix A U.S. EPA Questionnaire

A-15 ANNEX 3. CARBON RE GENERATION KILN

1. Please provide an identification of each such unit, including a process description and the mechanism by which mercury emissions are released. (Note: if facility has more than 1 carbon regeneration kiln, copy this Annex 3 and comp lete a separate copy for each such unit).

Description: __________________________________________________

______________________________________________________________

____________________________________________________________

2. Please provide the following information a bout the process described in Item 1:

a. Process capacity: tons carbon per hour

b. Annual hours this process was operated in 2005 (or most recent year for which data are available): hours for year: ______

c. Typical process operating temperature: oF

d. Type of regeneration process used: .

3. An estimate of the actual mercury air emissi ons released from this unit for 2005 (or most recent year for which data are available) a nd the basis of such estimate, in accordance with the following hierarchy of data:

• Direct testing and measurement.

• Based on engineering calculations that take into account the average mercury content of the ore processed, the amount of ore processed and the potential for mercury releases from the specific processes utilized to recover gold.

Estimated mercury emissions from carbon regeneration kiln = ________ pounds for year _____.

Basis of estimate: ___________________________________________

________________________________________________________________________

________________________________________________Appendix A U.S. EPA Questionnaire

A-16 4. Circle the code numbers for the type of ai r pollution control (APC) device and the type of fume capture system used: APC device: Fume capture system:

0 No device is used 0 None

1 Fabric filter 1 Side-draft or canopy hood

2 Wet scrubber 2 Close-fitting hood or direct process vent

3 Selenium filter 3 Other: _________________

4 Carbon adsorption unit

5 Other: ________________

5. Provide exit exhaust vent (or stack) parameters (for gaseous streams):

height: __________________ feet

diameter: ________________ feet

flow rate: ________________ acfm (actual cubic feet per minute)

temperature: ______________ E F

6. Describe any work practices or other measures that preven t mercury emissions from this carbon regeneration operation:

________________________________________________________________________

______________________________________________

7. Have tests been conducted for mercury air emissions on these carbon regeneration operations?

0 No

1 Yes [ Enclose summary measurement data, including data on mercury speciation, if available, the test methods used, information on actual production or processing rates and on process conditions at the time the measurements were made, and a statement that any APC devices (if present) were operating normally duri ng the test, or if not, what the abnormal operating conditions were. ]

8. Additional comments and information:

_________________________________________________________________

_________________________________________________________________

___________________________________________________________Appendix A U.S. EPA Questionnaire

A-17 ANNEX 4. ELECTROWINNING

1. Please provide an identification of each such unit, including a process description and the mechanism by which mercury emissions are released. (Note: if facility has more than 1 electrowinning process, copy this Annex 4 and co mplete a separate copy for each such unit.)

Description: ___________________________________________________

_____________________________________________________________________

_______________________________________________________

2. Please provide the following information a bout the process described in Item 1:

a. Process capacity: gallons per minute of preg solution

b. Annual hours this process was operated in 2005 (or most recent year for which data are available): hours for year: _______

c. Typical process operating temperature: oF

3. An estimate of the actual mercury air emissi ons released from this unit for 2005 (or most recent year for which data are available) a nd the basis of such estimate, in accordance with the following hierarchy of data:

• Direct testing and measurement.

• Based on engineering calculations that take into account the average mercury content of the ore processed, the amount of ore processed and the potential for mercury releases from the specific processes utilized to recover gold.

Estimated mercury emissions from electrowinning unit = ________ pounds for year: _____.

Basis of estimate:

______________________________________________________________________________

______________________________________________________________________________

_____________________Appendix A U.S. EPA Questionnaire

A-18 4. Circle the code numbers for the type of ai r pollution control (APC) device and the type of fume capture system used:

APC device: Fume capture system:

0 No device is used 0 None

1 Fabric filter 1 Side-draft or canopy hood

2 Wet scrubber 2 Close-fitting hood or direct process vent

3 Carbon adsorption unit 3 Other: ________________

4 Other: ______________

5. Provide exit exhaust vent (or stack) parameters (for gaseous streams):

height: __________________ feet

diameter: ________________ feet

flow rate: ________________ acfm

temperature: ______________ E F

6. Describe any work practices or other measures that preven t mercury emissions from this electrowinning operation:

__________________________________________________________

____________________________________________________

7. Have tests been conducted for mercury air emissions on these electrowinning operations?

0 No

1 Yes [Enclose summary measurement data, including data on mercury speciation, if available, the test methods used, information on actual production or processing rates and on process conditions at the time the measurements were made, and a statement that any APC devices (if present) were operating normally duri ng the test, or if not, what the abnormal operating conditions were.]

8. Additional comments and information:

________________________________________________________________________

________________________________________________________________________

___________________________________Appendix A U.S. EPA Questionnaire

A-19 ANNEX 5. RETORT

1. Please provide an identification of each such unit, including a process description and the mechanism by which mercury emissions are released. (Note: if facility has more than 1 retort process, copy this Annex 5 and complete a separate copy for each such unit).

Description:

_____________________________________________________________________

_____________________________________________________________________

_________________________________________________

2. Please provide the following information a bout the process described in Item 1:

a. Process capacity: tons sludge per cycle

b. Annual hours this process was operated in 2005 (or most recent year for which data are available): hours for year: _____

c. Typical process operating temperature: oF

d. Typical cycle time: hours

3. An estimate of the actual mercury air emissi ons released from this unit for 2005 (or most recent year for which data are available) a nd the basis of such estimate, in accordance with the following hierarchy of data:

• Direct testing and measurement.

• Based on engineering calculations that take into account the average mercury content of the ore processed, the amount of ore processed and the potential for mercury releases from the specific processes utilized to recover gold.

Estimated mercury emissions from retort = ______ pounds for year: ______

Basis of estimate:

_________________________________________________________________________________

_________________________________________________________________________________

__________________________

4. Do you recover mercury? ____________________Appendix A U.S. EPA Questionnaire

A-20 5. Is it processed further onsite? ___________________________

6. Circle the code numbers for the type of ai r pollution control device and the type of fume capture system used:

APC device: Fume capture system:

0 No device is used 0 None

1 Fabric filter 1 Side-draft or canopy hood

2 Wet scrubber 2 Close-fitting hood or direct process vent

3 Carbon adsorption unit 3 Other: ________________

4 Other: ________________

7. Provide exit exhaust vent (or stack) parameters (for gaseous streams):

height: __________________ ft

diameter: ________________ ft

flow rate: ________________ acfm

temperature: ______________ E F

8. Describe any work practices or other measures that preven t mercury emissions from this retort operation.

________________________________________________________________________

________________________________________________

9. Have tests been conducted for mercury air emissions on these retort operations?

0 No

1 Yes [Enclose summary measurement data, including data on mercury speciation, if available, the test methods used, information on actual production or processing rates and on process conditions at the time the measurements were made, and a statement that any APC devices (if present) were operating normally duri ng the test, or if not, what the abnormal operating conditions were.]

10. Additional comments and information:

____________________________________________________________

____________________________________________________________

____________________________________________________________Appendix A U.S. EPA Questionnaire

A-21 ANNEX 6. SMELTING FURNACE

1. Please provide an identification of each such unit, including a process description and the mechanism by which mercury emissions are released. (Note: if facility has more than 1 smelting furnace, copy this Annex 6 and complete a separate copy for each such unit.)

Description: _________________________________________________

___________________________________________________________

____________________________________________________________

2. Please provide the following information a bout the process described in Item 1:

a. Process capacity: tons total charge per cycle

b. Annual hours this process was operated in 2005 (or most recent year for which data are available): hours for year: ______

c. Typical process operating temperature: oF

d. Typical cycle time: hours

3. An estimate of the actual mercury air emissi ons released from such unit for 2005 (or most recent year for which data are available) a nd the basis of such estimate, in accordance with the following hierarchy of data:

• Direct testing and measurement.

• Based on engineering calculations that take into account the average mercury content of the ore processed, the amount of ore processed and the potential for mercury releases from the specific processes utilized to recover gold.

Estimated mercury emissions from furnace = _____ pounds for year _____

Basis of estimate:

__________________________________________________________________________

__________________________________________________________________________

________________________________________Appendix A U.S. EPA Questionnaire

A-22 4. Circle the code number(s) fo r materials added for smelting:

1 Lime

2 Fluxing materials (e.g., magnesium chloride, calcium chloride, etc.) 3 Inhibitive gases

4 Alloying agents (describe): _______________
5 Other (describe): _______________________

5. Circle code which describes how molten ma terial is transferred to molds for casting:

1 Hand ladling

2 Pumping

3 Tilt pouring

4 Other (describe): ______________________

6. For charging, melting, and tapping operations associated with th is furnace, circle the code numbers for the types of air pollution cont rol devices and fume capture systems used.

Charging: APC device: Fume capture system:

0 No device is used 0 None

1 Fabric filter 1 Side-draft or canopy hood

2 Wet scrubber 2 Close-fitting hood or direct process vent

3 Carbon adsorption unit 3 Other: _____________________

4 Other: ________________

Melting: APC device: Fume capture system:

0 No device is used 0 None

1 Fabric filter 1 Side-draft or canopy hood

2 Wet scrubber 2 Close-fitting hood or direct process vent

3 Carbon adsorption unit 3 Other: _____________________

4 Other: ________________

Tapping: APC device: Fume capture system:

0 No device is used 0 None

1 Fabric filter 1 Side-draft or canopy hood

2 Wet scrubber 2 Close-fitting hood or direct process vent

3 Carbon adsorption unit 3 Other: _____________________

4 Other: ________________Appendix A U.S. EPA Questionnaire

A-23 7. Provide exit exhaust vent (or stack) parameters (for gaseous streams):

height: __________________ feet

diameter: ________________ feet

flow rate: ________________ acfm

temperature: ______________ E F

8. Describe any work practices or other measures that preven t mercury emissions from this furnace operation:

__________________________________________________________

______________________________________________________

9. Have tests been conducted for mercury air emissions on this furnace?

0 No

1 Yes [Enclose summary measurement data, including data on mercury speciation, if available, the test methods used, information on actual production or processing rates and on process conditions at the time the measurements were made, and a statement that any APC devices (if present) were operating normally duri ng the test, or if not, what the abnormal operating conditions were.]

10. Additional comments and information:

________________________________________________________________________

________________________________________________________________________

___________________________________Appendix A U.S. EPA Questionnaire

A-24 ANNEX 7. OTHER THERMAL PROCESS UNITS

1. Please provide an identification of other th ermal process units, including a process description and the mechanism by which mercury emissions are released. (Note: if facility has more than 1 “other thermal process” process, copy this Annex 7 and complete a separate copy for each such unit.)

Description: ___________________________________________________

_____________________________________________________________________

_________________________________________________________

2. Please provide the following information a bout the process described in Item 1:

a. Process capacity: (specify units)

b. Annual hours this process was operated in 2005 (or most recent year for which data are available): hours for year: _____

c. Typical process operating temperature: oF

d. Typical cycle time, if applicable: hours

3. An estimate of the actual mercury air emissi ons released from such unit for 2005 (or most recent year for which data are available) a nd the basis of such estimate, in accordance with the following hierarchy of data:

• Direct testing and measurement.

• Based on engineering calculations that take into account the average mercury content of the ore processed, the amount of ore processed and the potential for mercury releases from the specific processes utilized to recover gold.

Estimated mercury emissions from unit = _____ pounds for year: ____

Basis of estimate:

__________________________________________________________ ______________

__________________________________________Appendix A U.S. EPA Questionnaire

A-25 4. Circle the code numbers for the type of ai r pollution control device and the type of fume capture system used:
APC device ID no.: __________ Fume capture system:

0 No device is used 0 None

1 Fabric filter 1 Side-draft or canopy hood

2 Wet scrubber 2 Close-fitting hood or direct process vent

3 Carbon adsorption unit 3 Other: _______________________

4 Other: ________________

5. Provide exit exhaust vent (or stack) parameters (for gaseous streams):

height: __________________ ft

diameter: ________________ ft

flow rate: ________________ acfm

temperature: ______________ E F

6. Describe any work practices or other measures that preven t mercury emissions from this operation:

________________________________________________________________________

_______________________________________________

7. Have tests been conducted for mercury air emissions on this unit?

0 No

1 Yes [Enclose summary measurement data, including data on mercury speciation, if available, the test methods used, information on actual production or processing rates and on process conditions at the time the measurements were made, and a statement that any APC devices (if present) were operating normally duri ng the test, or if not, what the abnormal operating conditions were.]

8. Additional comments and information:

______________________________________________________________________________

______________________________________________________________________________

_______________________Appendix A U.S. EPA Questionnaire

A-26 ANNEX 8. FABRIC FILTER DESCRIPTION

1. Please describe the fabric filters including an explanation of the mechanism for mercury removal (for example physical or chemical adsorption). (Note: if facility has more than 1 fabric filter, copy this Annex 8 and complete a separate copy for each fabric filter.)

Device description:

___________________________________________________________

________________________________________________________________________

______________________________________________

2. Year installed/rebu ilt: /______________

3. The estimated control efficiency with an explanation as to how that was calculated:

________________________________________________________________________

________________________________________________________________________

____________________________________

4. Describe the chemical and physical form of the mercury generated by the control (for example, elemental mercury, calomel scrubbe r solution, carbon loaded with mercury, etc.) and the handling, storage and disposition of same:

________________________________________________________________________

________________________________________________________________________

___________________________________

5. Circle the code number for device type:

1 Fabric filter 2 Cartridge collector

6. Circle the code number for pressure mode of operation:

1 Positive pressure 2 Negative pressureAppendix A U.S. EPA Questionnaire

A-27 7. Circle the code number for bag cleaning method:

1 Pulse jet

2 Shaker

3 Reverse air

4 Other (describe):

8. Circle the code number for bag cleaning mode:

1 On line 2 Off line

9. Cloth type:

10. Number of compartments:

11. Gas inlet temperature: E F

12. Gas flow rate: acfm

13. Gross filtering area: square feet

14. Net filtering area: square feet

15. Air to cloth ratio: fpm (Note: fpm = foot/minute = actual cubic feet per minute per square foot of filter area = ft 3 /min/ft 2 )

16. Referring to the processes described in A nnexes 1 through 7, identify each process served by this device.

Annex No. Process Description Operation

17. Amount of particulate matte r collected by this device:

A. Tons of dust material collected: _________________ tons

B. Time period for which dust mate rial was collected: _____________ hours of operation

C. Amount of metal or material pr ocessed or treated: _____________ tonsAppendix A U.S. EPA Questionnaire

A-28 18. Has this material been analyzed?

0 No 1 Yes [Enclose analysis (but not TCLP data).]

19. Have tests been conducted for merc ury air emissions on this device?

0 No

1 Yes [ Enclose summary measurement data, including data on mercury speciation, if available, the test methods used, information on actual production or processing rates and on process conditions at the time the measurements were made, and a statement that any APC devices (if present) were operating normally duri ng the test, or if not, what the abnormal operating conditions were. ]

20. Additional comments and information:

________________________________________________________________________

________________________________________________________________________

____________________________________Appendix A U.S. EPA Questionnaire

A-29 ANNEX 9. WET SCRUBBER DESCRIPTION

1. Please describe the wet scrubber system in cluding an explanation of the mechanism for mercury removal (for example physi cal or chemical adsorption). (Note: if facility has more than 1 wet scrubber, copy this Ann ex 9 complete a separate copy for each.)

Device description:

____________________________________________________________

________________________________________________________________________

________________________________________________

2. Year installed/rebu ilt: /___________

3. a.) Estimated control efficiency: _________________

b.) Basis of estimated control efficien cy (circle appropriate code number):

1 Performance source test

2 Vendor performance guarantee

3 Engineering design efficiency

4 Other (specify): _________________________________

4. What is the chemical and physical form of the mercury generated by the control (circle all that apply)?

1 Elemental mercury

2 Calomel scrubber solution (mercurous chloride; Hg 2 Cl 2 )

3 Hypochlorite scrubber solution

4 Carbon loaded with mercury

5 Other (specify): _________________________________

5. Specify the handling, storage and dispositi on of mercury generated from Item 4; if multiple forms/dispositions are used, indicate the approximate percent of total mercury generated attributable to each?

1 Elemental mercury collected in containers and sold off-site

2 Scrubber solution sent to tailings pond

3 Scrubber solution regenerated; mercury precip itated as solid; se nt off-site for land disposal

4 Scrubber solution regenerated; mercury pr ecipitated as solid; sent to on-site

landfill

5 Mercury remaining on processed or e; disposed of in tailings pond

6 Other (specify): ____________________________________Appendix A U.S. EPA Questionnaire

A-30 6. Circle the code number for scrubber type:

1 Venturi

2 Mercurous Chloride Scrubber

3 Vertical packed bed

4 Horizontal packed bed

5 Tray Tower

6 Spray Chamber

7 Other (specify):

7. Circle the code number for pressure mode of operation:

1 Positive pressure 2 Negative pressure

8. Gas flow rate: acfm

9. Typical gas inlet temperature: E F

10. Typical gas outlet temperature: E F

11. Pressure drop: ____ inches water column

12. Liquid to gas ratio: gallons per 1,000 actual cubic feet

13. Chemical usage rate (specify ch emical and typical usage rate):

Chemical Added Usage Rate Units for Usage Rate

14. Referring to the processes described in Anne xes 1 through 7, identify each process served by this device.

Annex No. Process Description OperationAppendix A U.S. EPA Questionnaire

A-31 15. Have tests been conducted for merc ury air emissions on this device?

0 No

1 Yes [ Enclose summary measurement data, including data on mercury speciation, if available, the test methods used, information on actual production or processing rates and on process conditions at the time the measurements were made, and a statement that any APC devices (if present) were operating normally duri ng the test, or if not, what the abnormal operating conditions were. ]

16. Additional comments and information:

________________________________________________________________________

________________________________________________________________________

___________________________________Appendix A U.S. EPA Questionnaire

A-32 ANNEX 10. ELECTROSTATIC PREC IPITATOR (ESP) DESCRIPTION

1. Please describe the ESP system including an explanation of the mechanism for mercury removal (for example physical or chemical adsorption). (Note: if facility has more than 1 ESP, copy this Annex 10 and complete a separate copy for each.)

Device description:

____________________________________________________________

________________________________________________________________________

________________________________________________

2. Year installed/rebuilt : /_______________

3. The estimated control efficiency with an explanation as to how that was calculated:

________________________________________________________________________

________________________________________________________________________

___________________________________

4. The chemical and physical form of the merc ury generated by the control (for example, elemental mercury, calomel scrubber solution, carbon loaded with mercury, etc.) and the handling, storage and disposition of same:

________________________________________________________________________

________________________________________________________________________

____________________________________

5. Circle the code number for the device type:

1 High-voltage, single-stage 2 Low-voltage, two-stage

6. Collection plate surface area: _______________________

7. Gas inlet temperature: _____________ E F

8. Voltage: _____________ kV

9. Gas inlet flow rate: ___________________ acfm

10. Pressure drop: _______________ inches H 2 OAppendix A U.S. EPA Questionnaire

A-33 11. Referring to the processes described in Anne xes 1 through 7, identify each process served by this device.

Annex No. Process Description Operation

12. Have tests been conducted for merc ury air emissions on this device?

0 No

1 Yes [ Enclose summary measurement data, including data on mercury speciation, if available, the test methods used, information on actual production or processing rates and on process conditions at the time the measurements were made, and a statement that any APC devices (if present) were operating normally duri ng the test, or if not, what the abnormal operating conditions were. ]

13. Additional comments and information:

________________________________________________________________________

________________________________________________Appendix A U.S. EPA Questionnaire

A-34 ANNEX 11. CARBON ADSORPTION UNITS

1. Please describe the carbon adsorption units including an explanation of the mechanism for mercury removal (for example phys ical or chemical adsorption). (Note: if facility has more than 1 carbon adsorption unit, c opy this Annex 11 and complete a separate copy for each such unit.)

Device description:

________________________________________________________________________

________________________________________________________________________

____________________________________

2. Year installed/rebuilt: /____________

3. The estimated control efficiency with an explanation as to how that was calculated:

4. The chemical and physical form of the merc ury generated by the control (for example, elemental mercury, calomel scrubber solution, carbon loaded with mercury, etc.) and the handling, storage and disposition of same:

5. Circle the code for the type of stream treated:

1 Gaseous 2 Aqueous/liquid

6. Flow rate:

__________________ acfm or gallons/min (circle appropriate units)

7. Inlet temperature: ________________ E F

8. Circle the code for the type of carbon adsorption system:

1 Canisters (nonregenerative)

2 Regenerative

3 Other (specify): ___________________

9. Total number of beds in system: ___________________

10. Total number of beds used (actively adsorb ing) in parallel at any given time: _________

11. Total number of beds used in series: ___________________Appendix A U.S. EPA Questionnaire

A-35 12. Carbon bed dimensions (in feet):

length: _____________

width: _____________

13. Superficial carbon bed velocity: ____________________

14. Adsorbtion bed temperature (if different than inlet): ____________________ E F

15. Mass of carbon per bed: ______________ lbs

16. Type of carbon used: ____________________________

17. Disposition of carbon:

1 Regenerated on-site:

a steam

b chemical

c other: _________________

2 Reactivated by carbon supplier

3 Land disposed

4 Incinerated

5 Other: ___________________

18. For your regenerable systems:
Method of carbon regeneration:

1 steam

2 chemical leaching

3 other: _______________

Length of the adsorbtion cycle: ______________________

Length of desorption cycle: ______________________

Number of beds desorbing at one time: ______________________Appendix A U.S. EPA Questionnaire

A-36 19. Method of monito ring breakthrough:

1 Monitor for mercury at system outlet

2 Monitor for mercury within adsorption bed near outlet

3 Monitor for mercury outlet of first bed in a system with beds in series

4 Do not monitor/replace beds at fixed intervals

Replacement frequency __________ months

5 Do not monitor/replace beds at fixed volume of gas processed

Gas processing set point __________ scf/bed

6 Other: _______________________________

20. If monitoring mercury breakthrough : Sampling and Analytic method used:

1 EPA Method 29

2 EPA Method 101, 101A, 102, 105

3 Ontario Hydro Method

4 Other atomic adsorption spectroscopy method: ______________

5 Other: ____________________

Frequency of monitoring:

1 Continuous (sample at least once every 15 minutes)

2 Periodic _______________ times per month

21. Referring to the processes described in Anne xes 1 through 7, identify each process served by this device.

Annex No. Process Description OperationAppendix A U.S. EPA Questionnaire

A-37 22. Have tests been conducted for merc ury air emissions on this device?

0 No

1 Yes [ Enclose summary measurement data, including data on mercury speciation, if available, the test methods used, information on actual production or processing rates and on process conditions at the time the measurements were made, and a statement that any APC devices (if present) were operating normally duri ng the test, or if not, what the abnormal operating conditions were. ]

23. Additional comments and information:

________________________________________________________________________

________________________________________________Appendix A U.S. EPA Questionnaire

A-38 ANNEX 12. OTHER AIR POLLUTION CO NTROL (APC) DEVICE DESCRIPTION

1. Please describe the other APC devices (such as condensers, or othe r controls) including an explanation of the mechanism for mercury removal (for example physical or chemical adsorption). (Note: if facility has more than 1 “o ther APC device”, copy this Annex 12 and complete a separate copy for each such device.)

Device description:

____________________________________________________ ____________________

________________________________________________________________________

___________________________________

2. Year installed/rebu ilt: /_____________

3. The estimated control efficiency with an explanation as to how that was calculated:

4. The chemical and physical form of the merc ury generated by the control (for example, elemental mercury, calomel scrubber solution, carbon loaded with mercury, etc.) and the handling, storage and disposition of same:

5. Relevant design and operating data (e .g., refrigerated non-contact water-cooled condenser; water recirculat ion set to achieve outlet gas temperature of _____ E F):

________________________________________________________________________

________________________________________________________________________

____________________________________Appendix A U.S. EPA Questionnaire

A-39 6. Exit Exhaust Vent (or Stack) Para meters (for gaseous streams):

height: __________________ ft

diameter: ________________ ft

flow rate: ________________ acfm

temperature: ______________ E F

7. Referring to the processes described in A nnexes 1 through 7, identify each process served by this device.

Annex No. Process Description Operation

8. Have tests been conducted for merc ury air emissions on this device?

0 No

1 Yes [ Enclose summary measurement data, including data on mercury speciation, if available, the test methods used, information on actual production or processing rates and on process conditions at the time the measurements were made, and a statement that any APC devices (if present) were operating normally duri ng the test, or if not, what the abnormal operating conditions were. ]

9. Additional comments and information:

__________________________________________________________

__________________________________________________________Appendix A U.S. EPA Questionnaire

A-40 ANNEX 13. MERCURY CONTROL DEVICE COST INFORMATION

1. Do you have recent (within the last 10 years) cost data for a control device described in a prior Annex installed specifi cally to reduce mercury emissions or produces a mercury product/byproduct?

0 No [ You do not need to complete the rest of this Annex. ]

1 Yes [ Please complete this Annex for each such control device. ]

2. Mercury control device descrip tion for which costs are provided. (Note: if cost information is available for more than 1 c ontrol device, copy this Annex 13 and complete a separate copy for each such unit)

________________________________________________________________________

________________________________________________

Annex Number in which this cont rol device was described: ________________

3. Please provide available cost informati on for this control de vice by completing the Control Cost Table on the following page. E ngineering estimates a nd vendor quotes are acceptable. Where available, please provide th e cost breakdown. If only total costs are available, indicate which cost s are “Included in Total” (t o the best of your knowledge) by placing a check in the appropria te box. If a given cost item is unavailable or not included, place a check under “Not known.”

4. Please provide the basis of the costs provide d by circling the appropria te code number:

1 Actual

2 Vendor quote

3 Engineering estimate

4 Other (specify) .Appendix A U.S. EPA Questionnaire

A-41 

### Control Cost Table
(For control device described in Annex )

Cost Item Description Cost ($) Year of

Cost Included

in Total Not

Known

1. Total Installed Cost of APCD

a. Cost of APCD equipment

b. Cost of auxiliary equipment 1

c. Cost of monitoring/instrumentation

d. Direct installation costs 2

e. Indirect installation costs 3

2. Annual O&M Cost for APCD 4

a. Operating labor

b. Maintenance labor

c. Utilities (electric, water, natural gas)

d. Waste disposal

e. Monitoring, recordkeeping & reporting

f. Indirect annual costs 4,5

1 Auxiliary equipment includes: fan, pumps, motors, duct work, stack

2 Direct installation costs include: foundation, supports, installation, electrical, piping

3 Indirect installation costs include: engineeri ng selection, start-up, testing, contingencies

4 Do not include capital recovery in the annua l operating and maintenance (O&M) costs

5 Indirect annual costs include: overhead, administration, taxes, and insurance.Appendix B U.S. EPA Survey Responses

B-1 

# Appendix B

U.S. EPA Survey Responses

Appendix B contains detailed resu lts of the questionnaire responses that were not provided in

Section 3.0.Appendix B U.S. EPA Survey Responses

B-2.

B-3 Appendix B U.S. EPA Survey ResponsesTable B-1. Summary of Responses to NDEPand U.S. EPA Gold Mines Questionnaire.ParentcompanyFacility nameStateCurrentlyoperatingOremercuryconc.≥0.1 mg/kgThermaloperationsGoldproduced(oz)Silverproduced(oz)Oreprocessed(tons)Ore roasted(tons)Oreautoclaved(tons)Elementalmercuryproduced(lbs)Est. Hgemission(lbs)Newmont Lone Tree Mine NV Yes Yes Yes 412,364- 6,068,995 - 1,039,607- -Coeur d'Alene Coeur Rochester, Inc. NV Yes Yes Yes 69,456 5,669,073 12,435,346 - -31,875 4.9Florida Canyon/JipanguFlorida Canyon Mine NV Yes Yes Yes 73,082 60,405 6,256,953 - - 11 5.52Glamis Glamis Marigold Mine NV Yes Unknown Yes 155,010 2,4359,858,024 - -140 -Newmont Reona and PhoenixProjectsNV Yes Yes Yes 7,664 - 1,940,439 - - - -Glamis Glamis Dee Gold Mine NV No - - - - - -- - -Barrick Placer Turquoise RidgeInc.NV Yes Yes Yes - - - - - - -Vista Hycroft Mine NV No Unknown Yes 61 1- - -- -AnglogoldAshantiBig Springs Project NV No - - -- - - -- -Silver Standard Candelaria MiningCompanyNV Yes No - - - - - - - -Newmont North Operations Area NV Yes Yes No - - 4,144,930 -- - -- Rain Mill Mine NV No - - - - - - -- -Kinross/ Barrick Round Mountain Gold -Smoky Valley CommonOperationNV Yes Yes Yes 762,966 764,992 55,352,143 - - - 22.6- South Operations Area NV No - - -- - - -- -U.S. Gold Tonkin Springs Mine NV No - - -- - -- - -- Northumberland Mine NV No - - - - - - -- -Newmont Mule Canyon NV No - - - - - - -- -Newmont McCoy/Cove Mine NV No - - - - - - -- 0.5Barrick/KennecottCortez Gold Mines Mill#2 (Pipeline Mill)NV Yes Yes Yes 999,961 58,458 41,603,701 - - 1,744 492Kinross Kinross GoldbanksMiningNV No - - - - - - - - -Newmont Trenton Canyon Project NV Yes Yes No 17,243 - 1,052,658 - -- -- Mineral Ridge Mine NV No Unknown Yes 3,484 2,927 280,000 - -- 33Barrick Ruby Hill Mine NV Yes Yes Yes 1,695 694 - - -80 3Newmont Twin Creeks Mine NV Yes Yes Yes 1,123,755 305,0347,123,665 - 3,296,841 15,742 563Barrick Goldstrike Mines NV Yes Yes Yes 1,942,660253,480 12,809,234 5,789,4177,019,817 144,945 2174.6.

B-4 Appendix B U.S. EPA Survey ResponsesTable B-1. Summary of Responses to NDEP and U.S. EPA Gold Mines Questionnaire (Continued)ParentcompanyFacility nameStateCurrentlyoperatingOremercuryconc.≥0.1 mg/kgThermaloperationsGoldproduced(oz)Silverproduced(oz)Oreprocessed(tons)Ore roasted(tons)Oreautoclaved(tons)Elementalmercuryproduced(lbs)Est. Hgemission(lbs)Newmont Midas Operations NV Yes Yes Yes 214,538 2,334,764 407,985 - -1 12.97- Jerritt Canyon NV Yes Yes Yes 242,912 6,4541,305,833 1,305,833 - 1,570 461Newmont Gold Quarry Operations NV Yes Yes Yes 872,945 527,04922,090,847 3,040,233 - 6,000 658.8Barrick Gold Exploration NV No - -- - - -- --- Columbus S M LLC NV No - - - - - - ---GoldSprings Plum Mining CompanyLLCNV Yes Unknown Yes 2,836 12,695 176,739 - - - 1.89Kennecott Goldwedge Gravity Mill NV Yes No Yes - - - -- --- Willow Creek Mine NV No No - 195 89 - - - --Hew Sleeper Sleeper Mining CompanyLLCNV No - --- - - - --MetallicVenturesEsmeralda Mine NV No - --- - - - --Newmont Ames Construction, Inc. -Newmont ProjectNV No - --- - - - --Hecla Hollister DevelopmentBlock ProjectNV No - --- - - - --Barrick/ PlacerDomeBald Mountain Mine -Mooney Basin ProjectNV Yes Yes No-- - - - --Barrick/ PlacerDomeBald Mountain Mine(including Mooney Basin)NV Yes Yes Yes 46,685 27,635 2,225,405 - - 825 53.25- Imlay Mine NV Yes Unknown No-- - - - --Newmont Midas Borrow NV No - --- - - - --Newmont Midas Exploration NV No - --- - - - --Kennecott Denton-Rawhide Mine NV Yes Unknown Yes 54,758 506,806 - -- 21-Standard Gold/JipanguStandard Mine NV Yes Yes --- - - - --Altenberg Window Peak TraceMineralsNV No - --- - - - --Newmont Double Deck ScreenPlantNV No - --- - - - --Barrick/KennecottCortez Gold Mines Mill#1NV No - --- - - - --Atna Pinson ExplorationProjectNV No - --- - - - --.

B-5 Appendix B U.S. EPA Survey ResponsesTable B-1. Summary of Responses to NDEP and U.S. EPA Gold Mines Questionnaire (Continued)ParentcompanyFacility nameStateCurrentlyoperatingOremercuryconc.≥0.1 mg/kgThermaloperationsGoldproduced(oz)Silverproduced(oz)Oreprocessed(tons)Ore roasted(tons)Oreautoclaved(tons)Elementalmercuryproduced(lbs)Est. Hgemission(lbs)Newmont Emigrant Mine NV No - --- - - - --Newmont Copper Basin Landfill NV No - --- - - - --- Geodesy Resources, Ltd. NV No - --- - - - --Apollo Montana Tunnels Mining,Inc.MT Yes No - 46,938 659,536 4,955,302 - - --AnglogoldAshanti/ GoldenCycleCripple Creek & VictorGold Mining CompanyCO Yes No -329,625169,189 21,157,243 - - - 34.3Kennecott/HeclaKennecott Greens CreekMining CompanyAK Yes - Yes 60,873 8,482,752 717,564 - - - 5.43Barrick Golden Sunlight Mines,Inc.MT Yes Yes Yes 88,592 32,388 2,600,000 - - - 0.12Kinross Fort Knox Mine AK Yes No - 329,59825,391 14,374,841 - -- 1.11E-05Kinross Echo Bay Minerals Co.,Kettle River OperationsWA No Unknown Yes 65,117 46,442 278,248 - - --WesternGoldfieldsMesquite Mine CA Yes Yes Yes 23,818 2,548 4,225,516 - - -1.2Nevada Total7,004,270 10,532,992 185,132,89710,135,483 11,356,265 202,954 4,487.0Non-Nevada Total944,561 9,418,246 48,308,714 - - - 41.1U.S. Total7,948,831 19,951,238233,441,611 10,135,48311,356,265 202,954 4,528.1.

B-6 Appendix B U.S. EPA Survey ResponsesTable B-2. Summary of Controls Used at Top FiveMercury Emitting Gold Mines in the United States.ControlsThermalProcessGoldstrike Mines(Barrick)Gold Quarry Operations(Newmont)Twin Creeks Mine(Newmont)Cortez Gold Mines(Barrick/Kennecott)Jerritt Canyon Mine(Queenstake)AutoclaveFabric filter (1988/1993)Venturi scrubbers (1990, 1992,and 1993)Not applicable Venturi scrubbers (1996) Not applicable Not applicableRoasterWet scrubber, calomel (1999)Electrostatic precipitator (1999)Off-gas quencher (1999)Off-gas condenser (1999)Fabric filters (1994)Wet scrubber, caustic (50% NaOH, 1994)Wet scrubber, calomel (1994)Wet scrubber, peroxide (1994)Electrostatic precipitators (1994)Waste heat boiler (1994)Wash tower (1994)Gas cooler (1994)Fluorine tower (1994)Not applicable Not applicableWet scrubber, hypochlorite(1989, hypochlorite added2001)Carbonregeneration kilnVenturi scrubber (1998/1999)Carbon adsorption unit(1998/1999)Condenser (2005)Venturi scrubbers (1989, 1993)Carbon adsorption units (1989, 1993)Wet scrubbers(1987/1996, 1990/1997,2003)Venturi scrubber (2005)Venturi scrubber (2002)Carbon adsorption unit (2002)ElectrowinningCarbon adsorption unit (2001)Wet scrubber (1986)Carbon adsorption unit (1998)None None NoneRetortWet scrubbers (1988, 1990, and1993)Carbon adsorption units (1988,1990, and 1993)Fabric filter (1993)Carbon adsorption units (1985, 1993)Condensers (1985)Carbon adsorption units Not applicableVenturi scrubber (2002)Carbon adsorption unit (2002)Condenser (1980)Smelting furnaceCarbon adsorption unit (2001)Fabric filters (1990, 1992)Carbon adsorption unit (1992)Fabric filter (1987) Fabricfilter (1996) Fabric filter.

B-7 Appendix B U.S. EPA Survey ResponsesTable B-3. Summary of Gold Mining FacilitiesUsing Electrowinning in the United States.Parent companyFacility nameStateTotal oreprocessed byfacility (tons)UnitIDControl technologiesEstimated mercuryemissions fromunit (tons)Newmont Lone Tree Mine NV 6,068,995 01 None No dataFlorida Canyon/JipanguFlorida Canyon Mine NV 6,256,953 01 None No dataGlamis Glamis Marigold Mine NV 9,858,024 01 None 9.64Newmont Reona and Phoenix Projects NV 1,940,439 01 None No dataKinross/ Barrick Round Mountain Gold -Smoky Valley CommonOperationNV 55,352,143 01 None 2.98Barrick/ Kennecott Cortez Gold Mines Mill #2(Pipeline Mill)NV 41,603,701 01 None de minimusGolden Phoenix Mineral Ridge Mine NV 280,000 01 None No dataBarrick Ruby Hill Mine NV 0 01 Wet scrubber de minimusNewmont Twin Creeks Mine NV 7,123,665 01 None 42.57Barrick Goldstrike Mines NV 12,809,234 01 Carbon adsorption unit 20.3Queenstake Jerritt Canyon NV 1,305,833 01 None 0Newmont Gold Quarry Operations NV22,090,847 01 Carbon adsorption unitWet scrubber5.16Barrick/ PlacerDomeBald Mountain Mine (includingMooney Basin)NV 2,225,405 01 None No dataBarrick Golden Sunlight Mines, Inc. MT 2,600,000 01 None 0Barrick Golden Sunlight Mines, Inc. MT 2,600,000 02 None 0Barrick Golden Sunlight Mines, Inc. MT 2,600,000 03 None 0Barrick Golden Sunlight Mines, Inc. MT 2,600,000 04 None 0Kinross Echo Bay Minerals Co., KettleRiver OperationsWA 278,248 01 None No dataWestern Goldfields Mesquite Mine CA 4,225,516 01 Wet scrubber No dataTotal>80.7.

B-8 Appendix B U.S. EPA Survey ResponsesTable B-4. Summary of Gold Mining Facilities Using Retorts in the United States.Parent companyFacility nameStateTotal oreprocessed byfacility (tons)UnitIDControl technologiesEstimated mercuryemissions from unit(tons)Coeur d'Alene Coeur Rochester, Inc. NV 12,435,346 01 Carbon adsorption unitCondenser0.000625Coeur d'Alene Coeur Rochester, Inc. NV 12,435,346 02 Carbon adsorption unitCondenser0.000625Florida Canyon/JipanguFlorida Canyon Mine NV 6,256,953 01 Condenser 1.69Florida Canyon/JipanguFlorida Canyon Mine NV 6,256,953 02 Condenser 1.69Glamis Glamis Marigold Mine NV 9,858,024 01 Condenser 0.61Newmont Reona and Phoenix Projects NV 1,940,439 01 Carbon adsorption unit No dataVista Hycroft Mine NV 0 01 Condenser No dataVista Hycroft Mine NV 0 02 Condenser No dataVista Hycroft Mine NV 0 03 Condenser No dataBarrick Ruby Hill Mine NV 0 01 Carbon adsorption unitCondenserNo dataNewmont Twin Creeks Mine NV 7,123,665 01 Carbon adsorption unitCondenserMist eliminator0.45Newmont Twin Creeks Mine NV 7,123,665 02 Carbon adsorption unitCondenserMist eliminator0.98Newmont Twin Creeks Mine NV 7,123,665 03 Carbon adsorption unitCondenserMist eliminator0.09Newmont Twin Creeks Mine NV 7,123,665 04 Carbon adsorption unitCondenserMist eliminator0.94Barrick Goldstrike Mines NV 12,809,234 01 Carbon adsorption unitCondenserCyclone2.6Barrick Goldstrike Mines NV 12,809,234 02 Carbon adsorption unitCondenserCyclone1.9.

B-9 Appendix B U.S. EPA Survey ResponsesTable B-4. Summary of Gold Mining FacilitiesUsing Retorts in the United States (Continued)Parent companyFacility nameStateTotal oreprocessed byfacility (tons)UnitIDControl technologiesEstimated mercuryemissions from unit(tons)Barrick Goldstrike Mines NV 12,809,234 03 Carbon adsorption unitCondenserCyclone2.9Newmont Midas Operations NV 407,985 01 Carbon adsorption unitWet scrubber0.1Newmont Midas Operations NV 407,985 02 Carbon adsorption unitWet scrubber0.09Queenstake Jerritt Canyon NV 1,305,833 01 Carbon adsorption unitCondenserWet scrubberNo dataNewmont Gold Quarry Operations NV22,090,847 01 Carbon adsorption unitCondenserFabric filter0.36Newmont Gold Quarry Operations NV22,090,847 02 Carbon adsorption unitCondenserFabric filter0.36Newmont Gold Quarry Operations NV22,090,847 03 Carbon adsorption unitCondenserFabric filter0.36Newmont Gold Quarry Operations NV22,090,847 04 Carbon adsorption unitCondenserFabric filter0.36Newmont Gold Quarry Operations NV22,090,847 05 Carbon adsorption unitCondenserFabric filter0.36Newmont Gold Quarry Operations NV22,090,847 06 Carbon adsorption unitCondenserFabric filter0.36Barrick / PlacerDomeBald Mountain Mine (includingMooney Basin)NV 2,225,405 01 Carbon adsorption unit 1.45Kennecott Denton-Rawhide Mine NV 0 01 Carbon adsorption unit 1Total>18.7.

B-10 Appendix B U.S. EPA Survey ResponsesTable B-5. Summary of Gold Mining Facilities Using Smelting in the United States.Parent companyFacility nameStateTotal ore processedby facility (tons)UnitIDControl technologiesEstimated mercuryemissions from unit (tons)Coeur d'Alene Coeur Rochester, Inc. NV12,435,346 01 Electrostatic precipitatorWet scrubber4.9Florida Canyon/ Jipangu Florida Canyon MineNV 6,256,953 01 Fabric filter 1.12Florida Canyon/ Jipangu Florida Canyon MineNV 6,256,953 02 Fabric filter 1.12Glamis Glamis Marigold Mine NV 9,858,024 01 None No dataVista Hycroft Mine NV 0 01 Wet scrubber No dataVista Hycroft Mine NV 0 02 Wet scrubber No dataVista Hycroft Mine NV 0 03 Wet scrubber No dataBarrick/ Kennecott Cortez Gold Mines Mill#2 NV 41,603,701 01Fabric filter 19Barrick/ Kennecott Cortez Gold Mines Mill#2 NV 41,603,701 02Fabric filter 11Golden Phoenix Mineral Ridge Mine NV 280,000 01 Wet scrubber 9.9Barrick Ruby Hill Mine NV 0 01 Wet scrubber 3Newmont Twin Creeks Mine NV 7,123,665 01 Fabric filter 0.82Newmont Twin Creeks Mine NV 7,123,665 02 Fabric filter 0.85Barrick Goldstrike Mines NV 12,809,234 01 Carbon adsorption unitFabric filter2.6Barrick Goldstrike Mines NV 12,809,234 02 Carbon adsorption unitFabric filter2.6Newmont Midas Operations NV 407,985 01 Carbon adsorption unitWet scrubber12.77Queenstake Jerritt Canyon NV 1,305,833 01 Fabric filter No dataNewmont Gold Quarry Operations NV22,090,847 01 Carbon adsorption unitFabric filter9.785Newmont Gold Quarry Operations NV22,090,847 02 Carbon adsorption unitFabric filter9.785GoldSprings Plum Mining Company LLC NV 176,739 01 None 1.89Kennecott Goldwedge Gravity Mill NV 0 01 None No dataBarrick/ Placer Dome Bald Mountain MineNV 2,225,405 01 Fabric filter 43.74Kennecott Denton-Rawhide Mine NV 0 01 Fabric filter 0Barrick Golden Sunlight Mines, Inc. MT 2,600,000 01 Wet scrubber 0.44Western Goldfields Mesquite Mine CA 4,225,516 01 None No dataTotal >135.32.

B-11 Appendix B U.S. EPA Survey ResponsesTable B-6. Summary of Gold Mining Facilities Using Other Thermal Processes in the United States.Parent companyFacility nameStateTotal oreprocessed byfacility (tons)ProcessControl technologiesEstimated mercuryemissions from unit(tons)Newmont Lone Tree Mine NV 6,068,995 Pregnant/barren solution tank None No dataNewmont Lone Tree Mine NV 6,068,995 Drying oven None <10Newmont Lone Tree Mine NV 6,068,995 Drying oven None <10Newmont Lone Tree Mine NV 6,068,995 Drying oven None <10Newmont Lone Tree Mine NV 6,068,995 Drying oven None <10Newmont Lone Tree Mine NV 6,068,995 Fire assay furnace Fabric filter 0.008Newmont Lone Tree Mine NV 6,068,995 Fire assay furnace Fabric filter 0.008Newmont Lone Tree Mine NV 6,068,995 Fire assay furnace Fabric filter 0.008Newmont Lone Tree Mine NV 6,068,995 Fire assay furnace Fabric filter 0.008Newmont Lone Tree Mine NV 6,068,995 Lime slaker None <1Newmont Lone Tree Mine NV 6,068,995 LECO furnace Fabric filter 0.003Newmont Lone Tree Mine NV 6,068,995 LECO furnace Fabric filter 0.003Coeur d'Alene Coeur Rochester, Inc. NV 12,435,346 Drying oven None No dataCoeur d'Alene Coeur Rochester, Inc. NV 12,435,346 Drying oven None No dataCoeur d'Alene Coeur Rochester, Inc. NV 12,435,346 Drying oven None No dataCoeur d'Alene Coeur Rochester, Inc. NV 12,435,346 Drying oven None No dataCoeur d'Alene Coeur Rochester, Inc. NV 12,435,346 Fire assay furnace None 0.003Coeur d'Alene Coeur Rochester, Inc. NV 12,435,346 Fire assay furnace None 0.003Coeur d'Alene Coeur Rochester, Inc. NV 12,435,346 Fire assay furnace None 0.003Coeur d'Alene Coeur Rochester, Inc. NV 12,435,346 Fire assay furnace None 0.003Coeur d'Alene Coeur Rochester, Inc. NV 12,435,346 Miscellaneous assay processes None No dataCoeur d'Alene Coeur Rochester, Inc. NV 12,435,346 Miscellaneous assay processes None No dataCoeur d'Alene Coeur Rochester, Inc. NV 12,435,346 Miscellaneous assay processes None No dataCoeur d'Alene Coeur Rochester, Inc. NV 12,435,346 Miscellaneous assay processes None No dataCoeur d'Alene Coeur Rochester, Inc. NV 12,435,346 Miscellaneous assay processes None No dataCoeur d'Alene Coeur Rochester, Inc. NV 12,435,346 Miscellaneous assay processes None No dataCoeur d'Alene Coeur Rochester, Inc. NV 12,435,346 Miscellaneous assay processes None No dataFlorida Canyon/ Jipangu Florida Canyon Mine NV 6,256,953 Pregnant/barren solution tank None No dataFlorida Canyon/ Jipangu Florida Canyon Mine NV 6,256,953 Pregnant/barren solution tank None No dataFlorida Canyon/ Jipangu Florida Canyon MineNV 6,256,953 Drying oven None No data.

B-12 Appendix B U.S. EPA Survey ResponsesTable B-6. Summary of Gold Mining Facilities Using Other Thermal Processes in theUnited States (Continued)Parent companyFacility nameStateTotal oreprocessed byfacility (tons)ProcessControl technologiesEstimated mercuryemissions from unit(tons)Florida Canyon/ Jipangu Florida Canyon MineNV 6,256,953 Drying oven None No dataFlorida Canyon/ Jipangu Florida Canyon MineNV 6,256,953 Drying oven None No dataFlorida Canyon/ Jipangu Florida Canyon MineNV 6,256,953 Drying oven None No dataFlorida Canyon/ Jipangu Florida Canyon Mine NV6,256,953 Fire assay furnace None No dataFlorida Canyon/ Jipangu Florida Canyon Mine NV6,256,953 Fire assay furnace None No dataFlorida Canyon/ Jipangu Florida Canyon Mine NV6,256,953 Fire assay furnace None No dataFlorida Canyon/ Jipangu Florida Canyon Mine NV 6,256,953 Miscellaneous assay processes None No dataFlorida Canyon/ Jipangu Florida Canyon Mine NV 6,256,953 Miscellaneous assay processes None No dataFlorida Canyon/ Jipangu Florida Canyon Mine NV 6,256,953 Miscellaneous assay processes None No dataFlorida Canyon/ Jipangu Florida Canyon Mine NV 6,256,953 Miscellaneous assay processes None No dataGlamis Glamis Marigold Mine NV 9,858,024 Miscellaneous assay processes None 0.002Barrick Placer Turquoise Ridge Inc. NV 0 Fire assay furnace Fabric filter 0.008Barrick Placer Turquoise Ridge Inc. NV 0 Fire assay furnace Fabric filter 0.008Barrick Placer Turquoise Ridge Inc. NV 0 Fire assay furnace Fabric filter 0.008Barrick Placer Turquoise Ridge Inc. NV 0 Fire assay furnace Fabric filter 0.008Kinross/ Barrick Round Mountain Gold - SmokyValley Common OperationNV 55,352,143 Drying oven None 1.49Kinross/ Barrick Round Mountain Gold - SmokyValley Common OperationNV 55,352,143 Drying oven None 1.49Kinross/ Barrick Round Mountain Gold - SmokyValley Common OperationNV 55,352,143 Drying oven None 0.001Kinross/ Barrick Round Mountain Gold - SmokyValley Common OperationNV 55,352,143 Drying oven None 0.001Kinross/ Barrick Round Mountain Gold - SmokyValley Common OperationNV 55,352,143 Drying oven None 0.001Kinross/ Barrick Round Mountain Gold - SmokyValley Common OperationNV 55,352,143 Drying oven None 0.001Kinross/ Barrick Round Mountain Gold - SmokyValley Common OperationNV 55,352,143 Drying oven None 0.001Kinross/ Barrick Round Mountain Gold - SmokyValley Common OperationNV 55,352,143 Induction furnace Wet scrubber 2.98Kinross/ Barrick Round Mountain Gold - SmokyValley Common OperationNV 55,352,143 Fusion furnace Wet scrubber 0.001.

B-13 Appendix B U.S. EPA Survey ResponsesTable B-6. Summary of Gold Mining Facilities Using Other Thermal Processes in theUnited States (Continued)Parent companyFacility nameStateTotal oreprocessed byfacility (tons)ProcessControl technologiesEstimated mercuryemissions from unit(tons)Kinross/ Barrick Round Mountain Gold - SmokyValley Common OperationNV 55,352,143 Fusion furnace Wet scrubber 0.001Kinross/ Barrick Round Mountain Gold - SmokyValley Common OperationNV 55,352,143 Fusion furnace Wet scrubber 0.001Kinross/ Barrick Round Mountain Gold - SmokyValley Common OperationNV 55,352,143 Fusion furnace Wet scrubber 0.001Kinross/ Barrick Round Mountain Gold - SmokyValley Common OperationNV 55,352,143 Fusion furnace Wet scrubber 0.001Kinross/ Barrick Round Mountain Gold - SmokyValley Common OperationNV 55,352,143 Fusion furnace Wet scrubber 0.001Kinross/ Barrick Round Mountain Gold - SmokyValley Common OperationNV 55,352,143 Fusion furnace Wet scrubber 0.001Kinross/ Barrick Round Mountain Gold - SmokyValley Common OperationNV 55,352,143 Fusion furnace Wet scrubber 0.001Kinross/ Barrick Round Mountain Gold - SmokyValley Common OperationNV 55,352,143 Fusion furnace Wet scrubber 0.001Kinross/ Barrick Round Mountain Gold - SmokyValley Common OperationNV 55,352,143 Fusion furnace Wet scrubber 0.001Barrick/ Kennecott Cortez Gold Mines Mill #2(Pipeline Mill)NV 41,603,701 Drying oven Fabric filter No dataBarrick/ Kennecott Cortez Gold Mines Mill #2(Pipeline Mill)NV 41,603,701 Drying oven Fabric filter No dataBarrick/ Kennecott Cortez Gold Mines Mill #2(Pipeline Mill)NV 41,603,701 Drying oven Fabric filter No dataBarrick/ Kennecott Cortez Gold Mines Mill #2(Pipeline Mill)NV 41,603,701 Drying oven Fabric filter No dataGolden Phoenix Mineral Ridge Mine NV280,000 Drying oven None No dataNewmont Twin Creeks Mine NV 7,123,665 Pregnant/barren solution tank Wet scrubber 142.79Newmont Twin Creeks Mine NV 7,123,665 Pregnant/barren solution tank None No dataNewmont Twin Creeks Mine NV 7,123,665 Drying oven Fabric filter <0.10Newmont Twin Creeks Mine NV 7,123,665 Fire assay furnace Fabric filter 1Newmont Twin Creeks Mine NV 7,123,665 Fire assay furnace Fabric filter 1Newmont Twin Creeks Mine NV 7,123,665 Fire assay furnace Fabric filter 1Newmont Twin Creeks Mine NV 7,123,665 Fire assay furnace Fabric filter 1Newmont Twin Creeks Mine NV 7,123,665 Lime slaker Wet scrubber 1Newmont Twin Creeks Mine NV 7,123,665 Lime slaker Wet scrubber 1.

B-14 Appendix B U.S. EPA Survey ResponsesTable B-6. Summary of Gold Mining Facilities Using Other Thermal Processes in theUnited States (Continued)Parent companyFacility nameStateTotal oreprocessed byfacility (tons)ProcessControl technologiesEstimated mercuryemissions from unit(tons)Newmont Twin Creeks Mine NV 7,123,665 LECO furnace Fabric filter 0.000046Barrick Goldstrike Mines NV 12,809,234 Drying oven None No dataBarrick Goldstrike Mines NV 12,809,234 Drying oven None No dataBarrick Goldstrike Mines NV 12,809,234 Drying oven None No dataBarrick Goldstrike Mines NV 12,809,234 Drying oven None No dataBarrick Goldstrike Mines NV 12,809,234 Drying oven None No dataBarrick Goldstrike Mines NV 12,809,234 Fire assay furnace Fabric filter No dataBarrick Goldstrike Mines NV 12,809,234 Fire assay furnace Fabric filter No dataBarrick Goldstrike Mines NV 12,809,234 Fire assay furnace Fabric filter No dataBarrick Goldstrike Mines NV 12,809,234 Fire assay furnace Fabric filter No dataBarrick Goldstrike Mines NV 12,809,234 Fire assay furnace Fabric filter No dataBarrick Goldstrike Mines NV 12,809,234 Fire assay furnace Fabric filter No dataBarrick Goldstrike Mines NV 12,809,234 Fire assay furnace Fabric filter No dataBarrick Goldstrike Mines NV 12,809,234 Miscellaneousassay processes Fabric filter No dataBarrick Goldstrike Mines NV 12,809,234 Miscellaneousassay processes Fabric filter No dataQueenstake Jerritt Canyon NV 1,305,833 Drying oven None 1.27Queenstake Jerritt Canyon NV 1,305,833 Drying oven None 1.27Queenstake Jerritt Canyon NV 1,305,833 Drying oven None 0.6755Queenstake Jerritt Canyon NV 1,305,833 Drying oven None 1.27Queenstake Jerritt Canyon NV 1,305,833 Drying oven None 1.27Queenstake Jerritt Canyon NV 1,305,833 Drying oven None 0.1046Queenstake Jerritt Canyon NV 1,305,833 Miscellaneous assay processes None 0.31Queenstake Jerritt Canyon NV 1,305,833 Miscellaneous assay processes None 0.31Queenstake Jerritt Canyon NV 1,305,833 Miscellaneous assay processes None 0.31Queenstake Jerritt Canyon NV 1,305,833 Miscellaneous assay processes None 0.31Queenstake Jerritt Canyon NV 1,305,833 Miscellaneous assay processes None 0.31Queenstake Jerritt Canyon NV 1,305,833 Miscellaneous assay processes None 0.31Queenstake Jerritt Canyon NV 1,305,833 Miscellaneous assay processes None 0.31Queenstake Jerritt Canyon NV 1,305,833 Miscellaneous assay processes None 0.31Queenstake Jerritt Canyon NV 1,305,833 Miscellaneous assay processes None 0.31Queenstake Jerritt Canyon NV 1,305,833 Miscellaneous assay processes None 0.0027.

B-15 Appendix B U.S. EPA Survey ResponsesTable B-6. Summary of Gold Mining Facilities Using Other Thermal Processes in theUnited States (Continued)Parent companyFacility nameStateTotal oreprocessed byfacility (tons)ProcessControl technologiesEstimated mercuryemissions from unit(tons)Queenstake Jerritt Canyon NV 1,305,833 Miscellaneous assay processes None 0.0027Newmont Gold Quarry Operations NV 22,090,847 Drying oven None 0.023Newmont Gold Quarry Operations NV 22,090,847 Drying oven None 0.023Newmont Gold Quarry Operations NV 22,090,847 Drying oven None 0.023Newmont Gold Quarry Operations NV 22,090,847 Fire assay furnace Fabric filter 0.055Newmont Gold Quarry Operations NV 22,090,847 Fire assay furnace Fabric filter 0.055Newmont Gold Quarry Operations NV 22,090,847 Fire assay furnace None <0.01Newmont Gold Quarry Operations NV 22,090,847 Fire assay furnace None <0.01Newmont Gold Quarry Operations NV 22,090,847 Fire assay furnace None <0.01Newmont Gold Quarry Operations NV 22,090,847 Fire assay furnace None <0.01Newmont Gold Quarry Operations NV 22,090,847 Fusion furnace None <0.01Newmont Gold Quarry Operations NV 22,090,847 Fusion furnace None <0.01Newmont Gold Quarry Operations NV 22,090,847Electrolyte tank Carbon adsorption unit 6.74Barrick/ Placer Dome BaldMountain Mine (includingMooney Basin)NV 2,225,405 Drying oven None No dataBarrick/ Placer Dome BaldMountain Mine (includingMooney Basin)NV 2,225,405 Drying oven None No dataBarrick/ Placer Dome BaldMountain Mine (includingMooney Basin)NV 2,225,405 Drying oven None No dataBarrick/ Placer Dome BaldMountain Mine (includingMooney Basin)NV 2,225,405 Drying oven None No dataBarrick/ Placer Dome BaldMountain Mine (includingMooney Basin)NV 2,225,405 Fire assay furnace None No dataBarrick/ Placer Dome BaldMountain Mine (includingMooney Basin)NV 2,225,405 Fire assay furnace None No dataKennecott/ Hecla Kennecott Greens Creek MiningCompanyAK 717,564 Dore furnace None 0Kinross Echo Bay Minerals Co., KettleRiver OperationsWA 278,248 Induction furnace Fabric filter 0.017Total>181.5