Draft 

Final Report to 

U.S. Environmental Protection Agency 

Region IX

Mercury and Modern Gold Mining in 

Nevada 

Greg Jones 

Glenn Miller 

Dept. of Natural Resources and Environmental Sciences 

Mail Stop 199 

University of Nevada 

Reno, NV 89557 

gcmiller@unr.edu

775-784-4108 

March 31, 2005 
2

A. Introduction 

 Mercury has long been associated with precious metals mining, and releases into the 

environment remain a concern, due to the health effects of mercury on humans and other 

organisms. Much of the historic release of mercury has been associated with either primary 

mercury mining, or use of that mercury for recovery of gold and silver via amalgamation for 

extraction of these precious metals from processed ore. For example, amalgamation 

processes were the primary source of mercury releases to the Carson River Superfund Site 

during the late 1800’s, and occurred via tailings disposal, thermal processes, and other 

discharges to surface water, land and the atmosphere. In the United States, mercury 

amalgamation for precious metals recovery has effectively ceased, and introduction of new 

mercury from hard rock mining activities is primarily associated with inadvertent release of 

mercury during precious metals mining and processing. In recent years, all of the primary 

mercury mines in the U.S. have been closed, and the only significant source of new 

anthropogenic mercury into commerce is byproduct production, again, primarily from the 

precious metals mining industry. 

In 2003, approximately 82% of gold produced in the U.S. came from Nevada mines 

(Nevada Bureau of Mines and Geology, 2003). Based on a review of the available 

information, the large majority of new byproduct mercury is also produced in Nevada. This 

report assesses how mercury is managed in precious metals mines in Nevada. 

B. Objectives and Purpose of Report 

Because of concerns about production and release of mercury into the environment, 

information is required to determine the sources of mercury from precious metals mining and 

how these are managed. We sought to answer the following questions: 

(1) What is the total amount of by-product mercury produced annually in Nevada gold 

mining facilities? How is this mercury managed? Who purchases this mercury? 

(2) How much mercury is released into the atmosphere from precious metals mines in 

Nevada? Are reductions in emissions observed, due to the current voluntary mercury 

emissions reduction program? 
3

(3) What other sources of mercury from precious metals mining exist? What is the 

significance of those sources? 

 

C. Mercury Background 

Mercury is a naturally occurring metal, and the only metallic element that is a liquid at 

ambient temperatures, having the appearance of a silver shiny metal. Mercury is 13.5 times 

heavier than water, although it is relatively volatile in the metallic state, with a vapor pressure 

of 1.2 x 10-3 torr at 20o

C (CRC, 1969). Mercury is geologically concentrated in regions 

associated with volcanic activity, high heat flow, and plate tectonic boundaries, and is 

commonly found associated with gold deposits although the ratio of mercury to gold in ore 

can vary widely. The mercury released to the living environment has increased since the 

industrial age, and the increased loading presumably has come from human activity (EPA, 

Mercury White Paper, 2003). The new non-anthropogenic mercury released into the living 

environment from natural sources (e.g. volcanoes and geothermal springs) is generally 

assumed to be relatively constant over geologic time frames (Gustin, 2003). 

Mercury is known to cycle extensively in the atmosphere, and plant, soil and water 

systems involving complex processes that are not completely understood. Mercury 

undergoes extensive biological cycling in sediments to toxic and biologically available forms 

and back to stable and less available sulfide complexes. Mercury can be photochemically 

released from soils as elemental mercury into the atmosphere, and, subsequently is 

transported in the atmosphere, where it is reoxidized in the atmosphere to an ionic form and is 

deposited on soils, plants or water (Gustin, et al., 2004). Certain natural sources of recycled 

mercury can be substantial (e.g. forest fires). Due to the difficulties in accurately measuring 

the loading of natural cyclical mercury, disagreement remains on the total mercury burden in 

the environment. Various discussions on mercury are available, and a recent extensive and 

widely considered overview is available from United Nations Environmental Program website 

(UNEP, 2003) 

New anthropogenic mercury is that mercury that is released into the living ecosystem 

from previously geologically isolated sources, and is most often derived from coal and metal 

mining activity, and, to a lesser extent from geothermal heat recovery. Air emissions and land 

releases of new mercury from anthropogenic sources include electric utility facilities, lime 
4

kilns, chemical manufacturers, mining operations and other thermal processes that utilize 

fossil fuels. The U.S. EPA suggests that 1/3 of the total U.S. emissions of new mercury are 

deposited through wet and dry deposition in the continental 48 states. The remaining 2/3 is 

transported into the global reservoir outside the boarders of the United States. One estimate 

has noted a total of 5,500 tons of atmospheric cyclical mercury is released into the global 

reservoir annually from natural, oceanic, and newly produced anthropogenic emission sources 

(U.S. EPA, August 2003). 

Until 1998, the amount of mercury released into the atmosphere from gold mining 

activities had not been systematically measured, and reliable estimates from this sector were 

not available. Since that time the amount of mercury released from mining to the atmosphere 

has been estimated, based on a series of emission measurements as a result of EPA’s Toxics 

Release Inventory (TRI) requirements. These estimates showed that a sizeable amount of 

mercury was being released from a small number of large mines, and subsequent efforts have 

been made to reduce those emissions. 

Because gold mining is concentrated in Nevada, and mercury releases from these 

mines is considered a significant environmental issue, we focused on Nevada gold mining 

operations. Some efforts were made to examine gold producing facilities out of state, 

although very little data is available. 

Governmental Regulations 

The U.S. EPA has developed an extensive array of regulatory requirements for 

atmospheric release of mercury. Summarized below is a short list of dates for regulation of 

mercury in the U.S. Shortly after the passage of the 1970 Clean Air Act, as well as the 

increasing awareness of the toxicity of mercury, domestic use began to decline, although a 

demand still exists and will likely continue. 

Table C-1. Federal and State Regulations/Programs Affecting Mercury 

Year Federal Regulation Comments 

1970 Clean Air Act 

Established EPA to set regulatory 

standards for hazardous air pollutants. 

1971 

In March of this year, mercury was 

designated a hazardous pollutant. 
5

1972 

Federal Insecticide, Fungicide, 

and Rodentcide Act (FIFRA) 

Stopped the production of many 

pesticides which contained mercury. 

1972 

Federal Water Pollution Control 

Act 

Gave EPA authority to enforce and 

regulate the discharge of mercury into 

waterways. 

1973 

In September of this year, mercury was 

designated a toxic pollutant. 

1973 

In October of this year, the dumping of 

mercury or mercury compounds in the 

ocean became prohibited. 

1974 Safe Drinking Water Act 

EPA was given the authority to establish 

and regulate safe standards for drinking 

water. 

1978 

Resource Conservation and 

Recovery Act 

Regulations were established for the 

disposal of mercury-bearing waste. 

1980 

Comprehensive, Environmental 

Response, Compensation, and 

Liability Act 

Established a $1.6 billion fund for clean 

up of toxic waste sites. 

1986 

Emergency Planning and 

Community Right-to-Know Act 

with 

Sec. 313 - TRI 

Required specific industries to report 

releases of over 650 chemical and 

chemical categories. Establishing Sec. 

313 as the Toxic Release Inventory 

1997 

U.S. EPA changed TRI toxic release 

requirements and required the metal 

mining industry to report, beginning in 

1998. 

2001 

Voluntary Mercury Reduction 

Program 

Four mining facilities in Nevada 

voluntarily agreed to VMRP goals on 

December 18 of this year. 

2005 

Clean Air Mercury Rule (Coal 

Fired Power Plants) 

New regulations designed to reduce 

mercury emissions from coal power 

plants. 

* Jasinski, 1994 

* State of Nevada, 2000 

* U.S. EPA, 28 October 2003 

The laws and regulations above were originally a response to excessive mercury 

releases from four specific emission industries, accounting for roughly 83% of all 1995 
6

anthropogenic emissions of mercury. These industries consist of medical waste incineration 

facilities (27% of total), municipal waste combustion facilities (23% of total), utility boilers 

(21% of total) and commercial/industrial boilers (12% of total) (U.S. EPA, 1996). Mining 

was not included in these totals. These values encompass both land release as well as 

atmospheric release, and the relative significance of these releases, as discussed previously is 

related to the availability of mercury in the receiving ecosystem. 

Neither the U.S. EPA nor the Nevada Division of Environmental Protection (NDEP) 

currently regulates mercury emissions from Nevada mines, other than as water pollutants 

(Johnson, 2002). Except for primary mining of mercury, which no longer exists in the U.S., 

mercury emissions from mining operations are not regulated under the National Ambient Air 

Quality Standards Act (NAAQS), the National Emission Standards for Hazardous Air 

Pollutants (NESHAP), or under Nevada’s Hazardous Air Pollutants (NHAP) program. In 

spite of the fact that the larger gold mines emit more mercury per facility than the average 

coal fired power plants, the imposition of regulations was seen as costly to both the regulating 

agency and to the mining industry (U.S. EPA, October 2003). One regulatory option 

available to the EPA falls under the Clean Air Act allows the EPA to establish Maximum 

Achievable Control Technology (MACT) air emission limits for the mining industry in a 

voluntary program. In late 2001 the EPA (Region IX) and the NDEP, four gold mining 

companies in Nevada implemented a Voluntary Mercury Reduction Program (VMRP) in their 

facilities. As part of this agreement, the four companies agreed to take proactive steps to 

reduce their mercury stack emissions by 50% in three years time. The Toxic Release 

Inventory for Nevada indicates that these four Nevada mining companies emit roughly 90% 

of all reported mercury from Nevada. (U.S. EPA, October 2003). The participating Nevada 

facilities underwent investigations at each site to better understand mercury sources, to 

explore emission prevention solutions, and then began implementation of these source 

reductions. Under this program atmospheric mercury emissions from Nevada gold mines 

have demonstrated decreases for atmospheric mercury release. 

D. Mercury from precious metals mining 

Mercury is commonly observed in gold bearing areas of Nevada, and a major mercury 

belt exists in western Nevada, although concentrations vary substantially depending on each 
7

site. Reports of oncentrations of mercury in gold ore can range from undetectable to 0.01% 

by weight. (USGS, 2003; van Zyl and Eurick, 2001 ). Management of mercury generally falls 

in three categories; byproduct production captured for sale, atmospheric emissions, and 

wastes deposited on site, primarily as a minor component of waste rock. (van Zyl and Eurick, 

2001) 

D. 1 By-Product Production Recoverable for Sale

Extraction of gold from ore most commonly utilizes basic solutions of cyanide as the 

lixiviant. Cyanide, in the presence of oxygen, converts elemental gold to a water soluble 

gold cyanide complex. These process fluids are then passed over activated charcoal, which 

captures the gold cyanide complex, and is thus removed from the aqueous solution. Mercury 

closely follows the chemistry and mechanism of capture of gold cyanide. In the presence of 

cyanide, mercury is converted to a highly water soluble di- or tetra-cyano mercury complex. 

Hg++ + CN- Æ Hg(CN)2 + Hg(CN)4

2- 

Mercury cyanide complexes are then captured with gold cyanide on activated charcoal and 

can ultimately be collected via retorts as liquid metallic mercury (van Zyl and Eurick, 2001). 

This is the primary source of mercury recovered as a byproduct. Additional mercury can be 

collected from roasters or autoclaves using air pollution control processes, although data on 

the amount of byproduct mercury collected from these processes is not generally available. 

Recovered byproduct mercury is placed into either 76 pound or one-ton flasks and 

stored on site until it can delivered to commercial facilities that are able to further refine the 

mercury for use in a variety of products. 

This report has examined only the Nevada byproduct mercury production. The 

byproduct production data were mostly obtained through voluntary reports from the various 

companies, because mercury by-product production is not reported in a publicly available 

manner. We were unable to obtain information on byproduct production in other states and 

also found that international by-product mercury production is not reported in a manner that is 

accessible. However, based on discussions with the recycling companies that receive 

mercury from mines, byproduct mercury is produced primarily from precious metals 
8

production, and these data will provide the majority of byproduct mercury production in the 

U.S. 

Previous information on mercury by-product production was found to generally be 

unreliable. There does not appear to be a systematic approach for recording mercury 

byproduct production in Nevada or the U.S., and when available, the data are incomplete. 

Because by-product mercury is not released into the atmosphere, land or water, it is not 

reported in the Toxic Release Inventory (TRI). Mercury production is, however, reported to 

the Nevada Tax Board on the annual reporting basis in the Net Proceeds of Mineral reports. 

Due to the relatively diminutive totals, the Tax Board does not publish them in their annual 

bulletins (Ewell, 2003), and they are apparently not available to the public. 

The Nevada Division of Minerals has kept records of mercury production when the 

information was submitted. In Table 2-D, the available Nevada data are provided. For 

example, in 1990, the total Nevada reported mercury byproduct production was 

approximately 112 tons (plus 504 metric tons of primary mercury). For this same year, 

Sznopek and coworkers reported 114 metric tons for all of the U.S. mines. Nevada produced 

approximately 60% of the nation gold at that time (Nevada Bureau of Mines and Geology, 

1993). This also did not include the Hycroft/Crofoot/Lewis mine, which produced about the 

same amount of gold in 1990 that it did in 1995 when it reported 24.5 metric tons of 

byproduct mercury. Sznopek and coworkers also reported 65 tons of U.S. byproduct 

mercury production in 1996 (Sznopek, et al, 1999), a year when both Paradise Peak and 

Hycroft were still producing gold but did not report mercury production, although Paradise 

Peak production had dropped substantially. In 1992, the EPA estimated that 70 tons of byproduct mercury was produced in the U.S. (EPA, July 2002), although at that time both 

Paradise Peak and Hycroft mines were in full production, and while the mercury production at 

Paradise Peak was not reported, they produced 74 metric tons mercury in 1991, and up to 120 

tons in previous years. Thus, the amount of mercury produced as byproduct mercury in the 

U.S. in previous years remains uncertain. At present, however, we are unaware of any 

remaining large producers of byproduct mercury in the precious metals mining industry. 

Both the Paradise Peak mine (now closed) and the Hycroft Mine (residual leaching) are no 

longer significant sources of mercury. Another large producer of gold in California, the 
9

McLaughlin Mine, was historically a mercury mine and produced byproduct mercury, 

although specific production data are not available (USGS, 1994). This mine is now closed. 

Table D. 1. Reported mercury production from mines in Nevada 1988-2000. All mines, except for 

the McDermitt Mine are gold mines. (from the Nevada Division of Minerals files, 2003) 

 1988 1989 1990 1991 1992 1993 1994 1995 1996

-

1998 

1999 2000 

Hycroft 54,000 40,000 7,447 

Paradise Peak 237,708 252,000 227,000 164,075 

Alligator 

Ridge 

 189 

Newmont 5548 16,264 12,388 8,512 16,872 14,187 14,192 

Alhambra 162 

Borealis 1824 

Hog Ranch 7,935 8,208 

McDermitt 

(primary Hg 

mine) 

846,488 1,008,216 0 0 

Table D 2 is a breakdown in pounds of the total amount of by-product elemental 

mercury recovered for sale for the four companies. The by-product production totals, 

representing years 1999 – 2003 (partial) have been provided directly from Barrick, Placer 

Dome , Queenstake (Jerritt Canyon mine, previously owned by Anglo Gold) and Newmont. 

Table D. 2. Total Mercury By-Product Recovered for Sale 1999-2003 (pounds and metric 

tons) ( data provided by each company, except where noted) 

 1999 2000 2001 2002 2003

Jerritt Canyon 4,041 4,313 3,709 5,045 

Placer Dome 831 302 31,505 0 
10

Barrick 13,629 22,850 55,457 49,208 

Newmont (E. Operations) N/A 14,192* 19,484 16,944 16,888 

Newmont (W. Operations) N/A 7,986 8,367 11,891 

Total pounds 41657 118,141 79564 

Total Metric Tons 18.9 53.6 36.1 

 * From Nevada Division of Minerals data (total Newmont byproduct mercury) 

As displayed in the Figure D-8, 53.6 tons of by-product elemental mercury was 

recovered in 2001 by the four gold mining companies, and then subsequently sold into 

commerce. The spike of 2001 was largely due to the increase of mercury recovered by Placer 

Dome. The reduction in 2002 was due to the addition of a chemical agent, Cherokee UNR 

811, during cyanidization at Placer Dome mines that kept the mercury bound to the rock. The 

data, as a whole show how different technologies can affect mercury capture efficiency, as 

well as the differences in the mercury content in ore. 

Nevada precious metals mining companies generally store the by-product mercury for 

periodic sales to secondary production/recovery companies who receive and, if necessary, 

further purify the mercury. These companies include Bethlehem Apparatus Co. Inc., 

Hellertown, PA; D.F. Goldsmith Chemical and Metal Corp, Evanston, IL; and Mercury Waste 

Solutions, Inc., Mankato, MN (Reese, 2001). These companies also remove mercury from a 

variety of products, including fluorescent lamps, dental amalgams, and a variety of control 

instruments. The received mercury is purified, by further retorting and washing, as necessary 

to meet the various product standards. Once this process is complete, the recyclers will then 

sell the refined mercury to various industries that use it in commercial products such as 

lighting, dental amalgam, thermometers, etc. 

 Barrick sells their by-product elemental mercury recovered for sale to Bethlehem 

Apparatus in Bethlehem, PA. Cortez has sold its mercury to Mercury Waste Solutions in 

Union Grove, WI. and Newmont sells its mercury to the D.F. Goldsmith Chemical and Metal 

Corp. Phone discussions with representatives of the three companies indicated that 

Bethlehem Apparatus and D.F. Goldsmith are the largest recipients of by-product mercury. 

The D.F. Goldsmith representative reported approximately 20 tons of mercury received from 

the gold mining industry. During March of 2005, the price of a flask of mercury on web 
11

sources ranged to over $800/76 lb flask, and had risen from a price of approximately $200/76 

lb flask the previous year. A representative of Bethlehem Apparatus indicated that they 

receive both metallic mercury, but also mercuric chloride and mercury-containing material 

from scrubbers and other mercury-trapping process material. Because the demand for 

mercury in the U.S. is larger than the current supply, mercury continues to be imported, and 

two of the three representatives were interested in obtaining information about mercury 

production from the mines, as well as contact information. Each of the representatives, when 

asked if there were any problems in how mercury was being transported to the secondary 

production facilities, reported that the procedures worked well and without notable problems. 

Management Options: The U.S. still has a demand for mercury, 150-200 tons/year, 

although it has been substantially reduced over the past 30 years (Sznopek and Goonan, 2000) 

due to increasingly strict regulations on use of even small amounts of mercury in products. 

The mercury demand in 1996 was 372 tons, down from 720 tons in 1990. The current U.S. 

demand could be supplied by secondary recovery of stored mercury or the strategic stockpile 

for several decades, currently reported to be greater than 7000 tons from U.S. military and 

chlorine-caustic manufacturing facilities (Brooks, 2003). Because of the concerns about 

mercury toxicity, keeping mercury out of the environment continues to be a goal of both 

national and international regulators and scientists, and suggestions have been advanced that 

mercury should be sequestered in repositories that prevent it from being added to the global 

burden of mercury (Bender, 2000). Such methods exist, and include conversion to mercuric 

sulfide and storage in permanent repositories (UNEP, 2003). 

 However, byproduct mercury, similar to recycled mercury from a variety of products, 

is produced and needs to be managed in a safe and cost-effective manner. Byproduct 

mercury production is a minor component of the total mercury presently available, and the 

several 1-20 ton sources of byproduct mercury require management that is safe, reliable and, 

from an industry perspective, reduces liability. Under the current legal framework, liability 

for mercury is removed when the product is sold into commerce. 

 Byproduct mercury production from gold mining is likely to increase, due to 

reductions in atmospheric emissions. While this increase is likely to be relatively small, it is 

far more environmentally benign to produce byproduct mercury for sale rather than release it 
12

into the air, or into waste facilities. Since byproduct mercury will be produced, and, with the 

current demand (albeit decreasing), there appears to be no compelling reason to establish a 

process for permanent sequestration of the byproduct mercury produced. Unless a 

mechanism and national (and international) policy and procedures exist for permanent 

retirement of mercury, retention of the present market mechanism for management of the 

byproduct mercury from these several sources appears prudent. Additionally, the significant 

price increase in mercury in the recent past is ominous in that primary mercury mines may 

again become economically feasible, and any mercury management of byproduct mercury 

that involves sequestration should consider the utility of this approach if the price structure 

encourages new mercury mine development, either in the U.S. or abroad. Management of 

metallic mercury is presently under extensive discussions in both the UNEP as well as the 

European Union, and byproduct mercury should be considered as a component (albeit 

relatively small) of the larger mercury management plans. 

D. 2. Atmospheric Emissions of Mercury

Because metallic mercury is a relatively volatile liquid, it can escape to the 

atmosphere, particularly from thermal processes. Several mercury sources from precious 

metals mining have been identified, and the amount released to the atmosphere can vary 

dramatically depending on the ore, the specific process and the effectiveness of the mercury 

control measures. 

For those ores that are unoxidized, the single largest atmospheric source of mercury is 

from sulfide or carbonaceous ore roasters, autoclaves or other thermal processes that convert 

reduced (sulfidic or carbonaceous) gold ore to a form that can be more efficiently extracted 

with cyanide. In these ores, mercury occurs primarily as mercury sulfide (HgS), which is 

also thermally oxidized and converted to either metallic (mostly) or divalent mercury. The 

metallic mercury is volatilized and released into the atmosphere, in the absence of any 

controls. 

 

HgS(s) + O2(g) + heat Æ Hg + SO2(g) 
13

A second major source of atmospheric release of mercury is from the processes that 

convert gold cyanide to dore bars. Because mercury follows gold through the processing 

circuit (discussed previously), and several of these processes utilize elevated temperatures, 

mercury (but not gold) is released into the atmosphere. These processes include 

electrowinning cells that convert gold to the elemental form and retorts specifically designed 

to remove and capture the mercury that is part of the metal sludge on the electrodes or a 

component of the gold that has been precipitated on zinc dust, sometimes in greater quantity 

than gold. In years past, anecdotal accounts are common where no retort was utilized, and 

mercury condensed on the metal roofs of the processing facilities and formed visible droplets 

on the sides of the building. Finally, the charcoal used to initially capture the gold cyanide 

and mercury cyanide complexes, is reused. However, it needs to be thermally treated for 

reactivation, and during this process residual mercury on the carbon can be volatilized. This 

latter source can be a substantial fraction of the total amount of mercury released from a 

specific mine. For each of these sources of mercury, control measures are available to capture 

a majority of the mercury, and are being utilized in mining. The efficiency of the capture of 

this form of mercury is variable, depending on the specific processes utilized. 

A third type of atmospheric release of volatilized mercury from gold mining is from 

waste rock dumps, tailings facilities and extracted heap leach piles. This source of mercury is 

reported to be relatively minor, although methods for measurement of this volatilized mercury 

do not appear to be well-tested. 

Of the releases of mercury into the environment, the most problematic are those where 

exposure to living systems is most likely. While mercury release to land in a secure land fill 

may be of a much larger magnitude, this mercury is most often unavailable and carries a 

relatively low risk. However, releases to surface water and to the atmosphere are much more 

biologically available and these releases, while much smaller, can present much greater 

environmental risks. Thus, atmospheric emissions are a particular concern for precious 

metals mining, since the quantities that have been released from several of the mines are 

large. Two sets of data have been used to estimate the recent and current amount of mercury 

released from precious metals mines in Nevada. The first is the TRI data and the second is 

the Voluntary Mercury Reduction program. These data should be generally consistent, 

although some differences have been noted. 
14

D. 2. 1. TRI Reported Data 

The Toxic Release Inventory (TRI), was formulated in 1986 within Section 13 of the 

Congressional Emergency Planning and Community Right-to-Know Act (EPCRA). This 

inventory requires specific industries to report releases of particular chemical and chemical 

categories released to the air, land and water from industries ranging from energy production 

to metal mining. The “TRI is designed to provide citizens with information about chemicals 

being used, processed, manufactured, or released from facilities in their communities. The 

basic premise of TRI is that citizens have a ‘right to know’ about toxic chemicals that are 

handled or released in their community” (State of Nevada, 2000). The EPA, in 1997, changed 

the TRI reporting requirements to include releases within the metal mining industry. 

The section of TRI that is most relevant to this study is the Form-R. Form-R is 

broken into eight sections: 

1. Reporting Year 

2. Trade Secret Information 

3. Certification 

 This section states who is responsible for the forms authenticity. 

4. Facility Identification 

5. Parent Company Information and the Quantity of the Toxic Chemical Entering 

Each Environmental Medium On-Site 

 This section encompasses all data for mercury released to land on-site. 

6. Transfers of the Toxic Chemical in Wastes to Off-Site Locations 

 This section gives the name of the off-site location where mercury was sent 

for further refinement or disposal. 

7. On-Site Waste Treatment Methods and Efficiency 

 On-Site Energy Recovery Processes 

 On-Site Recycling Processes 

8. Source Reduction and Recycling Activities 

 This section is an accumulative total of data from sections 5, 6 and 7. 

 This section shows columnar references of data from the previous reporting 

year, the current reporting year, and expected reporting totals for two years 

in the future. 

 

The data from Form-R is collected on paper copies from the reporting facilities and 

sent to the appropriate regulatory agency. Within a two year period, the forms are then 

finalized into electronic copy for public viewing over the web. In this two year period, 

facilities can change and alter their respective Form-R if, for instance, it is found that there 
15

was an initial error in calculating release. It is the understanding in this report that release 

documented in 2003 TRI paper copies are not finalized until the EPA finalization occurs in 

the summer of 2005. 2002 TRI reports were published on the web in the summer of 2005, 

and are therefore finalized. At the EPA’s TRI homepage (www.epa.gov/tri/report/trime/), one 

can narrow down a search by chemical, facility, or industry using the helpful TRI Explorer

search engine application. 

Because the exact form of mercury is unknown (although assumed to be primarily 

metallic mercury, Hgo

) that is released into the atmosphere, the total amount of mercury is 

expressed as “mercury” or “mercury compounds”. The atmospheric emissions are presented 

below. 

Total Air Emission includes “Stack or Point Source Air Emissions” and “Fugitive or 

Non-Point Air Emissions”. Stack or point source air emissions are from stacks, vents, pipes 

or ducts, while fugitive or non-point source air emissions is mercury released from less well 

defined sources. 

The EPA Report to Congress (1997) stated that in the US, the highest concentration of 

anthropogenic emissions is east of the Rocky Mountains, and that the Great Basin region 

generally has the lowest emissions rates (ES-10). Furthermore, the Report suggests that 

combustion point sources, such as utility and industrial broilers make up for 86.9% of 1995 

mercury emission in the United States (ES-6). On an industry wide basis, Nevada gold 

mining is a relatively minor source of total natural and anthropogenic emissions to 

atmosphere. However on an individual facility basis, gold mining emissions are significant. 

In 1998, four of the gold mines from Nevada reported individual facility mercury 

stack emissions totaling 13,560 pounds (U.S. EPA website, 2003). One facility alone, the 

Jerritt Canyon Mine, reported release of 9,400 pounds of the 13,560 pounds released by all of 

the reporting mines. In comparison with the average coal-fired power plants in the East, 

emitting an average of 250-400 pounds per year of mercury, Nevada gold mines are 

individually large sources of anthropogenic emissions of mercury. 

Regulation of mercury releases is complicated by the fact that mercury commonly 

occurs naturally in the earth and atmosphere. In the Report to Congress in 1997, the EPA 

estimated that 5,500 tons of new mercury was released world wide into the atmosphere in 

1995 from all sources including natural emissions, oceanic emissions, and anthropogenic 
16

emissions. In the same year, it was reported that 159 tons (or 3% of total) were emitted into 

the atmosphere due to US human industrial sources, such as coal-burning utilities, municipal 

and hospital waste incinerators, industrial broilers, chlor-alkali plants, and cement 

manufacturers (Report to Congress, 1997). The report did not include emissions originating 

from mining operations. In 1998, seven Nevada mines reported emission release of 

approximately 7 tons (or 4.3% of total US) of mercury emitted into the atmosphere (Johnson, 

2000). In 2001, TRI data shows that four Nevada mining companies released roughly 6 tons 

(or 8% of US total) of mercury and mercury compounds as emissions. This amount dropped 

to 6.1% of the total U.S. emissions in 2002, and will likely be 3-4% in 2003, using the TRI 

data. 

 
17

Table D 3. Mercury Air Emissions from Precious Metals Mining, 1998-2003. Toxics 

Release Inventory data, U.S. EPA, 2004) 

Facility 1998 1999 2000 2001 2002 2003 

Placer Bald Mountain 0 0 0 0 

Barrick Goldstrike 1,500 1,400 1,467 1,243 1,253 1,122 

Coeur Rochester 0 0 0 1 0 

Cortez Joint Venture Pipeline 2200 1,500 1,351 1378 

Echo Bay McCoy Cove 

(Newmont, 2003) 

226 363 118 7 

Florida Canyon Mine 2 1 1 

Getchell 0 1 0 0 

Glamis Dee 0 

Glamis Marigold 4 0 1 

Jerritt Canyon Joint Venture 9,400 9,400 6,700 7,990 4,740 793 

Ken Snyder 11 

Newmont Carlin North 3 3 2 24 

Newmont Carlin South 53 71 80 490 513 565 

Newmont Lone Tree 0 0 1 5 1 8 

Newmont Rain 0 0 0 

Newmont Twin Creeks 2200 1200 630 570 530 588 

Ruby Hill 0 0 0 

Smoky Valley Common 0 0 

Total from Metal Mining 

 (Point source- stack) 

13,153 12,072 11,322 12,162 8,510 4488 

(est.) 

Fugitive Nevada Total 

(from mining) 

423 95 1,183 212 196 

Nevada Total (all industries) 13,576 12,167 12,912 12,959 9,266 
18

Table D. 4. Ranking of states for atmospheric point source release of mercury and mercury 

compounds for 2001 and 2002 from all industries. Note that this list does not included the 

fugitive emissions, which are generally less than 10% of the point source (stack) emissions, 

except for West Virginia, Ohio and Alabama. 

 

The TRI data show rather clearly that for the years 1998 to 2003, precious metals 

mining was the largest industrial source of atmospheric release of mercury in Nevada. It also 

shows that Nevada, during 2001 had a #2 ranking for total mercury atmospheric discharge, 

and in 2002 was #4, and will probably decrease to #7 in 2003, based on preliminary data from 

Nevada mines and the expectation that approximately 500 lbs would be emitted from the three 

coal fired power plants in Nevada. Based on discussions with staff at the Cortez Pipeline 

mine a mercury capture system on the carbon kiln is likely to result in a substantial reduction 

of mercury at that site. Thus, a decrease in total mercury release in 2005 to under 4000 lbs is 

anticipated. Further reductions in mercury are likely to be less dramatic than in previous 

Rank 

(2002) 

State Pounds 

released

(2001)

Pounds 

released

(2002) 

Pounds 

released 

(2003) 

1 Texas 14,766 14,505 

2 Ohio 11,405 9,625 

3 Pennsylvania 9,089 9,177 

4 Nevada 12,959 9,069 4500 (est) 

5 Indiana 7,168 7,645 

6 Illinois 5,963 5,610 

7 Alabama 5,903 4,729 

8 North Carolina 4164 4,507 

9 California 5,668 4,173 

10 West Virginia 6,282 4,051 

11 Kentucky 5,256 3,670 
19

years, however and will depend on the type of ore being mined, as well as the improvements 

in mercury control technology that will be utilized. 

D. 2. 2. Voluntary Mercury Air Emissions Reduction Program (VMRP) data.

 As discussed previously, the four companies with the largest emissions agreed in 2001 

to participate in the Voluntary Mercury Air Emissions Reduction Program. In lieu of a 

lengthy regulatory process, the four companies, the Nevada Division of Environmental 

Protection and the U.S. Environmental Protection Agency all agreed that a voluntary 

approach for reducing mercury emissions would be a much more rapid process for mercury 

reduction. Note that for the first 4 years of the TRI program for mining, only two of the 

mines showed substantial reductions in mercury emissions. With the voluntary program that 

was initiated in 2001, further reductions in emissions would be expected. The VMRP data are 

much more extensive than found in the TRI reports, and the VMRP reports are available from 

the Nevada Division of Environmental Protection (NDEP), but are summarized below. 

The actual reports provide additional detail and interested persons are referred to staff 

of the NDEP for a complete copy of the reports. Several issues should be noted regarding 

these data. First, the methods used determine mercury are not generally provided, although 

individual reports discuss (e.g. Jerritt Canyon) issues of how mercury is measured at various 

heights in the stacks, and how these affect estimates of atmospheric emissions. Second, the 

estimates of mercury release, are, in some cases, based on actual source test measurements 

made two years earlier (e.g. Gold Quarry). While the data presented in the VMRP reports 

are the best available, improved methods for actually measuring mercury release are 

desirable, as would be increased testing frequency. 
20

Table D 5. VMRP data from Barrick Goldstrike (NDEP, 2004) 

Source Emissions 

 (2001, Baseline) 

Emissions 

(2002) 

Emissions 

(2003) 

Retorts 1,2,3 11 11 11 

Mill furnace 1,402 161 161 Carbon column added. 

March 2002 

Electrowinning 

cell 

613 Included 

above 

Included 

above 

Emissions sent through 

mill furnace carbon column

Carbon kiln 4380 4380 1927 Carbon filtration unit 

added in March, 2002 

Autoclave 

circuit 

548 548 548 Controls installed prior to 

2001 

Roaster 814 814 166 Controls installed prior to 

baseline year 

Total 7768 5920 2819 

 
21

Table D 6. VMRP data from Cortez Joint Pipeline Project (Placer Dome) (NDEP, 2004) 

Source Baseline 

Emissions 

(1998) 

Emissions 

(2001) 

Emissions 

(2002) 

Emissions 

(2003) 

Carbon in 

leach 

981.4 249.3 218.3 N/A 

Carbon in 

columns 

14.7 41.2 67.4 Carbon column added 

Area 28 heap 

leach pad 

carbon 

columns 

134.8 234.7 293.9 Emissions sent through 

mill furnace carbon 

column 

Refinery 

furnaces 

3174 160.2 473.3 Substantial reductions are 

due to chemical 

treatment (see text) 

Total 4305 685.4 1053 
22

Table D 7. VMRP data from Jerritt Canyon (Queenstake) (NDEP, 2004) 

Source Emissions 

(2001) 

(Baseline) 

Emissions 

(2002) 

Emissions 

(2003) 

Carbon 

regeneration 

kilns 

1543 294 0.28 Venturi mercury wet 

scrubbing/carbon polishing 

system installed in March 

Refinery 365 250 (included 

above) 

Emissions routed to carbon 

regeneration kiln control system 

in September 

Roaster west 4667 2777 599 Sodium hypochlorite injection 

system installed in September, 

2002 

Roaster east 1405 1417 188 Sodium hypochlorite injection 

system installed in September, 

2002 

Total 7980 4738 787 
23

Table D 8. VMRP data from Twin Creeks Mine (Newmont) (NDEP, 2004) 

Source Emissions 

(1999) 

Baseline 

Emissions 

(2001) 

Emissions 

(2002) 

Emissions 

(2003) 

Comments 

Autoclave phase 

I 

844 119 121 120 Venturi Scrubber 

Autoclave phase 

II 

380 112 119 126 Venturi Scrubber 

Retorts A,B,C,D 3 3 3 3 Carbon Columns 

Juniper kiln 252 253 268 125 Wet scrubber 

Electrowinning 

cells 

3 3 3 3 

Pinion kiln 113 67 2 0 Wet scrubber 

Induction 

furnace 

4 4 8 4 

Total 1599 561 524 381 

 
24

Table D 9. VMRP data from Gold Quarry Mine (Newmont) (NDEP, 2004) 

Source Emissions 

(2001) 

Baseline 

Emissions 

(2002) 

Emissions 

2003 

Comments 

Mercury Retorts 24.35 18.54 17.71 Mercury condenser and 

scrubber previously 

installed 

Furnaces 15.19 15.72 11.43 Carbon adsorption unit 

previously installed 

Carbon kilns 31.23 30.74 55.40 Venturi scrubber; carbon 

adsorption unit 

previously installed 

Prenant and 

barren tanks 

 12.90 12.90 12.90 Carbon adsorption unit 

and tank scrubber 

previously installed 

Ore Preheater 85.05 90.74 91.33 Baghouses and SO2

scrubber previously 

installed 

Ore Roaster 23.97 25.75 25.60 Wet scrubber, 

electrostatic precipitator, 

SO2 scrubber and 

mercurous chloride 

scrubber previously 

installed 

Mill 6 

drying/grinding 

circuit 

291 314 328 Baghouses for particulate 

Total 484 508 542 
25

The differences between the TRI atmospheric emissions data and the VMRP data are, 

in some cases significant. For 2001, the Barrick Goldstrike mine reported 1324 pounds of 

atmospheric emissions, while for the VMRP data, Barrick reported 7768 pounds of 

atmospheric emissions. For the Cortez mine, 1503 pounds were reported for the TRI data in 

2001 and for the VMRP data, 685 pounds were reported. The other differences for the 2001 

data were relatively small: Jerritt Canyon (7,991 vs. 7980); Newmont Gold Quarry (South 

Operations Area) (603 vs. 508); Newmont Twin Creeks (501 vs. 561), respectively for TRI 

vs. VMRP data. Differences in VMRP data and TRI data were also noted in subsequent 

years. As discussed previously, measurements of mercury release are difficult, and the 

VMRP program appears to have increased the focus on these measurements. As can be 

observed in the tables above, the amount of information from each source is substantially 

greater than presented in the TRI data. While data consistency for mercury is warranted, 

these somewhat inconsistent data show the need for both agreement on the methods for 

measurement and the number of actual measurement to ensure that the data provided is 

consistent and accurate. Reliable methods that will both reduce the cost of analysis and 

allow much more convenient measurement of mercury in the various emission sources 

appears to be available. Frontier Geosciences, a laboratory in Seattle, Washington is now 

routinely measuring mercury at a cost of $100-$150 per sample (Bob Brunette, Frontier 

Geosciences, personal communication, 2005). 

If the 2001 VMRP data are used, instead of the TRI data for atmospheric emissions, 

the total amount of mercury emitted to the atmosphere in Nevada in 2001 was 18,539 pounds, 

making it the state with the largest amount atmospheric emissions of mercury, with Texas 

now second at 14,766 pounds. However, the VMRP process is showing results. For 2002, 

the atmospheric emissions from these VMRP reporting mines had decreased, from 17,478 

pounds in 2001 to 12,743 pounds in 2002, a 27% reduction. Because several units of the 

control technology were implemented in the last half of 2002, further reductions for 2003 are 

noted, particularly the substantial reductions in mercury emissions from Jerritt Canyon. 

One concern about the VMRP data that exists is the definition of the Maximum 

Achievable Control Technology (MACT) standards that have been applied to the gold mines. 

There does not appear to be a rigorous technical definition or comprehensive review of the 
26

definition of MACT, and this should be evaluated as part of a larger discussion of mercury 

regulation in gold mines. 

For comparison purposes, the new Clean Air Mercury rule released in March of 2005 

(U.S. EPA, 2005) has provided limits for mercury emissions from coal fired power plants in 

each state. In 2002, TRI data showed that the three Nevada coal fired power plants released 

524 lbs. of mercury to the atmosphere. The new mercury rule will require the total amount of 

mercury from these three plants and all new similar power plants to be no more than 570 lbs 

in 2010 and 224 lbs by 2018. This rule also requires extensive monitoring of power plant 

emissions to ensure that the reported quantities are being measured on a routine basis. Thus, 

while gold mining emissions are not regulated under the new rule, the differences in mercury 

emissions between coal fired power plants in Nevada and gold mines are likely to be a topic 

of discussion. 

D. 3. Mercury released to surface impoundments or waste dumps: 

Because very large amounts of rock are excavated in gold mines, particularly in open pit 

mines, the amount of waste rock containing mercury is large and the total amount of mercury 

in these waste facilities is consequently very large, and constitutes the single largest release of 

mercury in the Toxics Release Inventory reports. For example, in 2002 the total amount of 

mercury released to surface impoundments or other land disposal was 4.68 million pounds. 

Similar amounts were reported in previous years. We have not included these data in this 

report, although they are available from the EPA Toxics Release Inventory web site. 

While these releases are certainly non-trivial, the large tonnages of mercury released do 

not provide a realistic sense of the relative risk of these sources of mercury. If the mercury 

remains in the rock or other waste material and is appropriately contained in waste disposal 

units, it generally does not present an increase in environmental risk, compared to when that 

same mercury and rock were geologically isolated before the rock was brought to the surface. 

Consequently these values, although indeed very large, need to be considered with a 

perspective of risk. 

In certain circumstances, particularly in acidic drainage, release of this mercury can be 

important in specific watersheds. Additionally, a relatively unknown component is the 

amount of mercury that is photochemically released from this rock. Additional research is 
27

required to assess this source of atmospheric mercury, and whether it is a significant source, 

relative to other atmospheric releases. Undoubtedly, however, this risk will not be 

proportional to the large tonnages reported in the TRI data. 

D. 4. Company Profiles in the Voluntary Mercury Reduction Program (VMRP) 

The companies represented in the VMRP include three of the largest gold mining 

companies in Nevada- Newmont, Barrick, and Placer Dome, and a mid-sized mining 

company, Queenstake. As shown in Table D-9, the gold production of these companies 

comprises about 80% of the total Nevada gold production during these two years, and it has 

not appreciably changed since that time. If Round Mountain Mine is included, jointly owned 

by Kinross and Barrick, the number increases to 87-89% of gold production in Nevada. The 

Round Mountain Mine has not reported significant amounts of mercury released into the 

atmosphere from the TRI data, and apparently has a low mercury content in the ore. Also, 

based on TRI reports, >95% of the mercury released to the atmosphere is reported by the 

VMRP companies. A short discussion of each mining company is presented below, to 

provide a background on the diversity of issues that exist with each mine and mercury. 

Substantial differences exist in ore type as well as approaches for control of mercury at each 

mine. Mercury emission controls are driven by both the need to maintain worker 

environmental health and safety, as well as reduction in mercury released to the atmosphere. 

Table D-9 

Top 5 Gold Producing Mine Companies and Mines in 2000-2001 

# Company Mine 2000 2001 

1 Newmont Total 3,047,900 2,703,000

2 Barrick Betze-Post and Meikle 2,452,300 2,280,600

3 Placer Dome/Kennecott Cortez Joint Venture 1,009,000 1,188,100

4 Kinross/Barrick Round Mountain 640,100 747,000

5 Queenstake Jerritt Canyon Joint Venture 343,200 326,700

 Total Nevada Gold 

Production 

 8,585,000 8,125,000
28

Jerritt Canyon Joint Venture 

Gold was discovered at Jerritt Canyon, 60 NE of Elko, NV, in 1973. Mining began in 

the summer of 1980 on approximately 125 square miles in the Independence Mountain 

Range. The first gold bar was produced on July 4, 1981. During that first year, operation 

consisted of producing 23,000 oz of gold. Today, Jerritt Canyon Joint Venture (JCJV) 

produces approximately 360,000 oz of gold annually. 

Until the mid-1990’s, JCJV conducted mostly surface mining. Surface mines were 

planned and permitted with the USFS and NDEP prior to disturbance. Since then, JCJV has 

mined underground as they have identified ore bodies at increased depths. All underground 

mines are also planned and permitted with the USFS and NDEP prior to disturbance. 

 In conjunction with the Voluntary Mercury Reduction Program, Jerritt Canyon has 

been upgrading their production processes with carbon filter systems. In 2001, JCJV spent 

$170,000 in carbon kiln upgrades for emission controls. In that same year, they spent 

$120,000 in a hypochlorite system for emission control in the roasters. Each year forward, 

JCJV will be spending roughly $60,000 per year in emission analysis of their facility. 

JCJV assumes there is approximately 1 million oz of gold remaining in reserves that 

will keep the facility operational for 3-4 more years. By adding up the total cost of control 

devices beginning in 2001 until the end of their anticipated reserves (2007), JCJV will have 

invested in the neighborhood of $1.25 million on environmental compliance upgrades. 

Average gold production of these dates is estimated at 300,000 per year. On average, control 

device spending at JCJV is roughly $.60/oz of gold produced. 

The gaseous mercury emissions from Jerritt Canyon’s two large roasters of mercury 

began to be treated with roaster carbon scrubber systems in 2001. The fourth quarter of 2002 

was when most of Jerritt Canyon’s mercury controls were implemented for control processes. 

At the carbon regeneration kiln, Jerritt installed a venturi mercury wet scrubbing/carbon 

polishing system that reduced emissions from a 2001 baseline by 81%. At their refinery, 

installation of ducting from the refinery to the carbon regeneration kiln system has reduced 

emissions from the 2001 baseline by 31.5%. Finally, Jerritt Canyon’s addition of a 

hypochlorite injection system in late 2002 produced the cumulative 90+% reduction in 

mercury emissions from the facility. The aggressive efforts at this mine have been primarily 

responsible for the substantial reductions in total mercury emitted by Nevada mines. This 
29

company mine went from being the single largest source of atmospheric release of mercury in 

the U.S. in 2001 to the lowest of the VMRP companies in 2003. 

. 

Cortez Pipeline Joint Venture 

The Cortez Pipeline mine is located roughly 90 miles South-West of Elko, NV, 

producing roughly 1 million oz of gold per year. Cortez has experienced elevated mercury in 

process fluids in the recent past. These concentrations equated to potential hazardous 

working conditions with potentially elevated exposure levels of mercury to employees, and 

concerns about employee exposure were a primary driver for implementing reductions in 

mercury in the process fluids. The majority of ore at this mine is oxide and does not require 

thermal treatment for precious metals recovery. 

In 1999 and in conjunction with the Voluntary Mercury Reduction Program, Cortez 

began initiating a chemical treatment using an organic dithiocarbamate mercury trapping 

agent from the Cherokee Chemical Co. called UNR-811. UNR-811 is added to process fluids. 

which then complexes aqueous mercury as a stable organic sulfide precipitate (Upton, 2003). 

The complexed mercury is attached to either the heap material, or is carried to the tailings 

impoundment as a complex aqueous slurry. When trapped on heap material or rock, it does 

not appear to be remobilized, and represents a novel approach to management of mercury for 

reduction of exposure to workers as well as reducing mercury in the process fluids. In the 

past year, the efficiency of mercury capture on the solid material appears to have decreased 

somewhat and a significant increase of mercury release from the carbon kilns has been noted. 

In 2005 a mercury capture system will be added for capture of the mercury emissions from 

the carbon regeneration kilns and designed to substantially reduce the mercury release from 

this primary source. 

Barrick Goldstrike 

Barrick Goldstrike, located roughly 60 miles North-West of Elko, NV, produces 

roughly 2 million oz of gold per year and is currently the largest single gold mining complex 

in the United States. In 2001, Barrick completed the development of a new roasting facility. 

This facility cost an estimated $45 million (included in this price is the cost of Research and 

Development). Barrick has estimated that roughly 20 million oz of their estimated 30 
30

million oz of reserves will pass through the new facility for roasting; the remainder will be 

processed through their autoclave. Cost analysis would show that this new facility will cost 

Barrick roughly $2.25/oz of gold produced, from its first ounce to its final ounce in reserve. 

Barrick has two gaseous emission sources of mercury recovery (byproduct) within 

their facility. The first is at the roaster where mercury is recovered from the mercury 

scrubbing system. The second source of mercury comes from the retort recovery process 

between the electro winning cells and the furnace. All mercury collected on carbon scrubbers 

is roasted and the emissions are captured by the roaster mercury scrubber system. 

Installations of wet venturi scrubbers in the carbon kiln and autoclave circuit, carbon filters in 

the mill furnace, mercury condensers and carbon scrubbers in the retort units, and process 

controls in the roaster consisting of wet gas condensers a Hg absorption tower all contribute to 

the reduction in Barrick’s mercury emissions. This installation has a large and diverse array 

of mercury sources, as well as the diverse array of mercury control methods. 

 All of the recoverable elemental mercury by-product at Barrick, recovered from 

oxidation at the roaster, is sold to Bethlehem Apparatus. 

Newmont Gold Company 

 Newmont has been actively mining and recovering gold in Northern Nevada since 

1965. In Nevada, it currently mines from 14 open pits and 5 underground operations, and, 

combined with the international operations, is the largest gold producer in the world. Unlike 

the other companies in the VMRP, Newmont has several sites in Nevada that potentially can 

produce mercury, although these are generally grouped into the western operations (primarily 

Twin Creeks) and the complex near Gold Quarry in the Carlin Trend. At Newmont’s 

numerous operations in Nevada, two general technologies, wet scrubbers and sulfurimpregnated carbon filters, are utilized for mercury capture and management. Technologies 

utilized at Newmont have been in place for many years and many were in place prior to the 

requirement that mines report under the Toxic Release Inventory reporting program and prior 

to the establishment of the Voluntary Mercury Reduction program. At one process area at the 

Twin Creeks mine, a new technology (to Newmont) uses of a wet scrubber with a 

hypochlorite solution, is being tested. 
31

 Mercury recovered in the processes is ultimately captured in two refineries at 

Newmont’s operations in Nevada. Newmont’s byproduct mercury from Nevada is shipped to 

DF Goldsmith. 

E. Conclusions and Recommendations 

Nevada gold mines are a previously unrecognized large source of atmospheric 

mercury releases, and constitute the largest source of new byproduct mercury in the U.S. 

Data for estimating mercury released to the atmosphere has been available only since the TRI 

reporting requirements were applied to mines in 1998 and only sporadically for the amount of 

byproduct mercury produced. Mercury content in ore is highly variable, and any 

determination of releases of mercury to the air or byproduct production require direct 

measurements at each mine. 

 Future demand for commodity mercury in the U.S. is decreasing due to substitution of 

previous mercury-containing products. World demand is also decreasing, as manufacturing 

companies are turning away from its use in common household and industrial products. 

Ceramic composites are replacing dental amalgams, digitized instruments are replacing 

mercury thermometers, membrane cells are replacing mercury cells in electrolytic production 

of chlorine and caustic soda, and indium compounds are being substituted for mercury in 

alkaline batteries. Governments from many parts of the world are regulating its use and 

manufactured applications, due to increasing public concerns regarding mercury 

contamination and health warnings. However, mercury use remains in many products, and a 

demand will continue to exist for the foreseeable future. Thus, byproduct mercury from 

precious metals mines is best managed via recycling facilities to meet that demand. 

A brief comment was made in the report comparing mercury regulations in the coal 

fired power plants to mercury in gold mining and while the mercury releases from gold mines 

are not included in the new mercury rule for power plants, it is useful to examine how these 

plants are meeting the new and stringent requirements. The analytical requirements for 

measurement of mercury in the power plants are potentially closely applicable to gold mines 

as are the mercury control technologies. 

The following recommendations are based on the findings of this study. 
32

1. The Voluntary Mercury Reduction Program, a cooperative effort of the four major 

producers of mercury has been successful for reduction of atmospheric mercury, based on 

TRI data. From a high of 13,576 lbs in 1998, the release of atmospheric mercury has been 

reduced to 4488 lbs in 2003, and represents a 2/3 reduction, primarily from the Queenstake 

Jerritt Canyon Mine during this time period. Application of a hypochlorite technology at the 

Jerritt Canyon mine deserves special note, in that it resulted in a >90% reduction in mercury 

released to the atmosphere from the roasters. 

2. The data released to the Voluntary Mercury Reduction Program for atmospheric 

release are not completely consistent with the TRI data. While the inconsistencies are 

apparently based on different modeling efforts to predict total emissions, the data need to be 

the best estimates and should be consistent in the various reports, or a clear explanation 

should be provided as a variance report. 

3. Because of the complexity of the mercury emission sources, a systematic 

evaluation of the methods used to determine mercury emissions rates and concentrations 

should be undertaken. EPA commonly has detailed protocols for measurement of 

contaminants in a variety of industries, and mercury release from mining is sufficiently 

different that a thorough study should be made of how mercury release is measured at these 

sites, and development of common methods for use at these sites. As noted above, the 

methods used for measurement of mercury in the coal power industry are probably applicable. 

4. At present, it is very difficult to estimate how much mercury is volatilizing from 

mine disturbed areas, particularly waste rock surfaces, compared to the naturally elevated 

background in Nevada. Further study is required to determine if mercury emissions from 

these disturbed areas are significant relative to natural sources. 

5. Each mine needs to establish a mercury management program that includes a 

comprehensive mass balance understanding of the fate of mercury that is removed from the 

original ore. This includes a determination of mercury in the various process fluids (before 

and after gold recovery), and in the ore that is subject to any heat treatment (before and after 

the treatment). This is in addition to the mercury emission monitoring, since the mass balance 

should be complete- any mercury that is not accounted perhaps should be considered released 

into the atmosphere. This mercury management program should be developed cooperatively 
33

with both the state and federal regulators and be required prior to a regulatory decision to 

open a mine. 

6. Byproduct mercury production rates should be reported on a yearly basis to the 

Nevada Division of Minerals (or the USGS) and be made available to the public. These data 

are important not only to Nevada, but on a national basis to have a better understanding of 

mercury pathways in commerce, and total mercury accounting from the national inventory. 

7. Byproduct mercury appears to be managed well by the participating members of 

the voluntary mercury reduction program. Since a demand for mercury presently exists, and a 

good method for transfer of that mercury to mercury recyclers exists, there is no present need 

to further regulate byproduct mercury, other than a comprehensive mercury byproduct 

reporting requirement. 

8. Either or both the U.S. EPA and the Nevada should regulate mercury atmospheric 

emissions with the expectation that further atmospheric release reductions can be realized. 

While the present VMRP has resulted in a substantial reduction in mercury emissions, the 

lack of consistent reporting of mercury emissions, the lack of a required plan for mercury 

management at gold mines and the severe problems with mercury in biological systems all 

provide compelling reasons for the agencies to move forward in a cooperative manner to 

reduce mercury emissions from all present and future gold mines. Nevada apparently has the 

authority to independently regulate mercury emissions as a toxic chemical using its authority 

as designated state under the Clean Air Act. 

9. A workshop on atmospheric emissions from gold mining should be held for the 

mining industry, involved analytical laboratories, regulators and other interested persons, to 

discuss methods for reduction of atmospheric mercury emissions and overall management of 

mercury in gold mines. These discussions should focus on mercury management at mines, 

analytical methods for measurement of mercury and development of procedures and protocols 

for reduction of mercury releases to the atmosphere. 

Acknowledgements 

 We wish to thank the U.S. EPA Region IX for support of this study, and 

representatives of the State of Nevada NDEP (particularly Jolaine Johnson) and 
34

representatives of the VMRP companies for providing valuable contributions and comments 

on this report. 
35

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37

Reese, Robert G. Jr. “Mercury.” Minerals Yearbook, 1999. USGS 

(http://minerals.usgs.gov/minerals/pubs/commodity/mercury/430499.pdf) 

Reese, Robert G. Jr. “Mercury.” Minerals Yearbook, 2000. USGS 

(http://minerals.usgs.gov/minerals/pubs/commodity/mercury/430400.pdf) 

Reese, Robert G. Jr. “Mercury.” Minerals Yearbook, 2001. USGS 

(http://minerals.usgs.gov/minerals/pubs/commodity/mercury/hgmyb2001.pdf) 

State of Nevada. Department of Conservation and Natural Resources, Division of 

Environmental Protection. A Guide to the Toxic Release Inventory for Nevada.

Nevada, 2000. 

State of Nevada. Division of Environmental Protection. State of Nevada Mining Operations: 

Voluntary Mercury Air Emissions Reduction Program. Program Summary. 2002. 

Sznopek, John L. and Goonan, Thomas G. “The Materials Flow of Mercury in the Economies 

of the United States and the World.” U.S. Geological Survey Circular 1197, 1999. 

(http://pubs.usgs.gov/circ/2000/c1197/c1197.pdf) 

UNEP. “Global Mercury Assessment report” (2003) 

http://www.chem.unep.ch/mercury/Report/Final 

United States. Environmental Protection Agency. Mercury Study Report to Congress: 

Whitepaper. 22 May 2003. (http://www.epa.gov/air/merwhite.html). 

United States. Environmental Protection Agency. Mercury White Paper. 19 August 2003. 

(http://www.epa.gov/air/whtpaper.pdf). 

United States. Environmental Protection Agency. “Nevada Mining Partnership Program”. 

Region 9: Cross-Program Activities. David Jones, Adam Browning. 28 Oct. 2003. 

(http://www.epa.gov/region9/cross_pr/innovations/mining.html) 

United States. Environmental Protection Agency, Office of Air Quality Planning and 

Standards, and Office of Research and Development. Mercury Study Report to 

Congress. Volume I: Executive Summary. SAB Review Draft. June 1996. 

United States. Environmental Protection Agency. Office of Research and Development. 

“Assessing and Managing Mercury from Historic and Current Mining Activities.” 

Draft. 5 July 2002. 

United States. Environmental Protection Agency. Toxic Chemical Release Inventory 

Reporting Forms and Instructions. Revised 2002 Version. 
38

 “Toxics Release Inventory (TRI) Program.” 18 March 2003. (www.epa.gov/tri/report/trime) 

United States. Environmental Protection Agency. March (2005) “Clean Air Mercury Rule: 

Basic Information: http://www.epa.gov/air/mercuryrule/basic.htm 

Upton, Bill. Letter to the Nevada Division of Environmental Protection. 16 Jan. 2003. 

van Zyl, D.J.A. and G. M. Eurick, “The Management of Mercury in the Modern Gold Mining 

Industry” EPA Conference Proceedings on Mercury in the Environment, 2001. 
39

 Appendix 1, Mercury Supply and Demand in the U.S. 

Secondary Production/Recovery 

Chlor-Alkali plants are part of a growing source for secondary production/recovery of 

mercury for U.S. commercial products. In 2002, 15 of the 24 chlor-alkali plants in the U.S. 

closed their doors. It was estimated in 1996 that an estimated 3,000 tons of recoverable 

mercury exist in all 24 U.S. sites (Sznopek, et all, 2000). The un-used mercury cells from 

these plant closures have re-entered the consumer market. Deep discounts are typically given 

for the sale of scrap mercury. Here again, as in the purchasing of by-product mercury from 

mining operations, refineries buy mercury cells used in the plants and retorts them to produce 

pure elemental mercury. The refinery then sells this mercury back to the market, creating a 

source of revenue for their company. The chlor-alkali plants have then removed the liability 

of mercury, and in the process have gained a percentage share of capital in return. Phase out 

periods for the remainder of the plants are expected to extend thirty years (Sznopek and 

Goonan, 2000). Given this time frame and the estimated total of 3,000 tons recoverable, 

chlor-alkali plant are in a position of supplying the U.S. market with 100 tons of mercury per 

year for 30 years. 

United States Government Stockpile 

The U.S. Government stockpile is the final source for supply of mercury to the United 

States market. The US Department of Defense and the US Department of Energy owns, as of 

September 2002, a 4,435 ton stockpile of mercury (Brooks, 2003)This stockpile threatens the 

price of mercury, both in the US and abroad. If this stockpile is slated for release, then unit 

supply will magnify while the unit price will decrease. The government sold off quantities of 

the stockpile through 1994, however, due to environmental concerns, sales has since been 

suspended (Brooks, 2002). 

 U.S. and World Sources of Elemental Mercury 

The EPA Report to Congress states that US mercury demand of manufacturers in a 

myriad of product applications can be attained from five main sources: 

(1) Primary production 

(2) By-product production recoverable for sale 

(3) Secondary production/recovery 

(4) Government stock 
40

(5) Imports 

Primary Production 

 Primary production of mercury comes from mercury mines. The last primary 

mercury mine in the U.S. was the McDermitt mine in Northern Nevada. The mine shut down 

in 1990, after providing 448 metric tons of mercury in that year. U.S. primary mercury 

production peaked in the late 1970’s, producing 2,500 metric tons per year (Jasinski, 1994). 

Primary production mercury mines are still in operation in other countries, including 

Spain, China, Kyrgyzstan, Russia, Ukrane, Slovenia, and Algeria (Brooks, 2002). World 

production of primary mercury for 2002 was reported to be 1,400 metric tons (Brooks, 2003). 

Between 1990 to 2000, the average world primary production of mercury was 2,000 metric 

tons annually (Reese, 2001). World reserves are reported to total roughly 600,000 metric 

tons, primarily located in Kyrgyzstan, Russia, Slovenia, Spain and the Ukraine (Brooks, 

2003). 

Decreases in world demand for mercury, in large part due to environmental and health 

concerns, has been reflected in decreased production of primary mercury over the past two 

decades. Table A-1 are the production rates of the three largest producers of primary mercury 

by country, the world production yearly totals, and U.S. primary production totals pre 1991. 

Table A-1 

U.S. and World Primary Production (metric tons/year) 

 1979 1990 1998 1999 2000 2001 2002

Algeria 224 240 216 320 800 

Kyrgyzstan 250 300 275 300 250 

Spain 675 433 500 500 300 

World Total 1,580 1,310 1,350 1,490 1,800

United States 2,500 448 N/A N/A N/A N/A N/A 

 * Source: Brooks, 2002 

E. Supply and Demand 

Many legislative events have occurred over the years regarding public health impacts 

of mercury, however, the single most significant event affecting mercury production and price 
41

has been the 1971 U.S. EPA declaration that established mercury as a hazardous air pollutant. 

In recent years, Federal and State governments have implemented regulations that decrease 

the use of mercury in common household and commercial products. These efforts have been 

driven by the need to prevent mercury from entering our common waste streams. Several 

states have passed legislation which aim at the reduction of mercury in waste. Such 

legislation strives to ban the sale of certain mercury-laden products and implement collection 

and recycling programs for these products. In addition to governmental regulations, a number 

of industry and non-governmental organizations have been making impressive steps to reduce 

their use of mercury in the market products. 

According to Reese, the USGS reported the total 1998 U.S. demand for mercury was 

200 tons. Consumption of mercury in 1990 was 720 tons. Consumption in 1980 was 2,042 

tons. Market demand reveals a 90% reduction in mercury use in a twenty year period. 2001 

demand totals for mercury are estimated at 200 tons, “estimated at 30% - 50% for chlorine 

manufacture, 30% - 50% for electronics, and the balance for other uses such as dental 

applications, lamps, switches, and thermostats” (Brooks, 2002). Historically, the highest 

domestic annual use of mercury has been in electrolytic production of chlorine and caustic 

soda, which has since dropped to second highest or 30% of domestic consumption (Reese, 

2001). The highest use is reported to be in electrical consumption, 40% of domestic 

consumption for products such as oscillators, relays, tilt-switches, batteries, and fluorescent 

lamps (Reese, 2001). The remainder of consumption was used in various application products 

such as dental amalgams and control instruments (Brooks, 2003). Much progress has been 

made to reduce the use of mercury in common consumer products. Decrease in demand for 

mercury can be attributed to federal restrictions on additives in paint and pesticides, voluntary 

reductions in industries, state regulations on mercury in products, and recycling programs 

(EPA, Mercury White Paper). Alternative materials and recycling efforts on manufacturer’s 

behalf have been the driving force behind the decrease in demand. Domestic consumption of 

mercury will continue to decline as mercury is eliminated from products or as substitutes for 

mercury are made available. 

Major contributors to this effort have come from all types of manufacturing companies 

and industries. In 2001 Ford announced that it had totally eliminated all mercury-containing 

switches in their new vehicle lines. GM projects that by 2004, all mercury lighting switches 
42

in their vehicles will be replaced with non-mercury alternatives. The Mercury-Containing and 

Rechargeable Battery Management Act of 1996 severely limited the sale of most mercurycontaining batteries in the US. In anticipated response, battery manufacturers have reduced 

their use of mercury by over 98% since 1980. Battery manufacturers are turning to the use of 

nickel-cadmium, lithium, and zinc-air batteries as a substitution (Brooks, 2003). Since 1985, 

mercury in a typical four-foot mercury laden fluorescent bulb has been reduced by 75%. 

Health Care Without Harm, is currently in the process of a campaign to end the sale of 

mercury thermometers at major pharmacy chains in the U.S. To date, several of the largest 

chains have already agreed to remove the product from their stores, including Walgreen, WalMart, Rite-Aid and Albertson’s. Many industries are finding substitutes for the use of 

mercury as well. For instance, chlorine and caustic soda electrolytic production is replacing 

mercury cells for diaphragm and membrane cells (Brooks, 2003). Dental amalgams are being 

replaced with ceramic composites and mercury thermometers are being substituted for 

digitized instruments (Brooks, 2003). 

Table A-2 shows the U.S. supply data from years 1993 – 2001. Annual supply totals 

is a combination of world imports for consumption, industrial secondary recovery production, 

and up until 1994, shipments from the National Defense Stockpile (Reese, 1997). Brooks 

reports that on average, the U.S. was supplied with 30% of its imports from the United 

Kingdom, 15% from Chile, 13% from Kazakhstan, 13% from Germany, and the remaining 

29% from other countries. 

Table A-2 

U.S. Mercury Supply (metric tons/year) 

* Source: Reese, Mineral Commodity Summary, 1998 – 2001 

* Source: Reese, Mineral Yearbook, 1997 – 2001 

* Source: Brooks, 2002 

* Source: Plachy, 1997 

1993 1994 1995 1996 1997 1998 1999 2000 2001 2002

Imports for 

Consumption

40 129 377 345 164 128 62 103 100 209 

Secondary Production: 

Industrial Recovery

350 466 534 446 389 N/A N/A N/A N/A N/A 

National Defense 

Stockpile

543 86 -- -- -- -- -- -- -- -- 

Mercury By-Product 

from Gold Mining

N/A N/A N/A 65 N/A N/A 18.9 53.6 36.1 N/A 

Total Supply 933 681 911 856 553 N/A N/A N/A N/A N/A 

Reported Demand 558 483 436 372 346 N/A N/A N/A N/A N/A 
43

* Source: Given by-product totals by Barrick, Cortez, Jerritt and Newmont 

Figure A-1 below graphically depicts the decreasing U.S. supply and demand of 

mercury in the United States from 1965 – 2001. Total supply data from 1998 to present 

could not be found. Therefore, in the figure below, the graphical depiction stops in 1997. It 

is determined that the secondary supply production from industrial recovery is a large enough 

number to warrant an incomplete total supply from years 1998 to present. Demand totals 

from 1998 were also difficult to determine, however it was noted that estimated demand for 

2001 in the U.S. was 200 metric tons (Brooks, 2002). 

Figure A-1 

U.S. Mercury: Supply and Demand

0

500

1000

1500

2000

2500

3000

1965 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 2001

Quantity (metric tons)

Demand

Total US Supply

* Source: U.S. EPA 1997 Report to Congress 

* Source: Reese, 1997 – 2001 

* Source: Brooks, 2002 

The price of mercury has been very volatile during the 20th century. There were 

significant price increases in the high demand periods of World Wars I and II, mostly for 

munitions production. The price peaked again in 1965, at $575 per flask, and has been in a 

steady decline since then. The 2002 price was $140 per flask (Brooks, 2003), and represents a 

90% drop in price in 35 years, although the price has clearly increased in the last two years. 

This continual decline in price is almost certainly associated with the health and 

environmental concerns surrounding mercury. Ongoing environmental concerns have 

resulted in numerous regulatory restrictions and/or elimination of mercury in various 

commodity applications altogether. 

Figure A-2 below, represents the typical supply chain where new elemental mercury 

will go in a product life cycle. Emissions and releases are not shown in the diagram, 
44

however, typical release and emission points occur throughout the supply chain functions. 

Economic and environmental liabilities of mercury are released from a company, once a 

transfer of ownership of mercury has occurred. This transfer might come in the form of the 

sale of the mercury or by giving it away to a customer. It is unclear as to how many more 

years a mining company producing by-product mercury will be able to sell the metal and 

thereby release the liability. In time, continued mercury production will increase the potential 

liabilities for a mining company should demand fall. 

Figure A-2 

Mercury-laden Product Supply Chain 

The concentration of mercury in ore varies substantially between ore bodies, and even 

within an ore body. Estimating of the concentration of mercury in ore and waste rock is based 

on rock sampling, and is generally highly variable. Concentrations of gold, as well as other 

elements contained within the ore and waste rock are determined on representative samples, 

and estimates provided for the TRI reports. 

By-Product 

Production 

Secondary

/Recovery

Mercury

Refinery

Manufacturer 

Consumer

Primary Production, 

Imports

and Government

Stockpiles

Waste 

Dump 

Intermediary 

Recycling 

Efforts