### 1 Date: June 2 8 , 2010 Subject: Minutes of the June 23 , 20 10 Conference Call with representatives from Alaska Tribes EPA Contract No. EP
- D
- 06
- 118; EPA Work Assignment No. 4
- 06 RTI Project No. 0210426.004.006 From: Chuck French OAQPS/SPPD/MMG (D243
- 02) U.S . Environmental Protection Agency Research Triangle Park, NC 27711 To: Docket ID No. EPA
- HQ
- OAR
- 2010
- 0239 I . Introduction A conference call with representatives from Alaskan Tribes was held o n June 23 , 20 10 . The purpose of the meeting was for EPA to in troduce the proposed National Emission Standards for Hazardous Air Pollutants: Gold Mine Ore Processing and Production Area Source Category and Addition to Source Category List for Standards to the Alaskan Trives . This memorandum summarizes the major top ics discussed during the meeting . II . Attendees Representatives from Alaskan Tribes Chuck French, U.S. EPA, OAQPS Tami Fordham, U.S. EPA, Region 10 Mahri Lowinger, U.S. EPA, Region 10 Marvin Branscome, RTI International Gabrielle Raymond, RTI International III . Discussion The EPA presented their webinar from May 2 5 , 2010 that covers an overview of the background information and the proposed gold mine ore processing and production rule. The EPA answered general questions about the proposed rule. Attachment 1 contains the fact s heet f or the proposed rule. Attachment 2 contains the presentation from the May 25, 2010 webinar.Attachment 1PROPOSED RULE TO REDUCE MERCURY EMISSIONS FROM GOLD ORE PROCESSING AND PRODUCTION SOURCES FACT SHEET ACTION
**•** On April 1 5, 2010 the U.S. Environmental Protection Agency (EPA) proposed National Emissions Standards for Hazardous Air Pollutants for gold ore processing and production facilities, the sixth largest source of mercury air emission in the United States.
**•** The propos ed standards would cut mercury emissions from this industry by more than 70 percent from 2007 levels.
**•** Gold ore processing and production facilities extract gold from mined ore. About 20 gold ore processing facilities in the United States will be subject to the proposed rule.
**•** Some facilities in Nevada already, including some of the nation’s largest gold ore processing facilities, are making significant progress toward the proposed reductions under the Nevada Mercury Air Emissions Control Program, which r equires controls at precious metal mining facilities.
**•** At full implementation, the proposed rule is estimated to reduce mercury emissions to 0.7 tons per year (1,390 pounds), a 73 percent reduction from 2007 levels.
**•** EPA estimates capital costs of this p roposed rule at $6.2 million, with annual costs of $3.8 million a year.
**•** Mercury is the only air toxic that would be regulated under this proposed rule. Gold processing and production facilities have not been identified as major sources of hazardous air p ollutants, also known as air toxics. A “major source” emits 10 or more tons a year of a single air toxic, or 25 or more tons a year of a combination of toxics.
**•** However, because gold ore processing and production is a significant source of mercury emissio ns, it falls under a section of the Clean Air Act that requires EPA to establish standards known as maximum achievable control technology (MACT) for sources of seven air toxics known as persistent, bioaccumulative pollutants, including mercury.

**•** Mercury in the air eventually deposits into water, where it transforms into methylmercury, a highly toxic form that builds up in fish. Americans are primarily exposed to mercury by eating contaminated fish.

**•** Because methylmercury can damage children’s developing brains and nervous systems, even before they are born, women of childbearing age and children are the population of greatest concern.**•** EPA will accept comments on this proposed rule for 30 days following publication of the proposed rule in the Federal Re gister. The Agency will hold a public hearing if requested; requests for a hearing must be made within 10 days after the rule is published. (If a hearing is requested, the comment period will be extended by 15 days.) WHAT THE PROPOSED RULE WOULD REQUIRE
**•** The proposed rule would establish mercury emissions limits for three types of processes found at gold production facilities: ore
- pretreatment processes (primarily heating processes used to prepare ore for gold extraction); and two other processes known as carbon and non
- carbon concentrate processes (both separate gold from ore). The proposed emissions limits are based on the existing emissions level of the best
- performing U.S. facilities, which are well controlled for mercury.
**•** The proposed mercury limi ts are as follows: Proposed Emissions Limit Pre
- treatment processes (in pounds per million tons of ore) Carbon processes (in pounds per ton of concentrate) Non
- carbon concentrate processes (in pounds per ton of concentrate) Existing sources 149 l b 2.6 lb 0.25 lb New sources 149 lb 0.14 lb 0.20 lb

**•** For new carbon processes, we are proposing a compliance alternative of 97 percent control efficiency.
**•** At full implementation, these limits are estimated to reduce mercury emissions to 0.7 ton s per year, a 73 percent reduction from 2007 levels.

**•** Today’s action also proposes several requirements for monitoring. These include requiring each facility to conduct annual mercury emissions tests at all emissions stacks. In addition, EPA is seeking c omment on two options for continuous or frequent (weekly) testing at facilities using roasters to pretreat ore. BACKGROUND
**•** The Clean Air Act requires EPA to identify and, develop regulations for, the sources of 90 percent of the air emissions of seven pollutants known as persistent, bioaccumulative pollutants. The seven pollutants are: mercury, alkylated lead compounds, polycyclic organic matter (POM), hexachlorobenzene, polychlorinatedbiphenyls (PCBs), 2,3,7,8
- tetrachlorodibenzofurans (TCDF) and 2,3,7, 8
- tetrachlorodibenzo
- p - dioxin (TCDD).

**•** EPA identified gold processing and production as one of these sources in 2008.**•** The State of Nevada and the gold processing and production industry have made significant progress in reducing mercury emissions in th at state, under a combination of voluntary and regulatory programs. Fifteen of the gold ore production and processing facilities in the U.S. are located in Nevada. Emissions have been reduced from about 11.5 tons in 1999 down to about 2.5 tons in 2007. Tod ay’s proposed rule would further reduce emissions from those facilities, in addition to limiting emissions from gold ore processing and production facilities in other states. HOW TO COMMENT
**•** EPA will accept comment on the proposal for 30 days after pub lication in the Federal Register. Comments, identified by Docket ID No. EPA
- HQ
- OAR
- 2010
- 0239, may be submitted by one of the following methods: o www.regulations.gov: Follow the on
- line instructions for submitting comments. o E
- mail: Comments may be sent by electronic mail (e
- mail) to a
- and
- r Docket@epa.gov. o Fax: Fax your comments to: 202
- 566
- 1741. o Mail: Send your comments to: Air and Radiation Docket and Information Center, Environmental Protection Agency, Mail Code: 2822T, 1200 Pennsylvania Ave., NW, Was hington, DC, 20460. o Hand Delivery or Courier: Deliver your comments to: EPA Docket Center, Room 3334, 1301 Constitution Ave., NW, Washington, DC, 20460. Such deliveries are only accepted during the Docket’s normal hours of operation, and special arrangeme nts should be made for deliveries of boxed information. FOR MORE INFORMATION
**•** To download a copy the proposed rule, go to EPA's Web site at http://www.epa.gov/ttn/oarpg/new.html **•** For more information about the proposed rule for gold ore processing, cont act Chuck French of EPA’s Office of Air Quality Planning and Standards at (919) 541
- 7912 or french.chuck@epa.gov.

### Attachment 2

# Summary of the Proposed National Emissions Standard for Gold Mine Ore Processing and Production Webinar May 25, 2010 Presentation by Chuck French, U.S. EPA Metals and Minerals Group Office of Air Quality and Planning and Standards Email: french.chuck@epa.gov Phone: 919 - 541 - 7912


# Outline

 

### Background  

### Summary of the proposed regulation for mercury emissions  

### Discussion of Non - mercury HAPs  

### Schedule/next steps  

### Questions?

2

# Background

 23 facilities in U.S. (15 in Nevada and 8 in other Western States)  Gold Mines were identified in the 1999 National Emissions Inventory as a source of mercury emissions (estimated 11.5 tons per year)

 Most emissions were from facilities located in Nevada  Initial Nevada Voluntary Program (2001
- 04) achieved some reductions
 Targeted 5 large facilities  In 2006 Nevada DEP established a mandatory Mercury Control Program to achieve further reductions:

 covers all gold and silver production operations in Nevada  requires best available control technology at facilities in Nevada  In 2007, Gold Mines emitted an estimated 2.5 tons of mercury nationwide  In 2008, EPA determined that mercury emissions from Gold Mines should be regulated under the National MACT program

 Pursuant to Section 112(c)(6) of the Clean Air Act 3 

### Summary of Gold Mine Production Processes in U.S.A.

 

### All facilities:
 mine, crush ores.....  conduct various other processes, depending on ore type, etc.  

### 5 facilities use high temperature ore pre - treatment (roasters or autoclaves) before cyanide leaching.  

### About 18 facilities process ores without pre - treatment (no roaster or autoclave), but have other thermal processes:

 About 14 facilities add carbon to leaching, therefore have carbon kilns

and 2 - 4 other processes (e.g., electrowinning, retorts, furnaces).
 About 4 facilities use no carbon (therefore no kiln), but have other

processes (e.g., furnaces, retorts). 4CARBON ADSORPTION & DESORPTION CARBON REGENERATION KILN

PREGNANT

TANK BARREN TANK EW CELL ELECTROWINNING

FURNACE RETORT RETORTING & SMELTING CARBON ORE MINING GOLD LEACHING 

### Overview of Gold Mine Production Processes

ROASTERS & AUTOCLAVES

FURNACE RETORT RETORTING & SMELTING MERRILL-CROWE Hg Hg Hg Hg Hg Hg Hg Hg

Hg

Hg

5 

## Gold Mine Ore Processing - Mercury Emissions in 2007 by Process Type

Roasters (1.15 tons, 48%)

Autoclaves (0.41 tons, 17%) Melt Furnaces (0.36 tons, 15%) Carbon Kilns (0.27 tons, 11%)

Preg Tanks (0.1 ton, 4%) Electrowinning (0.1 ton, 4%) Retorts (0.01 ton, 1%)

Total = about 2.5 tons 6

# Summary of Mercury Controls for Gold Production Facilities

 

### A number of facilities already have effective mercury controls on many units.  

### Facilities apply various control technologies and pollution prevention measures to limit mercury emissions, including:

 

### gas condensers  

### carbon adsorption units  

### wet scrubbers  

### fabric filters  

### mercurous chloride scrubbers (calomel scrubbers)  

### wet venturi scrubbers  

### chemical additives to improve mercury capture. 7 

# Summary of the Proposed National Emissions Standard

 Coordinated with Nevada DEP and other stakeholders in development of the proposal

 We believe the proposed requirements are compatible with the Nevada Mercury Control Program  Emissions limits are proposed for mercury, based on Maximum Achievable Control Technology (MACT), for the 3 types of affected processes:

8 Ore - pretreatment Processes Carbon Processes Non - carbon Processes Existing sources 149 lb/million tons of ore 2.6 lb/ton of concentrate 0.25 lb/ton of concentrate New Sources 149 lb/million tons of ore 0.14 lb/ton of concentrate or 97% reduction 0.20 lb/ton of concentrateCARBON ADSORPTION & DESORPTION CARBON REGENERATION KILN

PREGNANT

TANK BARREN TANK EW CELL ELECTROWINNING

FURNACE RETORT RETORTING & SMELTING CARBON ORE MINING GOLD LEACHING 

### Gold Ore Processing – 3 Process Groups - Proposed Approach for MACT limits

ROASTERS & AUTOCLAVES

FURNACE RETORT RETORTING & SMELTING MERRILL-CROWE Hg Hg Hg Hg Hg Hg Hg Hg

Hg

Hg Ore pre - treatment group Non - carbon group Carbon group 9 

## Proposed Compliance Testing and Monitoring Requirements

 For all thermal units, annual stack tests for mercury (using method 29, 30A, 30B, or the Ontario Hydro method).  For carbon beds, facilities need to monitor temperatures and do one of the following to prevent breakthrough:

 weekly test with method 30B, and as mercury concentrations approach an “operating limit” established during the performance test, facility must change carbon;  periodic sampling of carbon bed at specified depths, and when carbon reaches 90% capacity, carbon must be changed; or  replace carbon at specified frequency based on knowledge of bed life demonstrated by one of the above methods.  Wet Scrubbers:  Monitor water flow rate and pressure drop. 10

# Proposed Monitoring Requirements for Roasters

 Continuous emissions monitoring for mercury using either:  Hg CEMS (daily average), or
 Method 30B (sorbent trap) with weekly sampling and analysis  Concentrations would be compared to an “operating limit” established during the performance test to assure that controls are working, but not used to demonstrate compliance to the MACT emission limit.  Any deviation must be reported to permitting authority and corrective action taken.  We also propose that for roasters that are not monitored with a Hg CEMS that facilities must monitor various parameters of the calomel scrubbers including: scrubber liquid flow; pressure drop; inlet temperature; and chloride ion concentration or oxidation reduction potential and pH 11

Affected Processes Uncontrolled emissions

(lb/yr) 2007 emissions

(lb/yr) Reductions due to Federal MACT and Nevada Hg Program (lb/yr) % Reduction from 2007 emissions % Reduction from uncontrolled emissions Ore Pre treatment processes 18,976 3,383 2,150 64% 94% Carbon processes 14,465 1,537 1,397 91% 99% Non - carbon processes 768 139 125 90% 98% Total 34,209 5,059 3,672 73% 96% 

## Estimated Mercury Emissions Reductions

Estimates of Costs and Cost Effectiveness Case Capital cost Total annualized cost MACT emission reduction (lb/yr) Average cost effectiveness Hg controls only $4.8 million $2.3 million/year 1,650 $1,400/lb Hg With monitoring $6.0 million $3.4 million/year 1,650 $2,100/lb Hg 12

# Non - Mercury HAP

 In 2009, we requested that industry conduct emissions tests for non - mercury HAPs, including cyanide and non - mercury metals

 Cyanide is mainly emitted from large non - point sources (e.g., leach pads, tailings ponds), and non
- mercury metals are mainly emitted from stacks  Testing was completed, and all data submitted to EPA in early 2010  Results indicate there are no major sources
 The largest facility emits an estimated 5 to 9 tons of cyanide per year  All other HAPs are individually significantly lower than the 10 tons per year (tpy) threshold for a single HAP and the 25 tpy threshold for a combination of HAP.  The proposed rule text has no requirements for non - mercury HAPs.
 However, the preamble discusses cyanide and requests comments on possible management practices or other approaches to limit cyanide emissions. 13 

# Seeking comments on several specific topics, including:

 Title V:  About 6 of the 15 facilities currently have Title V permits  We are soliciting comment on whether an exemption is appropriate for any particular sources in this category.  Hg CEMs:  Technology not yet demonstrated on these facilities.  We request comments on the viability of using mercury CEMs, specifically for monitoring mercury emissions from roasters.  Carbon vs concentrate metric for “Carbon Group”  The proposed emissions limits for this group are in units of pounds of mercury per ton of concentrate.  We seek comment on whether “loaded carbon” might be another option worth further consideration as the denominator (e.g., pounds of mercury per ton of loaded carbon)  Cyanide Emissions - Management Practices? 14

# Schedule

 

### April 15, 2010 – Proposed rule was signed by EPA Administrator  

### April 28, 2010 – Proposed rule published in Federal Register  

### May 20, 2010 – Published Notice of extension of comment period to 6/28/2010  

### June 28, 2010 – Public Comment period ends  

### December 16, 2010 – Final rule deadline (court
- ordered) 15