### 1 Date: August 10 , 2010 Subject: Minutes of the August 9 , 2010 Conference Call with Ne vada Division of Environmental Protection 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 Nevada Division of Environmental Protection (NDEP) was held o n August 9 , 20 10 . The purpose of t he meeting was to clarify a few of NDEP’s comments on the proposed rule and how data are handled in the Nevada Mercury Control Program (NMCP).

II

. Attendees Mike Elges, NDEP Rob Bamford, NDEP Chuck French, U.S. EPA, OAQPS
Marvin Branscome, RTI Internationa l Gabrielle Raymond, RTI International

III

. Discussion The major topics discussed during the meeting included h ow the hours of operation are reported in the NMCP Annual Emissions Report, how NDEP requires facilities to be measure ore “as fed” to the autoclave , e missions from the quenching units at Jerritt Canyon , new Twin Creeks autoclave data , Goldstrike preheater data , gold mine definition, carbon new source MACT limit , roaster parametric monitoring, and mercury concentration monitoring

. Attachment 1 conta ins the discussion items for the conference call with NDEP provided by the EPA.2 

### Attachment 1DRAFT

- Do Not Cite or Quote August 6, 2010

1 

### Discussion Items for Conference Call with NDEP on 8/9/2010

1

. How do you require facilities to determine operating hours for different types of process units for the Annual Emission Reports (AER)? We will need to specify this in the rule, and an important consideration is that what we require is the same as or similar to how the data were collected that we used to derive the emission limits, which we think is cons istent with NDEP’s AER.
2

. How do you require facilities to measure and report throughput of ore for the autoclaves? Industry recommended that the weight or the density and volumetric flow rate of the ore slurry be allowed to be measured as it is fed or as i t exits the autoclave(s). They explained that this change would allow the m the flexibility to monitor the density and volumetric flow rate of the ore slurry either before or after the autoclave, which they say is the same mass flow for all practical purpo ses
. We proposed measuring the feed to the autoclave. If the two are different, we hypothesize that what comes out would be slightly less than what is fed, which would be a more stringent compliance determination (i.e., the denominator would be lower). Is this correct? Anyway, if we allowed industry to use ore exiting the autoclave because that is what they measure, is there any problem with this?
3

. For Jerritt Canyon Mine (Queenstake) , wh at is the emission point(s) for emissions from the roaster quenchi ng exhaust (e.g., the roaster control s ystem , a separate stack , and un

- testable release point) ? Let’s discuss how the quencher is configured and how the rule might address any unusual characteristics at Jerritt Canyon. The industry commented that Jerrit Canyon’s quenching emissions must be accounted for and included in the MACT analysis, and they suggested that we use an average of Goldstrike and Gold Quarry’s quenching data based on percent of total emissions from quenching to represent the quenching em issions for Jerritt. Another approach might be to use the lb/MM tons of ore contribution from quenching at the other facilities with quenching emissions data. Any other ideas?
4

. Do you know why the new data for Twin Creek’s autoclaves shows lower emission s than the data we used at proposal (about 50% lower in lb/MM tons ore)? Were there changes in operation or controls that would justify using only the new data and not the higher 2007/2008 data? Or are all the measurements representative of normal variab ility?DRAFT

- Do Not Cite or Quote August 6, 2010

2 Autoclave Date Test Method Avg Hg Emissions

(lbs/hr) Ore Throughput (tph) Avg Hg Conc. (gr/dscf) lb Hg/MM ton ore Hg Conc in Ore (ppm) 1 6/14/2007 101A 4.34E

- 02 220.7 8.37E

- 04 197 40.8 1 6/14/2007 OHM 5.26E

- 02 227.3 9.68E

- 04 231 40.8 1 6/15/2007 101A 6.62E

- 02 246 1.15E

- 03 269 27 1 6/15/2007 OHM 6.55E

- 02 245 1.02E

- 03 267 27 1 8/18/2008 29 8.47E

- 02 242 1.72E

- 03 350 29.7 2 6/17/2007 101A 3.30E

- 02 232 6.06E

- 04 142 28.8 2 6/17/2007 OHM 2.54E

- 02 235.3 4.23E

- 04 108 28.8 2 8/21/2008 29 3.30E

- 02 239.3 6.73E

- 04 138 44.33 1 11/3/2009 3.42E

- 02 247.9 5.73E

- 04 138 34.7 2 11/5/2009 1.29E

- 02 236.5 2.44E

- 04 55 40.4 2 3/9/2010 2.16E

- 02 * 245 4.00E

- 04 88 20.5 1 5/3/2010 4.36E

- 03 * 234 7.76E

- 05 19 28.5



### * Estimate based on gr/dscf (we need to get lb/hr data).
5

. Do you know why there is so much variability in between the runs for the following tests at Goldstrike? See the high relative standard deviations (RSDs). Are there reasons not to use the data?

Unit Test Date Run 1 (lb/hr) Run 2 (lb/hr) Run 3 (lb/hr) Average (lb/hr) Standard deviation RSD

North

- Mill 1 7/9/2009 4.30E

- 04 6.70E

- 04 4.80E

- 04 5.27E

- 04 1.27E

- 04 0.24 North

- Mill 1 8/3/2007 4.00E

- 01 4.00E

- 02 2.10E

- 02 1.54E

- 01 2.14E

- 01 1.39 North

- Mill 1 3/14/2007 1.30E

- 03 9.00E

- 04 7.80E

- 04 9.93E

- 04 2.72E

- 04 0.27 North

- Mill 1 10/22/2007 2.70E

- 03 2.10E

- 03 4.00E

- 04 1.73E

- 03 1.19E

- 03 0.69 North

- Mill 1 10/22/2007 3.30E

- 03 1.70E

- 03 4.00E

- 04 1.80E

- 03 1.45E

- 03 0.81 South

- Mill 2 7/14/2009 1.14E

- 02 6.19E

- 03 2.25E

- 03 6.62E

- 03 4.59E

- 03 0.69 South

- Mill 2 8/4/2007 1.10E

- 02 8.00E

- 03 1.10E

- 02 1.00E

- 02 1.73E

- 03 0.1 7 South

- Mill 2 3/12/2007 3.60E

- 02 7.70E

- 03 1.20E

- 03 1.50E

- 02 1.85E

- 02 1.23 South

- Mill 2 10/22/2007 1.30E

- 03 1.30E

- 03 6.00E

- 04 1.07E

- 03 4.04E

- 04 0.38 South

- Mill 2 10/23/2007 2.50E

- 03 1.30E

- 03 6.00E

- 04 1.47E

- 03 9.61E

- 04 0.65DRAFT

- Do Not Cite or Quote August 6, 2010

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### 6

. We received several comments that the rule as proposed would apply to many people and operations for which it was not intended, such as individuals (prospectors), laboratories, pilot plants, small mining operations, and non

- leaching operations. Apparen tly the proposed rule would capture those entities that have any type or size of melt furnace, whether used by an individual or by a lab for assays. Do you have any suggestions how we could clearly exclude those not intended to be covered by the rule, pot entially, and as appropriate?
7

. We continue to recognize that using Round Mountain as the basis for new source MACT for the carbon group is problematic. Industry suggested a separate subcategory for facilities without retorts or a subcategory for low mercur y in the ore. We anticipate potential problems with subcategorizing by mercury in the ore. Any thoughts on subcategorizing facilities without retorts or any other ideas?
8

. What should be the operating parameters to be monitored for roasters at Gold Quarry (and other roasters)? Newmont took great issue with monitoring pressure drop and inlet temperature, plus they do not like setting any operating limits based on monitoring during the compliance tests. We need something to ensure proper operation on a con tinuous basis. Has NDEP developed their final permit requirements for monitoring roasters?