### From: Mike Elges < melges@ndep.nv.gov > Date: Thu, Sep 23, 2010 at 4:40 PM Subject: To: "Chuck French ( french.chuck@gmail.com )" < french.chuck@gmail.com >
Cc: Rob Bamford < rbamford@ndep.nv.gov >

Chuck,

Please find attached the information that we discussed regarding the monthly emissions testing and process monitoring being conducted at the Jerritt Canyon roasters. As we described, NDEP believes that this data helps support how continuous monitoring of process and pollution control device parameters provides reliable information to ensure that Hg emissions from the roasters are being controlled appropriately. Further, the data supports that even when the system deviates from a discrete set point that the Hg controls have sufficient capability to compensate for variability. Therefore, it is not necessary to require immediate shutdown of the system. It is more appropriate to allow for system corrections to bring operations back into the established

parameters.

The NDEP continues to support the concept that the federal rule be structured such that continuous parametric monitoring of ro aster process and/or pollution control device parameters coupled with routine emissions testing of roasters is an appropriate methodology for ensuring compliance with the proposed Hg standard. We believe that semi

- annual emissions testing based

on Method 29 (or an alternative method approved by the Permitting Authority) for the first two years, coupled with continuous parametric monitoring will provide adequate information to ensure ongoing compliance. Assuming that the two years results of the Method 29 tests are relatively consistent, we believe that the testing frequency should be reduced to an annual

schedule.

The NDEP also believes that the proposed rule should be revised to rely upon Method 29 as the primary test method for measuring Hg emissions for demonstrating compliance with the proposed standard. We believe that this Method is best suited for the types of processes and gas streams found in this industry. Further, it is our understanding that the proposed standards have

been established base d solely on data measured by Method 29. To date, the NDEP is unaware of any analyses or demonstration that correlates the data collected through the other proposed test

methods. In particular, we are concerned that factors such as particulate, moisture a nd sample volume can have a significant negative effect on the results obtained from the different methods. For example, units throughout this industry differ in whether the gas streams contain particulate

bound mercury or not. Utilizing a test method th at does not appropriately account for the particulate

- bound portion of the sample will result in Hg emissions not being accurately

measured. Should information become available that demonstrates that alternative methods can provide consistent results with out significant variance between the methods, the NDEP would support their use. Therefore, we are recommending that the rule be revised to provide for the use of alternative methods by providing language that allows the Permitting Authority the ability to approve an alternative test method. We believe that this provides an appropriate mechanism to approve other test methods once they’ve been determined to provide comparable results.

### If you have any questions, or would like to discuss these items in more detail, please let me

know.

Thanks,

Mike Elges

See attached file: Jerritt Canyon Roasters v4.docPage 1 of 15 

### Jerritt Canyon Roasters’ Test Data A Review of Parametric Monitoring and Emissions

Nevada Division of Environmental Protection

Bureau of Air Pollution Co ntrol / Nevada Mercury Control Program

Introduction



### Prior to the review and subsequent development of robust continuous parametric monitoring the Jerritt Canyon roasters historically demonstrated poor mercury recovery and variable emissions of mercury

, SOx and PM. The October 2008 Consent Decree required a thorough engineering design review of the roasters’ emissions controls to define and “fine

- tune” the optimal operating parameters to minimize mercury emissions. The Consent Decree also required frequ ent stack testing to evaluate the various operational parameters’ set

- points, to define ranges for alarms and to define interlock trigger values. The process of determining the optimal operational parameters

is still a work in progress as an adequate data base must be established to represent the range of facility/roaster operations. The Consent Decree test events have demonstrated the efficacy of

conti n uous paramet ric monitoring with notable reductions in mercury emissions and less variability in measured emissions.

Jerritt Canyon has 2 fluidized bed roasters that oxidize run of mill ore prior to Carbon

- In

- L each (CIL) and/or Merrill

- Crowe (MC) zinc precipitation. The roasters emissions controls were constructed in the late 1980s

. They roasters are dupli cate systems, but operate autonomously. Each roaster has an emissions control system for the control of PM, SO 2 

### and Hg.

Hot, oxidized ore (calcine) exiting the roaster is quenched with process water into a slurry tank

to await CIL /MC

. The combustion e xhaust and quench steam is then routed to an entoleter to remove particulate from the gas stream. The entoleter utilizes high

- pressure water and a spinning “squirrel cage” to impact particulate with water droplets. After the entoleter, t he exhaust gas tr avels through four wet scrubbers with packed media (SO2, Hg#1, Hg#2 and tail)

. See Figure 1, below. The system was re

- configured in 2009 to add mercury scrubber #2, and to switch from NaOCl as a reagent in liquid form to chlorine gas as the reagent.Page 2 of 15 

### Fi gure 1. Jerritt Canyon Roaster Emissions Control Train Configuration



### The SO2 scrubber utilizes lime to scrub SOx. The mercury scrubber #1 utilizes chlorine gas to react with elemental mercury to form mercuric chloride. Mercury scrubber #2 reacts the mercuric chloride from Mercury Scrubber #1 with any remaining mercury in the exhaust gas stream to create mercurous chloride (calomel). The tail gas scrubber uses water to “polish” any remaining pollutants. Lime may be added to any of the four scrubbers to maintain desired process pH. The calomel is a precipitate which may be filtered and collected from the scrubbers’ liquor.

Prior to the Consent Decree of October 2009, the company had a history of inconsistent mercury

emissions and excess emissions eve nts which became an ongoing compliance issue. After several enforcement actions were taken by the NDEP, the NDEP began a detailed investigation into the operations of the roasters and emissions controls to determine what was needed to bring

the roasters b ack into compliance.

The investigation began with a review of the Title 5 permit, which required nominal work practices related to the performance of the mercury emissions control. The requirements contained in the Title 5 permit, were to monitor (7) p oints for a “specified operating range”; however, no ranges are actually specified, and monitoring was required to be performed only once per day. The requirements had no operating ranges, alarms or interlocks. The chemistry of

the desired reactions of t he mercury scrubber were also absent.

Table 1and Figure 2, below, display all available roaster testing data for the Jerritt Canyon
roasters. In Table 1, data is listed in des cending order, starting with the most recent tests. Tests shaded in green we re performed under the Consent Decree and expanded work practice

standards . Figure 2 displays the same data on a graph.Page 3 of 15 

### Table 1. All Available Roaster Mercury Emissions Test Data (Green

- shaded Fields are Consent Decree Tests).

Date Method West (#40) gr/dscf Hg Date Method East (#42) gr/dscf Hg

06/17/2010 Method 29 2.02E

- 05 06/15/2010 Method 29 2.77E

- 05

04/29/2010 Method 29 1.60E

- 05 04/27/2010 Method 29 1.67E

- 05

02/24/2010 Method 29 7.58E

- 05 03/29/2010 Method 29 3.29E

- 05

01/22/2010 Method 29 1.39E

- 04 02/22/2010 Method 29 9.45E

- 04 [3 ]

12/05/2009 Method 29 3.25E

- 04 [1] 01/20/2010 Method 29 1.79E

- 04

06/13/2008 Method 29 2.27E

- 04 12/03/2009 Method 29 1.70E

- 03 [2 ]

05/08/2008 Ontario Hydro 1.36E

- 03 06/12/2008 Method 29 6.55E

- 04

07/27/200 7 Ontario Hydro 4.70E

- 04 06/12/2008 Ontario Hydro 8.61E

- 04

07/25/2007 Method 29 4.93E

- 03 05/20/2008 Ontario Hydro 2.17E

- 02

10/25/2006 Ontario Hydro 1.80E

- 02 07/27/2007 Ontario Hydro 5.37E

- 04

12/02/2004 Method 29 2.65E

- 03 07/26/2007 Method 29 1.58 E

- 03

12/02/2004 Method 29 4.70E

- 03 10/27/2006 Ontario Hydro 2.96E

- 03

08/31/2004 Method 29 8.00E

- 04 12/01/2004 Method 29 3.00E

- 04

07/20/2004 Method 29 9.79E

- 02 11/30/2004 Method 29 2.00E

- 04

10/02/2002 Method 29 2.23E

- 03 08/31/2004 Method 29 3.00 E

- 03

10/02/2002 Method 29 2.10E

- 01 07/20/2004 Method 29 1.09E

- 01

05/12/2000 Method 29 2.57E

- 02 10/01/2002 Method 29 7.33E

- 04

04/14/2000 Method 29 2.75E

- 02 10/01/2002 Method 29 1.40E

- 01

04/13/2000 Method 29 8.80E

- 03

[1] The entoleter pres sure drop was also below the set point for all three runs during testing of the west roaster. Also during testing the SO 2 heat exchangers were bypassed.

[2] They state that the high emission rate from the east roaster is a result of combustion in the 2 nd stage bed level. Although Jerritt would normally shut down the roaster if combustion was detected in

the 2 nd stage, they choose not to shut down in order to continue with testing. Additionally, Jerritt states that increased SO 2 in the roasters can change t he effectiveness of the calomel system by consuming chlorine gas.

[3] While removing the test probe from the stack at the end of run #1 of the east roaster, the probe nozzle caught the edge o f the sample port and broke off. During sample train recovery no glass

shards were found in the filter. All three runs of the east roaster exceeded the emission limit set in the consent decree. T he average total gaseous mercury emitted by the east roaster was ten times greater than the average amount emitted from the west roaster. The east roaster also had a lower average flow rate, by around 2,000 dscfm, then the west roaster.The moisture content in the east roaster stack was greater than that of the west roaster. The average moisture content in the east roaster stack was 6.04%, while in the west roaster it was 3.54%.Page 4 of 15 

### Figure 2. Graph of All Available Mercury Emissions Test DataPage 5 of 15 

### To evaluate the existing state of operations the NDEP required a series of multiple, simultaneous, OHM tests at specific locations in the roaster control train to characterize the operations and

c hemical processes of the system (see Figures 3 and 4, below).

The OHM tests demonstrate that the East roaster had a 70% greater particulate loading after the

entoleter than the West roaster at 0.0 103 lb/hr. Following the entoleter, the SO2 scrubber appears to add particulate matter to the exhaust gas by 300%, and mercury emission actually

increased across the mercury scrubber by 0.7 lb/hr. Somehow, the tail gas scrubber then drops the mercury emi ssions from 1.0 lb/hr mercury to 0.9 lb/hr at the stack. This is suspicious as the tail gas scrubber does not use a chemical reagent to capture mercury but rather it only utilizes water as its scrubber liquor. Mercury exiting the stack was 39% oxidized mercury and 61% elemental, potentially indicating some successful conversion and collection of elemental mercury to the soluble oxidized form; however, the system still fails overall, emitting 0.9 lb/hr mercury. The majority of the emissions are in the el emental form, indicating that rate of elemental to soluble oxidized form conversion was not adequate and that the management of the control system’s chemistry is lacking.

The OHM tests demonstrate that for the West Roaster, particulate loading after the e ntoleter was measured at 0.0072 lb/hr and subsequent mercury measured in the exhaust gas at each scrubber in the control train decreased until exiting the stack at 0.04 lb/hr. The mercury scrubber performed the bulk of mercury removal with an input of 1.4 6 lbs/hr and an output of 0.06 lb/hr. Following the entoleter, the SO2 scrubber appears to add particulate matter by 56%. The SO2 scrubber appears to act as a “store house” for PM. While emissions at the West roaster were low(er), the mercury exiting th e stack was 65.3% oxidized, and 31.5% elemental. During its path through the scrubber train, the exhaust gas mercury enters as 40% oxidized, increases to 47%, and then 72% before dropping back down to its final 65%. The mercury scrubber appears

to succes sfully oxidize mercury: 47% oxidized entered the Hg scrubber, and 72% exited; however the oxidized mercury is not being captured by the scrubber liquor. More oxidized mercury exits this system than enters

— the chemical reactions are clearly increasing the portion of oxidized mercury and then not catching it in its soluble form in the scrubber liquor. Clearly the chemistry is an issue.Page 6 of 15 

### Figure 3. OHM Testing, May 2008

– West Roaster

NaOC

l Hg PM 0.0072 (0.5%) Hg2+ 0.6045 (40%) Hg0 0.8990 (59.5%)

Total = 1.4622 lbs/hr Hg PM 0.0127 (0.9%) Hg2+ 0.6819 (46.6%) Hg0 0.7676 (52.5%)

Total = 1.4622 lbs/hr Hg PM 0.0039 (6%) Hg2+ 0.0465 ( 72.2%) Hg0 0.0140 (21.7%)

Total = 0.0644 lb/hr Hg PM 0.0014 (3.2%) Hg2+ 0.0290 (65.3%) Hg0 0.0140 (31.5%)

Total = 0.0444 lb/hrPage 7 of 15 

### Figure 4. OHM Testing, May 2008

– East Roaster

NaOCl Hg PM 0.0103 (0.7%) Hg2+ 0.7882 (51.3%) Hg0 0.7390 (48.0%)

Total = 1.5107 lbs/hr Hg PM 0.0304 (2.4%) Hg2+ 0.4175 (33.3% ) Hg0 0.8068 (64.3%)

Total = 1.2548 lbs/hr Hg PM 0.0078 (0.4%) Hg2+ 0.4577 (23.5%) Hg0 1.4804 (76.1%)

Total = 1.9459 lbs/hr Hg PM 0.0016 (0.002%) Hg2+ 0.3558 (38.9%) Hg0 0.5535 (60.5%)

Total = 0.9143 lb/hrPage 8 of 15 

### When sulfur slips through to the NaOCl scrubber, the sulfur reacts with NaOCl pulling out the oxygen and bonding with it. NaCl is stable and with the chlorine having a full outer shell containing 8 electrons. Sodium has 1 electron and shares that electron with chlorine. NaCl will almost always be favored over HgCl 2 

### because both the sodium and chlorine electrons are happy

with their outer shells filled. The sulfur molecule has 2 unfilled electrons in its outer shell so 2 oxygen will bond with the sulfur to make sulfur dioxide leaving the mercury unreactive. When there is a lot of sulfur in the gas stream, equation (1) will be favored over equation (2).

S + Hg 0 

### + 2NaOCl → 2NaCl + SO 2 

### + Hg 0 

### (1) S + Hg 0 

### + 2NaOCl → HgCl 2 

### + Na 2 

### + SO 2 

### (2)

Ideally, we do not want sulfur present in the system in order to allow equation (3) to be favored.

Hg 0 

### + 4NaOCl → 2HgCl 2 

### + 2Na 2 

### O + 2O 2 

### (3)

The updated emission control system at Jerritt Canyon adds cho rine gas to the NaOCl scrubber in order to produce more mercuric chloride since there is some sulfur present in the gas stream. This provides ample chlorine for both mercury and sodium to bond with as shown in equation (4).

2S + Hg 0 

### + Cl 2 

### + 2NaOCl → HgC l 2 

### + 2NaCl + 2SO 2 

### (4)

New WPS Defined by Consent Decree



### Data from OHM testing was used to establish new work practice standards for several process and pollution control devices to ensure continuous compliance with the emissions requirements.

Th e new standards focused on scrubber and entoleter performance and the desired chemical

reactions at various stages of the control process . pH and ORP values were added as indicators of the optimal chemical reactions. Scrubber and entoleter pressure drop values were added for

each unit. For each work practice parameter there is a set point, a deviation range with an alarm

and an interlock.Page 9 of 15 

### Table 2. NDEP

- Developed Operational Parameters for Jerritt Roaster

(A) Entoleter

Parameter Set Point Deviatio n Alarm Interlock

pressure drop 30 in. WC 5 in. WC 20 in. WC

(B) SO 2 Scrubber

Parameter Set Point Deviation Alarm Interlock

pressure drop 8 in. WC 5 in. WC

-- pH 8.0 0.2 7.5
(C) Mercuric chloride (HgCl 2 ) Scrubber

Parameter Set Point Deviati on Alarm Interlock

pressure drop 8 in. WC 5 in. WC

-- chlorine feed pressure 5 psi

pH 6.9 0.2 7.5

ORP 900 25 850

(D) Calomel (HgCl) Scrubber

– Hg Scrubber #2

Parameter Set Point Deviation Alarm Interlock

pressure drop 8 in. WC 5 in. WC

pH 6.9 7.5
Solution temperature

(heat exchanger) 85o F 3o F 104o F

(E) Tail Gas Scrubber

Parameter Set Point Deviation Alarm Interlock

pressure drop 4 in. WC 2 in. WC

-- pH 8.0 0.2 7.0



### The deviation alarm provides a range with which the syste m may deviate from a set point without requiring system shutdown. The deviation alarm provides an opportunity to bring a parameter back to its optimal set point without adversely impacting the mercury emission profile, assuming that the sum of all work pr actice parameters are robust, as is the case demonstrated by the Jerritt Canyon data below.

Conclusion



### The emissions testing conducted demonstrates that maintaining roaster circuit operations within established process and pollution control device oper ational parameters ensures that emissions

reduction are maximized. The testing also demonstrates that excursions from the established set point, within a reasonable range, are not by default excess emission events. The control systems

have demonstrated s ufficient capability to absorb additional Hg emissions that may be generated without immediately exceeding the established Hg emissions limitations. Therefore, it is not necessary to require immediate shutdown of the system. Rather, it is more appropriat e to allow the operator to bring the system back into the established range(s) of the operational parameters.

### Appendix: Consent Decree Test Data

Page 10 of 15 

### December 2009

Parameter East

Roaster

Tested West

Roaster

Tested Set

Point Deviation

Alarm Interlock

Entoleter DP (in. WC) 30.3 19.4 25 5 15

SO 2 Scrubber DP (in. WC) 8.9 1.5 8 5

-- SO 2 Scrubber pH 8 7.9 8 0.2 7.5 HgCl 2 Scrubber DP (in. WC) 3 1.9 8 5

-- HgCl 2 Scrubber pH 6.9 7.6 6.9 0.2 7.5 HgCl 2 Scrubber ORP 825 25 750 HgCl

– Hg scrubber #2 DP (in. WC) 0.46 2.5 8 5

-- HgCl

– Hg scrubber #2 pH 7.1 6.9 6.9

-- 7.5 HgCl

– Hg scrubber #2 solution temp (°F) 85 3 104

Tail gas scrubber DP 0.03 0 4 2

-- Tail gas scrubber pH 8 8 8 0.2 7

No tested values were provided for the solution temperature of mercury scrubber #2, and no ORP values were provided for mercury scrubber #1. The pressure drops across mercur y scrubber #1, mercury scrubber #2, and the tail gas scrubber were lower then the set point determined in the consent decree for both roasters during all three runs. The entoleter pressure drop was also below the set point for all three runs during testing of the west roaster. While testing the west roaster the pH of mercury scrubber #1 was 7.6 for all test runs, including the method 5 test runs, which should have triggered the interlock to shut down the ore roaster system. Also during testing the SO 2 heat exchangers were bypassed. This process deviation was observed by Joseph Prary of NDEP during a compliance inspection, but it is not mentioned any where in the source test report.

In a letter dated January 7, 2010 Jerritt tries to address the cause of thei r failure to meet the emission limit established within the consent decree. They state that the high emission rate from the east roaster is a result of

combustion in the 2 nd stage bed level. Although Jerritt would normally shut down the roaster if combusti on was detected in the 2 nd stage, they choose not to shut down in order to continue with testing. Additionally, Jerritt states

that increased SO 2 in the roasters can change the effectiveness of the calomel system by consuming chlorine gas.

Jerritt would li ke to install an additional ORP probe in order to better maintain the ORP value throughout the calomel system. Thermal

Unit Tested

Production (tons/hour) Permitted Throughput (tons/hour) Percent of

Permitted Throughput Process Sample Loading

(ppm) Mercury Emission Rates (gr/dscf) Average

Tested

Hg

Emissions (gr/dscf) Permitted Hg

Emission

Rate (gr/dscf) Run #1 Run #2 Run #3

West

Roaster 70.4 90 78.2% 12.7 5.55x10 - 4 2.13x10 - 4 2.08x10 - 4 3.25x10 - 4 2.61x10 - 4

East

Roaster 68 90 75 .6% 11 1.58x10 - 3 2.12x10 - 3 1.39x10 - 3 1.7 0 x10 - 3 2.61x10 - 4

### Appendix: Consent Decree Test Data

Page 11 of 15 

### January 2010

Parameter East

Roaster

Tested West Roaster

Tested Set

Point Deviation

Alarm Interlock

Entoleter DP (in. WC) 42.7 42. 4 25 5 15

SO 2 Scrubber DP (in. WC) 1.06 2.3, 7.9, 2.8 8 5

-- SO 2 Scrubber pH 9.7 8.03 8 0.2 7.5 HgCl 2 Scrubber DP (in. WC) 4.5 1.6 8 5

-- HgCl 2 Scrubber pH 6.8 7.0 6.9 0.2 7.5 HgCl 2 Scrubber ORP 825 25 750 HgCl

– Hg scrubber #2 DP (in. WC) 1.6 3.3 8 5

-- HgCl

– Hg scrubber #2 pH 8.3 7.2 6.9

-- 7.5 HgCl

– Hg scrubber #2 solution temp (°F) 85 3 104

Tail gas scrubber DP

- 3.1 2.7 4 2

-- Tail gas scrubber pH 8 8 8 0.2 7

During testing of the west roaster water supply to the entoleter was lost, a nd testing was suspended for 50 minutes. This process upset was described on the deviations page of the stack test report. The first two runs of the east roaster collected less than the required 60 dscf of gas, with 55.7 and 52.24 dscf for runs 1 and 2 res pectively. This deviation from the method was discovered during run 3 of testing on the east roaster. Joseph Prary of NDEP was on site and allowed the two previous runs to be reported. The east roaster was re

- traversed over a period of 12 minutes (one poin t per minute) so that run 3 would collect the required 60 dscf of gas.

The west roaster showed higher particulate mercury concentrations than the east roaster. The west roaster also had higher particulate during both method 5 and method 29 testing. The ea st roaster’s flow rate averaged 3941 dscfm, which is significantly lower than the 5434 dscfm average seen by the west roaster. This low flow rate was probably the cause of the low volume collected during testing.

Average process parameters for the roaster control system during method 29 testing are displayed in the table below. No tested values were provided for the solution temperature of mercury scrubber #2, and no ORP values were provided for mercury scrubber #1. The pressure drops across mercury scrubb er #1, mercury scrubber #2, and the tail gas scrubber were well below the set point determined in the consent decree for both roasters during all three runs. The pressure drop across the SO 2 scrubber was also well below the set point for both roasters; how ever, during run

#2 of the west roaster the SO 2 scrubber pressure drop was near the set point, but that is the only run where the pressure drop neared the set point. While testing the east roaster the pH of mercury scrubber #2 was 8.3 for all

method 29 tes t runs, which should have triggered the interlock to shut down the ore roaster system. Thermal

Unit Tested

Production (tons/hour) Permitted Throughput (tons/hour) Percent of

Permitted Throughput Process Sample

Loadi ng

(ppm) Mercury Emission Rates (gr/dscf) Average

Tested

Hg

Emissions (gr/dscf) Permitted Hg

Emission

Rate (gr/dscf) Run #1 Run #2 Run #3

West

Roaster 68.9 ore

0.86 coal 90 ore

1.9 coal 76.6% ore

45.4% coal 11.3 1.33x10 - 4 1.31x10 - 4 1.52x10 - 4 1.39x 10 - 4 2.60x10 - 4

East

Roaster 70.3 ore

1.64 coal 90 ore

1.9 coal 78.1% ore

86% coal 9.3 2.29x10 - 4 2.01x10 - 4 1.08x10 - 4 1.79x10 - 4 2.60x10 - 4

### Appendix: Consent Decree Test Data

Page 12 of 15 

### February 2010

Parameter East

Roaster

Tested West Roaster

Tested Set

Point Deviation

Alarm Interlock

Entoleter DP (in. WC) 33 44.6 25 5 15

SO 2 Scrubber D P (in. WC) 1.9 1.6 8 5

-- SO 2 Scrubber pH 8 7.9 8 0.2 7.5 HgCl 2 Scrubber DP (in. WC) 3.1 6.2 8 5

-- HgCl 2 Scrubber pH 6.4 6.6 6.9 0.2 7.5 HgCl 2 Scrubber ORP 825 25 750 HgCl

– Hg scrubber #2 DP (in. WC) 1.8 3.4 8 5

-- HgCl

– Hg scrubber #2 pH 6.6 6. 6 6.9

-- 7.5 HgCl

– Hg scrubber #2 solution temp (°F) 85 3 104

Tail gas scrubber DP 0.7, 2.6,

3.4 1.9 4 2

--

Tail gas scrubber pH 8 8 8 0.2 7

While removing the test probe from the stack at the end of run #1 of the east roaster, the probe nozzle ca ught the edge of the sample port and broke off. During sample train recovery no glass shards were found in the filter.

All three runs of the east roaster exceeded the emission limit set in the consent decree. The average total gaseous mercury emitted by t he east roaster was ten times greater then the average amount emitted from the west roaster. The east roaster also had a lower average flow rate, by around 2,000 dscfm, then the west roaster.

The moisture content in the east roaster stack was greater then that of the west roaster. The average moisture content
in the east roaster stack was 6.04%, while in the west roaster it was 3.54%. Run #1 of the east roaster exhibited the highest moisture content and emissions at 8.71% and 0.0019 gr/dscf respectively. D uring a December 2009 test the east roaster exhibited similar readings, 8.3% moisture and 0.0017gr/dscf. During the January 2010 test, when both roasters met the emission limit, the moisture content averaged 3.2% for both roasters.

Average process parame ters for the roaster control system during method 29 testing are displayed in the table below. Jerritt is still not providing the temperature of mercury scrubber #2 or the ORP value for mercury scrubber #1. Most of the differential pressures across the scr ubbers remain well below their set points. Many of the differential pressure readings should have triggered deviation alarms. Thermal

Unit Tested

Production (tons/hour) Permitted Throughput (tons/hour) Percent of

Permitted Throughput Process Sample Loading

(ppm) Mercury Emission Rates (gr/dscf) Average

Tested

Hg

Emissions (gr/dscf) Permitted Hg

Emission

Rate (gr/dscf) Run #1 Run #2 Run #3

West

Roaster 68.9 ore

0.99 coal 90 ore

1.9 coal 76.6% ore

52.1% coal 11.3 1.06x10 - 4 5.00x10 - 5 7.13x10 - 5 7.59x10 - 5 2.60x10 - 4

East

Roa ster 69.4 ore

1.65 coal 90 ore

1.9 coal 77.1% ore

86.8% coal 11 1.90x10 - 3 4.79x10 - 4 4.57x10 - 4 9.47x10 - 4 2.60x10 - 4

### Appendix: Consent Decree Test Data

Page 13 of 15 

### March 2010

Parameter East

Roaster

Tested West Roaster

Tested Set

Point Deviation

Alarm Interlock

Entoleter DP (in. WC) 34.3

Not Tested 25.0 5.0 15.0

SO 2 Scrubber DP (in. WC) 2.2 8.0 5.0

-- SO 2 Scrubber pH 8.0 8.0 0 .2 7.5 HgCl 2 Scrubber #1 DP (in. WC) 1.23 8.0 5.0

-- HgCl 2 Scrubber #1 pH 6.8 6.9 0.2 7.5 HgCl 2 Scrubber #1 ORP 825 25 750 HgCl

– Hg scrubber #2 DP (in. WC)

- 0.6 8.0 5.0

-- HgCl

– Hg scrubber #2 pH 6.7 6.9

-- 7.5 HgCl

– Hg scrubber #2

solution temp (°F) 85.0 3 104.0

Tail gas scrubber DP 57.7 4.0 2.0

-- Tail gas scrubber pH 8.0 8.0 0.2 7.0

No excess emissions or exceedances, process upsets, or deviations during testing or laboratory recovery were reported.

Average process parameters f or the East Roaster control syst em during Method 29 testing are displayed in the table below. Jerritt is still not providing the temperature of mercury scrubber #2 or the ORP value for mercury scrubber #1. Most of the differential pressures across the scr ubbers remain well below their set points. Many of the differential pressure readings should have triggered deviation alarms, although the report states no deviations during testing. Thermal

Unit Tested

Production (tons/hour) Permitted Throughput (tons/hour) Percent of

Permitted Throughput Process

S ample Loading

(ppm) Mercury Emission Rates (gr/dscf) Average

Tested

Hg

Emissions (gr/dscf) Permitted Hg

Emission

Rate (gr/dscf) Run #1 Run #2 Run #3

East

Roaster 68.0 ore (avg.) 0.93 coal (avg.) 90 ore

1.9 coal 75.6% ore

48.9% coal 9.0 3.44x10 - 5 3 .16x10 - 5 3.26x10 - 5 3.29x10 - 5 2.60x10 - 5

### Appendix: Consent Decree Test Data

Page 14 of 15 

### April 2010

Parameter East

Roaster

Tested West

Roaster

Tested Set

Point Deviation

Ala rm Interlock

Entoleter DP (in. WC) 58.30 51.20 25 5 15

SO 2 Scrubber DP (in. WC) 1.57 2.28 8 5

-- SO 2 Scrubber pH 8.02 8.05 8 0.2 7.5 HgCl 2 Scrubber DP (in. WC) 2.16 4.56 8 5

-- HgCl 2 Scrubber pH 6.70 6.28 6.9 0.2 7.5 HgCl 2 Scrubber ORP

- - 825 25 750 HgCl

– Hg scrubber #2 DP (in. WC)

- 0.70 3.97 8 5

-- HgCl

– Hg scrubber #2 pH 6.40 6.10 6.9

-- 7.5 HgCl

– Hg scrubber #2 solution temp (°F) 120.90 70.47 85 3 104

Tail gas scrubber DP 57.70 1.55 4 2

-- Tail gas scrubber pH 8.00 8.11 8 0.2 7

Of note, the roasters’ mercury emissions had little variability between runs and between the roasters themselves, indicating (very) consistent operations of the roaster operations and their mercury emissions.

The consent decree requires a set of operational param eters for the roaster operation. The test report provides roaster and scrubber operating parameter values; however, some required in the consent decree are not present,

while additional non

- consent decree required parameters are included. For this test e vent the HgCL 2 scrubber ORP was not provided. For three parameters operations appeared out of range: SO 2 Scrubber DP, HgCl 2 Scrubber DP and HgCl

– Hg scrubber #2 DP. Mercury Emission Rates (gr/dscf)

Thermal

Unit Tested

Produ ction (tons/hour) *Permitted Throughput (tons/hour) Percent of

Permitted Throughput Process Sample Loading

(ppm) Run #1 Run #2 Run #3 Average Tested Hg

Emissions (gr/dscf) Permitted Hg

Emission

Rate (gr/dscf) (gr/dscf) (gr/dscf) (gr/dscf)

East

Roa ster 67.2

67.9

67.2 70 96

97

96 10.7 2.11x10 - 5 1.40 x10 - 5 1.51 x10 - 5 1.67 x10 - 5 2.6x10 - 4

West

Roaster 69.1

68.3

69.4 70 99

98

99 10.0 1.48 x10 - 5 1.64 x10 - 5 1.72 x10 - 5 1.61x10 - 5 2.6x10 - 4

### Appendix: Consent Decree Test Data

Page 15 of 15 

### June 2010

Parameter East Roaster

Tested West

Roaster

Tested Set

Point Deviation

Alarm Interlock

E ntoleter DP (in. WC) 59 50.2 25 5 15

SO 2 Scrubber DP (in. WC) 1.7 2.7 8 5

-- SO 2 Scrubber pH 8.5 8.5 8 0.2 7.5 HgCl 2 Scrubber DP (in. WC) 10, 10.1, 15.6 2.7 8 5

-- HgCl 2 Scrubber pH 6.9 6.6 6.9 0.2 7.5 HgCl 2 Scrubber ORP 825 25 750 HgCl

– Hg scrubb er #2 DP (in. WC)

- 0.6,

- 0.6, 4.2

- 0.7 8 5

-- HgCl

– Hg scrubber #2 pH 6.8 6.6 6.9

-- 7.5 HgCl

– Hg scrubber #2 solution temp (°F) 85 3 104

Tail gas scrubber DP 57.7 2.6 4 2

-- Tail gas scrubber pH 8.5 8.5, 8.5, 7.7 8 0.2 7

Testing was completed at an adequate level of production, and absence of cyclonic flow was verified for both units. Mercury emissions from all runs were well below the mercury emission limit established in the consent decree.

Jerritt is still not providing the temperature of mer cury scrubber #2 or the ORP value for mercury scrubber #1. Several of the differential pressure values are lower than their set points.

About 45 minutes into run #3 of the west roaster the production data shows that the pH in the tail gas scrubber dipped to 2.6. This dropped the average pH for that run to about 7.7, without that 2.6 the average rises to 8.5. This dip wasn’t reported as a deviation. Thermal

Unit Tested

Production (tons/hour) Permitted Throughput (tons/hour) Pe rcent of

Permitted Throughput Process Sample Loading

(ppm) Mercury Emission Rates (gr/dscf) Average Tested Hg

Emissions (gr/dscf) Permitted Hg

Emission

Rate (gr/dscf) Run #1 Run #2 Run #3

West

Roaster 78 ore

0.19 coal 90 ore

1.9 coal 86.7%

10% 9.7 2

. 11 x10 - 5 1

. 76 x10 - 5 2. 19 x10 - 5 2. 02 x10 - 5 2

. 6 0x10 - 5

East

Roaster 78.4 ore

0.17 coal 90 ore

1.9 coal 87.1%

8.9% 10.3 2

. 65 x10 - 5 2

. 72 x10 - 5 2

. 95 x10 - 5 2

. 77 x10 - 5 2.60x10 - 5