# Meteorological and Hydrogen Cyanide (HCN) Fence Line Monitoring

Preliminary Report

RMGC-SVCO, I NC



# .

P ROJECT 

## 99-11-4 F EBRUARY 

## 2010Roundmtn Hcn Monitoring Report.Docx 

### ii 

# CONTENTS Page

1.0 INTRODUCTION .............................................................................................................. ........................................... 1 1.1 HCN Monitor and Meteorological Station Locations .......................................................................... ..................... 1 1.2 HCN Monitoring System Description ......................................................................................... ............................. 6 1.3 Data Recovery ............................................................................................................. .......................................... 7 1.4 Quality Control ........................................................................................................... ............................................. 7

2.0 METEOROLOGY AT THE METEOROLOGICAL STATION ................................................................................. .... 8

2.1 Winds ..................................................................................................................... ................................................ 8 2.2 Temperature ............................................................................................................... ......................................... 11

3.0 HCN STATION ............................................................................................................... .......................................... 12

3.1 Winds ..................................................................................................................... .............................................. 12 3.2 Temperature, Relative Humidity, and Barometric Pressure ................................................................... ............ 12 3.3 HCN Concentration ......................................................................................................... ..................................... 13

4.0 DATA ANALYSI S ............................................................................................................. ........................................ 14



## Tables

Table 1: Sensor Locations .................................................................................................... ........................................... 6 Table 2: Data Recovery ....................................................................................................... ............................................ 7 Table 3: Frequency of Hourly Averaged Winds by Direction and Speed ........................................................... .............. 9 Table 4: Frequency of Hourly Averaged Winds by Direction and Stability ....................................................... ................ 9 Table 5: Temperature, Relative Humidity, and Barometric Pressure ............................................................. ................ 12
Table 6: HCN Concentration ................................................................................................... ....................................... 13 Table 7: Measured HCN Concentration Analysis ................................................................................. .......................... 14



## Figures
Figure 1: HCN Monitoring Site ................................................................................................ ......................................... 2 Figure 2: Large Scale Area Map ............................................................................................... ....................................... 3 Figure 3: ADR Area ........................................................................................................... ............................................... 4 Figure 4: Mill Area .......................................................................................................... .................................................. 5 Figure 5: Wind Frequency Distribution ........................................................................................ ................................... 10 Figure 6: Measured HCN Concentration Analysis ................................................................................ ......................... 15 Figure 7: Wind frequency for December 24, 2009 (Lowest Concentration Day) .................................................... ........ 16 Figure 8: Wind frequency for January 2, 2010 (Highest Concentration Day) ..................................................... ............ 16



## Appendices
Appendix A: Hourly Meteorological Data Appendix B: HCN Data Appendix C: Site Check Forms, Audits, and Calibration Appendix D: Hydrogen Cyanide (HCN) Fence Line Monitoring PlansRoundmtn Hcn Monitoring Report.Docx 

### 1 

## SECTION 1 

# INTRODUCTION

This report summarizes the meteorological and hydrogen cyanide (HCN) data collected at the Round Mountain Gold Corporation – Smoky Valley Co mmon Operation (RMGC-SVCO) meteorological station and HCN monitor through January 11, 2010. The HCN monitor station became operational on December 18, 2009, at 2:00 a.m. and the first 24-hour HCN sample was taken on December 18, 2009. The HCN monitoring equipment and sa mpling procedures followed RMGC-SVCO’s SiteSpecific Hydrogen Cyanide (HCN) Fence Line Monitoring Plan (Site Specific Plan), approved by EPA on November 12, 2009, and the general Hydrogen Cyanide (HCN) Fence Line Monitoring Plan , approved by EPA on October 9, 2009. The meteorological sa mpling procedures were performed in accordance
with the U. S. EPA Quality Assurance Handbook of Air Polluti on Measurement Systems Volume IV - Meteorological Measurements (EPA-600/R94-038D), March 1995.

RMGC-SVCO operates a gold mining facility located at #1 Smoky Valley Mine Road, Round Mountain, Nevada. The RMGC-SVCO facility consists of open-pit mining and gold recovery processes including ore crushing, heap leaching, or e milling, gravity separation, carbon adsorption, stripping and regeneration, electr owinning, and refining. The leac h solutions used in the gold recovery processes contain cyanide. These solutions have the potential for low levels of hydrogen cyanide (HCN) formation and emission to the atmosp here. To assess the ambient concentrations ofHCN emissions, RMGC-SVCO installed and continues to operate an HCN monitor near the RMGCSVCO operations area.



# 1.1 HCN Monitor and Meteorol ogical Station Locations

Aerial photos and shaded relief maps are provided as Figures 1 through 4. Figure 1 provides an aerial photo of the mine site, the operations boundary, the potential HCN sources, and the meteorological and HCN monitor locations. Figure 2 provides a shaded relief map of the area surrounding the RMGC-SVCO mine and shows the location of the meteorological station and the HCN monitor. The meteorological station is locate d at 493,898 meters east, 4,284,520 meters north, UTM Zone 11N, NAD83, elevation 6,361 feet. The HCN monitor is located at 485,949 meters east, 4,282,968 meters north, UTM Zone 11 N, NAD83, elevation, 5,797 feet.

Figures 1, 3, and 4 highlight the potential source s of HCN emissions at RMGC-SVCO. These sources include: active leach pads; pregnant and barren ponds; tailings impoundment and reclaim ponds; various tanks containing cyanide solutions at the mill area, Adsorption, Desorption and Refinery (ADR) area, and adjacent to the dedicated leach pa ds; and exhaust stacks fo r the EW cells and the pregnant and barren tanks at the ADR building. Closer views of the HCN sources at the mill and ADR areas are shown in Figures 3 and 4.Roundmtn Hcn Monitoring Report.Docx 

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# 1.2 HCN Monitoring System Description

The HCN monitoring system consists of a data logger connected to a low-flow pump which is connected through sorbent tubes to an ambient air inlet. The sorbent tubes capture HCN in the ambient air and are sent to the ALS Laboratory Group in Salt Lake City, Utah for analysis. The lab analysis is based on NIOSH Method 6010. The sa mpling schedule follows a 1-in-3 day calendar and will continue for a total sampling period of two months.

During a run day, all meteorological parameters ar e collected at more frequent intervals and timeaveraged into 15-minute values. Wind speed and wi nd direction are collected at the meteorological station. Ambient temperature, relative humidity , and barometric pressure as well as flow rate through the sorbent tubes are collected at the HCN mo nitor. Ambient temperature is also collected at the meteorological station and serves as a qualit y check for the HCN monitor data. The parameters
collected are shown in Table 1.

The measurement height of the inlet is two meters. The height of the wind instruments is 10 meters. All other parameters are measured at two meters.

Table 1: Sensor Locations (meters above the ground)



## Parameter Height Wind speed* 10.0
Wind direction* 10.0 Ambient temperature 2.0 Relative humidity 2.0 Barometric pressure 2.0 Sampler Flow 2.0
*Wind data are from the meteorological station.



## The hourly averaged data from the meteorological st ation are sent electronically to Air Sciences Inc. (Air Sciences) where they are transferred into a database. The meteorological data from the HCN monitor are recorded by the onsite digital Data Acquisition System (DAS) equipped with cellular internet for data transfer. The parameters are digitally processed by the DAS into 15-minute averages. The 15-minute averages are transmitte d to Air Sciences for quality assurance checks, population into the database, and calculation of one-hour averages.Roundmtn Hcn Monitoring Report.Docx 

### 7 

# 1.3 Data Recovery

Data recovery rates for all paramete rs are presented in Table 2.

The meteorological data recovery rate was 100 percen t for all parameters at the meteorological station and 99.1 percent at the HCN monitor. The lower da ta recovery rate at the HCN monitor was due to the site being shut down for maintenance and data logger program updates. The data recovery rates at the meteorological and HCN station are above the recommended rate of 90 percent for all meteorological parameters.

The data recovery rate for the flow rate to the sorb ent tubes was 99.1 percent. The data recovery rate for the HCN concentration from the sorbent tubes was 100 percent. Both parameters are above the recommended recovery rate of 75 percent.

Table 2: Data Recovery December 18, 2009 - January 11, 2010 (percent)



## Recorded Recommended

Parameter Observations Recovery Rate Recovery Rate Meteorological Station Wind speed 600 100.0 90
Wind direction 600 100.0 90 Ambient temperature 600 100.0 90
HCN Station Ambient temperature 214 99.1 90 Relative humidity 214 99.1 90 Barometric pressure 214 99.1 90 Flow 214 99.1 75
HCN concentration 9 100.0 75



# 1.4 Quality Control

The primary meteorological quality objectives are based on U.S. EPA guideline documents (EPA454/4-87-007, Section 6.1.1, Ambient Monitoring Guidelines for Prevention of Significant Deterioration [PSD] and EPA-454/R-99-005, February 2000, Table 5-1., Meteorological Monitoring Guidance for Regulatory Modeling Applications). The quality control objectives for the HCN monitor can be found in Appendix D.Roundmtn Hcn Monitoring Report.Docx 

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## SECTION 2 

# METEOROLOGY AT THE METEOROLOGICAL STATION

The instantaneous wind speed, wind direction, and temperature data collected at the meteorological station during the monitored period were processed into hourly averages. Appendix A presents the hourly averages for each parameter in SAROAD (Storage and Retrieval of Aerometric Data) format. A summary of this data for each parameter is shown in the following sections.



# 2.1 Winds

Hourly averaged winds measured at the site duri ng the sampling period are summarized in Table 3 as frequency distributions of winds by direction an d speed. The data period contains 25 days (600 hours) of complete wind information.

Figure 5 shows the distribution of hourly averag ed winds by direction and speed for the sampling period. The mean wind speed for the period was 1.9 m/s (4.3 mph). The winds were predominately
from the east-northeast to the east-southeast. A br eakdown of the wind speed profile for this period yields the following: There were 0.0 percent ca lm wind speeds (<0.447 m/s), 37.5 percent of the winds were between 0.5 m/s (1.1 mph) and 1.5 m/s (3.4 mph), 60.6 percent of the winds were between 1.5 m/s and 5 m/s (11.2 mph), and 1.9 percent of the wind speeds were greater than 5 m/s.

Table 4 shows a frequency distribution of hourly av eraged winds by directio n and stability class. Stability classes A, B, and C indicate low-speed daytime winds, which are categorized as unstable or high-dispersion-potential winds with class A being the least stable. Stability classes E and F indicate the frequency of low-speed nighttime winds, whic h are categorized as stable or low-dispersionpotential winds with class E being the least stable. The D stability class is a mixture of daytime and nighttime winds, generally at higher speeds. This class is also referred to as neutral stability.

The lower-speed daytime winds (classes A, B, and C) made up 32.6 percent of the total winds and were predominately from the north-northeast. The lower-speed nighttime winds (classes E and F) constituted 53.3 percent of the total winds and were predominately from the east to the eastsoutheast. The higher-speed winds (class D) comp rised 14.1 percent of the total winds and were predominately from the north-northeast to the east-southeast.Roundmtn Hcn Monitoring Report.Docx 

### 9 Direction A B C D E F All

N 1.2 0.5 0.9 0.7 0.3 0.5 4.2

NNE 0.9 2.1 2.1 1.9 0.9 0.2 8.0

NE 0.9 0.9 1.2 1.2 1.2 0.9 6.3

ENE 0.5 0.9 1.4 1.7 1.4 3.5 9.4

E 1.2 0.3 0.5 2.1 4.2 5.4 13.7

ESE 0.5 0.7 0.0 1.6 1.7 6.3 10.8

SE 0.9 0.3 0.5 0.5 1.2 4.7 8.2

SSE 0.2 0.5 0.5 0.5 0.7 5.6 8.0

S 0.3 0.3 0.3 0.7 1.4 2.6 5.7

SSW 0.5 1.2 1.2 0.3 1.4 1.9 6.6

SW 0.7 0.9 0.5 1.4 0.7 1.6 5.7

WSW 0.5 0.2 0.9 0.2 0.3 2.3 4.3

W 0.9 0.3 0.3 0.5 0.2 0.9 3.1

WNW 0.9 0.7 0.0 0.3 0.3 0.5 2.8

NW 0.5 0.5 0.2 0.2 0.3 0.0 1.7

NNW 0.3 0.3 0.3 0.2 0.2 0.2 1.6
All 10.9 10.8 10.9 14.1 16.5 36.8 100.0 Stability Class 

### Table 3: Frequency of Hourly Averaged Winds by Direction and Speed December 18, 2009 - January 11, 2010 (percent of occurrence)



## Calm (< 0.447 m/s) = 0.0% Mean wind speed = 1.9 m/s Data presented as direction from which wind is blowing.

Table 4: Frequency of Hourly Averag ed Winds by Direction and Stability December 18, 2009 - January 11, 2010 (percent of occurrence) Mean

Direction 0.5 <1.5 1.5 <3 3 <5 5 <7 7 <10 >=10 All Speed

N 0.9 3.0 0.2 0.2 0.0 0.0 4.2 2.0

NNE 0.7 5.6 0.5 1.0 0.2 0.0 8.0 2.7

NE 0.2 5.0 0.9 0.2 0.0 0.0 6.3 2.4

ENE 2.4 4.7 2.3 0.0 0.0 0.0 9.4 2.2

E 3.6 8.7 1.4 0.0 0.0 0.0 13.7 2.1

ESE 5.2 5.4 0.2 0.0 0.0 0.0 10.8 1.6

SE 6.3 1.9 0.0 0.0 0.0 0.0 8.2 1.2

SSE 5.7 1.7 0.3 0.2 0.0 0.0 8.0 1.4

S 3.3 1.4 0.9 0.2 0.0 0.0 5.7 1.8

SSW 1.0 3.6 1.9 0.0 0.0 0.0 6.6 2.6

SW 1.0 3.3 1.4 0.0 0.0 0.0 5.7 2.4

WSW 2.6 1.7 0.0 0.0 0.0 0.0 4.3 1.5

W 1.6 1.6 0.0 0.0 0.0 0.0 3.1 1.4

WNW 1.6 1.2 0.0 0.0 0.0 0.0 2.8 1.4

NW 0.9 0.9 0.0 0.0 0.0 0.0 1.7 1.5

NNW 0.5 1.0 0.0 0.0 0.0 0.0 1.6 1.6
All 37.5 50.7 9.9 1.7 0.2 0.0 100.0 1.9 Speed Class Intervals (m/s)Roundmtn Hcn Monitoring Report.Docx 

### 10 Figure 5: Wind Frequency Distribution



### 2%

4%

6%

8%

10%

12%

14%

16%

18%

20% N

NNE

NE

ENE

E

ESE

SE

SSE
S SSW SW WSW W WNW NW NNW

0.5 1 5 8 10 m/s

Hourly Met Data Wind Frequency Distribution: 12/18/09 - 01/11/10 Calm = 0 Missing = 0 Number of non-calm/missing = 600Roundmtn Hcn Monitoring Report.Docx 

### 11 

# 2.2 Temperature

The average 2-meter temperature for the period was -2.0 ° C (28.4 ° F). The maximum hourly averaged 2-meter temperature was 8.0 ° C (46.4 ° F) and occurred on the afternoon of January 11, 2010. The minimum hourly averaged 2- meter temperature was -11.3 ° C (11.7 ° F) and occurred on the evening of December 21, 2009, and again on the morning of December 31, 2009.Roundmtn Hcn Monitoring Report.Docx 

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## SECTION 3 

# HCN STATION

The instantaneous temperature, relative humidity, and barometric pressure data collected at the HCN monitor on each run day duri ng the monitored period were processed into hourly averages. Appendix A presents the hourly averages for each parameter in SAROAD (Storage and Retrieval of Aerometric Data) format. A summary of this data for each parameter is shown in the following

sections.



# 3.1 Winds

There was no wind data collected at the HCN monitor, see Section 2.1 above for wind data.


# 3.2 Temperature, Relative Humi dity, and Barometric Pressure

The temperature mean and extremes for the sampling period are presented in Table 5. The average 2-meter temperature for the period was -6.83 ° C (19.71 ° F). The maximum hour ly averaged 2-meter temperature was 4.74 ° C (40.53 ° F) and occurred on the afternoon of January 11, 2010. The minimum hourly averaged 2-meter temperature was -17.58 ° C (0.36 ° F) and occurred on the morning of January
5, 2010.

The relative humidity mean and extremes for the sampling period are presented in Table 5. The average relative humidity for the period was 79 percent. The minimum hourly average was 41 percent and the maximum was 98 percent.

Barometric pressure data collected during the sa mpling period are summarized in Table 5. The average barometric pressure for the period was 621 mmHg. The maximum hourly averaged barometric pressure for the period was 624 mmHg an d occurred for eleven consecutive hours in the morning of January 11, 2010. The minimum hourly averaged barometric pressure for the period was 611 mmHg and occurred for three consecutive ho urs in the evening of December 21, 2009.

Table 5: Temperature, Relative Humidity, and Barometric Pressure December 18, 2009 - January 11, 2010



## Parameter Temperature ( ° C) 

## Relative Humidity (%) Barometric
Pressure (mmHg) Avg. -6.83 79 621
Max. 4.74 98 624
Min. -17.58 41 611Roundmtn Hcn Monitoring Report.Docx 

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# 3.3 HCN Concentration

The HCN concentration data collected during the sa mpling period are summarized in Table 6. The average HCN concentration corrected to standard conditions 1 

## was 0.27 μg/m 3 

## . The minimum HCN concentrations for the period were below the detection level of 0.21 μg/sample and occurred on December 24, 2009, and January 8, 2010. Using the detection level mass of HCN and the sample flow rate, the HCN concentration was estimated to be <0.09 μg/m 3 

## on December 24, 2009, and <0.10 μg/m 3 

## on January 8, 2010. The maximum HCN concentration for the period was 0.62 μg/m 3 

## and occurred on January 2, 2010. The HCN concentrat ion in the field blanks was below the detectionlevel of 0.21 μg/sample. All HCN concentrations were below the EPA reference concentration of 3E3 mg/m 3



## . 2



### Table 6: HCN Concentration December 18, 2009 - January 11, 2010 (μg/m 3 

### )



## HCN Concentration

Run Day* Actual
Conditions Standard
Conditions 12/18/2009 0.24 0.26 12/21/2009 0.21 0.23 12/24/2009 <0.08 ^ 

## <0.09 ^ 

## 12/27/2009 0.25 0.27 12/30/2009 0.18 0.20 01/02/2010 0.57 0.62 01/05/2010 0.37 0.40 01/08/2010 <0.09 ^ 

## <0.10 ^ 

## 01/11/2010 0.22 0.25 Average 0.25 0.27

*Start time = 0:00:02; stop time = 0:00:00.

^ Below Detection Level of 0.21 μg/sample.

1 Standard conditions are 1 atmosphere and 25 ° C. 2 U.S. EPA Integrated Risk Information Syst em. http://www.epa.gov/iris/subst/0060.htm.Roundmtn Hcn Monitoring Report.Docx 

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## SECTION 4 

# DATA ANALYSIS

Based on the data collected from the first four week s of monitoring, an analys is of wind direction and measured HCN concentration was conducted. As shown in Figures 1 and 2, winds from 70 ° through

127 ° (approximately east-northeast th rough southeast) blow from th e potential HCN sources at the RMGC-SVCO mine towards to the HCN monitor. The percent of winds blowing within this range of directions on each sample day is shown in Table 7 and Figure 6.

As shown by Table 7 and Figure 6, there does not appear to be a correlation between wind direction
and measured HCN concentration. On the lowest HCN concentration day, the winds blew from the potential HCN sources towards the monitor 54 percen t of the time, which is the highest percent of winds blowing towards the monitor of any of the samp le days. On the highest concentration day, the winds blew towards the monitor only eight percent of the time, which is the lowest percent of winds blowing towards the monitor of any of the sample days.

Table 7 shows that a correlation may exist between wind speed and measured HCN concentration. It appears that the higher average wind speeds tend to be on the days with the lowest HCN

concentration.

Table 7: Measured HCN Concentration Analysis December 18, 2009 - January 11, 2010



## HCN
Concentration Winds Blowing from HCN
Sources towards Monitor Average Wind Speed Run Day (μg/m 3 

## ) No. of Hours Percent (m/s) 12/18/09 0.26 12 50 2.0 12/21/09 0.23 3 13 2.2 12/24/09 <0.09 ^ 

## 13 54 2.3 12/27/09 0.27 11 46 1.5 12/30/09 0.20 4 17 2.3 01/02/10 0.62 2 8 1.6 01/05/10 0.40 9 38 1.6 01/08/10 <0.10 ^ 

## 9 38 1.9 01/11/10 0.25 12 50 1.8 Average 0.27

^ Below Detection Level of 0.21 μg/sample.Roundmtn Hcn Monitoring Report.Docx 

### 15 Figure 6: Measured HCN Concentration Analysis



## Figures 7 and 8 summarize the 24-hour wind dire ction (the direction from which the wind is blowing) and wind speed for the lowest and hi ghest HCN concentration days. The lowest HCN concentration was measured on December 24, 2009. The highest HCN concentration was measured on January 2, 2010. The winds were predominately fr om the east-northeast to the east on the lowest concentration day and from the south on the highest concentration day. 0 10 20 30 40 50 60

0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7PercentofWinds(%)HCNConcentration(μg/m3)



### Run Day HCN Concentration Percent of Winds Towards MonitorRoundmtn Hcn Monitoring Report.Docx 

### 16 3%

6%

9%

12%

15%

18%

21%

24%

27%

30% N

NNE

NE

ENE

E

ESE

SE

SSE
S SSW SW WSW W WNW NW NNW

0.5 1 5 8 10 m/s

Hourly Met Data Wind Frequency Distribution: 1/2/2010 Calm = 0 Missing = 0 Number of non-calm/missing = 24 3%

6%

9%

12%

15%

18%

21%

24%

27%

30% N

NNE

NE

ENE

E

ESE

SE

SSE
S SSW SW WSW W WNW NW NNW

0.5 1 5 8 10 m/s

Hourly Met Data Wind Frequency Distribution: 12/24/2009 Calm = 0 Missing = 0 Number of non-calm/missing = 24 

### Figure 7: Wind frequency for December 24, 2009 (Lowest Concentration Day)

Figure 8: Wind frequency for January 2, 2010 (Highest Concentration Day)

# APPENDIX A 

# Hourly Meteorological DataDay 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Avg Max Min12/18/2009 1.5 2.1 1.0 1.3 2.3 1.5 2.3 1.3 1.7 1.5 2.1 1.6 1.9 2.2 2.0 1.9 2.6 2.6 3.6 1.9 2.4 2.2 2.4 0.7 1.9 3.6 0.712/19/2009 2.9 1.6 1.4 1.7 1.5 1.7 0.9 1.7 1.4 1.3 1.7 1.8 1.7 1.7 1.6 0.8 1.4 1.1 1.3 1.3 1.6 1.2 1.1 2.4 1.5 2.9 0.812/20/2009 0.7 0.9 1.2 0.9 1.1 0.7 0.9 1.0 1.3 1.8 2.3 3.2 2.6 3.7 3.4 3.8 4.5 2.6 4.1 2.8 3.7 2.5 1.3 2.2 2.2 4.5 0.712/21/2009 3.1 1.1 1.4 0.9 1.3 0.9 1.1 1.1 1.2 1.8 2.5 2.8 2.5 3.2 2.5 2.3 2.6 1.8 2.4 3.4 2.1 5.2 3.5 3.8 2.3 5.2 0.912/22/2009 2.5 2.8 1.4 2.1 2.7 2.1 2.2 2.4 2.2 1.8 4.2 4.4 5.4 5.7 5.6 5.8 6.4 7.1 6.8 5.9 5.1 3.7 3.6 1.2 3.9 7.1 1.212/23/2009 4.6 3.2 4.4 4.0 4.8 4.4 3.7 2.5 2.7 1.4 2.4 3.0 3.3 2.5 2.2 2.4 2.4 3.1 3.2 3.0 2.5 1.5 1.8 1.6 2.9 4.8 1.412/24/2009 1.6 3.1 2.8 2.9 1.8 1.1 1.2 1.2 1.5 1.8 2.0 2.2 2.1 2.2 2.3 2.6 3.4 3.7 4.0 3.6 2.3 1.4 2.0 3.4 2.3 4.0 1.112/25/2009 1.4 1.0 1.1 0.9 0.9 1.0 1.9 1.6 1.3 2.5 2.0 3.0 2.6 3.0 2.9 2.4 3.2 4.4 4.8 4.5 2.6 2.1 1.3 1.1 2.2 4.8 0.912/26/2009 2.5 2.2 1.4 1.8 1.7 0.9 0.5 1.2 1.3 0.9 1.3 1.5 1.7 1.3 1.4 3.1 4.0 2.9 1.0 1.4 1.6 1.3 1.0 1.8 1.6 4.0 0.512/27/2009 1.1 1.7 1.0 1.2 0.8 0.7 1.0 1.5 0.8 1.4 1.4 1.5 1.8 2.0 2.0 1.9 1.7 1.6 2.1 1.6 1.7 1.4 2.5 0.8 1.5 2.5 0.712/28/2009 1.2 0.9 2.1 2.5 2.5 1.6 1.9 2.0 1.6 1.7 1.9 1.8 1.8 2.2 2.1 1.7 1.2 0.6 0.5 0.6 1.3 1.2 1.2 1.6 1.6 2.5 0.512/29/2009 1.1 1.9 1.5 1.1 1.4 1.5 2.1 1.6 1.6 2.3 4.0 2.7 2.5 2.2 2.2 1.7 1.6 1.3 1.1 1.8 1.7 2.3 3.7 1.9 1.9 4.0 1.112/30/2009 1.6 1.8 2.4 2.3 2.9 2.3 3.4 3.0 2.6 2.2 2.3 2.1 1.5 2.3 3.3 2.5 2.5 2.0 2.2 1.4 2.9 1.7 1.5 1.4 2.2 3.4 1.412/31/2009 1.6 1.9 1.3 1.6 1.5 1.4 1.3 1.1 1.5 1.5 3.0 2.0 1.7 2.0 2.1 4.3 3.7 3.2 2.7 3.4 2.8 3.7 2.6 3.0 2.3 4.3 1.11/1/2010 1.7 1.2 0.9 1.4 1.1 1.3 1.1 1.4 1.6 1.5 2.1 2.1 1.6 1.2 1.5 1.8 3.6 2.7 2.2 1.8 2.7 2.6 2.8 1.1 1.8 3.6 0.91/2/2010 2.8 3.1 3.0 1.9 3.7 3.7 1.9 1.7 1.1 1.4 1.2 1.5 1.5 1.3 1.2 1.6 0.7 1.2 0.9 0.7 0.7 0.6 0.8 0.9 1.6 3.7 0.61/3/2010 1.0 1.1 2.0 1.4 1.2 2.1 0.8 1.3 1.4 1.9 2.1 1.7 1.9 1.9 1.8 1.3 1.4 1.4 0.7 1.5 1.1 0.9 1.0 0.6 1.4 2.1 0.61/4/2010 0.7 0.6 0.9 1.1 1.2 0.5 1.2 0.5 0.6 0.7 1.2 1.6 1.7 1.8 1.3 1.5 2.0 2.3 1.0 1.6 1.1 0.7 1.2 1.9 1.2 2.3 0.51/5/2010 1.0 1.2 1.8 2.2 1.9 1.3 1.5 2.2 1.2 1.5 1.8 1.9 1.6 1.9 1.4 1.1 1.0 1.5 2.3 1.4 0.8 1.6 1.3 0.8 1.5 2.3 0.81/6/2010 1.0 1.3 1.5 1.2 1.0 2.8 1.4 0.8 0.8 1.0 1.0 1.1 1.6 2.2 1.2 0.7 1.1 1.3 1.6 3.0 2.4 1.4 1.6 2.6 1.5 3.0 0.71/7/2010 1.2 0.9 0.6 0.6 0.8 2.3 1.8 2.4 1.1 1.1 1.4 2.1 1.9 1.6 2.1 1.8 2.8 2.7 2.4 1.3 1.9 2.3 2.3 1.3 1.7 2.8 0.61/8/2010 3.0 3.7 3.2 2.9 1.9 2.5 2.5 1.3 1.1 0.8 1.3 1.4 1.6 1.6 1.4 1.5 1.7 1.7 1.3 2.1 1.8 2.3 1.8 0.6 1.9 3.7 0.61/9/2010 1.6 1.9 1.9 1.8 1.6 2.2 2.0 1.5 0.9 1.5 1.9 2.0 1.9 1.9 2.1 1.7 1.8 1.6 2.3 2.1 1.7 0.9 1.2 2.0 1.7 2.3 0.91/10/2010 1.2 1.1 1.2 0.6 1.7 1.5 1.3 1.2 1.6 1.8 1.7 2.0 1.9 1.8 2.2 2.1 1.8 2.4 1.5 0.6 1.3 2.0 2.5 6.3 1.8 6.3 0.61/11/2010 1.6 2.5 1.8 1.8 1.9 2.0 2.0 1.3 1.0 1.0 1.2 1.7 1.0 1.9 1.7 1.3 1.6 0.6 1.2 1.3 2.0 1.6 1.9 5.4 1.7 5.4 0.6Avg 1.8 1.8 1.7 1.7 1.8 1.8 1.7 1.5 1.4 1.5 2.0 2.1 2.0 2.2 2.1 2.1 2.4 2.3 2.3 2.2 2.1 1.9 1.9 2.0 1.9‐‐ ‐‐Max 4.6 3.7 4.4 4.0 4.8 4.4 3.7 3.0 2.7 2.5 4.2 4.4 5.4 5.7 5.6 5.8 6.4 7.1 6.8 5.9 5.1 5.2 3.7 6.3‐‐7.1‐‐Min 0.7 0.6 0.6 0.6 0.8 0.5 0.5 0.5 0.6 0.7 1.0 1.1 1.0 1.2 1.2 0.7 0.7 0.6 0.5 0.6 0.7 0.6 0.8 0.6‐‐ ‐‐0.5SAROADforKinross,RoundmountainChannel:WS_ms_10mMonth:12/18/09‐01/11/10HourofdayDay 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Max Min12/18/2009 142 99 108 154 109 156 82 122 56 49 45 336 15 40 58 48 103 102 96 105 104 109 107 201 336 1512/19/2009 93 121 118 98 138 123 139 153 61 350 353 333 333 10 26 235 94 62 115 179 122 86 107 234 353 1012/20/2009 142 125 99 108 173 161 120 148 229 225 228 205 199 206 203 206 204 224 224 234 229 223 254 194 254 9912/21/2009 226 199 78 125 152 170 111 153 271 200 215 201 189 218 209 211 195 144 179 199 227 158 186 60 271 6012/22/2009 213 207 284 102 70 209 67 81 9 33 19 27 14 21 18 19 26 27 30 35 9 37 57 144 284 912/23/2009 20 50 72 79 66 45 38 55 48 313 42 51 62 53 57 36 105 76 79 84 88 132 95 112 313 2012/24/2009 114 83 80 97 71 83 135 162 125 72 17 48 32 31 42 44 71 63 64 77 58 117 100 81 162 1712/25/2009 215 125 170 153 164 148 91 96 91 34 33 56 46 54 61 67 71 94 93 93 79 85 120 270 270 3312/26/2009 91 111 140 64 73 120 187 159 258 305 263 247 350 282 301 208 201 199 242 186 194 208 215 126 350 6412/27/2009 265 243 74 109 148 141 121 90 271 290 290 270 299 291 8 17 86 104 114 55 90 92 104 234 299 812/28/2009 135 106 91 82 93 85 82 72 46 31 34 24 324 18 22 78 105 143 155 148 60 108 176 228 324 1812/29/2009 92 102 190 184 193 206 209 299 117 203 187 204 203 221 342 240 230 125 125 146 185 213 196 171 342 9212/30/2009 268 257 218 249 258 209 193 187 218 238 10 336 244 313 4 21 29 92 78 97 94 148 131 238 336 412/31/2009 150 124 112 135 135 192 26 240 242 275 234 262 311 264 233 218 215 234 235 219 211 214 230 167 311 261/1/2010 237 245 180 243 285 111 184 66 44 20 26 197 296 191 1 173 148 147 139 167 161 149 181 111 296 11/2/2010 194 173 171 171 176 164 166 136 180 242 266 258 263 276 250 311 145 116 151 171 136 188 127 134 311 1161/3/2010 107 120 94 109 91 100 149 94 76 44 34 17 353 17 35 355 83 116 147 117 146 139 158 160 355 171/4/2010 157 158 161 70 69 145 91 181 152 297 246 253 266 267 243 267 97 89 98 124 127 184 166 152 297 691/5/2010 148 109 122 97 75 130 154 110 248 93 17 7 311 10 30 11 136 86 75 139 138 98 140 102 311 71/6/2010 162 158 168 88 168 90 117 121 170 309 292 251 282 28 23 293 109 71 65 100 86 96 72 101 309 231/7/2010 80 114 127 79 84 47 73 82 353 40 342 34 53 40 25 26 5 10 30 28 68 65 72 169 353 51/8/2010 105 101 95 104 95 94 85 66 343 328 267 306 301 271 312 345 89 291 74 216 215 138 67 141 345 661/9/2010 119 57 101 87 83 98 91 65 63 16 35 11 11 28 6 36 110 82 93 94 115 73 91 108 119 61/10/2010 182 221 80 152 45 11 127 126 58 11 11 25 4 16 16 33 64 107 142 158 135 106 101 186 221 41/11/2010 110 95 92 96 113 132 80 79 106 54 101 271 262 224 241 240 197 81 101 78 233 314 210 183 314 54Max 270 245 209 247 285 213 191 290 353 328 342 306 359 346 358 355 213 291 217 250 233 314 210 218 355‐‐Min 80 55 41 46 45 11 49 65 44 6 8 7 4 1 1 5 5 10 30 28 44 34 55 75‐‐1SAROADforKinross,RoundmountainChannel:WD_10mMonth:12/18/09‐01/11/10HourofdayDay 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Avg Max Min12/18/2009‐3.3‐3.9‐4.2‐3.1‐3.6‐3.5‐3.9‐3.7 0.6 1.1 3.6 4.6 3.5 5.4 5.6 4.6 0.7 0.1 0.1‐0.8‐1.4‐1.5‐2.4‐3.3‐0.4 5.6‐4.212/19/2009‐2.4‐2.6‐4.2‐4.6‐4.8‐4.8‐5.0‐4.0‐0.6 1.5 2.2 3.0 3.4 3.4 3.5 3.0 0.5‐0.7‐0.9‐0.3‐0.6‐2.5‐3.7 0.6‐0.9 3.5‐5.012/20/2009‐3.5‐3.2‐3.7‐3.5‐3.7‐3.5‐4.1‐3.2 0.3 3.9 4.4 5.0 5.1 4.1 3.8 3.6 2.8 2.0 1.8 2.2 2.3 1.7‐0.3 0.4 0.6 5.1‐4.112/21/2009 0.8‐2.0‐4.5‐4.9‐5.0‐5.2‐5.6‐4.3‐2.0‐0.10.6 2.0 2.5 2.6 1.8 1.9 1.1 0.4 0.4 1.0‐0.2 1.5 2.1‐11.3‐1.1 2.6‐11.312/22/2009 0.3‐1.1‐2.2‐3.9‐2.3‐3.4‐3.2‐4.2‐2.4‐1.1‐2.2‐2.6‐2.9‐3.6‐4.8‐5.8‐6.6‐7.0‐6.9‐7.1‐7.9‐10.4‐11.2‐10.2‐4.7 0.3‐11.212/23/2009‐10.3‐11.1‐10.7‐10.3‐10.0‐9.7‐9.8‐10.1‐7.3‐6.1‐5.3‐5.1‐4.4‐3.4‐3.4‐3.5‐6.4‐7.2‐7.0‐7.2‐8.6‐8.7‐9.5‐7.2‐7.6‐3.4‐11.112/24/2009‐9.7‐7.6‐7.3‐8.0‐8.7‐9.0‐9.7‐9.8‐5.4‐2.7‐2.1‐2.6‐1.9‐1.5‐0.7‐1.3‐4.3‐4.7‐4.2‐4.9‐6.3‐9.6‐8.9‐5.7‐5.7‐0.7‐9.812/25/2009‐7.5‐9.9‐9.7‐10.4‐10.3‐10.3‐9.8‐8.8‐4.1‐1.5‐1.0‐0.50.5 0.3 0.5 0.9‐2.3‐4.0‐4.3‐4.6‐5.6‐7.3‐8.3‐3.8‐5.10.9‐10.412/26/2009‐7.5‐8.5‐9.2‐9.6‐10.7‐11.0‐10.6‐10.6‐6.0‐5.0‐4.3‐3.8‐4.0‐1.5‐0.8‐1.7‐2.0‐2.5‐4.0‐4.2‐3.1‐3.4‐3.7‐6.9‐5.6‐0.8‐11.012/27/2009‐5.1‐5.2‐6.5‐8.1‐7.4‐6.2‐5.8‐6.5‐2.7‐3.0‐1.9‐1.5‐0.5 0.5‐0.6‐2.6‐5.2‐6.3‐6.3‐7.3‐7.0‐7.3‐7.1‐3.6‐4.70.5‐8.112/28/2009‐7.6‐8.3‐8.4‐7.5‐7.5‐8.4‐8.7‐8.1‐5.2‐4.8‐3.4‐3.6‐1.5‐2.7‐3.4‐3.9‐4.7‐4.6‐4.3‐3.7‐3.8‐4.4‐3.9‐2.7‐5.2‐1.5‐8.712/29/2009‐5.5‐5.3‐4.8‐5.3‐3.6‐4.0‐3.8‐3.7‐3.1‐0.8‐0.5 0.6 1.5 2.5 2.6 0.4‐1.2‐3.2‐2.9‐2.5‐2.8‐1.9‐2.2‐8.8‐2.42.6‐8.812/30/2009‐2.8‐2.7‐2.1‐1.9‐1.4‐0.8‐0.1‐0.5‐1.0‐2.1‐1.2‐1.1‐0.6‐1.6‐2.1‐2.5‐3.5‐5.2‐6.8‐8.4‐7.9‐8.4‐9.9‐2.2‐3.2‐0.1‐9.912/31/2009‐9.5‐10.2‐11.3‐11.0‐10.7‐10.0‐9.1‐8.0‐5.3‐4.1‐3.1‐0.9 0.2‐1.0 0.0 1.0‐0.7‐1.0‐1.1‐0.9‐0.50.7‐0.9 2.9‐3.9 2.9‐11.31/1/2010‐4.0‐3.2‐4.1‐4.4‐3.2‐4.0‐3.7‐4.2‐4.2‐2.8‐1.1 2.1 2.2 1.0‐0.6‐0.9 4.0 3.2‐1.4‐2.1‐0.6 1.1 2.9‐5.6‐1.4 4.0‐5.61/2/2010 2.4‐2.6 0.9‐1.6 0.6 1.3 0.4‐2.7 1.5 3.2 1.6 2.1 3.9 3.5 4.0 1.7‐1.2‐2.4‐2.1‐2.1‐3.7‐4.4‐5.6‐4.7‐0.2 4.0‐5.61/3/2010‐5.5‐5.8‐5.8‐4.9‐5.8‐6.0‐5.9‐6.2‐1.5‐0.2‐2.51.0 1.8 1.6 1.9 3.0‐1.1‐2.6‐2.7‐3.1‐3.0‐3.2‐4.0‐4.3‐2.7 3.0‐6.21/4/2010‐4.1‐5.2‐5.4‐5.6‐5.6‐5.5‐6.5‐5.0 0.3 2.3 2.8 3.8 3.8 4.4 5.2 4.2‐0.3‐1.2‐2.7‐3.4‐3.8‐3.5‐4.3‐1.0‐1.5 5.2‐6.51/5/2010‐4.6‐5.6‐4.5‐3.8‐3.7‐4.3‐4.2‐3.7‐0.8 2.2 0.3 3.4 1.9 3.4 2.2 4.8 1.9 1.2‐0.3‐0.4‐1.1‐2.3‐1.1 1.1‐0.8 4.8‐5.61/6/2010‐1.7‐1.9‐1.2‐3.3‐2.7‐2.9‐3.0‐2.82.9 3.5 4.8 5.6 5.8 2.1 2.9 3.0 0.7 0.4‐0.1 1.4 1.8 2.0 2.6‐1.2 0.8 5.8‐3.31/7/2010 1.2 1.1 1.3 1.0 0.8 1.0‐0.4 0.0 1.0 1.4 1.9 1.7 1.8 2.0 2.0 1.5 0.8 0.7 0.6 0.5 0.4 0.3 0.0‐1.3 0.9 2.0‐1.31/8/2010‐2.6‐3.0‐3.4‐3.7‐4.1‐4.2‐3.9‐3.7‐3.7‐2.7‐2.2‐0.9 0.4 0.4 2.0 0.7‐0.9‐1.2‐2.3‐0.2 2.0 1.8‐1.9 0.5‐1.5 2.0‐4.21/9/2010‐2.2‐3.2‐2.8‐2.2‐2.4‐2.2‐2.2‐1.9 2.9 3.6 2.9 3.9 3.4 4.9 3.3 2.4 1.5 1.4 1.8 1.5 1.3 0.9 0.0 0.2 0.7 4.9‐3.21/10/2010 1.0 1.5 0.7 0.5 0.5‐0.5‐1.4‐0.5 2.9 2.8 4.5 4.8 5.2 6.3 6.6 6.2 3.5 2.3 1.3 0.8 0.1 0.4 0.7 6.8 2.4 6.8‐1.41/11/2010‐0.1‐0.8‐1.2‐1.2‐1.0‐0.3‐0.3‐0.41.1 1.8 3.1 2.5 3.3 5.0 6.6 8.0 5.5 2.7 2.7 1.8 4.8 4.6 4.1 6.5 2.5 8.0‐1.2Avg‐3.8‐4.4‐4.6‐4.9‐4.6‐4.7‐4.8‐4.7‐1.7‐0.4 0.1 0.9 1.4 1.5 1.5 1.1‐0.7‐1.6‐2.1‐2.2‐2.2‐2.5‐3.1‐2.6‐2.0‐‐ ‐‐Max 2.4 1.5 1.3 1.0 0.8 1.3 0.4 0.0 2.9 3.9 4.8 5.6 5.8 6.3 6.6 8.0 5.5 3.2 2.7 2.2 4.8 4.6 4.1 6.8‐‐8.0‐‐Min‐10.3‐11.1‐11.3‐11.0‐10.7‐11.0‐10.6‐10.6‐7.3‐6.1‐5.3‐5.1‐4.4‐3.6‐4.8‐5.8‐6.6‐7.2‐7.0‐8.4‐8.6‐10.4‐11.2‐11.3‐‐‐‐ ‐11.3SAROADforKinross,RoundmountainChannel:Temp_AMB_CMonth:12/18/09‐01/11/10HourofdayDay 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Avg Max Min12/18/2009‐‐ ‐‐ ‐11.17‐10.92‐11.00‐11.39‐11.94‐12.33‐8.06‐3.28‐0.86‐2.15 2.35 2.98 3.47 1.98‐2.31‐6.61‐7.99‐8.82‐9.19‐10.14‐10.39‐10.57‐6.29 3.47‐12.3312/19/200912/20/200912/21/2009‐10.77‐12.60‐12.20‐12.28‐12.38‐12.11‐12.92‐12.02‐9.48‐6.67‐4.98‐3.15‐0.85 1.34‐1.14 0.97‐0.62 0.11‐0.47‐2.02‐3.02‐1.18‐0.63 0.71‐5.35 1.34‐12.9212/22/200912/23/200912/24/2009‐15.59‐14.30‐15.24‐15.61‐15.99‐16.70‐16.07‐14.83‐7.38‐6.58‐5.75‐4.56‐3.64‐3.36‐2.18‐2.60‐8.46‐10.78‐13.05‐14.62‐14.76‐13.66‐14.36‐14.65‐11.03‐2.18‐16.7012/25/200912/26/200912/27/2009‐11.46‐11.57‐11.81‐12.70‐11.89‐11.01‐10.23‐9.59‐5.53‐4.94‐3.73‐1.95 0.10 1.17‐0.85‐2.47‐6.51‐9.74‐12.13‐12.75‐13.60‐13.68‐14.00‐13.62‐8.52 1.17‐14.0012/28/200912/29/200912/30/2009‐3.36‐2.32‐2.16‐2.54‐2.60‐2.62‐2.95‐3.25‐3.02‐2.53‐1.58‐1.58‐1.46 0.43‐0.89‐1.78‐2.95‐5.21‐5.66‐6.97‐10.03‐12.32‐13.64‐13.05‐4.33 0.43‐13.6412/31/20091/1/20101/2/2010‐9.43‐15.09‐14.98‐15.03‐16.35‐13.07‐12.55‐14.79‐11.35‐9.91‐6.50‐4.46‐2.62‐1.15‐0.55‐3.10‐7.37‐10.43‐12.02‐13.30‐13.93‐14.45‐14.57‐15.39‐10.52‐0.55‐16.351/3/2010Non‐Run‐DayNon‐Run‐DayNon‐Run‐DayNon‐Run‐DayNon‐Run‐DayNon‐Run‐DayNon‐Run‐DayNon‐Run‐DayNon‐Run‐DaySAROADforKinross,RoundmountainChannel:T_AMB_CMonth:12/18/09‐01/11/10HourofdayNon‐Run‐DayNon‐Run‐Day1/4/20101/5/2010‐15.91‐16.75‐17.58‐16.27‐15.88‐16.00‐16.22‐14.87‐10.83‐6.95‐5.17‐2.03‐2.22‐1.62‐1.51‐0.32‐2.99‐4.10‐6.35‐9.00‐10.16‐11.12‐11.15‐10.72‐9.40‐0.32‐17.581/6/20101/7/20101/8/2010‐3.42‐5.18‐6.57‐8.08‐9.78‐9.70‐9.30‐9.27‐7.89‐6.66‐4.05‐0.07 3.28‐0.86 0.68 0.10‐2.64‐3.19‐4.37‐4.32‐3.82‐3.62‐5.10‐5.83‐4.57 3.28‐9.781/9/20101/10/20101/11/2010‐5.99‐6.28‐8.50‐8.34‐7.77‐7.76‐6.73‐6.02‐5.88‐4.70‐2.36 0.73 0.78 1.97 3.61 4.74 0.36 1.50 3.74 3.16 3.93 4.28 3.98 3.14‐1.43 4.74‐8.50Avg‐9.49‐10.51‐11.13‐11.31‐11.51‐11.15‐10.99‐10.78‐7.71‐5.80‐3.89‐2.14‐0.47 0.10 0.07‐0.28‐3.72‐5.38‐6.48‐7.63‐8.29‐8.43‐8.87‐8.89‐6.83‐‐ ‐‐Max‐3.36‐2.32‐2.16‐2.54‐2.60‐2.62‐2.95‐3.25‐3.02‐2.53‐0.86 0.73 3.28 2.98 3.61 4.74 0.36 1.50 3.74 3.16 3.93 4.28 3.98 3.14‐‐4.74‐‐Min‐15.91‐16.75‐17.58‐16.27‐16.35‐16.70‐16.22‐14.87‐11.35‐9.91‐6.50‐4.56‐3.64‐3.36‐2.18‐3.10‐8.46‐10.78‐13.05‐14.62‐14.76‐14.45‐14.57‐15.39‐‐ ‐‐ ‐17.58‐‐IndicatesinvaliddataNon‐Run‐DayNon‐Run‐DayNon‐Run‐DayNon‐Run‐DayNon‐Run‐DayDay 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Avg Max Min12/18/2009‐‐ ‐‐95 95 94 94 94 93 93 73 71 75 61 57 55 60 73 83 87 90 88 92 90 95 82 95 5512/19/200912/20/200912/21/2009 92 92 94 93 92 93 93 92 93 86 74 74 65 64 69 69 74 70 71 76 79 77 76 73 81 94 6412/22/200912/23/200912/24/2009 87 88 86 90 90 89 87 83 56 53 55 52 48 48 44 43 62 70 76 79 80 80 79 79 71 90 4312/25/200912/26/200912/27/2009 79 80 81 83 82 80 78 77 56 52 51 47 42 41 49 53 67 76 81 83 83 85 86 88 70 88 4112/28/200912/29/200912/30/2009 87 78 74 76 75 75 83 92 92 91 88 90 90 81 86 83 81 94 92 92 93 93 91 91 86 94 7412/31/20091/1/20101/2/2010 81 89 92 90 89 91 86 83 67 61 58 56 58 58 54 61 73 81 85 89 88 92 92 90 78 92 541/3/2010Non‐Run‐DayNon‐Run‐DayNon‐Run‐DayNon‐Run‐DayNon‐Run‐DayNon‐Run‐DayNon‐Run‐DayNon‐Run‐DayNon‐Run‐DaySAROADforKinross,RoundmountainChannel:RH_percentMonth:12/18/09‐01/11/10HourofdayNon‐Run‐DayNon‐Run‐Day1/4/20101/5/2010 87 89 89 90 88 89 88 89 80 66 59 54 53 50 53 49 63 71 77 83 84 84 86 83 75 90 491/6/20101/7/20101/8/2010 94 95 96 96 97 96 96 95 95 93 84 70 73 69 64 65 79 82 86 89 89 88 91 89 86 97 641/9/20101/10/20101/11/2010 97 98 96 98 98 96 97 96 96 95 90 78 79 72 65 59 78 69 57 58 55 52 52 53 78 98 52Avg 88 89 89 90 89 89 89 89 81 74 70 66 63 60 60 60 72 77 79 82 82 83 83 82 79‐‐ ‐‐Max 97 98 96 98 98 96 97 96 96 95 90 90 90 81 86 83 81 94 92 92 93 93 92 95‐‐98‐‐Min 79 78 74 76 75 75 78 77 56 52 51 47 42 41 44 43 62 69 57 58 55 52 52 53‐‐ ‐‐41‐‐IndicatesinvaliddataNon‐Run‐DayNon‐Run‐DayNon‐Run‐DayNon‐Run‐DayNon‐Run‐DayDay 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Avg Max Min12/18/2009‐‐ ‐‐623 623 623 623 623 623 623 623 623 623 622 622 622 622 622 622 622 623 623 623 623 623 623 623 62212/19/200912/20/200912/21/2009 619 619 619 619 618 618 618 618 617 617 617 616 615 614 614 614 613 613 613 612 612 611 611 611 615 619 61112/22/200912/23/200912/24/2009 623 623 623 622 622 623 623 623 623 623 623 623 622 622 622 622 622 622 622 622 622 622 622 621 622 623 62112/25/200912/26/200912/27/2009 619 619 619 619 619 619 619 619 620 620 620 620 620 620 620 620 620 620 620 621 621 621 621 621 620 621 61912/28/200912/29/200912/30/2009 616 616 616 616 616 616 616 616 616 617 618 618 617 618 618 619 619 620 621 621 621 622 623 623 618 623 61612/31/20091/1/20101/2/2010 622 622 622 622 622 622 622 622 623 623 623 622 622 622 622 622 622 622 622 623 623 623 623 623 622 623 6221/3/20101/4/20101/5/2010 622 622 622 622 622 622 622 622 622 622 622 622 621 621 621 621 621 621 621 622 622 622 622 622 622 622 6211/6/20101/7/20101/8/2010 622 622 622 622 622 622 622 623 623 623 623 622 621 622 622 622 622 622 623 623 623 623 623 623 622 623 6211/9/20101/10/20101/11/2010 624 624 624 624 624 624 624 624 624 624 624 623 622 622 622 621 621 621 622 622 621 621 621 621 623 624 621Avg 621 621 621 621 621 621 621 621 621 621 621 621 620 620 620 620 620 620 621 621 621 621 621 621 621‐‐ ‐‐Max 624 624 624 624 624 624 624 624 624 624 624 623 622 622 622 622 622 622 623 623 623 623 623 623‐‐624‐‐Min 616 616 616 616 616 616 616 616 616 617 617 616 615 614 614 614 613 613 613 612 612 611 611 611‐‐ ‐‐611‐‐IndicatesinvaliddataNon‐Run‐DayNon‐Run‐DayNon‐Run‐DayNon‐Run‐DayNon‐Run‐DayNon‐Run‐DayNon‐Run‐DayNon‐Run‐DayNon‐Run‐DayNon‐Run‐DayNon‐Run‐DayNon‐Run‐DayNon‐Run‐DayNon‐Run‐DayNon‐Run‐DayNon‐Run‐DaySAROADforKinross,RoundmountainChannel:BP_mmHgMonth:12/18/09‐01/11/10Hourofday

# APPENDIX B 

# HCN DataPage 1 of 2 Wed, 01/20/10 1:21 PM 

# ANALYTICAL REPORT

Tom Brauch Air Sciences, Inc. 1301 Washington Ave, Suite 200 Golden, CO 80401 Phone:

E-mail: (303) 988-2960 x 207

tbrauch@airsci.com Report Date January 20, 2010

Project Manager 

## Rand Potter Workorder: 1001335 Purchase Order: Client Project ID: 

## Air Sciences Inc 011310

9911-5

Analytical Results
12/18/2009 1/13/2010 1001335001 Sample ID:
Lab ID: Media: Collected:
Received: SKC 226-28, Soda Lime-200/600 99111218-1 Sampling Location: Round Mountain

Method:

Analyte ug/sample mg/m3 ppm 

## NIOSH 6010 Analyzed: 1/19/2010

RL (ug/sample)

0.21 NA 0.64 

### NA Hydrogen Cyanide



## 12/18/2009 1/13/2010 1001335002 Sample ID:
Lab ID: Media: Collected:
Received: SKC 226-28, Soda Lime-200/600 99111221-2 

## Sampling Location: Round Mountain

Method:

Analyte ug/sample mg/m3 ppm 

## NIOSH 6010 Analyzed: 1/19/2010

RL (ug/sample)

0.21 NA 0.48 

### NA Hydrogen Cyanide



## 12/18/2009 1/13/2010 1001335003 Sample ID:
Lab ID: Media: Collected:
Received: SKC 226-28, Soda Lime-200/600 99111224-3 Sampling Location: Round Mountain

Method:

Analyte ug/sample mg/m3 ppm 

## NIOSH 6010 Analyzed: 1/19/2010

RL (ug/sample)

0.21 NA <0.21 NA Hydrogen Cyanide



## 12/18/2009 1/13/2010 1001335004 Sample ID:
Lab ID: Media: Collected:
Received: SKC 226-28, Soda Lime-200/600 Field Blank Sampling Location: Round Mountain

Method:

Analyte ug/sample mg/m3 ppm 

## NIOSH 6010 Analyzed: 1/19/2010

RL (ug/sample)

0.21 NA <0.21 NA Hydrogen Cyanide

IHREP-V9.8Page 2 of 2 Wed, 01/20/10 1:21 PM 

# ANALYTICAL REPORT

Project Manager 

## Rand Potter Workorder: 1001335 Purchase Order: Client Project ID: 

## Air Sciences Inc 011310

9911-5

Report Authorization

Method: NIOSH 6010

Sarah E. Adamson Rosemary Hanks Analyst Peer Review

Phone: (801) 266-7700 Email: lab@datachem.com Web: www.datachem.com 

## Laboratory Contact Information ALS Laboratory Group (formerly DataChem Laboratorie s, Inc.) 960 W Levoy Drive Salt Lake City, Utah 84123

The results provided in this report relate only to the items tested. Samples were received in acceptable condition unles s otherwise noted. Samples have not been blank corrected unless otherw ise noted. This test report shall not be reproduced, except in full, without written approval of ALS Laboratory G roup.
ALS Laboratory Group is accredited by AIHA for spec ific fields of testing as documented in its current scope of accreditation (ID#101574) which is available on request by contac ting your project manager or view on the internet a t http://www.aiha.org. The quality systems implemented in the laboratory apply to all methods performed by ALS Laboratory Group r egardless of this current scope of accreditation which does not include perfo rmance based methods, modified methods, and methods applied to matrices not listed in the methods.


### ALS DataChem provides professional analytical servi ces for all samples submitted. ALS Laboratory Grou p is not in a position to interpret the data and assumes no responsibility fo r the quality of the samples submitted.

All quality control samples processed with the samp les in this report yielded acceptable results unles s otherwise noted. 

## General Lab Comments

LOD = Limit of Detection = MDL = Method Detection L imit, A statistical estimate of method/media/instru ment sensitivity. LOQ = Limit of Quantitation = RL = Reporting Limit, A verified value of method/media/instrument sensit ivity. ND = Not Detected, Testing result not detected abov e the LOD or LOQ. ** No result could be reported, see sample comments for details. < This testing result is less than the numerical va lue. ( ) This testing result is between the LOD and LOQ and has higher analytical uncertainty than values a t or above the LOQ. 

## Definitions

IHREP-V9.8Page 1 of 2 Wed, 01/13/10 2:15 PM 

# ANALYTICAL REPORT

Tom Brauch Air Sciences, Inc. 1301 Washington Ave, Suite 200 Golden, CO 80401 Phone:

E-mail: (303) 988-2960 x 207

tbrauch@airsci.com Report Date January 13, 2010

Project Manager 

## Rand Potter Workorder: 1000807 Purchase Order: Client Project ID: 

## Air Sciences Inc 010810

9911-5

Analytical Results
12/27/2009 1/7/2010 1000807001 Sample ID:
Lab ID: Media: Collected:
Received: SKC 226-28, Soda Lime-200/600 991112272009-1 Sampling Location: Round Mountain

Method:

Analyte ug/sample mg/m3 ppm 

## NIOSH 6010 Analyzed: 1/12/2010

RL (ug/sample)

0.21 NA 0.51 

### NA Hydrogen Cyanide



## 12/27/2009 1/7/2010 1000807002 Sample ID:
Lab ID: Media: Collected:
Received: SKC 226-28, Soda Lime-200/600 991112302009-2 

## Sampling Location: Round Mountain

Method:

Analyte ug/sample mg/m3 ppm 

## NIOSH 6010 Analyzed: 1/12/2010

RL (ug/sample)

0.21 NA 0.48 

### NA Hydrogen Cyanide



## 12/27/2009 1/7/2010 1000807003 Sample ID:
Lab ID: Media: Collected:
Received: SKC 226-28, Soda Lime-200/600 9911122010-3 Sampling Location: Round Mountain

Method:

Analyte ug/sample mg/m3 ppm 

## NIOSH 6010 Analyzed: 1/12/2010

RL (ug/sample)

0.21 NA 1.1 

### NA Hydrogen Cyanide



## 12/27/2009 1/7/2010 1000807004 Sample ID:
Lab ID: Media: Collected:
Received: SKC 226-28, Soda Lime-200/600 Blank Sampling Location: Round Mountain

Method:

Analyte ug/sample mg/m3 ppm 

## NIOSH 6010 Analyzed: 1/12/2010

RL (ug/sample)

0.21 NA <0.21 NA Hydrogen Cyanide

IHREP-V9.8Page 2 of 2 Wed, 01/13/10 2:15 PM 

# ANALYTICAL REPORT

Project Manager 

## Rand Potter Workorder: 1000807 Purchase Order: Client Project ID: 

## Air Sciences Inc 010810

9911-5

Report Authorization

Method: NIOSH 6010

Sarah E. Adamson Rosemary Hanks Analyst Peer Review

Phone: (801) 266-7700 Email: lab@datachem.com Web: www.datachem.com 

## Laboratory Contact Information ALS Laboratory Group (formerly DataChem Laboratorie s, Inc.) 960 W Levoy Drive Salt Lake City, Utah 84123

The results provided in this report relate only to the items tested. Samples were received in acceptable condition unles s otherwise noted. Samples have not been blank corrected unless otherw ise noted. This test report shall not be reproduced, except in full, without written approval of ALS Laboratory G roup.
ALS Laboratory Group is accredited by AIHA for spec ific fields of testing as documented in its current scope of accreditation (ID#101574) which is available on request by contac ting your project manager or view on the internet a t http://www.aiha.org. The quality systems implemented in the laboratory apply to all methods performed by ALS Laboratory Group r egardless of this current scope of accreditation which does not include perfo rmance based methods, modified methods, and methods applied to matrices not listed in the methods.


### ALS DataChem provides professional analytical servi ces for all samples submitted. ALS Laboratory Grou p is not in a position to interpret the data and assumes no responsibility fo r the quality of the samples submitted.

All quality control samples processed with the samp les in this report yielded acceptable results unles s otherwise noted. 

## General Lab Comments

LOD = Limit of Detection = MDL = Method Detection L imit, A statistical estimate of method/media/instru ment sensitivity. LOQ = Limit of Quantitation = RL = Reporting Limit, A verified value of method/media/instrument sensit ivity. ND = Not Detected, Testing result not detected abov e the LOD or LOQ. ** No result could be reported, see sample comments for details. < This testing result is less than the numerical va lue. ( ) This testing result is between the LOD and LOQ and has higher analytical uncertainty than values a t or above the LOQ. 

## Definitions

IHREP-V9.8Page 1 of 2 Wed, 01/20/10 1:22 PM 

# ANALYTICAL REPORT

Tom Brauch Air Sciences, Inc. 1301 Washington Ave, Suite 200 Golden, CO 80401 Phone:

E-mail: (303) 988-2960 x 207

tbrauch@airsci.com Report Date January 20, 2010

Project Manager 

## Rand Potter Workorder: 1001930 Purchase Order: Client Project ID: 

## Air Sciences 011910

99-11-5

Analytical Results
1/13/2010 1/19/2010 1001930001 Sample ID:
Lab ID: Media: Collected:
Received: SKC 226-28, Soda Lime-200/600 9911152010-1 Sampling Location: Round Mountain

Method:

Analyte ug/sample mg/m3 ppm 

## NIOSH 6010 Analyzed: 1/19/2010

RL (ug/sample)

0.21 NA 0.71 

### NA Hydrogen Cyanide



## 1/13/2010 1/19/2010 1001930002 Sample ID:
Lab ID: Media: Collected:
Received: SKC 226-28, Soda Lime-200/600 9911182010-2 

## Sampling Location: Round Mountain

Method:

Analyte ug/sample mg/m3 ppm 

## NIOSH 6010 Analyzed: 1/19/2010

RL (ug/sample)

0.21 NA <0.21 NA Hydrogen Cyanide



## 1/13/2010 1/19/2010 1001930003 Sample ID:
Lab ID: Media: Collected:
Received: SKC 226-28, Soda Lime-200/600 99111112010-3 Sampling Location: Round Mountain

Method:

Analyte ug/sample mg/m3 ppm 

## NIOSH 6010 Analyzed: 1/19/2010

RL (ug/sample)

0.21 NA 0.40 

### NA Hydrogen Cyanide



## 1/13/2010 1/19/2010 1001930004 Sample ID:
Lab ID: Media: Collected:
Received: SKC 226-28, Soda Lime-200/600 Field Blank Sampling Location: Round Mountain

Method:

Analyte ug/sample mg/m3 ppm 

## NIOSH 6010 Analyzed: 1/19/2010

RL (ug/sample)

0.21 NA <0.21 NA Hydrogen Cyanide

IHREP-V9.8Page 2 of 2 Wed, 01/20/10 1:22 PM 

# ANALYTICAL REPORT

Project Manager 

## Rand Potter Workorder: 1001930 Purchase Order: Client Project ID: 

## Air Sciences 011910

99-11-5

Report Authorization

Method: NIOSH 6010

Sarah E. Adamson Rosemary Hanks Analyst Peer Review

Phone: (801) 266-7700 Email: lab@datachem.com Web: www.datachem.com 

## Laboratory Contact Information ALS Laboratory Group (formerly DataChem Laboratorie s, Inc.) 960 W Levoy Drive Salt Lake City, Utah 84123

The results provided in this report relate only to the items tested. Samples were received in acceptable condition unles s otherwise noted. Samples have not been blank corrected unless otherw ise noted. This test report shall not be reproduced, except in full, without written approval of ALS Laboratory G roup.
ALS Laboratory Group is accredited by AIHA for spec ific fields of testing as documented in its current scope of accreditation (ID#101574) which is available on request by contac ting your project manager or view on the internet a t http://www.aiha.org. The quality systems implemented in the laboratory apply to all methods performed by ALS Laboratory Group r egardless of this current scope of accreditation which does not include perfo rmance based methods, modified methods, and methods applied to matrices not listed in the methods.


### ALS DataChem provides professional analytical servi ces for all samples submitted. ALS Laboratory Grou p is not in a position to interpret the data and assumes no responsibility fo r the quality of the samples submitted.

All quality control samples processed with the samp les in this report yielded acceptable results unles s otherwise noted. 

## General Lab Comments

LOD = Limit of Detection = MDL = Method Detection L imit, A statistical estimate of method/media/instru ment sensitivity. LOQ = Limit of Quantitation = RL = Reporting Limit, A verified value of method/media/instrument sensit ivity. ND = Not Detected, Testing result not detected abov e the LOD or LOQ. ** No result could be reported, see sample comments for details. < This testing result is less than the numerical va lue. ( ) This testing result is between the LOD and LOQ and has higher analytical uncertainty than values a t or above the LOQ. 

## Definitions

IHREP-V9.8

# APPENDIX C 

# Site Check Forms, Audits, and Calibration**\ll ~** **~(** ) I '( I' 1'-'

_



## Calibration Form 

## Round Mountain Air Quality and Meteorological Monitoring

Site: Round Mountain Technician: Brian Smith

Date : 12/15/2009 Site Conditions: Cold, Clear

Invalid Data Range: Bef o re 12/15/2009 Logger Serial Number: 2959

Initial Prior to Departure Initials 

### 0 0 Data download (record date and time). BWS 

### 0 0 Time and date verified on datalogger. BWS 

### 0 0 Communications verified. BWS 

### 0 0 All public real-time values are confirmed and as expected. BWS 

### 0 WS/WD verification performed (complete audit form)

. N/A 

### 0 Temperature and RH verification performed (complete audit form). BWS 

### 0 Precipitation verification performed (complete audit form). N/A

Barometric pressure verification performed (complete audit form). BWS

# ~ Solar panel cleaned. BWS

Comments :

Site was installed and became operational on 12/15/2009

All sensors were calibrated

12/15/2009 

### I Signature Date:

99-11-12152009CALAQ-MET 1; \11 ;**~l ll** **',** I ' " l



### Calibration Form 

## Round Mountain Air Quality and Meteorological Monitoring

Temperature and Relative Humidity

- Co-Located Calibration

Time: 15:00 to 16:00 PST

Relative Humidity Measured

Oiff HMP45C Logger VWR Thermo Hygro

5N: 03250918 5N' 80357103 -0

. 1 1. 60 1. 61
0

. 1 2. 60 2. 62
-0.1 3. 61 3. 62
-0.1 4. 62 4. 61
0.0 5. 61 5. 62
0.1 6. 62 6. 63
-0

. 1 7. 61 7. 63 -0

. 1 8. 61 8. 62
0.0 9. 62 9. 63
0.0 10. 62 10. 62
0

. 0

Barometric Pressure

- Co-Located Calibration Time: 15:00 to 16:00 PST

Temperature HMP45C Logger

5N: 03250918 1. 1.5
2. 1.7
3. 1.7 4. 1.7
5. 1.8
6. 2.0
7. 2.0
8. 1.9
9. 1.9
10. 1.9 Average Difference

Difference = Site· Measured Oiff

-1
-2
-1
1
-1
-1
-2
-1
-1
0
-0.9

Time: 15:00 PST

Barometric Pressure

logger Reading mmHg
SN : D31400223
1. 639.0
2 639.0
3

. 639.0
4

. 638

. 0 Average Difference

-Difference 

### = Site

- Measured Measured

VWR Thermo Hygro

5N' 80357103 1. 1.6
2

. 1.6
3. 1.8
4. 1.8
5. 1.8
6

. 1.9
7. 2.1
8. 2

. 0
9. 1.9
10

. 1.9

Measured
Brunton Altimeter Diff • mmHg SN : NA
1. 638 1
2. 637 2 3. 638 1 4. 638 

## o

Copy of**99-11-12152009CAL~Q-MET** 2

### Calibration Form 

## Round Mountai Air Quality and Meteorological Monitoring

HeN 

### Sampler System
Time: 15:00 to 16:00 PST BP{mm Hg)
1.511

mV Pressure Transducer SN'35543F3 Raw Inches Sampler SN'35542F3 Inches Digital
Manometer SN' 35545F3 Flow (L/min) Low
Flow BIOS SN'35583F3 Pl/Pa Qa (Flow Meter)

1. 1. 51.59 1

. 49

. 90 1. 1.931 1. 0.8491 1. 0.11646
2. 2

. 45

. 67 2. 45

. 00 2

. 1.79 2. 0.867 2. 0.10801
3. 3. 41.73 3. 40.40 3

. 1.65 3. 0.878 3

. 0.09956
4

. 4. 34 .8 2 4

. 34.50 4

. 1.44 4. 0.898 4. 0

. 08689
5. 5. 24.96 5. 24.70 5. 1.10 5. 0.927 5. 0.06637
6. 6. 6

. 6. 6. 6.
7. 7. 7. 7. 7. 7.
8. 8. 8. 8

. 8. 8.
9. 9. 9. 9

. 9. 9.
10. 10. 10. 10. 10. 10. 

## I #DIV/Ol 

## I 39.754 

## I 38.9 

## I 1.582

aDifference = Site

- Measured bDiHerence; ((Site

­ Measuredj/Measuredj*lOO Slope Intercept -1.5302 1.0299 Correlation -0.9982 Tube 1 Flow Tube 2 Flow Tube 3 Flow

Notes for next trip:

12/15/2009 SIgnature Date:

99-11-12152009CALAQ-MET 3

# APPENDIX D 

# Hydrogen Cyanide (HCN) Fence Line Monitoring Plans

# Site-Specific Hydrogen Cyanide (HCN) Fence Line Monitoring Plan

RMGC-SVCO, I NC



# .

P ROJECT 

## 99-6-1 O

CTOBER 

## 2009

### ii 

# CONTENTS Page

1 INTRODUCTION ................................................................................................................ ............................................ 1 1.1 Mine Description and Proposed Monitoring .................................................................................. .......................... 1

2 METEOROLOGY ................................................................................................................. .......................................... 2 2.1 Prevailing Wind Direction ................................................................................................. ....................................... 2

3 PROPOSED HCN MONITORING SITE ................................................................................................ ......................... 4 3.1 Operations Boundary and Nearest Population Areas .......................................................................... ................... 4 3.2 Potential Sources of HCN .................................................................................................. ..................................... 4

3.2.1 Leach Pads .............................................................................................................. ....................................... 4 3.2.2 Tailings Impoundment .................................................................................................... ................................. 5 3.2.3 Mill and ADR Areas ...................................................................................................... ................................... 5 3.3 Proposed HCN Monitor Location ............................................................................................. ............................... 5

4 PROPOSED MODIFICATIONS TO THE GENERAL HCN MONITORING PLAN ....................................................... 10



## Figures
Figure 2.1: Calendar Year 2008 Wind Rose ..................................................................................... ............................... 2 Figure 2.2: Calendar Quarter Wind Roses for 2008 ............................................................................. ............................ 3 Figure 3.1: Proposed HCN Monitoring Site ..................................................................................... ................................. 6 Figure 3.2: Large Scale Area Map ............................................................................................. ...................................... 7 Figure 3.3: ADR Area ......................................................................................................... .............................................. 8 Figure 3.4: Mill Area ........................................................................................................ ................................................. 9



## Appendices Appendix A: Hydrogen Cyanide (HCN) Fence Line Monitoring Plan

### 1 

## SECTION 1 

# INTRODUCTION

1.1 Mine Description and Proposed Monitoring

Round Mountain Gold Corporation – Smoky Valley Common Operation (RMGC-SVCO) operates a gold mining facility located at #1 Smoky Valley Mine Road, Round Mountain, Nevada. The RMGC-SVCO facility consists of open-pit mining and gold recovery processes including ore crushing, heap leaching, ore milling, gravity separation, carbon adsorption, stripping and regeneration, electrowinning, and refining. The leach solutions used in the gold recovery processes contain cyanide. These solutions have the potential for low levels of hydrogen cyanide (HCN) formation and emission to the atmosphere. To assess the ambient concentrations of HCN emissions, RMGC-SVCO plans to install and oper ate an HCN monitor downwind of the potential HCN sources near the RMGC-SVCO operations area.

The HCN monitoring equipment and sa mpling procedures will follow the Hydrogen Cyanide (HCN) Fence Line Monitoring Plan , approved by EPA on October 9, 2009 (General HCN Monitoring Plan). This plan is provided in Appe ndix A. The purposes of the site-specific plan described herein are to identify the location where the monitor will be sited and to identify any modifications to the monitoring equipment and sampling procedures described in the General HCN Monitoring Plan that are specific to RMGC-S VCO. Per EPA’s instructions, the site location takes into consideration the proximity of the HCN sources to public access areas and the prevailing wind direction. The site location also takes into consideration accessibility for the RMGC-SVCO maintenance and project technicians.

The following sections describe the predominan t wind direction, the RMGC-SVCO boundary of public access, the nearest population areas to this boundary, the po tential sources of HCN emissions and their locations, and the proposed HCN monitoring site.

The HCN monitoring system proposed herein is a new system. Typically, a full field test and system verification of such a prototype monitor would be scheduled in advance of deploying the
monitor for data collection. This is done in orde r to identify system design problems, and refine the system configuration and operating and mainte nance procedures as appropriate. Due to the schedule that EPA has requested, only limited field testing and system verification will be possible prior to data collection. Because of this , it is possible that problems may arise with the monitoring system which will affect data collection; however, RMGC-SVCO will take all reasonable measures to avoid such problems in an effort to minimize any disruptions to the monitoring program.

### 2 

## SECTION 2 

# METEOROLOGY

2.1 Prevailing Wind Direction

RMGC-SVCO currently operates a meteorological station. This station is located at 493,898 meters east, 4,284,520 meters north, UTM Zone 11N, NAD83, elevation 6361 feet., near the northeast edge of the pit. Figure 2.1 summarizes the hourly wind directions (the direction from which the wind is blowing) and wind speeds for the 2008 calendar year. Figure 2.2 provides wind roses for each calendar quarter of 2008. As shown by the annual and quarterly wind roses, the prevailing winds are from the southerly and easterly directions, with some winds from the
north.

Figure 2.1: Calendar Year 2008 Wind Rose

2%

4%

6%

8%

10%

12%

14%

16%

18%

20% N

NNE

NE

ENE

E

ESE

SE

SSE
S SSW SW WSW W WNW NW NNW

2 4 8 12 18 mph

Wind Frequency Distribution - Hourly Met. Data 01/01/08 - 12/31/08 Calm hours = 0 Missing hours = 0 Number of non-calm/missing hours = 8,783

### 3 Figure 2.2: Calendar Quarter Wind Roses for 2008



## First Quarter Second Quarter 01/01/08 - 03/31/08 04/01/08 - 06/30/08

Third Quarter Fourth Quarter 07/01/08 - 09/30/08 10/01/08 - 12/31/08 2%

4%

6%

8%

10%

12%

14%

16%

18%

20% N

NNE

NE

ENE

E

ESE

SE

SSE
S SSW SW WSW W WNW NW NNW

2 4 8 12 18 mph

Wind Frequency Distribution - Hourly Met. Data 01/01/08 - 03/31/08 Calm hours = 0 Missing hours = 0 Number of non-calm/missing hours = 2,184 2%

4%

6%

8%

10%

12%

14%

16%

18%

20% N

NNE

NE

ENE

E

ESE

SE

SSE
S SSW SW WSW W WNW NW NNW

2 4 8 12 18 mph

Wind Frequency Distribution - Hourly Met. Data 04/01/08 - 06/30/08 Calm hours = 0 Missing hours = 0 Number of non-calm/missing hours = 2,183

2%

4%

6%

8%

10%

12%

14%

16%

18%

20% N

NNE

NE

ENE

E

ESE

SE

SSE
S SSW SW WSW W WNW NW NNW

2 4 8 12 18 mph

Wind Frequency Distribution - Hourly Met. Data 07/01/08 - 09/30/08 Calm hours = 0 Missing hours = 0 Number of non-calm/missing hours = 2,208 2%

4%

6%

8%

10%

12%

14%

16%

18%

20% N

NNE

NE

ENE

E

ESE

SE

SSE
S SSW SW WSW W WNW NW NNW

2 4 8 12 18 mph

Wind Frequency Distribution - Hourly Met. Data 10/01/08 - 12/31/08 Calm hours = 0 Missing hours = 0 Number of non-calm/missing hours = 2,208

### 4 

## SECTION 3 

# PROPOSED HCN MONITORING SITE

3.1 Operations Boundary a nd Nearest Population Areas

Aerial photos and shaded relief maps are provided as Figures 3.1 through 3.4. Figure 3.1 provides an aerial photo of the mine site, the operations boundary, and the potential HCN sources. Figure 3.2 provides a shaded relief map of the area surrounding the RMGC-SVCO mine. The nearest residents are in the subdivision of Hadley located two miles east of the mine and in the old town of Round Mountain adjacent to the northeast side of the mine.



# 3.2 Potential Sources of HCN

Figures 3.1, 3.3, and 3.4 highlight the potential sources of HCN emissions at RMGC-SVCO. These
sources include:

 active leach pads;

 pregnant and barren ponds;

 tailings impoundment and reclaim ponds;

 various tanks containing cyanide solutions at the mill area, Adsorption, Desorption and Refinery (ADR) area, and adjacent to the dedicated leach pads; and

 exhaust stacks for the EW cells and the pregna nt and barren tanks at the ADR building.

Closer views of the HCN sources at the mill and ADR areas are shown in Figures 3.3 and 3.4.



# 3.2.1 Leach Pads
RMGC-SVCO operates several leach pads (the we st dedicated pad, the reusable pad, and the south dedicated pad). Cyanide leach solution is applied to portions of these pads via drip emitters. Potential HCN emissions come from the cyanide solution applied to the ore on the pads, the pregnant ponds used to collect solution from the pads, and the barren ponds used to supply solution to the pads. Carbon-in-Column (CIC) tanks used to adsorb gold from the pregnant solution are also potential HCN sources. The CIC tanks are located within buildings at the dedicated plant and ADR area, which are vented to the atmosphere via normal building ventilation. There is also a cyanide solution ma nagement tank at the dedicated plant. These pads, ponds, and tanks are shown in Figure 3.1.

### 5 

# 3.2.2 Tailings Impoundment
Cyanide solution used in the mill to extract gold in the Carbon-in-Leach (CIL) tanks is sent to a cyanide destruct tank and then discharged to the tailings impoundment. Underflow from the tailings impoundment is collected in the reclaim ponds. The residual cyanide in the tails solution has the potential to produce HCN air emissions. The tailings impoundment and reclaim ponds are shown in Figure 3.1. The cyanide destruct tank is shown in Figure 3.4.



# 3.2.3 Mill and ADR Areas
The ADR and mill areas, shown in Figures 3.3 and 3.4, contain stack and tank sources of potential HCN emissions. At the ADR building, there is one stack associated with the EW cells and one stack associate with the pregnant and barren tanks. On the west side of this building are three cyanide solution management tanks. The ADR bu ilding also houses CIC ta nks, which are vented to the atmosphere via normal building ventilation. At the mill, in addition to the cyanide destruct and thickener tanks described above, there are six CIL tanks and three cyanide leach solution tanks, which are open to the atmosphere at the top.


# 3.3 Proposed HCN Monitor Location

RMGC-SVCO proposes to place the HCN monitor at a property owned by RMGC-SVCO within the subdivision of Hadley. As shown in Figure 3.1, the proposed locati on is approximately two miles west of the mine. Hadley is the principle community near the mine site and the monitoring
data collected here will inform EPA of the HCN ex posure to the Hadley residents. This location is in a favorable position to detect emissions from the potential HCN sources due to the prevailing winds from the easterly directions.

The proposed monitor location has line power an d is easily accessible . The proposed site coordinates are 485,949 meters east, 4,282,968 me ters north, UTM Zone 11 N, NAD83, elevation, 5,797 feet.

### 10 

## SECTION 4 

# PROPOSED MODIFICATIONS TO THE GENERAL HCN MONITORING PLAN

RMGC-SVCO does not propose any modifications to the General HCN Monitoring Plan with regards to the HCN sampling equipment. RM GC-SVCO does, however, propose to use its existing meteorological station to collect the meteorological parameters (with the exception of relative humidity and barometric pressure) outlin ed in the General HCN Monitoring Plan in lieu of installing the meteorological measurement equipment described in the general plan.

The existing station is located at the mine site an d, therefore, it will provide representative data for the overall mine and the monitor site. See Figu re 3.1. The sensors for wind direction, wind speed, and ambient temperature at the existing meteorological station meet the data quality objectives and criteria described in Section 2.1 of the General HCN Monitoring Plan. Because the existing station is not equipped to measure re lative humidity and barometric pressure, these
sensors will be installed at the HCN monitor si te per the General HCN Monitoring Plan. The existing station is also audited on a quarterly basis.

As discussed in Section 3.3, line power is available at the proposed HCN monitor location. Therefore, the solar power system described in the General HCN Monitoring Plan will not be
needed.

# APPENDIX A 

# Hydrogen Cyanide (HCN) Fence Line Monitoring Plan

# Hydrogen Cyanide (HCN) Fence Line Monitoring Plan

N EVADA 

# M INING 

# A SSOCIATION

P ROJECT 

## 59-43-70 O

CTOBER 

## 2009Hcn Sampling Plan_V7.Docx 

### ii 

# CONTENTS Page

1 PROJECT MANAGEMENT ELEMENTS ................................................................................................. ...................... 1 1.1 Sampling Purpose .......................................................................................................... ........................................ 1 1.2 System Description ........................................................................................................ ......................................... 1

2 QUALITY OBJECTIVES AND CRITERIA FOR DATA MEASUREMENT ...................................................................... 3 2.1 Data Quality Objectives and Criteria ...................................................................................... ................................. 3

3 SPECIAL TRAINING REQUIREMENTS/CERTIFICATION ................................................................................. .......... 4

4 DOCUMENTATION OF RECORDS .................................................................................................... .......................... 5 4.1 Data Reporting Package Format and Documentation Control ................................................................... ............ 5

5 DATA GENERATION AND ACQUISITION ............................................................................................. ....................... 6 5.1 Sampling Process Design and Methods Requirements .......................................................................... ............... 6

5.1.1 Purpose ................................................................................................................. .......................................... 6 5.1.2 Sampling Network Design ................................................................................................. .............................. 6 5.1.3 Equipment Description ................................................................................................... ................................. 7 5.1.4 Data Logger ............................................................................................................. ........................................ 7 5.1.5 Wind Speed .............................................................................................................. ....................................... 7 5.1.6 Wind Direction .......................................................................................................... ....................................... 8 5.1.7 Temperature Sensor and Radiation Shield ................................................................................. .................... 8 5.1.8 Relative Humidity ....................................................................................................... ..................................... 8 5.1.9 Barometric Pressure ..................................................................................................... ................................... 8 5.1.10 HCN Sampling System .................................................................................................... .............................. 8 5.1.11 Power and Data Transfer ................................................................................................ ............................ 12 5.1.12 Meteorological Towers .................................................................................................. .............................. 12 5.2 Rationale for Design ...................................................................................................... ....................................... 12 5.3 Scheduled Measurement Activities .......................................................................................... ............................. 12 5.4 Measurement System Failure Response ....................................................................................... ....................... 13

6 SAMPLING METHOD REQUIREMENTS ................................................................................................ .................... 14 6.1 Sample Handling and Custody Requirements .................................................................................. .................... 14 6.2 Analytical Methods Requirements and Breakthrough Check .................................................................... ........... 14 6.3 Quality Control Requirements .............................................................................................. ................................. 14
7 INSTRUMENT/EQUIPMENT TESTING, INSPECTI ON, AND MAINTENANCE REQUIREMENTS ............................ 16

7.1 General Procedures ........................................................................................................ ...................................... 16 7.2 Instrument Calibration and Frequency ...................................................................................... ............................ 16

7.2.1 Calibration Equipment Maintenance ....................................................................................... ...................... 16 7.2.2 Calibration Records and Traceability .................................................................................... ........................ 17

8 INSPECTION/ACCEPTANCE REQUIREMENTS FOR SUPPLIES AND CONSUMABLES ....................................... 18

9 DATA MANAGEMENT ............................................................................................................. .................................... 19 9.1 Data Custody .............................................................................................................. .......................................... 19

10 DATA VALIDATION AND USABILITY .............................................................................................. ......................... 20
10.1 Data Review, Validation, and Certification ............................................................................... ........................... 20

10.1.1 Data Validation ........................................................................................................ .................................... 20 10.1.2 Data Collection ........................................................................................................ .................................... 20 10.1.3 Data Reduction ......................................................................................................... ................................... 20 10.2 Validation Methods ....................................................................................................... ...................................... 21

10.2.1 Data Review and Validation Requirements ................................................................................ ................. 21Hcn Sampling Plan_V7.Docx 

### iii 

# CONTENTS - Continued Page



## Tables
Table 1: Sensor Height on Towers ............................................................................................. ...................................... 2 Table 2: System Accuracies and Resolution .................................................................................... ................................ 3 Table 3: System Performance and Data Custody Forms ........................................................................... ...................... 5 Table 4: System Components ................................................................................................... ....................................... 6 Table 5: Sampling Frequency .................................................................................................. ...................................... 12 Table 6: Scheduled Sampling Activities ....................................................................................... .................................. 13 Table 7: Project Quality Control Checks ...................................................................................... .................................. 15
Table 8: Preventive Maintenance Schedule ..................................................................................... .............................. 16 Table 9: Calibration Equipment Testing ....................................................................................... .................................. 17
Table 10: Data Recorded on Site .............................................................................................. ..................................... 20



## Figures
Figure 1: HCN Sampling System Flow Diagram - Static Mode ..................................................................... ................... 9 Figure 2: HCN Sampling System Flow Diagram - Warm-Up Mode .................................................................... ........... 10 Figure 3: HCN Sampling System Flow Diagram - Sampling Mode Sorbent Tube 1 .................................................... .. 11



## Appendices
Appendix A: NIOSH Method 6010Hcn Sampling Plan_V7.Docx 

### 1 

## SECTION 1 

# PROJECT MANAGEMENT ELEMENTS

1.1 Sampling Purpose

This sampling plan is being developed to determine the levels of hydrogen cyanide (HCN) in ambient air at the fence line of a mine site. This plan describes the general HCN sampling equipment, collection methods, and data recording procedures. Separate site-specific plans will be submitted for individual mine sites where HCN monitoring will take place. The site-specific plans will be in accordance with this general plan unless otherwise noted, in which case the specific plan will take precedence.

There is currently no EPA method for measuring trace levels of HCN in ambient air. The method described in this monitoring plan was develope d using some elements of both EPA and NIOSH sampling and analytical guidelines. Meteorological parameters will be collected. In addition, an optional video surveillance system may be deployed to determine the operability of the sampler as well as identify any unusual conditions at the sampler.

The design of the system uses elements of U.S. EPA Quality Assurance Handbook of Air Pollution Measurement Systems Volume II as well as the NIOSH Manual of Analytical Methods, Method 6010. All meteorological parameters will be collected consistent with U.S. EPA Quality Assurance Handbook of Air Pollution Measurement System s Volume IV - Meteorological Measurements (EPA600/R94-038D), March 1995, and as provided in this plan.


# 1.2 System Description

The system will consist of a data logger connected to a low-flow pump which is connected through sorbent tubes to an ambient air inlet. The sorbent tubes will capture any HCN in the ambient air and will be sent to a certified lab for analysis. The sampling schedule will follow a 1- in-3 day calendar for a period of two months. During a run day, all parameters will be collected every two seconds and time-averaged into 15-minute values. The parameters collected are shown in Table 1. Wind speed, wind direction, ambient temperature, relative humidity, and barometric pressure are collected as well as flow rate through the sorbent tubes.

The measurement height of the inlet is two meters. The height of the wind instruments will be 3.5 meters. All other parameters are measured at 2 meters.Hcn Sampling Plan_V7.Docx 

### 2 Table 1: Sensor Height on Towers (meters above ground)



## Parameter Height Wind speed 3.5
Wind direction 3.5 Ambient temperature 2 Relative humidity 2 Barometric pressure 2 Sampler Flow 2Hcn Sampling Plan_V7.Docx 

### 3 

## SECTION 2 

# QUALITY OBJECTIVES AND CRITERIA FOR DATA MEASUREMENT

2.1 Data Quality Objectives and Criteria

The primary quality objectives are taken from EPA guidance where applicable. The following tables present the guidelines for each sensor as well as the relevant references for each.

Table 2: System Accuracies and Resolution

Parameter Sensor* Range Accuracy Standard Measurement
Resolution Reference

Wind direction R.M. Young 05305-AQ Range: 0 ° to 360 ° + 3 ° Accuracy:

+ 5 ° 1.0 ° EPA-454/4-87-007 Section 6.1.1, EPA-454/R-99-005, February 2000, Table 5-1 Wind speed R.M. Young 05305-AQ 0.4 to 45 m/s + 0.2 m/s Accuracy:

+ 0.25 m/s

up to speeds of 5

m/s and

+ 5% thereafter 0.1 m/s EPA-454/4-87-007 Section 6.1.1 EPA-454/R-99-005, February 2000, Table 5-1

Ambient temp. Campbell Scientific Model HMP45C -39.2 ° C to +60 ° C + 0.3 ° + 0.5 ° C 0.1 ° C EPA-454/4-87-007 Section 6.1.5 EPA-454/R-99-005, February 2000, Table 5-1 Relative humidity Campbell Scientific Model HMP45C 0.8 to 100% + 2% (0-90% RH) and

+ 3% (90- 100% RH) 1.5 ° C dew point temperature

error 1% EPA-454/4-87-007 Section 6.1.4 EPA-454/R-99-005, February 2000, Table 5-1
Barometric
pressure Vaisala PT101B -40 ° C to 60 ° C + 0.5 mb + 3 mb + 0.1 mb EPA-454/4-87-007 Section 6.1.7 EPA-454/R-99-005, February 2000, Table 5-1 Flow rate Pressure transducer N/A + 5% + 10% of observed 0.1 l/min N/A

* Or equivalent sensor.Hcn Sampling Plan_V7.Docx 

### 4 

## SECTION 3 

# SPECIAL TRAINING REQUIREMENTS/CERTIFICATION

The monitoring equipment should be operated unde r the guidance of the Project Technician. The Project Technician will receive training in the equipment operation. Any non-routine work on this system must be conducted by a qualified technician.Hcn Sampling Plan_V7.Docx 

### 5 

## SECTION 4 

# DOCUMENTATION OF RECORDS

All of the forms which will be used to document the system performance and data custody are
listed in Table 3.

Table 3: System Performance and Data Custody Forms



## Component Hard Copy or Electronic Copy Comments Site Check Form Hard Copy Include check of flow and meteorological sampling. Chain of Custody Form Hard Copy Record handling of sorbent tube through analytical process. Site-Specific Journal Record Hard Copy and Electronic Copy Record any anomalous

occurrences. Flow Audit Hard Copy and Electronic Copy Conduct at end of 2 month sampling period.



# 4.1 Data Reporting Package Format and Documentation Control

A report will be prepared and submitted to EPA within 30 days of the conclusion of the data collection program. The report will contain:

• A calculation of the percentage of valid data collected with an explanation of any instrument malfunction for each parameter,

• All valid hourly meteorological data,

• All valid flow data,

• All HCN concentrations determined by laboratory analysis,

• Copies of Site Check Forms,

• Copies of any calibrations and audits performed,

• Anecdotally conveyed no tes and anomalies, and

• Corrective actions taken (if any).
After the first four weeks of sampling, prelim inary data will be supplied to EPA after the analyses are received from the laboratory.Hcn Sampling Plan_V7.Docx 

### 6 

## SECTION 5 

# DATA GENERATION AND ACQUISITION

5.1 Sampling Process Design and Methods Requirements 5.1.1 Purpose
The monitoring requirements subject to EPA an d federal guidelines are strictly defined for meteorology but not for HCN. The equipment se lection and operation of the station is in accordance with available guidelines. In cases where an existing meteorological station at the mine meets all applicable guidelines, this station may be used in lieu of the meteorological equipment specified herein. The site-specific pl an submitted by each mine will address the proposed location of the meteorological monito ring station that will be used to provide meteorological data for the ambient fence line monitoring program.


# 5.1.2 Sampling Network Design
The monitoring system will consist of the following parts, or equivalent, as specified in the sitespecific plan. Each part will have a serial number and will be calibrated upon installation.

Table 4: System Components



## Item Manufacturer Model Name Enclosure Campbell Scientific ENC 12/14 3-meter tower Campbell Scientific 25G Wind sensor mount Campbe ll Scientific 019ALU Pyranometer mounting arm Campbell Scientific 015ARM Data logger CR3000 Campbell Scientific CR23X or CR10X Power supply with battery Ca mpbell Scientific PS12LA Solar panel Campbell Scientific MSX10R

Wind sensor R.M. Youn g Wind Monitor 05305-AQ Wind sensor cable R.M. Young Solar power system Kyocera Solar Electric System Temperature and relative humidity

sensor Campbell Scientific HMP45C

Barometric pressure sensor Vaisala PT101B

Flow meter Newark Electronics TE525

Flow meter Newark Electronics Pressure TransducerHcn Sampling Plan_V7.Docx 

### 7 

# 5.1.3 Equipment Description
The following section describes the air quality and meteorological instrumentation that will be used for the HCN monitoring program. The inst rumentation is selected consistent with the requirements of:

• U.S. EPA Quality Assurance Handbook of Air Pollution Measurement Systems Volume II, September 1997.

• NIOSH Manual of Analytical Methods, Method 6010, August 1994

.

• U.S. EPA Quality Assurance Handbook of Air Pollution Measurement Systems Volume IV - Meteorological Measurements (EPA-454/B-08-002), March 2008.
The data collection systems are designed to ex ceed the recommended quarterly data recovery rate of 90 percent for all meteorological parameters and 75 percent for HCN.


# 5.1.4 Data Logger
A Campbell Scientific, Inc. Model CR3000 data logger is used as the digital acquisition system for the stations. The data logger records the data every two seconds, computes 15-minute averages of each of the meteorological parameters, and stores the averages in its internal memory. The CR3000 has 4 mB of Flash Electrically Erasable Programmable Read Only Memory (EEPROM) for the operating system and user programs. It also has 512K of Static Random Access Memory (SRAM) used for storing approximately three months of data and running the program. It has a
16-bit micro-controller with 32-bit internal CPU ar chitecture. The resolution and accuracy of the analog inputs are 6.67 microvolts and ± 0.04%, respectively. The CR3000 is equipped with a solidstate storage module. The 15-minute averages are written to the CR3000's internal memory and to the external storage module. The storage module can store nearly six mo nths of data and will provide a backup of the data and the CR3000 prog ram in the unlikely event of a power loss. The data logger is designed to operate in temperatures from –25 ° C to 50 ° C.


# 5.1.5 Wind Speed
Wind speed is continuously measured using an R.M. Young Model 05305 sensor interfaced directly to the data logger. The wind speed sens or of the Model 05305 is a helicoid-shaped, fourblade propeller. Rotation of th e propeller produces an AC sine wave; the frequency is directly proportional to the wind speed. The AC signal is induced in a transducer coil by a six-pole magnet mounted on the propeller shaft. The coil is located on the non-rotating central portion of the main mounting assembly, eliminating the need for slip rings and brushes. Power for the sensor is supplied by the data logger. The Model 05305 has a range of 0.4 - 45 m/s, a starting threshold of 0.4 m/s, an accuracy of 0.2 m/s, and a distance constant of 2.1 meters.Hcn Sampling Plan_V7.Docx 

### 8 

# 5.1.6 Wind Direction
Wind direction is also continuously measured using an R.M. Young Model 05305 sensor interfaced directly to the data logger. The Model 05305 sensor provides a 1 ° to 360 ° format through the use of a precision potentiometer powered by the data logger. The potentiometer outputs a varying voltage proportional to the wind direction in degrees. The sensor is constructed from lightweight thermoplastic materials to give it a starting threshold of less than 0.5 m/s. The sensor has an accuracy of ±3 ° , a damping ratio of 0.45, and a delay distance of less
than 2 meters.


# 5.1.7 Temperature Sensor and Radiation Shield
The temperature measurements are continuously monitored using a Campbell Scientific HMP45C Platinum Resistance Temperature (PRT) detector. Temperature is measured by the data logger as a varying resistance across a platin um resistor that is proportional to the ambient temperature. The range of the sensor is –40°C to +60°C. The radiation shield for the temperature sensor prevents interference from solar radiatio n. The radiation error is less than 0.1°F.


# 5.1.8 Relative Humidity
Relative humidity is continuously measured using a Campbell Scientific Model HMP45C sensor.
The HMP45C contains a Vaisala HUMICAP TM 

## 180 capacitive relative humidity sensor. The HMP45C sensor is housed inside a non-aspirated shield. Relative humidity is measured by the data logger as an output voltage. The range of the sensor is from 0.8 to 100% (non-condensing) with an accuracy of ±2% when the humidity is less than 90%, and ±3% when the humidity is greater than 90%. The response time for th e relative humidity sensor is 15 seconds.



# 5.1.9 Barometric Pressure
Barometric pressure is measured every 15 minute s using a Vaisala PT101B sensor. The sensor is mounted inside the data logger enclosure. Barome tric pressure is measured by the data logger using Vaisala’s Barocap silicon capacitive pressu re sensor, which outputs a linear 0 to 2.5 VDC signal. The operating range of the sensor is –40 ° C to 60 ° C. The CS105 has a warm-up time of one second, an uncertainty of 0.15 millibar, and a linearity of 0.45 millibar.


# 5.1.10 HCN Sampling System
This instrument is designed to measure HCN at trace levels in ambient air. There is currently no
EPA certified method for this determination. Th e design combines elements of EPA air quality measuring guidelines along with NIOSH sampling protocols. The sampler consists of soda lime sorbent tubes (SKC part number 226-28) connected to a glass inlet. On the other side of the sorbent tubes is a low flow pump controlled by a data logger via a feedback loop with a pressure transducer. The flow is regulated by a critical orifice, and ambient meteorological parameters are collected to determine the exact volume of gas pass ed through the sorbent tubes. Data collection is in twenty-four hour increments. Upon complete exposure of a sorbent tube, it is sealed andHcn Sampling Plan_V7.Docx 

### 9 

## shipped to a certified laboratory for analysis in accordance with NIOSH Method 6010. The complete NIOSH Method 6010 is included as Appendix A.



## 5.1.10.1 Operating Principle
As discussed above, the HCN sampling system consis ts of an open-air inlet, sorbent tubes, and a pump which pulls air through the sorbent tubes at a rate of 1 liter per minute. The system is designed to hold two or more sorbent tubes, where each tube will collect a 24-hour sample. Based on the 1-in-3 day schedule, a site visit to change out the tubes will be required every 5-7 days (or longer if more than two tubes are design ed into the system). The total volume of air pulled through each sorbent tube is 1,440 liters. This exceeds the recommended total volume of NIOSH Method 6010 but is within the capture volu me of the sorbent tube and necessary to reach the required limits of detection.

A data logger turns the pump on and off and cont rols the solenoid valve according to the 1-in-3 day schedule. The solenoid valve opens and closes to allow air to pass through a sorbent tube only during a run day. The data logger al so records ambient barometric pressure and temperature to calculate the volume of air passed through the sorbent tube during the run day. Flow diagrams of the HCN sampling system, show ing the system in static mode, warm-up mode, and sampling mode, are provided in Figures 1 through 3.

Figure 1: HCN Sampling System Flow Diagram - Static Mode

INLET

SOLENOID VALVE



### SORBENT TUBE 1



### PRESSURE TRANSDUCER

PUMP

POWER RELAY 

### POWER 

### OUTLET DATA LOGGER

BAROMETRIC PRESSURE

TEMPERATURE 

### SORBENT TUBE 2



### CHECK VALVE 

### CALIBRATION VALVEHcn Sampling Plan_V7.Docx 

### 10 Figure 2: HCN Sampling System Flow Diagram - Warm-Up Mode

INLET

SOLENOID VALVE



### SORBENT TUBE 1



### PRESSURE TRANSDUCER

PUMP

POWER RELAY 

### POWER 

### OUTLET DATA LOGGER

BAROMETRIC PRESSURE

TEMPERATURE 

### SORBENT TUBE 2



### CHECK VALVE 

### CALIBRATION VALVEHcn Sampling Plan_V7.Docx 

### 11 Figure 3: HCN Sampling System Flow Diagram - Sampling Mode Sorbent Tube 1



## On a run day, at 15 minutes before the sampling commences, the data logger turns the pump on and switches the solenoid valve to allow air to flow around the sorbent tubes and through the pump. This gives the pump time to warm up and ensures that the air in the inlet is homogenous when the sampling begins. To initiate sampling, the data logger switches the solenoid valve to allow air to flow through the first sorbent tube an d the sampling begins. After 24 hours, the data logger closes the solenoid valve, stopping flow to the sorbent tube, and turns the pump off. On the next run day, after the warm-up period, to initiate sampling, the data logger switches the solenoid valve to allow air flow through the second sorbent tube. After 24 hours, the data logger closes the solenoid valve, stopping flow to the second sorbent tube. The tubes are replaced before the next run day and the sampling process repeats.

After the 24-hour sampling is complete, each sorbent tube is sealed and shipped to a certified laboratory where the HCN is extracted and anal yzed using spectroscopy. One in every five
sorbent tubes will be a field bl ank. The blank tubes will follow the same path as the sampled tubes, with the exception of being inserted into the sampling system. INLET

SOLENOID VALVE



### SORBENT TUBE 1



### PRESSURE TRANSDUCER

PUMP

POWER RELAY 

### POWER 

### OUTLET DATA LOGGER

BAROMETRIC PRESSURE

TEMPERATURE 

### SORBENT TUBE 2



### CHECK VALVE 

### CALIBRATION VALVEHcn Sampling Plan_V7.Docx 

### 12 

## The detection limit for this HCN sampling method is reported to be approximately 0.2 ppb 1



## , which is an order of magnitude less than the EPA reference concentration of 2.8 ppb.



# 5.1.11 Power and Data Transfer
Solar power is used to operate the equipment. The data logger is powered separately via a smaller solar cell to prevent total data and commu nications loss during periods of power loss. A cellular Internet modem is installed providing real-time satellite communications.


# 5.1.12 Meteorological Towers
A 10-foot Rohn 25G meteorological tower will be installed for the purpose of mounting the sensors. The tower will be grounded, and lightning protection will be installed on all signal lines.


# 5.2 Rationale for Design

The equipment has been selected based on its conformity to current EPA standards for meteorology and current NIOSH standards for HCN monitoring.



# 5.3 Scheduled Measurement Activities

The sampler pump will be activated on 1-in-3 da y schedule. During this period all parameters, with the exception of HCN concentration, will be collected every two seconds. This is
summarized in Table 5 and Table 6.

Table 5: Sampling Frequency



## Parameters Engineering
Units Sampling Rate Averaging Rate Number of Samples per
24-Hour Period Wind speed Meters/second Every 2 seconds Every 15 minutes 96 Wind direction Degrees Every 2 seconds Every 15 minutes 96
Ambient temperature and relative humidity Degrees Celsius and percent Every 2 seconds Every 15 minutes 96

Barometric
pressure Millibar Every 2 seconds Every 15 minutes 96

HCN sampler flow Liters/minute Every 2 Seconds Every 15 minutes 96
HCN concentration* Parts per billion Every 24 hours Every 24 hours 1

*HCN concentration can only be determined upon completion of laboratory analysis.

1 Kenneth G. Orloff et al., Hydrogen cyanide in ambient air near a gol d heap leach field: Measured vs. modeled concentrations, Atmospheric Environment, 2006, p. 3023.Hcn Sampling Plan_V7.Docx 

### 13 Table 6: Scheduled Sampling Activities



## Activity Frequency Required Personnel
Site Check Every 5-7 days Maintenance Technician Calibration At installation Project Technician
Flow Audit At close out Auditor



# 5.4 Measurement Syst em Failure Response

The primary mechanism for ensuring normal sy stem operation will be comprised of on-site checks conducted after the tubes have been sample d and before the next run day. The site check schedule will be every 5-7 days (or longer if more than two tubes are designed into the system). The Maintenance Technician is responsible for on-site checks and completion of Site Check Forms. Any issues that are detected during the site checks will be resolved as soon as possible.

If a run day sampling is missed or incomplete, a substitute 24-hour sampling can be used if it is completed before the next scheduled run day.Hcn Sampling Plan_V7.Docx 

### 14 

## SECTION 6 

# SAMPLING METHOD REQUIREMENTS

6.1 Sample Handling and Custody Requirements

A new sorbent tube will be inserted into the sampler system prior to midnight of a run day. After completion of the run, the sorbent tube will be removed and prepared for shipment to a certified lab. All sorbent tubes used for sampling will be tracked in a Chain of Custody Form.


# 6.2 Analytical Methods Requi rements and Breakthrough Check

The sample will be digested at the lab and a coloring agent will be added to make the cyanide spectroscopically active. UV/Vis spectroscopy will be employed to determine the cyanide concentration. The quantity of cyanide present will be combined with the known flow of the sample exposure to generate a 24-hour HCN sample concentration. The analysis will be
conducted in accordance with NIOSH Me thod 6010 (included as Appendix A).

As part of the HCN analysis, each tube will be checked for breakthrough. The sorbent tubes
consist of a front half and back half. Each half will be analyzed separately to determine the mass of cyanide. Any sample where the mass of cyanid e in the back half is greater than one-tenth of the mass of cyanide in the front half will be flagged indicating that breakthrough has occurred.


# 6.3 Quality Control Requirements

Quality control for the program will be affected through the use of site checks, post-installation calibration, and close out audits. Information pr ovided by each of these methods is documented
in the Table 7 below.Hcn Sampling Plan_V7.Docx 

### 15 Table 7: Project Quality Control Checks



## QC Check Information Provided Frequency Site Checks All information about the station status, which cannot be determined from the raw data. Additionally, it provides real-time data for comparison with hourly averages to insure that station is functioning within prescribed guidelines. Every 5-7 days

Calibrations Determines the serviceability, accuracy, and precision of the equipment operating on site. Sensors are tested over a full range of operating conditions to ensure that they are performing within prescribed guidelines. At installation

Flow Audit Determines the serviceability, accuracy, and precision of the equipment operating on site. Sensors are tested over a full range of operating conditions to ensure that they are performing within prescribed guidelines. At close outHcn Sampling Plan_V7.Docx 

### 16 

## SECTION 7 

# INSTRUMENT/EQUIPMENT TESTING, INSPECTION, AND MAINTENANCE REQUIREMENTS

The sensor/equipment maintenance schedule is based on the manufacturer’s guidelines. All routine maintenance tasks will be accomplishe d by the Project Technician. In addition, preventive maintenance tasks are summarized in Table 8.

Table 8: Preventive Maintenance Schedule



## Parameter Sensor Replacement Frequency
Wind speed and direction R.M. Young 05305-AQ Every 2 years.
Temperature/relative humidity Campbe ll Scientific HMP45C Every 2 years.
Barometric pressure Vaisala PT101B Every 2 years. Sampling pump SKC Low Flow Pump to be refurbished annually.

*Due to the duration of the sampling program, it is anticipated that preventive maintenance will not be needed.



# 7.1 General Procedures

The Project Technician will review the Site Chec k Forms and compare them to the 15-minute data averages to ensure proper syst em operation and data transfer.


# 7.2 Instrument Calibration and Frequency

The following section outlines the preventive ma intenance/recalibration of the equipment used to test the performance of the on-site systems.


# 7.2.1 Calibration Eq uipment Maintenance
The identity, frequency, and governing standard for all calibration equipment can be found in
Table 9.Hcn Sampling Plan_V7.Docx 

### 17 Table 9: Calibration Equipment Testing



## Parameter Calibration Equipment Calibration Frequency Reference Wind speed Anemometer Drive 200 to 15,000 RPM Biannually EPA 600/R-94/038D, Section 4.2.2 Wind direction Degree Wheel N/A EPA 600/R-94/038D, Section 4.2.2 Temperature Temperature Standard Annually EPA 600/R-94/038D, Section 4.3.2 Barometric pressure Altimeter N/A EPA 600/R-94/038D, Section 4.6 Relative humidity Collocated HMP45C Biannually EPA 600/R-94/038D, Section 4.6 Data logger Voltmeter Annually EPA 600/R-94/038D, Section 4.1.4.1 Flow Flow Meter Annually N/A

The equipment supplier will be required to maintain calibration equipment certifications in hard

copy.



# 7.2.2 Calibration Reco rds and Traceability
Calibration Forms are completed and maintained by project personnel. All Calibration Forms indicate the sensor calibrated, its serial numb er, the date calibrated, and any other pertinent information/anomalies.Hcn Sampling Plan_V7.Docx 

### 18 

## SECTION 8 

# INSPECTION/ACCEPTANCE REQUIREMENTS FOR SUPPLIES AND CONSUMABLES

The only consumable used in this process is the sorbent tubes. All tubes will be inspected upon receipt. Any tubes which show signs of physical damage will be discarded. Documentation sent with the maintenance items are kept on file as they apply to each sensor and its serial number.Hcn Sampling Plan_V7.Docx 

### 19 

## SECTION 9 

# DATA MANAGEMENT

The data will be collected and stored in the da ta logger and backed up in the on-site storage module. The data can be automatically or manually transferred to the user’s database. The data will then be quality controlled/quality assura nce checked (QA/QC’d) and stored on a server.


# 9.1 Data Custody

Data retrieval, quality control, and processing will be documented. Site Check Forms and all other program documentation will be archived. Additionally, a journal will be kept to record any
anomalous occurrences.Hcn Sampling Plan_V7.Docx 

### 20 

## SECTION 10 

# DATA VALIDATION AND USABILITY

10.1 Data Review, Validation, and Certification
10.1.1 Data Validation
The data will be reviewed, quality controlled/quality assurance checked (QA/QC’d), and validated in accordance with EPA guidelines.



# 10.1.2 Data Collection
Data received from the site will consist of 15-minute averages for all parameters. A complete list of parameters from the site can be found in Table 10.

Table 10: Data Recorded on Site



## Parameter Units Frequency Array ID N/A Every 15 minutes Year -- Every 15 minutes Day Julian Day Every 15 minutes Time Hour/Minute Every 15 minutes Wind speed Meters/Second Every 15 minutes Wind direction Degrees from Every 15 minutes
Wind direction standard devi ation None Every 15 minutes Barometric pressure Millibar Every 15 minutes Relative humidity Percent Every 15 minutes Ambient temperature Degrees Celsius Every 15 minutes Data logger battery voltage DCV Every 15 minutes SIN wind direction None Every 15 minutes COSINE wind direction None Every 15 minutes Flow l/min. Every 15 minutes



# 10.1.3 Data Reduction
On-site data is collected every two seconds and pl aced into temporary storage. Every 15 minutes the data is reduced and stored in the ring memory of the data logger. The wind speed, temperature, relative humidity, barometric pressure, and flow data are reduced as scalar averages using the equation below.


# ∑
= N

i 

## u N u

1 

## 1

The wind direction data is reduced as a unit vector according to the following equations.Hcn Sampling Plan_V7.Docx 

### 21 

# ∑
= N

i S 

## Sin N V

1 

## 1 θ



# ∑
= N

i C 

## Cos N V

1 

## 1 θ



# X V V ArcTan

C S 

# + ⎟ ⎟ ⎠ ⎞ ⎜ ⎜ ⎝ ⎛

= θ

If Vc < 0 then X = +180 If Vs < 0 then X = +360 If Vs > 0 then X = +0

The wind direction deviation is reduced using the Yamartino algorithm found below. 

# ( ) ( ) 

# [ ] 3 

## 1547

. 0 1 1 ε ε θ σ + = ArcSin

where, 

# () () 

# ( ) 

# [ ] 2 1 2 2 

## 1 C S 

## V V +

− = ε

and Vs and Vc are as defined above.

After the 15-minute data has been downloaded, it is processed into one-hour averages using the same equations listed above.



# 10.2 Validation Methods
10.2.1 Data Review and Validation Requirements
The data review and validation requirements follow the protocols outlined in Section 5 of this monitoring plan. The validation is accomplished by using quality control standards based on federal and manufacturer’s guidelines as well as expected sampler performance. If a quality control standard is not met, the data will be flagged initially, and the causes immediately investigated. All data, which is found to be invali d, will be removed from the data set. All data, which is subsequently proven to be valid, will be processed for inclusion in the reports.

# APPENDIX A 

# NIOSH Method 6010

## HYDROGEN CYANIDE 6010



## HCN MW: 27.03 CAS: 74-90-8 RTECS: MW6825000

METHOD: 6010, Issue 2 EVALUATION: FULL Issue 1: 15 May 1989 Issue 2: 15 August 1994

OSHA : 10 ppm (skin) NIOSH: STEL 4.7 ppm ACGIH: C 10 ppm (skin)

(1 ppm = 1.105 mg/m 3 @ NTP) PROPERTIES: gas; BP 26 °C; vapor density 0.93 (air = 1.00); d(liq) 0.69 g/mL @ 20 °C; VP 82.7 kPa (620 mm Hg) @ 20 °C; explosive range 5 to 40% v/v in air

SYNONYMS: hydrocyanic acid, prussic acid, formonitrile

SAMPLING

SAMPLER: SOLID SORBENT TUBE

(soda lime, 600 mg/200 mg)

FLOW RATE: 0.05 to 0.2 L/min

VOL-MIN: 2 L @ 5 ppm -MAX: 90 L

SHIPMENT: routine

SAMPLE STABILITY: at least 2 weeks @ 25 °C [1]

BLANKS: 2 to 10 field blanks per set MEASUREMENT

TECHNIQUE: SPECTROPHOTOMETRY,

VISIBLE ABSORPTION

ANALYTE: cyanide ion complex

DESORPTION: 10 mL deionized water; stand 60 min

COLOR DEVELOPMENT: N-chlorosuccinimide/ succinimide oxidizing agent and barbituric acid/pyridine coupling agent; absorption @ 580 nm in 1-cm cuvette

CALIBRATION: standard solutions of KCN in 0.1 N NaOH

RANGE: 10 to 300 μg CN - per sample [1]

ESTIMATED LOD: 1 μg CN - per sample [1]

PRECISION ( S r ): 0.041 @ 10 to 50 mg per sample [1] ACCURACY

RANGE STUDIED: 2 to 15 mg/m 3 [1] (3-L samples)

BIAS: Not significant

OVERALL PRECISION ( S ˆ rT ): 0.076 [1]

ACCURACY: ± 15.0%

APPLICABILITY: The working range is 0.3 to 235 ppm (3 to 260 mg/m 3 ) for a 3-L air sample. This method is applicable to STEL measurements. Particulate cyanides are trapped by the initial glass fiber membrane disk. This method is more sensitive a nd subject to fewer interferences than NIOSH Method 7904, which uses ion specific electrode analysis. The method was used t o determine HCN in firefighting environments [2].

INTERFERENCES: A high concentration of hydrogen sulfide gives a negative interference.

OTHER METHODS: This is based on the method of Lambert, et al. [3]. NIOSH Method 7904 uses an ion specific electrode for measurement. The method has been adapted for use with a Technicon Autoanalyzer [4].

NIOSH Manual of Analytical Methods (NMAM), Fourth Edition, 8/15/94

### HYDROGEN CYANIDE: METHOD 6010, Issue 2, dated 15 August 1994 - Page 2 of 5

SAMPLING: REAGENTS:

1. Potassium cyanide*, reagent grade. 2. Succinimide, reagent grade. 3. N-Chlorosuccinimide, reagent grade. 4. Barbituric acid, reagent grade. 5. Pyridine, spectrophotometric quality. 6. Phenolphthalein, 1% (w/v) in ethanol or methanol, reagent grade. 7. Hydrochloric acid, concentrated, reagent grade. 8. Sodium hydroxide (NaOH), reagent grade.* 9. Sodium lime (CaO + 5-20% NaOH), reagent grade (Aldrich #26,643-4 or equivalent). Crush and sieve to 10/35 mesh. Store in capped container.* 10. Water deionized-distilled. 11. Sodium hydroxide solution, 0.1 N .* 12. Calibration stock solution. 1 mg /mL CN -



### . Dissolve 0.125 g KCN in 0.1 N NaOH in a 50- mL volumetric flask. Dilute to mark with 0.1 N NaOH. Standardize by titration with standard AgNO 3 

### solution (see APPENDIX). 13. Hydrochloric acid solution, 0.15 N

. 14. N-Chlorosuccinimide/succinimide oxidizing reagent. Dissolve 10.0 g succinimide in about 200 mL distilled water. Add 1.00 g Nchlorosuccinimide. Stir to dissolve. Adjust volume to 1 liter with distilled water. Stable 6 months when refrigerated. 15. Barbituric acid/Pyridine reagent. Add about 30 mL distilled water to 6.0 g barbituric acid in a 100-mL Erlenmeyer flask. Slowly add 30 mL pyridine with stirring. Adjust the volume to 100 mL with water. Stable 2 months when refrigerated. EQUIPMENT:

1. Sampler, glass tube, 9 cm long, 7-mm OD, 5-mm ID, with plastic caps, containing two sections (front = 600 mg; back = 200 mg) granular soda lime 10/35 mesh, separated and contained with silanized glass wool plugs, with a 5-mm diameter glass fiber filter disk placed before the plug on inlet side. Tubes are commerically available. (SKC, Inc. 226-28 or equivalent.) 2. Spectrophotometer, visible, 580 nm, with cuvettes, 1-cm light path. 3. Personal sampling pump, 0.05 to 0.2 L/min, with flexible connecting tubing. 4. Pipets, volumetric 0.1-, 0.5-, 1.0-, 2.0-, 10.0-mL. 5. Vials, glass or plastic, 15-mL with PTFE-lined caps. 6. Flasks, volumetric, 25-, 50-, 100-, 1000-mL, with stoppers. 7. Pipets, transfer, disposable. 8. Syringes, 10-μL, readable to 0.1 μL. 9. Flask, Erlenmeyer, 100-mL. 10. Syringes, 10-mL, polyethylene with luer tip. 11. Filter cassette, with membrane filter, 13-mm diameter, 0.45-μm pore size, with luer fitting.

* See SPECIAL PRECAUTIONS

SPECIAL PRECAUTIONS: HCN gas and cyanide particulates are highly toxic and may be fatal if swallowed, inhaled, or absorbed through the skin [5]. Soda lime and NaOH are very caustic [5]. Use gloves and a fume hood for handling these chemicals. 1. Calibrate each personal sampling pump with a representative sampler in line. 2. Break ends of sampler immediately before sampling. Attach sampler to personal sampling pump with flexible tubing. 3. Sample at an accurately known flow rate between 0.05 and 0.2 L/min for a total sample size of 0.6 to 90 L. 4. Cap tube. Pack securely for shipment.

NIOSH Manual of Analytical Methods (NMAM), Fourth Edition, 8/15/94

### HYDROGEN CYANIDE: METHOD 6010, Issue 2, dated 15 August 1994 - Page 3 of 5

SAMPLE PREPARATION:

5. Score each sampler with a file. Break sampler at score line. 6. Transfer front and back sorbent sections to separate vials. Discard glass wool plugs separating and retaining sorbent sections. NOTE: An estimate of particulate cyanide may be obtained by analyzing the initial glass fiber filter disk as follows; however, no evaluation data are available for particulate cyanides determined in this manner. (i) Transfer the glass wool plug at the tube inlet and the glass fiber filter disk immediately behind it to a third vial. (ii) Add 10.0 mL 0.1 N NaOH to each vial. (iii) Proceed with step 8. 7. Add 10.0 mL deionized-distilled water to each vial containing a sorbent section. Cap each vial. 8. Allow to stand 60 minutes, with occasional agitation. Transfer to a 10-mL plastic syringe fitted with an in-line 0.45-μm filter. Collect the filtrate in a clean vial.

CALIBRATION AND QUALITY CONTROL:

9. Calibrate daily with at least six working standards over the range 1 to 300 μg CN - 

### per sample.

a. Prepare a working standard solution, 1.00 μg /mL.CN - 

### , by diluting 100 μL of calibration stock solution to 100 mL with 0.1 N NaOH. b. Pipet 0.5-, 1.00-, 1.50-, 2.00- and 2.50-mL of the working standard solution into 25-mL volumetric flasks to make 0.50-, 1.00-, 1.50-, 2.00- and 2.50- μg CN - 

### standards.

c. Analyze together with field samples and blanks (steps 12 through 19). d. Prepare calibration graph (absorbance vs. μg CN - 

### ). 10. Determine desorption efficiency (DE) at least once for each lot of soda lime used for sampling. Prepare at least three tubes at each of five levels plus three media blanks.

a. Remove and discard back sorbent section of a blank sampler. b. Inject a known amount of calibration stock solution directly onto the soda lime with a microliter syringe.

c. Cap, and allow to stand overnight. d. Desorb (steps 5 through 8) and analyze together with working standards and blanks (steps 12 through 19).

e. Prepare a graph of DE vs. μg CN - 

### recovered. 11. Analyze three quality control blind spikes and three analyst spikes to ensure that the calibration graph and DE graph are in control.

MEASUREMENT:

12. Set spectrophotometer according to manufacturer's recommendations and to conditions on p. 6010-1. 13. Pipet a sample aliquot estimated to contain 0.5 to 2.5 μg CN - 

### into a 25-mL volumetric flask. Alternately, to cover an unknown sample concentration range, pipet 0.5-, 1.00-, and 3.00-mL aliquots into separate 25-mL vol. flasks for each field sample. Larger or smaller aliquots may be taken, based on prior knowledge of expected analyte level. 14. Pipet 0.5 mL 0.1 N NaOH into a 25-mL volumetric flask for reagent blank. 15. Add one drop phenolphthalein solution to each standard or sample. NOTE: Add a little deionized-distilled water to increase volume for easier mixing. All solutions should be alkaline (pink) at this point. 16. Starting with the reagent blank, add dropwise 0.15 N HCl, with mixing, until pink color just disappears. CAUTION: HCN may be produced. Work in hood. Immediately add 1.0 mL N-chlorosuccinimide/succinimide oxidizing reagent. Mix and let stand.

NIOSH Manual of Analytical Methods (NMAM), Fourth Edition, 8/15/94

### HYDROGEN CYANIDE: METHOD 6010, Issue 2, dated 15 August 1994 - Page 4 of 5

NOTE 1: To avoid possible loss of HCN, add the oxidizing agent before proceeding to the

next sample. NOTE 2: Do not prepare more samples than can be analyzed within the 30-minute maximum

time for color development. 17. After at least 5 min. standing (but not longer than 15 min), starting with the reagent blank, add 1.0-mL barbituric acid-pyridine coupling reagent. Mix. 18. Adjust sample volume to 25 mL with deionized-distilled water and allow to stand at least 12 min (but not longer than 30 min) for color development. 19. Read absorbance at 580 nm in a 1-cm light path cuvette on a spectrophotometer. If sample absorbance is outside the range of the calibration standards, take an aliquot, re-analyze (steps 12 through 19), and apply the appropriate aliquot factor in calculations.

CALCULATIONS:

20. Calculate the mass, μg, of CN - 

### in aliquot analyzed. Apply the appropriate aliquot factor to calculate the mass, μg, of CN - 

### in the original 10-mL solution. 21. Determine the mass, μg CN - 

### (corrected for DE), found in the sample front (W f 

### ) and back (W b 

### ) sorbent sections and in the average media blank front (B f 

### ) and back (B b 

### ) sorbent sections. If W b 

### > W f 

### /10, report breakthrough and possible sample loss. 22. Calculate concentration, C, of HCN in the air volume sampled, V(L).

where 1.039 = conversion factor, CN - 

### to HCN

EVALUATION OF METHOD:

The method was evaluated by sampling the test atmospheres of HCN generated from a compressed mixture of HCN in nitrogen [1]. The range of HCN concentration was equivalent to 2 to 15 mg/m 3 

### for a 3-L air sample. Twenty-two samples collected at 0.2 L/min for 15 minutes indicated overall precision S ˆ rT 

### of 0.076 with nearly 100% recovery. Breakthrough occurred after 40 minutes of sampling at the flow rate of 0.2 L/min at an HCN concentration of 148 mg/m 3 

### . Sample tubes spiked with solutions of KCN and analyzed after storage, indicated that the samples of cyanide ions were stable on the tube for at least 2 weeks. Analysis of 22 tubes which were spiked with KCN standard solutions in the range 10 to 50 μg indicated a recovery of nearly 100% with a pooled precision of 0.041. Desorption efficiency may be poor below 10 μg CN - 

### [6].

REFERENCES:

[1] Williamson, George. "Method Development Protocol and Backup Data Report on Hydrogen Cyanide" Internal NIOSH/MRSB Report, Unpubl. NIOSH (1988). [2] Williamson, George. "Analysis of Air Samples on Project 166 (Firesmoke) on HCN; Sequence NIOSH/MRSB-6366A, Unpubl. NIOSH, (1988). [3] Lambert, J. L., Ramasamy, J., and J. V. Paukstelis, "Stable Reagents for the Colorimetric Determination of Cyanide by Modified Konig Reactions," Analyt. Chem.

, 47 , 916-918 (1975). [4] DataChem Laboratories, NIOSH Sequence #6837-K (unpublished, March 21, 1990). [5] NIOSH/OSHA Occupational Health Guidelines for Chemical Hazards, U.S. Department of Health and Human Services. Publ. (NIOSH) 81-123 (1981), available as stock #PB 83-154609 form NTIS, Springfield, VA 22161. [6] DataChem Laboratories, User Check, NIOSH Sequence #6837-J (unpublished, March 19, 1990).

METHOD WRITTEN BY: George Williamson, NIOSH/DPSE.

NIOSH Manual of Analytical Methods (NMAM), Fourth Edition, 8/15/94

### HYDROGEN CYANIDE: METHOD 6010, Issue 2, dated 15 August 1994 - Page 5 of 5

APPENDIX: STANDARDIZATION OF CALIBRATION STOCK SOLUTION

Titrate an aliquot of the cyanide standard stock solution (Reagent 12) with standard silver nitrate (AgNO 3 

### ) solution. The end point is the first formation of a white precipitate, Ag[Ag(CN) 2 

### ]. Calculate the cyanide concentration with the following equation:

M c 

### = 52.04 V a 

### (M
a 

### /V
c 

### )

Where M c



### = cyanide concentration (mg/mL) V a 

### = volume (mL) of standard silver nitrate solution M a 

### = concentration (moles/L) of standard silver nitrate solution V c 

### = volume (mL) of calibration stock solution titrated

NIOSH Manual of Analytical Methods (NMAM), Fourth Edition, 8/15/94