Meteorological and 

Hydrogen Cyanide 

(HCN) Fence Line 

Monitoring 

Preliminary Report 

RMGC-SVCO, INC. 

PROJECT 99-11-4 

FEBRUARY 2010 
Roundmtn 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 ANALYSIS ..................................................................................................................................................... 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 Plans 
Roundmtn 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 Common 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 sampling 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 sampling procedures were performed in accordance 

with the U. S. EPA Quality Assurance Handbook of Air Pollution 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, 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 installed and continues to operate an HCN monitor near the RMGCSVCO operations area. 

1.1 HCN Monitor and Meteorological 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 located 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 11N, NAD83, elevation, 5,797 feet. 

Figures 1, 3, and 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 

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 2
Roundmtn Hcn Monitoring Report.Docx 3
Roundmtn Hcn Monitoring Report.Docx 4
Roundmtn Hcn Monitoring Report.Docx 5
Roundmtn Hcn Monitoring Report.Docx 6 

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 sampling 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 are collected at more frequent intervals and timeaveraged into 15-minute values. Wind speed and wind 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 monitor. Ambient temperature is also collected at 

the meteorological station and serves as a quality 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 station 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 transmitted 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 parameters are presented in Table 2. 

The meteorological data recovery rate was 100 percent for all parameters at the meteorological station 

and 99.1 percent at the HCN monitor. The lower data 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 sorbent 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 8 

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 during the sampling period are summarized in Table 3 

as frequency distributions of winds by direction and speed. The data period contains 25 days (600 

hours) of complete wind information. 

Figure 5 shows the distribution of hourly averaged 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 breakdown of the wind speed profile for this period 

yields the following: There were 0.0 percent calm 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 averaged winds by direction 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, which 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) comprised 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 Averaged 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 = 600
Roundmtn 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 12 

SECTION 3 

HCN STATION 

The instantaneous temperature, relative humidity, and barometric pressure data collected at the 

HCN monitor on each run day 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. 

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 Humidity, 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 hourly 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 sampling 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 and 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 hours 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 41 611 
Roundmtn Hcn Monitoring Report.Docx 13 

3.3 HCN Concentration 

The HCN concentration data collected during the sampling period are summarized in Table 6. The 

average HCN concentration corrected to standard conditions1 was 0.27 μg/m3. 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/m3 on December 24, 2009, and <0.10 

μg/m3 on January 8, 2010. The maximum HCN concentration for the period was 0.62 μg/m3 and 

occurred on January 2, 2010. The HCN concentration in the field blanks was below the detection 

level of 0.21 μg/sample. All HCN concentrations were below the EPA reference concentration of 3E3 mg/m3.

2

Table 6: HCN Concentration 

December 18, 2009 - January 11, 2010 

(μg/m3) 

 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 System. http://www.epa.gov/iris/subst/0060.htm. 
Roundmtn Hcn Monitoring Report.Docx 14 

SECTION 4 

DATA ANALYSIS 

Based on the data collected from the first four weeks of monitoring, an analysis of wind direction and 

measured HCN concentration was conducted. As shown in Figures 1 and 2, winds from 70° through 

127° (approximately east-northeast through southeast) blow from the 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 percent of the time, which is the highest percent of 

winds blowing towards the monitor of any of the sample 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/m3) 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 direction (the direction from which the wind is 

blowing) and wind speed for the lowest and highest 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 from 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

0.7

Percent of Winds (%)

HCN Concentration (μg/m3)

Run Day

HCN Concentration Percentof Winds Towards Monitor
Roundmtn 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 Data 
Day 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 

12/18/2009 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 12/19/2009 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 12/20/2009 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 12/21/2009 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 12/22/2009 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 12/23/2009 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 12/24/2009 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 12/25/2009 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 12/26/2009 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 12/27/2009 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 12/28/2009 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 12/29/2009 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 12/30/2009 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 12/31/2009 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 

1/1/2010 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 1/2/2010 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 1/3/2010 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 1/4/2010 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 1/5/2010 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 1/6/2010 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 1/7/2010 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 1/8/2010 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 1/9/2010 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 

1/10/2010 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 1/11/2010 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 

Avg 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 

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 

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 

SAROAD for Kinross, Roundmountain

Channel: WS_ms_10m

Month: 12/18/09 ‐ 01/11/10

Hour of da

y
Day 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 

12/18/2009 142 99 108 154 109 156 82 122 56 49 45 336 15 40 58 48 103 102 96 105 104 12/19/2009 93 121 118 98 138 123 139 153 61 350 353 333 333 10 26 235 94 62 115 179 122 12/20/2009 142 125 99 108 173 161 120 148 229 225 228 205 199 206 203 206 204 224 224 234 229 12/21/2009 226 199 78 125 152 170 111 153 271 200 215 201 189 218 209 211 195 144 179 199 227 12/22/2009 213 207 284 102 70 209 67 81 9 33 19 27 14 21 18 19 26 27 30 35 9 12/23/2009 20 50 72 79 66 45 38 55 48 313 42 51 62 53 57 36 105 76 79 84 88 12/24/2009 114 83 80 97 71 83 135 162 125 72 17 48 32 31 42 44 71 63 64 77 58 12/25/2009 215 125 170 153 164 148 91 96 91 34 33 56 46 54 61 67 71 94 93 93 79 12/26/2009 91 111 140 64 73 120 187 159 258 305 263 247 350 282 301 208 201 199 242 186 194 12/27/2009 265 243 74 109 148 141 121 90 271 290 290 270 299 291 8 17 86 104 114 55 90 12/28/2009 135 106 91 82 93 85 82 72 46 31 34 24 324 18 22 78 105 143 155 148 60 12/29/2009 92 102 190 184 193 206 209 299 117 203 187 204 203 221 342 240 230 125 125 146 185 12/30/2009 268 257 218 249 258 209 193 187 218 238 10 336 244 313 4 21 29 92 78 97 94 12/31/2009 150 124 112 135 135 192 26 240 242 275 234 262 311 264 233 218 215 234 235 219 211 

1/1/2010 237 245 180 243 285 111 184 66 44 20 26 197 296 191 1 173 148 147 139 167 161 1/2/2010 194 173 171 171 176 164 166 136 180 242 266 258 263 276 250 311 145 116 151 171 136 1/3/2010 107 120 94 109 91 100 149 94 76 44 34 17 353 17 35 355 83 116 147 117 146 1/4/2010 157 158 161 70 69 145 91 181 152 297 246 253 266 267 243 267 97 89 98 124 127 1/5/2010 148 109 122 97 75 130 154 110 248 93 17 7 311 10 30 11 136 86 75 139 138 1/6/2010 162 158 168 88 168 90 117 121 170 309 292 251 282 28 23 293 109 71 65 100 86 1/7/2010 80 114 127 79 84 47 73 82 353 40 342 34 53 40 25 26 5 10 30 28 68 1/8/2010 105 101 95 104 95 94 85 66 343 328 267 306 301 271 312 345 89 291 74 216 215 1/9/2010 119 57 101 87 83 98 91 65 63 16 35 11 11 28 6 36 110 82 93 94 115 

1/10/2010 182 221 80 152 45 11 127 126 58 11 11 25 4 16 16 33 64 107 142 158 135 1/11/2010 110 95 92 96 113 132 80 79 106 54 101 271 262 224 241 240 197 81 101 78 233 

Max 270 245 209 247 285 213 191 290 353 328 342 306 359 346 358 355 213 291 217 250 233 

Min 80 55 41 46 45 11 49 65 44 6 8 7 4 1 1 5 5 10 30 28 44 

SAROAD for Kinross, Roundmountain

Channel: WD_10m

Month: 12/18/09 ‐ 01/11/10

Hour of da

y
Day 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 

12/18/2009 ‐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 

12/19/2009 ‐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 

12/20/2009 ‐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 

12/21/2009 0.8 ‐2.0 ‐4.5 ‐4.9 ‐5.0 ‐5.2 ‐5.6 ‐4.3 ‐2.0 ‐0.1 0.6 2.0 2.5 2.6 1.8 1.9 1.1 0.4 0.4 1.0 ‐0.2 1.5 

12/22/2009 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 

12/23/2009 ‐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 

12/24/2009 ‐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 

12/25/2009 ‐7.5 ‐9.9 ‐9.7 ‐10.4 ‐10.3 ‐10.3 ‐9.8 ‐8.8 ‐4.1 ‐1.5 ‐1.0 ‐0.5 0.5 0.3 0.5 0.9 ‐2.3 ‐4.0 ‐4.3 ‐4.6 ‐5.6 ‐7.3 

12/26/2009 ‐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 

12/27/2009 ‐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 

12/28/2009 ‐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 

12/29/2009 ‐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 

12/30/2009 ‐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 

12/31/2009 ‐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 ‐0.5 0.7 

1/1/2010 ‐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 

1/2/2010 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 

1/3/2010 ‐5.5 ‐5.8 ‐5.8 ‐4.9 ‐5.8 ‐6.0 ‐5.9 ‐6.2 ‐1.5 ‐0.2 ‐2.5 1.0 1.8 1.6 1.9 3.0 ‐1.1 ‐2.6 ‐2.7 ‐3.1 ‐3.0 ‐3.2 

1/4/2010 ‐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 

1/5/2010 ‐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 

1/6/2010 ‐1.7 ‐1.9 ‐1.2 ‐3.3 ‐2.7 ‐2.9 ‐3.0 ‐2.8 2.9 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 

1/7/2010 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 

1/8/2010 ‐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 

1/9/2010 ‐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 

1/10/2010 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 

1/11/2010 ‐0.1 ‐0.8 ‐1.2 ‐1.2 ‐1.0 ‐0.3 ‐0.3 ‐0.4 1.1 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 

Avg ‐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 

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 

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 

SAROAD for Kinross, Roundmountain

Channel: Temp_AMB_C

Month: 12/18/09 ‐ 01/11/10

Hour of da

y
Day 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 

12/18/2009 ‐‐ ‐‐ ‐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 ‐

12/19/200912/20/200912/21/2009 ‐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 ‐

12/22/200912/23/200912/24/2009 ‐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 ‐

12/25/200912/26/200912/27/2009 ‐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 ‐

12/28/200912/29/200912/30/2009 ‐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 ‐

12/31/2009

1/1/20101/2/2010 ‐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 ‐

1/3/2010

Non‐Run‐Day

Non‐Run‐DayNon‐Run‐DayNon‐Run‐DayNon‐Run‐DayNon‐Run‐DayNon‐Run‐DayNon‐Run‐DayNon‐Run‐Day

SAROAD for Kinross, Roundmountain

Channel: T_AMB_C

Month: 12/18/09 ‐ 01/11/10

Hour of day

Non‐Run‐Day

Non‐Run‐Day

1/4/20101/5/2010 ‐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 ‐

1/6/20101/7/20101/8/2010 ‐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 ‐

1/9/2010

1/10/20101/11/2010 ‐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 

Avg ‐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 ‐

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 

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 ‐

‐‐ Indicates invalid data

Non‐Run‐Day

Non‐Run‐Day

Non‐Run‐Day

Non‐Run‐Day

Non‐Run‐Day
Day 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 

12/18/2009 ‐‐ ‐‐ 95 95 94 94 94 93 93 73 71 75 61 57 55 60 73 83 87 90 88 

12/19/200912/20/200912/21/2009 92 92 94 93 92 93 93 92 93 86 74 74 65 64 69 69 74 70 71 76 79 12/22/200912/23/200912/24/2009 87 88 86 90 90 89 87 83 56 53 55 52 48 48 44 43 62 70 76 79 80 12/25/200912/26/200912/27/2009 79 80 81 83 82 80 78 77 56 52 51 47 42 41 49 53 67 76 81 83 83 12/28/200912/29/200912/30/2009 87 78 74 76 75 75 83 92 92 91 88 90 90 81 86 83 81 94 92 92 93 12/31/2009

1/1/20101/2/2010 81 89 92 90 89 91 86 83 67 61 58 56 58 58 54 61 73 81 85 89 88 1/3/2010

Non‐Run‐DayNon‐Run‐Day

Non‐Run‐Day

Non‐Run‐Day

Non‐Run‐Day

Non‐Run‐Day

Non‐Run‐Day

Non‐Run‐Day

Non‐Run‐Day

SAROAD for Kinross, Roundmountain

Channel: RH_percent

Month: 12/18/09 ‐ 01/11/10

Hour of day

Non‐Run‐Day

Non‐Run‐Day

1/4/20101/5/2010 87 89 89 90 88 89 88 89 80 66 59 54 53 50 53 49 63 71 77 83 84 1/6/20101/7/20101/8/2010 94 95 96 96 97 96 96 95 95 93 84 70 73 69 64 65 79 82 86 89 89 1/9/2010

1/10/20101/11/2010 97 98 96 98 98 96 97 96 96 95 90 78 79 72 65 59 78 69 57 58 55 

Avg 88 89 89 90 89 89 89 89 81 74 70 66 63 60 60 60 72 77 79 82 82 

Max 97 98 96 98 98 96 97 96 96 95 90 90 90 81 86 83 81 94 92 92 93 

Min 79 78 74 76 75 75 78 77 56 52 51 47 42 41 44 43 62 69 57 58 55 

‐‐ Indicates invalid data

Non‐Run‐Day

Non‐Run‐Day

Non‐Run‐Day

Non‐Run‐Day

Non‐Run‐Day
Day 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 

12/18/2009 ‐‐ ‐‐ 623 623 623 623 623 623 623 623 623 623 622 622 622 622 622 622 622 623 623 12/19/200912/20/200912/21/2009 619 619 619 619 618 618 618 618 617 617 617 616 615 614 614 614 613 613 613 612 612 12/22/200912/23/200912/24/2009 623 623 623 622 622 623 623 623 623 623 623 623 622 622 622 622 622 622 622 622 622 12/25/200912/26/200912/27/2009 619 619 619 619 619 619 619 619 620 620 620 620 620 620 620 620 620 620 620 621 621 12/28/200912/29/200912/30/2009 616 616 616 616 616 616 616 616 616 617 618 618 617 618 618 619 619 620 621 621 621 12/31/2009

1/1/20101/2/2010 622 622 622 622 622 622 622 622 623 623 623 622 622 622 622 622 622 622 622 623 623 1/3/20101/4/20101/5/2010 622 622 622 622 622 622 622 622 622 622 622 622 621 621 621 621 621 621 621 622 622 1/6/20101/7/20101/8/2010 622 622 622 622 622 622 622 623 623 623 623 622 621 622 622 622 622 622 623 623 623 1/9/2010

1/10/20101/11/2010 624 624 624 624 624 624 624 624 624 624 624 623 622 622 622 621 621 621 622 622 621 

Avg 621 621 621 621 621 621 621 621 621 621 621 621 620 620 620 620 620 620 621 621 621 

Max 624 624 624 624 624 624 624 624 624 624 624 623 622 622 622 622 622 622 623 623 623 

Min 616 616 616 616 616 616 616 616 616 617 617 616 615 614 614 614 613 613 613 612 612 

‐‐ Indicates invalid data

Non‐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‐Day

SAROAD for Kinross, Roundmountain

Channel: BP_mmHg

Month: 12/18/09 ‐ 01/11/10

Hour of da

y
APPENDIX B 

HCN Data 
Page 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

1001335001 1/13/2010

Sample ID:

Lab ID:

Media: Collected:

Received:

99111218-1 SKC 226-28, Soda Lime-200/600

Sampling Location: Round Mountain

Method:

Analyte ug/sample mg/m3 ppm

NIOSH 6010 Analyzed: 1/19/2010

RL (ug/sample)

Hydrogen Cyanide 0.64 NA NA 0.21

12/18/2009

1001335002 1/13/2010

Sample ID:

Lab ID:

Media: Collected:

Received:

99111221-2 SKC 226-28, Soda Lime-200/600

Sampling Location: Round Mountain

Method:

Analyte ug/sample mg/m3 ppm

NIOSH 6010 Analyzed: 1/19/2010

RL (ug/sample)

Hydrogen Cyanide 0.48 NA NA 0.21

12/18/2009

1001335003 1/13/2010

Sample ID:

Lab ID:

Media: Collected:

Received:

99111224-3 SKC 226-28, Soda Lime-200/600

Sampling Location: Round Mountain

Method:

Analyte ug/sample mg/m3 ppm

NIOSH 6010 Analyzed: 1/19/2010

RL (ug/sample)

Hydrogen Cyanide <0.21 NA NA 0.21

12/18/2009

1001335004 1/13/2010

Sample ID:

Lab ID:

Media: Collected:

Received:

Field Blank SKC 226-28, Soda Lime-200/600

Sampling Location: Round Mountain

Method:

Analyte ug/sample mg/m3 ppm

NIOSH 6010 Analyzed: 1/19/2010

RL (ug/sample)

Hydrogen Cyanide <0.21 NA NA 0.21

IHREP-V9.8
Page 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 Laboratories, 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 unless otherwise noted.

Samples have not been blank corrected unless otherwise noted.

This test report shall not be reproduced, except in full, without written approval of ALS Laboratory Group.

ALS Laboratory Group is accredited by AIHA for specific fields of testing as documented in its current scope of accreditation

(ID#101574) which is available on request by contacting your project manager or view on the internet at http://www.aiha.org. The

quality systems implemented in the laboratory apply to all methods performed by ALS Laboratory Group regardless of this current

scope of accreditation which does not include performance based methods, modified methods, and methods applied to matrices

not listed in the methods.

ALS DataChem provides professional analytical services for all samples submitted. ALS Laboratory Group is not in a position to

interpret the data and assumes no responsibility for the quality of the samples submitted.

All quality control samples processed with the samples in this report yielded acceptable results unless otherwise noted.

General Lab Comments

LOD = Limit of Detection = MDL = Method Detection Limit, A statistical estimate of method/media/instrument sensitivity.

LOQ = Limit of Quantitation = RL = Reporting Limit, A verified value of method/media/instrument sensitivity.

ND = Not Detected, Testing result not detected above the LOD or LOQ.

** No result could be reported, see sample comments for details.

< This testing result is less than the numerical value.

( ) This testing result is between the LOD and LOQ and has higher analytical uncertainty than values at or above the LOQ.

Definitions

IHREP-V9.8

Page 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

1000807001 1/7/2010

Sample ID:

Lab ID:

Media: Collected:

Received:

991112272009-1 SKC 226-28, Soda Lime-200/600

Sampling Location: Round Mountain

Method:

Analyte ug/sample mg/m3 ppm

NIOSH 6010 Analyzed: 1/12/2010

RL (ug/sample)

Hydrogen Cyanide 0.51 NA NA 0.21

12/27/2009

1000807002 1/7/2010

Sample ID:

Lab ID:

Media: Collected:

Received:

991112302009-2 SKC 226-28, Soda Lime-200/600

Sampling Location: Round Mountain

Method:

Analyte ug/sample mg/m3 ppm

NIOSH 6010 Analyzed: 1/12/2010

RL (ug/sample)

Hydrogen Cyanide 0.48 NA NA 0.21

12/27/2009

1000807003 1/7/2010

Sample ID:

Lab ID:

Media: Collected:

Received:

9911122010-3 SKC 226-28, Soda Lime-200/600

Sampling Location: Round Mountain

Method:

Analyte ug/sample mg/m3 ppm

NIOSH 6010 Analyzed: 1/12/2010

RL (ug/sample)

Hydrogen Cyanide 1.1 NA NA 0.21

12/27/2009

1000807004 1/7/2010

Sample ID:

Lab ID:

Media: Collected:

Received:

Blank SKC 226-28, Soda Lime-200/600

Sampling Location: Round Mountain

Method:

Analyte ug/sample mg/m3 ppm

NIOSH 6010 Analyzed: 1/12/2010

RL (ug/sample)

Hydrogen Cyanide <0.21 NA NA 0.21

IHREP-V9.8
Page 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 Laboratories, 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 unless otherwise noted.

Samples have not been blank corrected unless otherwise noted.

This test report shall not be reproduced, except in full, without written approval of ALS Laboratory Group.

ALS Laboratory Group is accredited by AIHA for specific fields of testing as documented in its current scope of accreditation

(ID#101574) which is available on request by contacting your project manager or view on the internet at http://www.aiha.org. The

quality systems implemented in the laboratory apply to all methods performed by ALS Laboratory Group regardless of this current

scope of accreditation which does not include performance based methods, modified methods, and methods applied to matrices

not listed in the methods.

ALS DataChem provides professional analytical services for all samples submitted. ALS Laboratory Group is not in a position to

interpret the data and assumes no responsibility for the quality of the samples submitted.

All quality control samples processed with the samples in this report yielded acceptable results unless otherwise noted.

General Lab Comments

LOD = Limit of Detection = MDL = Method Detection Limit, A statistical estimate of method/media/instrument sensitivity.

LOQ = Limit of Quantitation = RL = Reporting Limit, A verified value of method/media/instrument sensitivity.

ND = Not Detected, Testing result not detected above the LOD or LOQ.

** No result could be reported, see sample comments for details.

< This testing result is less than the numerical value.

( ) This testing result is between the LOD and LOQ and has higher analytical uncertainty than values at or above the LOQ.

Definitions

IHREP-V9.8

Page 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

1001930001 1/19/2010

Sample ID:

Lab ID:

Media: Collected:

Received:

9911152010-1 SKC 226-28, Soda Lime-200/600

Sampling Location: Round Mountain

Method:

Analyte ug/sample mg/m3 ppm

NIOSH 6010 Analyzed: 1/19/2010

RL (ug/sample)

Hydrogen Cyanide 0.71 NA NA 0.21

1/13/2010

1001930002 1/19/2010

Sample ID:

Lab ID:

Media: Collected:

Received:

9911182010-2 SKC 226-28, Soda Lime-200/600

Sampling Location: Round Mountain

Method:

Analyte ug/sample mg/m3 ppm

NIOSH 6010 Analyzed: 1/19/2010

RL (ug/sample)

Hydrogen Cyanide <0.21 NA NA 0.21

1/13/2010

1001930003 1/19/2010

Sample ID:

Lab ID:

Media: Collected:

Received:

99111112010-3 SKC 226-28, Soda Lime-200/600

Sampling Location: Round Mountain

Method:

Analyte ug/sample mg/m3 ppm

NIOSH 6010 Analyzed: 1/19/2010

RL (ug/sample)

Hydrogen Cyanide 0.40 NA NA 0.21

1/13/2010

1001930004 1/19/2010

Sample ID:

Lab ID:

Media: Collected:

Received:

Field Blank SKC 226-28, Soda Lime-200/600

Sampling Location: Round Mountain

Method:

Analyte ug/sample mg/m3 ppm

NIOSH 6010 Analyzed: 1/19/2010

RL (ug/sample)

Hydrogen Cyanide <0.21 NA NA 0.21

IHREP-V9.8
Page 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 Laboratories, 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 unless otherwise noted.

Samples have not been blank corrected unless otherwise noted.

This test report shall not be reproduced, except in full, without written approval of ALS Laboratory Group.

ALS Laboratory Group is accredited by AIHA for specific fields of testing as documented in its current scope of accreditation

(ID#101574) which is available on request by contacting your project manager or view on the internet at http://www.aiha.org. The

quality systems implemented in the laboratory apply to all methods performed by ALS Laboratory Group regardless of this current

scope of accreditation which does not include performance based methods, modified methods, and methods applied to matrices

not listed in the methods.

ALS DataChem provides professional analytical services for all samples submitted. ALS Laboratory Group is not in a position to

interpret the data and assumes no responsibility for the quality of the samples submitted.

All quality control samples processed with the samples in this report yielded acceptable results unless otherwise noted.

General Lab Comments

LOD = Limit of Detection = MDL = Method Detection Limit, A statistical estimate of method/media/instrument sensitivity.

LOQ = Limit of Quantitation = RL = Reporting Limit, A verified value of method/media/instrument sensitivity.

ND = Not Detected, Testing result not detected above the LOD or LOQ.

** No result could be reported, see sample comments for details.

< This testing result is less than the numerical value.

( ) This testing result is between the LOD and LOQ and has higher analytical uncertainty than values at 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: Before 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 .82 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, INC. 

PROJECT 99-6-1 

OCTOBER 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 operate an HCN monitor downwind of the potential 

HCN sources near the RMGC-SVCO operations area. 

The HCN monitoring equipment and sampling 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 Appendix 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-SVCO. 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 predominant wind direction, the RMGC-SVCO boundary of 

public access, the nearest population areas to this boundary, the potential 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 order to identify system design problems, and refine 

the system configuration and operating and maintenance 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 and 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 pregnant and barren tanks at the ADR building. 

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

3.2.1 Leach Pads 

RMGC-SVCO operates several leach pads (the west 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 management 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 building also houses CIC tanks, 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 location 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 exposure 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 and is easily accessible. The proposed site 

coordinates are 485,949 meters east, 4,282,968 meters north, UTM Zone 11N, NAD83, elevation, 

5,797 feet. 

 
6
7
8
9
 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. RMGC-SVCO does, however, propose to use its 

existing meteorological station to collect the meteorological parameters (with the exception of 

relative humidity and barometric pressure) outlined 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 and, therefore, it will provide representative data 

for the overall mine and the monitor site. See Figure 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 relative humidity and barometric pressure, these 

sensors will be installed at the HCN monitor site 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 

NEVADA MINING ASSOCIATION

PROJECT 59-43-70 

OCTOBER 2009 
Hcn 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, INSPECTION, 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 ................................................................................................. 21 
Hcn 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 6010
Hcn 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 developed 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 Systems 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 2 
Hcn 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 under 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 notes and anomalies, and 

• Corrective actions taken (if any). 

After the first four weeks of sampling, preliminary 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 and federal guidelines are strictly defined for 

meteorology but not for HCN. The equipment selection 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 plan submitted by each mine will address the 

proposed location of the meteorological monitoring 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 Campbell Scientific 019ALU 

Pyranometer mounting arm Campbell Scientific 015ARM 

Data logger CR3000 Campbell Scientific CR23X or CR10X 

Power supply with battery Campbell Scientific PS12LA 

Solar panel Campbell Scientific MSX10R 

Wind sensor R.M. Young 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 Transducer 
Hcn 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 instrumentation 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 exceed 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 architecture. 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 months of data and will 

provide a backup of the data and the CR3000 program 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 sensor of the Model 05305 is a helicoid-shaped, fourblade propeller. Rotation of the 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 platinum 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 radiation. 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 HUMICAPTM 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 the relative humidity sensor is 15 seconds. 

5.1.9 Barometric Pressure 

Barometric pressure is measured every 15 minutes using a Vaisala PT101B sensor. The sensor is 

mounted inside the data logger enclosure. Barometric pressure is measured by the data logger 

using Vaisala’s Barocap silicon capacitive pressure 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. The 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 passed through the sorbent tubes. Data collection 

is in twenty-four hour increments. Upon complete exposure of a sorbent tube, it is sealed and 
Hcn 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 consists 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 designed 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 volume of the sorbent tube and necessary to reach 

the required limits of detection. 

A data logger turns the pump on and off and controls 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 also 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, showing 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 VALVE
Hcn 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 VALVE
Hcn 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 and 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 analyzed using spectroscopy. One in every five 

sorbent tubes will be a field blank. 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 VALVE
Hcn Sampling Plan_V7.Docx 12 

The detection limit for this HCN sampling method is reported to be approximately 0.2 ppb1, 

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 communications 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 day 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 gold 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 System Failure Response 

The primary mechanism for ensuring normal system operation will be comprised of on-site 

checks conducted after the tubes have been sampled 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 Requirements 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 Method 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 cyanide 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 provided 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 out 
Hcn 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 accomplished 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 Campbell 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 Check Forms and compare them to the 15-minute data 

averages to ensure proper system operation and data transfer. 

7.2 Instrument Calibration and Frequency 

The following section outlines the preventive maintenance/recalibration of the equipment used 

to test the performance of the on-site systems. 

7.2.1 Calibration Equipment 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 Records and Traceability 

Calibration Forms are completed and maintained by project personnel. All Calibration Forms 

indicate the sensor calibrated, its serial number, 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 data 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 assurance 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 deviation 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 placed 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

S i Sin

N

V

1

1 θ

= ∑

N

C Cos i 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 σ θ1 = ArcSin ε 1+ 0.1547ε

 where, [ ] (() () ) 2

1

2 2 1 = − VS + VC 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 invalid, 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/m3 @ 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 (Sr): 0.041 @ 10 to 50 mg per sample [1]

ACCURACY

RANGE STUDIED: 2 to 15 mg/m3 [1]

(3-L samples)

BIAS: Not significant

OVERALL PRECISION (Sˆ

rT): 0.076 [1]

ACCURACY: ± 15.0%

APPLICABILITY: The working range is 0.3 to 235 ppm (3 to 260 mg/m3) 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 and

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

AgNO3 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 (Wf) and back (Wb)

sorbent sections and in the average media blank front (Bf) and back (Bb) sorbent sections. If

Wb > Wf/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/m3 for a 3-L air sample. Twenty-two samples collected at 0.2 L/min for 15 minutes

indicated overall precision Sˆ

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/m3. 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

(AgNO3) solution. The end point is the first formation of a white precipitate, Ag[Ag(CN) 2]. Calculate the

cyanide concentration with the following equation:

Mc = 52.04 Va (Ma/Vc)

Where Mc = cyanide concentration (mg/mL)

Va = volume (mL) of standard silver nitrate solution

Ma = concentration (moles/L) of standard silver nitrate solution

Vc = volume (mL) of calibration stock solution titrated

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