1 M E M O R A N D U M

To: Nevada Division of Environmenta l Protection, Bureau of Air Quality

From: Air Quality Subcommittee of the Nevada Mining Association

Date: July 16, 1996

Subject: Recommended Methodology for Quantifica tion of Fugitive Dust Metals Emissions from Mining Activities for Title V Applicability

The Air Quality Subcommittee of the Nevada Mi ning Association (NMA), in response to the

Nevada Division of Environmental Protection = s (NDEP) letter of April 24, 1996, has developed a recommended procedure for estimating fugitive dust metals emissions from mining activities. The

metals of interest are those listed as a Hazardous Air Pollutant (HAP) in S ection 112(b) of the Clean Air Act. Part of this development process include d identification of specific operations at a typical precious metals mining facility that would produce fugitive particulate emissions and, consequently, fugitive dust metals emissions. The objective of developing a specific procedure for emissions estimation is to provide a standardized practi cal approach for Nevada precious metals mining facilities to use in assessing whether their facility is a major Title V source on the basis of HAP

emissions.

The emission factors and emissions estimation pro cedures presented in this memorandum represent what the Subcommittee believes to be the most appropriate for purposes of estimating fugitive dust and metals emissions for assessing Title V appli cability. While several different emission factors exist for each mining activity described which, in tu rn, provide a wide range of emission estimates, we believe the approach presented herein provides the most realistic and consistent method for

emissions estimation.

Identification of Mining Activities Generating Fugitive Dust

Operations at several Nevada precious metals mine s were evaluated to determine the primary types of mining activities that typically generate fugitive dust emissions. Other secondary activities occur within a typical precious metals mining operation that potentially generate fugitive dust emissions such as pick-up truck and employee vehicle traffi c and the intermittent use of heavy equipment for

short-term construction and maintenance tasks. However, total fugitive dust emissions potentially originating from these activities are small compar ed to those emissions attributable to mining activities that are integral to the operation of a mining facility. Thus, only the primary mining activities are considered in detail in this quantification evaluation.

The primary mining activities are grouped under the following categories, and discussed below:2 C

Pit Operations

C

Ore and Waste Rock Haul

C

Haul Road Repairs/Maintenance

C

Wind Erosion

Pit Operations

These operations include the initial removal of ore and surrounding waste rock from the pit by drilling and blasting and transfer of the blasted ore/waste rock material from the pit to haul trucks which transport the material to its next destination (i.e., crusher, leach pads, stockpiles, etc.). The first two pit operations specified are drilling a nd blasting. The remaining pit operations are handling of the blasted material by front end loaders and/or bulldozers to enable its transfer to haul trucks for transport to its next destination.

Ore and Waste Rock Haul

Once the ore/waste rock material ha s been removed from the pit, the ore and waste rock are typically separated and transferred to haul trucks for haulage to their specific destinations (i.e., haul routes). Fugitive particulate emissions generated during this process are associated with the contact of the

haul truck tires with the haul ro ad surface. Total emissions are significantly affected by the length of the haul routes, the number of trip s required to transport the material, the silt and moisture content of the roadbed material and the control practices used on the haul road surface. Once the ore or waste rock reaches its next destination (i.e., primary crushe r, waste rock stockpile, leach pad, etc.), the haul truck is then unloaded, generating fugitive dust emi ssions. Thus, activities associated with ore and

waste rock haul consist of sets of haul road travel and material transfer (unloading) operations. Each set corresponds to a distinct haul route. Controls for haul road emissions typically consist of the periodic application of water and, sometimes, a combination of water and chemical dust suppressants. Water sprays and/or enclosure are th e most typical control pr actices utilized for truck unloading.

Haul Road Repairs/Maintenance

To maintain proper safety conditions for haul truck travel, graders are used to level the haul road surface. To minimize fugitive dust emissions, water tr ucks are used to periodically moisten the haul road surface. Thus, grader maintenance and water truck travel on the haul roads are the two primary operations typically occurring at a Nevada precious metals mining facility, associated with haul road repairs and maintenance. The same control practices used for minimizing fugitive dust emissions from haul truck travel also apply to haul road repairs and maintenance activities.3 Wind Erosion

Various ore surge piles and stockpiles, waste ro ck dumps and stockpiles and tailings impoundments exist at a typical precious metals mining facilit y. Storage areas such as ore surge piles and stockpiles are frequently disturbed to transfer ore to the processing facilities. This frequent

disturbance does not allow the surface of the or e storage area to become crusted, allowing wind erosion to occur in the presence of sufficiently strong winds. Thus, these storage areas can be

considered active disturbance areas.

However, deposition of waste rock on dumps and stockpiles only occurs over a small proportion of the total storage area at any given time. Since the waste rock on the remaining portions of the storage area remains relatively undisturbed (i.e., not used as part of the mineral extraction process once deposited on the storage area) in between periods of higher wind speeds and are allowed to form a crust, these storage areas are essentially inactive areas.

Tailings differ significantly from the ore and waste rock in silt and moisture content. Thus, the wind erosion potential of tailings impoundments differ from either the actively disturbed ore storage areas or the relatively inactive waste rock storage areas . The ore storage areas, the waste rock storage areas and the tailings impoundments exhibit three di stinctly different potentials for particulate

emissions from wind erosion. The use of controls such as water and chemical dust suppressants are more effective for relatively inactive disturban ce storage areas and, consequently, are used less frequently on actively disturbed areas.

Recommended Particulate Emission Factors for Mining Activities

Various particulate emission factors for the identified mining activities were evaluated for appropriateness and reasonability of resultant emissi on estimates. On the basis of this evaluation, a set of particulate emission factors presente d in a memorandum authored by the Wyoming Department of Environmental Quality, Air Qu ality Division (WDEQ/AQD) , dated January 24, 1979

is recomme nded as the factors providing the most realistic estimates of fugitive particulate emissions from large surface mining operations. This emission factor set has been used successfully by the WDEQ/AQD for nearly 20 years in managing air re sources within the Powder River Basin where several very large surface coal mines operate in cl ose proximity. This emission factor set has also been accepted on a case-by-case basis by the reviewing agencies in Colorado, New Mexico, Alaska and Arizona for modeling/permit applications fo r mining sources. The WDEQ/AQD emission factor

set is reco mmended to be used with speci fic control practices on mining activities that are consistent with those implemented in other states such as Nevada, Wyoming, Colorado, New Mexico, Alaska

and Arizona.

The Powder River Basin Model Validation Anal ysis, prepared by TRC for the WDEQ/AQD and dated August 2, 1991, demonstrated, by comparing mode led to monitored total suspended particulate (TSP) values around the large surface co al mines, that the use of these factors with the Fugitive Dust Model (FDM) or the Industrial Source Complex (IS C) model provides more accurate estimates of

ambient concentrations than the use of emission f actors strictly from AP-42. Over predictions of4 modeled concentrations versus monitored concentrations are significantly reduced by using the WDEQ/AQD factors. The validati on study concluded that the ratios of annual-averaged modeled concentrations (using the short-term version of ISC) to corresponding monitored concentrations ranged from 0.78 to 1.23 when using the WDEQ/ AQD factors for the suite of 22 monitoring locations considered in the study. The aver age ratio of predicted, maximum modeled to corresponding monitored concentrations for 24-hour averaging periods was 2.5 when using ISC with the WDEQ/AQD emission factor set. Use of stric tly AP-42 factors would result in significantly higher modeling to monitoring concentration ratios than those identified above. These higher ratios would result because the general haul road emission factors found in Section 13.2.2 of AP-42, Miscellaneous Source - Unpaved Roads , are approximately one order of magnitude larger than the WDEQ/AQD haul road emission factors (assuming equa l control efficiencies are applied). Since haul road emissions are a significant portion of to tal fugitive dust emissions from mining activities,

use of the AP-42 factors would result in estimated modeling to monitored concentration ratios approaching one order of magnitude higher than those estimated from the WDEQ/AQD emission

factor set.

Further, nearly 20 years of sampling at a large num ber of ambient particulate sampler sites within

the Powder River Basin have demonstrated that st andards are not being thr eatened, validating earlier modeling for permit application analyses using WDEQ/AQD factors; however, the use of AP-42 factors in these same modeling analyses would ha ve suggested large numbers of exceedances. We suggest that the NDEP contact Mr. Bernie Dailey at the WDEQ/AQD [(307) 777-7391] should you have concerns regarding the use of these factors.

WDEQ/AQD emission factors for each identified mi ning activity are presented in the following activity-by-activity description. For certain mining activities which do not have WDEQ/AQD emission factors, the most appropriate AP-42 emissi on factor is specified. To maintain consistency with using the WDEQ/AQD emission factor approach, control efficiencies attributable to watering and chemical dust suppressants are simplified by a ssigning a control efficiency of 50% to water alone and a control efficiency of 60% for using wa ter combined with chemical dust suppressants or chemical dust suppressants alone. Except for specifically identified mining activities, the WDEQ/AQD emission factor for PM 10 is the TSP emission factor, multiplied by 0.30.

1. Drilling

The WDEQ/AQD does not have specific emission fact ors for drilling. The em ission factor proposed herein as the most appropriate for estimating drilling emissions is from Table 11.19.2-2 of AP-42 for wet drilling of unfragmented stone from crushed stone processing operations. This factor is chosen

over other candidate factors such as Table 11.9-4 fo r drilling of overburden at a western surface coal mines since the ore/waste rock material being drilled is more similar to unfragmented stone than overburden and some control for the initially moister condition of the ore/waste rock material during the drilling procedure is considered. Thus, the PM 10 emission factor (EF) is:

EF PM10 = 0.00008 lb/ton

EF TSP = 0.000168 lb/ton5 No specific EF for TSP is given; however, the f ootnote to Table 11.19.2-2 states that a ratio of 2.1 should be multiplied by the PM 10 emission factor to derive corresponding TSP, consistent with the

relative ratios found in Sections 13.2.2 and 13.2.4 of AP-42.

2. Blasting

The WDEQ/AQD memorandum of 1/24/79 presents emission factors of 50 and 35 lb/blast for blasting of overburden and coal, respectively. A multiplier of 0.75 to account for the proportion of particulate matter greater than 30 microns in diamet er, settling out prior to reaching off-site ambient air exposure locations, is also given; however, to provide for a more conservative estimate of total suspended particulate matter, the multiplicative factor of 0.75 is not used. Si nce the ore/waste rock material being blasted is more like overburden than coal, the TSP emission factor for overburden is

used. Therefore, the TSP emission factor is:

EF TSP = 50.00 lb/blast

3. In-pit Handling and Transfer of Ore/Waste Rock to Haul Trucks

The WDEQ/AQD memorandum of 1/24/79 presents an overburden removal emission factor of 0.02 lb/ton x 0.75 for truck/shovel operations. This em ission factor includes both the handling of the

ore/waste rock material after it has been blasted a nd the actual transfer of the material into haul trucks for transport to its next destination (i.e., primary crusher, waste rock dump, leach pad, etc.). Thus, this one calculation accounts for particulate emissions from handling and transfer of all materials leaving the pit and being hauled to thei r various destinations within the facility. The amount of fugitive dust generated from truck/shovel operations are assumed to be similar to frontend loaders or bulldozers performing the same func tions. Again, the multiplicative factor of 0.75 is not used to provide a more conservative estimate of TSP emissions. The TSP emission factor is:

EF TSP = 0.02 lb/ton

4. Hauling of Ore and/or Waste Rock

The WDEQ/AQD memorandum of 1/24/79 presents the following haul road emission factor equation for TSP:

EF TSP = 0.81s (S/30) n [(365-w)/365] T x 0.62, in lb/VMT

where: s = silt content of roadbed material, in percent S = average vehicle speed, in mph

n = 1 if S > 30; 2 if S < 30 w = no. days per year with precipitation > 0.01" T = tire correction factor, 2.5 for large haul trucks6 To use this equation to estimate annual TSP emissions, the total annual vehicle-miles for each haul route is calculated by dividing the amount of mate rial hauled (in tons) by the average carrying capacity of a haul truck (in tons) and then multiply ing by the round-trip distance (in miles) of each haul trip.

5. Primary Crusher Truck Dump

The transfer of ore from haul tr ucks to the primary crusher truck dump is distinguished from other transfer operations (i.e., transfer to stockpiles, between conveyors, etc.) because of its significant drop height. The WDEQ/AQD emi ssion factor presented in the 1/24/79 memorandum for product dumping (only coal and uranium are cited in the memo) for TSP is:

EF TSP = 0.017 lb/ton

6. Other Material Transfer Operations

The transfer of ore and/or waste rock from the ha ul trucks to various stockpiles, dumps, surge piles and leach pads does not have an applicable emission factor in the WDEQ/AQD memorandum of 1/24/79. The appropriate emission factor equation selected for this operation is presented in Equation No. 1 of Section 13.2.4.3 of AP -42 for transfer of aggregate materials. This equation has already been used in previous permit applica tion analyses for Nevada precious metals mining applicants. This emission factor equation for TSP is:

EF PM = k (0.0032) (U/5) 1.3 / (M/2) 1.4 , in lb/ton

where:

k = 0.74 for TSP; 0.35 for PM 10 U = average wind speed, in mph M = material moisture content (%)

7. Haul Road Repairs/Maintenance (Graders and Water Trucks)

Fugitive particulate emissions from the repair of ha ul roads by graders to maintain haul truck travel safety are estimated by the following emission factor equation, from the WDEQ/AQD memorandum

of 1/24/79, for TSP:

EF TSP = 32.00 x [(365-w)/365], in lb/hr

where: w = no. of days per year with precipitation > 0.01"

Typically, a control efficiency of 50% for watering is applied to the estimates of fugitive dust emissions from grader operations. The annual par ticulate emissions are es timated by multiplying the above value, in lb/hr per grader, by the total number of grader-hours of operation for the year.7 Fugitive particulate emissions from water truck trav el on the haul roads are based on the same haul road EF equation presented for the hauling of ore and/or waste rock. The tire correction factor is

assumed to be 2.5, the same as for haul trucks, and the average speed of the water trucks is input for

the variable, S.

8. Wind Erosion

Emission factor equations for estimating fugitive dust from wind erosion of active disturbance areas, inactive disturbance areas and tailings impoundments are selected not only for appropriateness, but also in consideration of easily obtaining input info rmation required for the emissions estimation. As a result, the following three emission factor equations are selected.

8a. Wind Erosion from Active Disturbance Areas

The WDEQ/AQD memorandum of 1/24/79 present emission factors that are representative of relatively inactive disturbance areas. AP-42 was reviewed for wind erosion algorithms appropriate for actively disturbed areas. Section 13.2.5 of AP-42 contains a procedure th at considers frequency of wind speeds exceeding certain thresholds necessary to disturb specific types of surfaces. The meteorological data required for this procedure cons ists of at least hourly wind speed records, with the instantaneously highest wind speed occurring duri ng that hour, collected at a site representative of the facility being evaluated. In addition, informati on either from on-site testing or from review of studies at reasonably similar facilities must be obtained concerning the erodibility potential of a specific type of surface (i.e., crusted, fine material, coarse material, dry, moist, etc.). Most Nevada precious metals mining facilities do not have acce ss to such data and would have to expend significant time and expense to gather the nece ssary information. A simpler emission factor equation, as found in previous (i.e., Fourth Edition) versions of AP-42 is selected which has been used widely accepted in numerous emission analyses for regulatory purposes. Specifically, this equation is from Section 11.2.3.3 of the Fourth Edition of AP-42, as follows:

EF PM = k (1.7)(s/5) [(365-w)/235] (f/15), in lb/day-acre

where:

k = 0.8 for TSP; 0.36 for PM 10 s = silt content of surface material, in percent w = no. of days per year with precipitation > 0.01" f = proportion of annual hourly wind speeds > 12 mph, in percent

8b. Wind Erosion from Inactive Disturbance Areas

The WDEQ/AQD memorandum of 1/24/79 contains wind erosion emission factor equations for short-term and long-term fugitive dust emissions that are not commonly used for recent permit application analyses in Wyoming. The TSP em ission factor currently utilized by the WDEQ/AQD for relatively inactive surface disturbance areas is:8 EF(TSP) = 0.25 tons/acre-yr

8c. Wind Erosion from Tailings Impoundments

The WDEQ/AQD memorandum of 1/24/79 and AP-42 do not contain emission factors specifically appropriate for the unique material character istics of tailings impoundments. Consequently, emission factors empirically derived from field studies conducted by Midwest Research Institute for EPA in the document, Gap Filling PM 10 Emission Factors for Selected Open Area Dust Sources (EPA, February, 1988) are used. Table 11 of Section 13.0 presents a summary of empirically

derived PM 10 emission factors from both controlled and uncontrolled coarse, dry tailings ponds

surfaces. The two field tests conducted on an uncontrolled area provided emission factors of 0.0738 grams/min-m 2 and 0.0256 grams/min-m 2 . Averaging these two values results in a mean PM 10 emission factor of 0.0497 or approximately 0.05 grams/min-m 2 . However, this emission factor applies during wind speeds in excess of 42 miles per hour or 19 meters per second (m/s). To obtain

an annual A average @ emission factor, this initial value must be divided by the average number of minutes occurring between each episode of wind speeds in excess of 19 m/s. If a typical value of 1,000 minutes (i.e., once every 16 to 17 hours) between episodes is used, the annual A average @ emission factors becomes 0.00005 grams/min-m 2

.

Converting this emission factor to more conventional units:

EF(PM 10 ) = 0.1172 tons/acre-yr

No specific EF for TSP is given; however, adopting the same approach used to estimate TSP emissions from drilling, the PM 10 emission factor is multiplied by 2.1 to derive corresponding TSP,

consistent with the relative ratios found in Sections 13.2.2 and 13.2.4 of AP-42. Thus, the TSP

emission factor is:

EF(TSP) = 0.2461 tons/acre-yr

Site-specific values for these emission factors can be estimated by using on-site meteorological data to determine the annual average duration between wind speed episodes in excess of 19 m/s.

Metals Content Data for Estimating Fugitive Dust Metals Emissions

Once a comprehensive fugitive dust emissions invent ory with reasonable estimates is compiled, the metals components of the TSP emissions are calcu lated by multiplying by appropriate metals content data. Considerations for selection of appr opriate metals content data include not only representativeness of site conditions, but also the availability and accessibility of such information. In view of these considerations, three pro cedures for obtaining metals content data are recommended. These procedures are:9 1. Use elemental metal analysis of whole rock samples previously performed for assaying purposes. This analysis can consist of one se t of whole rock samples, but ideally would include a suite of locations over a period of tim e to represent overall site conditions. From a statistical standpoint, the geometric mean for each metal from this suite of whole rock samples would be used to better represent site conditions. The metals concentrations, expressed in dimensionless units such as parts per million (ppm), are multiplied by the annual TSP emission rate for each specified mining activity.

2. If available, elemental metal analysis of ro ck samples separated into ore and waste rock categories would allow a better distinction of potential fugitive dust metals emissions from those mining activities associated with handling the ore and those associated with handling the waste rock. In particular, haul road emissions would be better represented by using metals content analysis for waste rock, rather than ore, since roadbed material is primarily waste rock. Again, using the geometric mean of a suite of ore and waste rock sample analyses would provide a better representation of site conditions.

3. If available, laboratory analyses for metals c ontent of exposed ambient particulate filters can be used to better represent ambient exposure. Special sampling protocols such as longer exposure times (i.e., greater than 24 hours) or hi gher flow rates may have to be implemented to provide metals mass capture that exceed laboratory detection limits using a typical laboratory analytical procedure such as IC AP (inductively coupled argon plasma emission spectroscopy). Otherwise, a more sensitive laborat ory analytical technique would need to be used. If metals analyses are below laborator y detection limits, then the typical practice of using 2 of the detection limit to represent concen trations of these metals is recommended. This procedure is the third alternative described since most Nevada precious metals mining operations do not have such data readily available and would have to expend significant time and expenses to procure such information.

Example of Fugitive Dust HAP Metals Emi ssion Estimates from a Generic Gold Mine

Fugitive dust HAP metals emissions from a generi c Nevada mining facility, named ABC Gold Mine, using the recommended emission factor equations and procedures are estimated and summarized below. The ABC Gold Mine is an example of a f acility with total PTE (Potential-to-Emit) emissions of each criteria pollutant below th e Title V major source threshold of 100 tpy. Potential fugitive dust

HAP metals emissions are estimated to evaluate the likelihood that this mining facility would still become a Title V major source solely based on total fugitive HAP metals emissions.

Operating statistics of the ABC Gold Mine, pertin ent to the estimation of fugitive dust HAP metals

emissions, are:10 C Annual Ore Throughput: 8,000,000 tons per year

C Annual Non-ore (Waste Rock) Throughput: 20,000,000 tons per year

C Total Round-trip Haul Road Distance: 11.25 miles per trip

C Average Moisture Content of Ore/Non-ore: 5 percent

C Average Silt Content of Ore/Non-ore: 7.6 percent

C Average Annual Wind Speed: 10 miles per hour

C Number of Days per Year of Precipitation > 0.01 inch: 90

C Carrying Capacity of Haul Trucks: 85 tons

C Average Speed of Haul Trucks: 17 miles per hour

C Control Practice(s) Used on Haul Roads: Water and chemical additive; 60% control

C Total Erodible Surface Area for Wind Erosion: 313.45 acres

ABC Gold Mine already has laboratory analyses of the metal content of a suite of rock samples, distinguished between ore and waste rock. To provide a better representation of metal content in ore and waste rock across the facility, the geometric mean of the analyzed sample concentrations of each HAP metal in the ore samples and in the waste ro ck samples are estimated and summarized in Table 1. Since some mining activities involve both ore a nd waste rock materials, the geometric mean

concentrations of the mixture of these two material types are also estimated. These HAP metals concentrations are multiplied by the estimated fugitive TSP emissions for each mining activity, using the Wyoming emission factor set, to provide corresponding fugitive HAP metal emission estimates. Table 2 is an overall summary of estimated fugitive dust HAP metals emissions from mining activities. As can be seen from Table 2, using the fugitive particulate emissions estimated from the recommended Wyoming emission factor set and HAP metals concentration data representative of overall site conditions produ ces HAP metals emission estimates that are considerably below the 10 and 25 t py Title V major source thresholds for individual and total HAPs, respectively. This conclusion is consistent with the designation of the ABC Gold Mine as a Title V minor source on the basis of total PTE emissions of each criteria pollutant.TABLE 2. SUMMARY OF FUGITIVE DUST HAP METALS EMISSIONS FROM ABC GOLD MINE OPERATIONSSource PM10 TSPDescription (lb/hr) (tons/yr) (lb/hr) (tons/yr)Drilling 0.34 1.12 0.71 2.35Blasting 15.00 2.67 50.00 8.90In-pit Material Handling & xfer of Ore/Waste 19.66 84.00 65.54 280.00Ore Haul from Pit to Primary Crusher 8.21 35.07 27.36 116.89Unloading Ore to Primary Crusher 2.39 10.20 7.96 34.00Haul from the Pit to the Low Grade Ore Stk. 1.13 4.82 3.76 16.07Unloading Low Grade Ore to the Stockpile 0.10 0.42 0.21 0.89Waste Rock Haul to Dump 28.69 122.58 95.64 408.58Unloading Waste Rock to Dump 1.69 7.23 3.58 15.28Loading of Crushed Ore for the Leach Pads 0.72 3.06 1.51 6.47Haul of Crushed Ore to the Leach Pads 5.80 24.77 19.33 82.56Unloading Crushed Ore on the Leach Pads 0.72 3.06 1.51 6.47Haul Road Repairs/Maintenance 12.08 50.12 40.28 167.08Wind Erosion (Ore/Waste/Tailings) 8.16 35.73 22.37 97.97Total fugitive emissions104.68 384.84 339.76 1,243.50Source Arsenic Beryllium Cadmium Cobalt Chromium Manganese Nickel Lead Antimony Selenium Mercury Total MetalsDescription (tons/yr) (tons/yr) (tons/yr) (tons/yr) (tons/yr) (tons/yr) (tons/yr) (tons/yr) (tons/yr) (tons/yr) (tons/yr) (tons/yr)Drilling 5.58E-04 M 3.06E-06 M 5.88E-06 M 1.93E-05 M 3.27E-04 M 5.69E-05 M 1.06E-04 M 1.16E-03 M 6.02E-04 M 9.64E-05 M 6.12E-06 M 2.94E-03Blasting 2.11E-03 M 1.16E-05 M 2.23E-05 M 7.30E-05 M 1.24E-03 M 2.15E-04 M 4.02E-04 M 4.38E-03 M 2.28E-03 M 3.65E-04 M 2.31E-05 M 1.11E-02In-pit Material Handling & xfer of Ore/Waste 6.64E-02 M 3.64E-04 M 7.00E-04 M 2.30E-03 M 3.89E-02 M 6.78E-03 M 1.27E-02 M 1.38E-01 M 7.17E-02 M 1.15E-02 M 7.28E-04 M 3.50E-01Ore Haul from Pit to Primary Crusher 1.55E-02 W 1.75E-04 W 3.74E-04 W 9.82E-04 W 1.57E-02 W 3.44E-03 W 5.80E-03 W 2.68E-02 W 2.89E-02 W 4.79E-03 W 1.17E-04 W 1.03E-01Unloading Ore to Primary Crusher 1.02E-02 O 4.08E-05 O 7.82E-05 O 2.75E-04 O 4.78E-03 O 7.62E-04 O 1.48E-03 O 2.27E-02 O 8.83E-03 O 1.39E-03 O 1.33E-04 O 5.07E-02Haul from the Pit to the Low Grade Ore Stk. 2.13E-03 W 2.41E-05 W 5.14E-05 W 1.35E-04 W 2.16E-03 W 4.73E-04 W 7.97E-04 W 3.68E-03 W 3.97E-03 W 6.59E-04 W 1.61E-05 W 1.41E-02Unloading Low Grade Ore to the Stockpile 2.66E-04 O 1.07E-06 O 2.04E-06 O 7.20E-06 O 1.25E-04 O 1.99E-05 O 3.88E-05 O 5.94E-04 O 2.31E-04 O 3.64E-05 O 3.47E-06 O 1.33E-03Waste Rock Haul to Dump 5.41E-02 W 6.13E-04 W 1.31E-03 W 3.43E-03 W 5.50E-02 W 1.20E-02 W 2.03E-02 W 9.36E-02 W 1.01E-01 W 1.68E-02 W 4.09E-04 W 3.58E-01Unloading Waste Rock to Dump 2.02E-03 W 2.29E-05 W 4.89E-05 W 1.28E-04 W 2.06E-03 W 4.49E-04 W 7.58E-04 W 3.50E-03 W 3.77E-03 W 6.26E-04 W 1.53E-05 W1.34E-02Loading of Crushed Ore for the Leach Pads 1.94E-03 O 7.76E-06 O 1.49E-05 O 5.24E-05 O 9.09E-04 O 1.45E-04 O 2.82E-04 O 4.32E-03 O 1.68E-03 O 2.65E-04 O 2.52E-05 O 9.64E-03Haul of Crushed Ore to the Leach Pads 1.09E-02 W 1.24E-04 W 2.64E-04 W 6.94E-04 W 1.11E-02 W 2.43E-03 W 4.10E-03 W 1.89E-02 W 2.04E-02 W 3.39E-03 W8.26E-05 W 7.24E-02Unloading Crushed Ore on the Leach Pads 1.94E-03 O 7.76E-06 O 1.49E-05 O 5.24E-05 O 9.09E-04 O 1.45E-04 O 2.82E-04 O 4.32E-03 O 1.68E-03 O 2.65E-04 O 2.52E-05 O 9.64E-03Haul Road Repairs/Maintenance 2.21E-02 W 2.51E-04 W 5.35E-04 W 1.40E-03 W 2.25E-02 W 4.91E-03 W 8.29E-03 W 3.83E-02 W 4.13E-02 W 6.85E-03 W 1.67E-04W 1.47E-01Wind Erosion (Ore/Waste/Tailings) 2.32E-02 M 1.27E-04 M 2.45E-04 M 8.03E-04 M 1.36E-02 M 2.37E-03 M 4.43E-03 M 4.82E-02 M 2.51E-02 M 4.02E-03 M 2.55E-04 M 1.22E-01Total fugitive emissions0.21 0.00 0.00 0.01 0.17 0.03 0.06 0.41 0.31 0.05 0.00 1.26O - Metal emissions based on TSP emission estimates; metal content is based on analyzed geometric mean of ore samplesW - Metal emissions based on TSP emission estimates; metal content is based on analyzed geometric mean of waste rock samplesM - Metal emissions based on TSP emission estimates; metal content is based on analyzed geometric mean of both ore and waste rock samples