# From: "Barbanell, Melissa (Salt Lake City )" <mbarbanell@barrick.com>

To: Chuck French/RTP/USEPA/US@EPA

Cc: < klewis@airsci.com >, < matt.zietlow@goldcorp.com >

Date: 03/03/2010 08:07 PM

Subject: FW: Marigold HCN emissions

Chuck,

Attached please find the Marigold HCN emissions cal culations. Please feel free to contact me if

you have any questions.

Thanks,

MelissaMARIGOLD HCN EMISSIONS51 days w/ 0.5+ in. 14% snow Wind: m/s Fw2009 Surface Area and 2009 Solution Parameters3.23 1.06Snow Cover Solution Parameters OverallAdjustment Free CN- TkGorFluxArea Source Cat. Category DescriptionAcresAcres pH g/m3 C pKa a0 Hm/sorg/m2-sFa*Fw g/s lb/yrLeach Pad Leach Pad PSW Active Pad, Wet Surface 45.00 38.71 snow 10.41 84.71 10.08 9.638 0.1433 0.003175.00E-060.47 1.41E-02 978.9PD Active Pad, Dry Surface 45.00 38.71 snow 10.41 84.71 10.08 9.638 0.1433 0.003177.82E-070.47 2.20E-03 153.2PI Inactive Pad 187.00 160.87 snow1.95E-081.00 1.27E-02 882.9Barren Ponds 1 and 2 BP Open Barren Ponds and Solution 2.2 2.2 10.41 84.71 10.08 9.638 0.1433 0.003178.37E-050.47 1.34E-02 932.1Pregnant Ponds 1, 2 and 3 CO Open Preg Channel, Tank, or Pond 0.080 0.1 9.86 25.66 10.08 9.638 0.3763 0.003171.87E-050.47 8.72E-05 6.1CIC Tanks (20) CO Open Preg Channel, Tank, or Pond 0.036 0.036 9.86 25.66 10.08 9.638 0.3763 0.003171.87E-050.47 3.91E-05 2.7Active Surface Subtotal 92.32Snow Adjustments Psn Pad, Snow Covered 38.70 snow1.84E-081.00 2.89E-03 200.7Snow Covered Surface Subtotal 38.7TOTAL AREA279.32 279.32Total (lb/yr)3,156.7Total (ton/yr)1.6Table 1: Measured Flux RatesCat. HCN Flux (ug/m2-min)Category ID CTZ GQ RM Overall Category DescriptionPonds/Channels CC 0.62 4 0.62 Channel Pregnant CoveredCO 25.38 2 28.88 4 5.08 5 12.81 Open Preg Channel, Tank, or PondBP 222.96 6 1155.65 5 712.57 7 553.30 Open Barren Ponds and SolutionTails TA 42.62 6 15.39 4 0.96 4 10.79 Tails, Aqueous SurfaceTW 6.46 5 5.50 4 1.80 10 3.18 Tails, Wet SedimentTD 1.55 2 2.50 2 0.35 1 1.40 Tails, Dry SedimentActive Pads PSW 21.92 13 48.64 20 43.25 25 38.67 Active Pad, Wet SurfacePsprink 72.98 2 265.85 3 158.51 Active Pad, Sprinkler, Wet SurfacePD 2.45 3 7.05 5 4.68 7 4.72 Active Pad, Dry SurfaceInactive Pads PI 0.78 16 1.17 Inactive PadPI1 2.22 3 Inactive Pad 1 moPI3 4.52 4 Inactive Pad 3 moPI12 0.41 2 1.82 3 Inactive Pad 12 moTanks TK 574.50 8 212.12 12 847.97 6 396.83 TanksIce/Snow Psn 0.92 5 1.74 2 1.11 Pad, Snow CoveredTsn 0.80 2 0.54 1 0.70 Tails, Snow CoveredBice 7.69 1 7.69 Barren Solution, FrozenTAice 0.62 1 2.53 4 1.90 Tails, Aqueous, FrozenTable 2: Measured Mass Transfer CoefficientsCat. kG (m/s)Category ID CTZ GQ RM Overall Category DescriptionPonds/Channels CC 5.33E-07 4 5.33E-07 Channel Pregnant CoveredCO 4.35E-06 2 1.94E-04 4 5.17E-06 5 1.87E-05 Open Preg Channel, Tank, or PondBP 3.91E-05 6 1.70E-04 5 9.70E-05 7 8.37E-05 Open Barren Ponds and SolutionTails TA 6.35E-05 6 2.43E-05 4 1.26E-06 4 1.57E-05 Tails, Aqueous SurfaceTW 9.62E-06 5 1.13E-05 3 1.02E-05 Tails, Wet SedimentTD 2.29E-06 2 2.29E-06 Tails, Dry SedimentActive Pads PSW 7.11E-06 13 7.34E-06 20 3.06E-06 25 5.00E-06 Active Pad, Wet SurfacePsprink 2.70E-05 2 4.37E-05 3 3.60E-05 Active Pad, Sprinkler, Wet SurfacePD 7.05E-07 3 2.48E-06 1 6.61E-07 5 7.82E-07 Active Pad, Dry SurfaceInactive Pads PIInactive PadPI1Inactive Pad 1 moPI3Inactive Pad 3 moPI12 Inactive Pad 12 moTanks TK 2.27E-04 4 3.64E-04 12 1.29E-04 6 2.51E-04 TanksIce/Snow Psn 2.02E-07 2 1.17E-07 1 1.69E-07 Pad, Snow CoveredTsnTails, Snow CoveredBice 1.40E-06 1 1.40E-06 Barren Solution, FrozenTAice 9.17E-07 1 9.17E-07 Tails, Aqueous, Frozen