Supporting Technical Assessments

| Existing Air Quality Effects | Waihi North Project Air Discharge Assessment - Waihi Surface Facilities | 4396626-1331619777-99 | 16/06/2022 | 46 Table 6-3. Summary of analysis of monthly dust-deposition data (January 2000 – December 2020) Monitoring Site Summary of Results 6.59 (Torrens opp Alex) Deposition rates are representative of rural background levels. Deposition rates are not expected to be impacted by mining operations. 6.60 (Torrens Town End) Deposition rates are representative of rural background levels. Deposition rates are not expected to be impacted by mining operations. 6.61 Leaches (Grey Street) Deposition rates are on average statistically slightly higher than background levels. 6.63 (Met Station) Deposition rates are on average statistically slightly higher than background levels. The higher deposition rates are potentially due to the site’s proximity to and downwind location from Martha Pit. 6.66 (College) Deposition rates are not statistically significantly different from background levels. 6.7 (Smith) Deposition rates are not statistically significantly different from background levels. 6.71 (Morrison) Deposition rates are on average statistically slightly higher than background levels. 6.72 (Baxters Road) Deposition rates are not statistically significantly different from background levels. 6.00 (Bulltown) Deposition rates are not statistically significantly different from background levels. 6.2.1 Comparison of deposited dust concentrations with annual production rates The annual average deposited dust levels measured at Site 6.63 (Met Station) are compared with the annual tonnage of material handled at the mine in Figure 6-4. The deposited dust levels measured at a site are dependent on the level and type of activity in proximity to the site and meteorological conditions. The graph in Figure 6.4 demonstrates that annual average dust deposition levels have varied at Site 6.63 (Met Station), generally in accordance with production rates, especially since 2005. Production at the Martha open pit stopped in 2015 which helps explains the lower deposition rates observed since 2015. Also, improvements to the Martha Eastern Perimeter Road in 2010 are also expected to have influenced the observed deposition rate. Figure 6-4 Annual dust deposition at Site 6.63 (Met Station) compared to annual tonnage of material handled (2001 - 2019) 0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 0.00 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 Annual production rates (Mt) Annual dust deposition (g/m2/30-Days) Annual Average Dust Deposition Rate Annual Production Rate

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