54 Boffa Miskell Ltd | Waihi North Project | Terrestrial Ecology Values and Effects of the WUG | 22 June 2022 6.3.4 Effects of Discharges to Air on Fauna Key features of the WUG infrastructure on Willows Road Farm that may affect air quality on the farm property and / or adjoining Coromandel Forest Park include earthworks and general construction for site establishment (approximately 1 year duration); construction of the initial tunnel drive including blasting for portal formation (approximately 3.5 years duration); and discharges from the tunnel ventilation raise (ongoing). There will be no crushing or rock processing on the site. Details of activities and predicted air discharges are provided in the Assessment of Effects of Discharges to Air report (‘Air Discharge Assessment (WUG and Willows)’, BECA, 2022). Potential discharges to air from the WUG include dust from surface sources; products of combustion from surface and underground vehicles31; dust from excavation discharged from the portal and ventilation raise; contaminants from underground blasting discharged from the portal and Willow Road Farm vent raise (as the tunnel progresses)32; and rehabilitation of surface areas after tunnel development. Blasting emissions will be infrequent and of short duration (during the tunnel drive, it is expected that blasting will comprise two blast events per day, with each event lasting for about 10 seconds) and emissions are expected to disperse rapidly. The results of air quality monitoring at Waihi Mine were used to assess the likely effects of emissions of key contaminants (deposited dust, TSP, PM2.5 and PM10 and silica) of the WUG. The Air Assessment concludes that there is a short-term moderate to high risk of dust, from the construction of the noise bund and storage of topsoil, adversely affecting the nearest houses along Willows Road to the east/southeast of the site. The risk of dust generated from other site activities, such as constructing the rock stack, blasting and tunnelling, adversely affecting residences (and thus, fauna and habitats) in the proximity of the project is low (BECA 2021). The Willows Road Farm vent shaft will be constructed close to the northern boundary of the property, adjacent to Coromandel Forest Park. The Air Discharge Assessment found that there may be some short-term localised disturbance and minor dust deposition during construction that will quickly wash off during subsequent rainfall. Any ongoing effects on native vegetation from dust at the raises during tunnelling will likely be minor. As such, we consider that the magnitude of effects of construction-related discharges to air on fauna and fauna habitats is Negligible. The ecological value of fauna and fauna habitats within Willows Road farm is Low. We further consider that habitats in the boundary of Coromandel Forest Park are likely lower value than in interior forest habitats being subject to edge effects33 already, although we have conservatively assessed the ecological value of fauna and vegetation / habitats on the park boundary as Low - Very High, consistent with the rest of the forest. Therefore, the level of effect of discharges to air is assessed as Very Low – Low. Vent shaft discharges to air from mining within Coromandel Forest Park are assessed in Section 6.4.4. 31 Such as particulate matter (PM10, PM2.5,), nitrogen oxides (NOx) and carbon monoxide (CO) 32 Blasting generates emissions of particulates (CO, NOx and small quantities of SO2), as well as dust from the shattering of rock. Blasting will occur using ammonium nitrate explosives (at any time in accordance with all relevant safety procedures). 33 Edge effects are a feature of ecological communities at the boundary of two habitat types, in this case, forest and farmland. This southern boundary of Coromandel Forest Park is subject to higher sunlight and wind penetration resulting in lower humidity, soil moisture and encouraging growth of opportunistic species (e.g. weeds) that are less common in the forest interior.
RkJQdWJsaXNoZXIy MjE2NDg3