| Potential Effects on the Environment of WNP | Waihi North Project Air Discharge Assessment - Waihi Surface Facilities | 4396626-1331619777-99 | 16/06/2022 | 58 The results of OGNZL and WRC ambient air monitoring programmes show the impact of emissions from Martha Mine have only a relatively small impact on TSP concentrations at downwind distances of 150 – 210 m from mine operations. TSP concentrations measured at Site 6.78 (Slevin St) and Site 6.61 (Grey Street) are only slightly higher than background TSP concentrations. Site 6.78 (Slevin St) and Site 6.61 (Grey Street) are both located in the prevailing wind direction and would therefore be frequently downwind of the mine and potentially exposed to site emissions. Only one exceedance of the consented TSP trigger limit was recorded at Site 6.78 (Slevin St) over the monitoring period. The monitoring results suggest that emissions from mine operations have only a small impact on the air quality at these locations Higher average TSP concentrations and dust deposition rates are measured at Site 6.63 (Met Station) which is located approximately 140 m from the mine operations. However, only 6 exceedances of the TSP consent trigger limit have occurred since 2005, and one exceedance of the dust deposition rate consent limit since 2000. Although it not possible to assess the occurrence of any short-term dust nuisance effects, the monitoring results suggest there is a relatively low risk that receptors located more than 150 – 210m from the mine would experience dust nuisance effects when appropriate mitigation procedures are implemented. The Institute of Air Quality Management (IAQM) provides guidance for the assessment of impact of dust emitted from mineral extraction and processing operations and consider receptors located more than 400 m from dust generation activities processing hard rock, or more than 250 m from dust generation activities processing soft rock (e.g. sand, gravel, and soil), are unlikely to experience adverse nuisance or health effect. 7.3 Sensitivity of the Receiving Environment As part of the FIDOL “location” factor (refer Section 6.1), the sensitivity of the receiving environment needs to be taken into consideration. Different locations have different sensitivities to dust can be broadly classified as having high, moderate or low sensitivity. The degree of sensitivity in any location is based on characteristics of the land use, including the time of day and the reason people are at the location (e.g. for work, home living, or recreation). In a residential area, an acceptable frequency of a dust (or odour) event is likely to be much lower than would be acceptable in an industrial or rural area. Similarly, the acceptance of deposited dust and odour in a residential area will be lower than what is acceptable in industrial areas. The GPG Dust provides guidance with regards to classifying the sensitivity of different land uses to dust nuisance effects. Different land uses are classified as having a either a “high”, “moderate”, or “low” sensitivity to dust. The GPG Dust classifies residential areas as having a high sensitivity to dust and odour nuisance effects for the following reasons; ● People can be present at all times of day and night, both indoors and outdoors ● People of high sensitivity (including children and the elderly) can be exposed ● People usually expect a high level of amenity in their home and tend to carry out activities at residences which are highly sensitive dust and odour such as dining, outdoor living, and drying clothes. Waihi’s main residential areas are therefore considered to have a high sensitivity to dust nuisance effects. Waihi residences are generally located more than 360 m from the proposed activities with the closest located on Moore Street to the north of the GOP. Like residential areas, people of high sensitivity can be present at schools and in retail areas. However, the occupancy rates of these areas tend to be higher during the day compared to night-time, which can
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