This document may not be reproduced in full or in part without the written consent of Marshall Day Acoustics Limited Rp 001 R0 20210601 SJP (Waihi North Noise Assessment) ISSUE 16 of 79 3.2 Waihi Noise Monitoring Survey (MDA) We undertook a comprehensive programme of noise surveys across the Waihi area in August 2020 to establish existing noise levels. Six remote noise monitoring units were installed at the locations shown in Figure 6. These positions were chosen to represent the different noise-receiving environments that each of the various aspects of OGNZL’s operations may affect. These positions were: MP1. 26 Islington Terrace. Representative of the closest dwellings to on the western side of the Martha pit. MP2. 14 Roycroft Street. Areas in the north-eastern corner of the town that may receive noise from the main processing plant at times. MP3. 126 Kenny Street. Dwellings close to the south-eastern face of Martha pit. MP4. 28 Russell Street. Representative of general dwellings in the township that are furthest fromWNP works. MP5. 34 Heath Road. Closest dwellings to the Gladstone Pit and Processing Plant areas. MP6. 131 Trig Road North. Representative dwellings closest to the TSF3 stockpiling area, being the closest part of the TSF works. The noise monitors were installed on Thursday 30 July 2020 and generally ran through until either Friday 14 August (MP2 and MP5) or Thursday 20 August (MP3, MP4 and MP6). Unfortunately, data from the unit at MP1 was lost after Sunday 2 August due to the unit being stolen. We have analysed meteorological records for the survey period to exclude periods of adverse weather from our analysis. Further information on this and the equipment used is provided in Appendix B. The recorded averaged data at each location is summarised opposite in Table 4, and Figure 7 overleaf provides the hourly ambient noise level at each position by averaging the data over the 14 to 20 days. Figure 8 shows the background noise level (LA90). Full time histories of the recorded ambient noise level data are provided in Appendix B. Overall, noise levels are considered typical of a small rural town environment. Daytime ambient noise levels are 43-50 dB LAeq, and daytime background noise levels are 37-45 dB LA90 depending on the proximity to local roads and the town centre. In Waihi township, noise levels are typical of a small rural town with a State Highway passing through. The most significant contribution to daytime noise levels is local road traffic, and it is observed that background noise levels reduce markedly during the night, by approximately 5 to 10 dB. In the rural areas, noise levels are generally lower than in town during the day, but background noise levels are slightly higher than in town at night. It is likely this is due to the distant State Highway traffic during the night impacting measured background noise levels. This means the diurnal variation is less in rural locations than in the town. Table 4: Summary of ambient noise monitoring results Site Address Time Period Measured Noise Level, dB LAeq LA90 † LAmax ‡ MP1 26 Islington Terrace Day (0700 - 2200 hrs) Night (2200 - 0700 hrs) 46 39 41 36 83 69 MP2 14 Roycroft Street Day (0700 - 2200 hrs) Night (2200 - 0700 hrs) 47 39 39 32 77 67 MP3 126 Kenny Street Day (0700 - 2200 hrs) Night (2200 - 0700 hrs) 49 39 44 30 92 84 MP4 28 Russell Street Day (0700 - 2200 hrs) Night (2200 - 0700 hrs) 43 42 36 33 75 76 MP5 34 Heath Road Day (0700 - 2200 hrs) Night (2200 - 0700 hrs) 46 40 39 35 78 68 MP6 131 Trig Road North Day (0700 - 2200 hrs) Night (2200 - 0700 hrs) 50 43 39 37 81 74 † LA90 is the mean of the 5 minute noise levels arithmetically averaged over each day or night period. ‡ LAmax is the mean of the maximum noise levels recorded in each day or night period through the survey. Figure 6: Waihi ambient noise level monitoring sites
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