| Air Quality Standards and Guidelines | Waihi North Project Air Discharge Assessment - Waihi Surface Facilities | 4396626-1331619777-99 | 16/06/2022 | 28 4.2 Dust Guidelines There are no New Zealand environmental standards or guidelines for deposited dust or TSP. However, the Ministry for the Environment’s “Good Practice Guide for Assessing and Managing Dust” (GPG Dust) 28 recommends “trigger” values for deposited dust and TSP which are intended to be used for proactive management of dust on site. They are not intended to be used for enforcement because exceedance of trigger values does not necessarily infer an adverse effect offsite. The trigger values are intended to apply beyond the site boundary. 4.2.1 Deposited Dust The recommended “trigger” value for deposited dust is 4 g/m2/30 days above background concentrations. The GPG Dust notes that deposition rates of more than 4 g/m2/30 days above background concentrations, in some industrial and sparsely populated areas may not cause nuisance, but conversely in sensitive residential areas dust concentrations in the order of 2 g/m2/30 days above background concentrations may cause nuisance. 4.2.2 TSP The GPG Dust suggests “trigger” values for TSP for various time-averaging periods and sensitivities of the receiving environment. The “trigger” values included in the GPG Dust for TSP are shown in Table 4-2. Table 4-2 GPG Dust TSP Trigger Values Trigger Averaging Period Sensitivity of receiving environment High Moderate Low Short term 5 min 250 µg/m3 n/a n/a Short term 1 hour 200 µg/m3 250 µg/m3 n/a Daily* 24 hours (rolling average) 60 µg/m3 80 µg/m3 100 µg/m3 * For managing chronic (ie, long term) dust only. The GPG Dust also provides guidance on the sensitivity of different receiving environments. For rural areas such as those surrounding the project site, the GPG Dust classifies the sensitivity to dust as low for rural activities but moderate to high for other activities such as industrial activities. Hence, in assessing the effects of dust the rural residences near the project sites are considered to have a moderate to high sensitivity to the dust generated from the proposed activity. Waihi residential area and urban area are also considered to have a high sensitivity to dust nuisance effects. 4.3 Resource Consent Trigger Values The current resource consents for the mining operation require trigger values and limits for deposited dust, TSP and PM10 to be included in the Air Quality Management Plan (AQMP) for the Martha, Favona, Trio and Correnso Mines. The trigger values included in the AQMP are shown in Table 4-3. 28 Ministry for the Environment “Good Practice Guide for Assessing and Managing Dust” 2016
RkJQdWJsaXNoZXIy MjE2NDg3