| Dispersion Model Predictions | WNP Processing Plant Air Discharge Assessment | 4397169-66885702-113 | 16/06/2022 | 21 Sensitivity: General highly unlikely to exceed any of the relevant guideline concentrations even if the plant was to be in continuous operation (i.e. 24-hours per day). Cadmium has the maximum concentration relative to the guideline. The predicted maximum cadmium concentration at the most impacted dwelling is 0.82% of the guideline concentration of 0.0056 µg/m3. As previously noted, discharges from the carbon regeneration stack have not been included in the model. However, any emissions from the regeneration stack are expected to be comparable or lower than emissions from the electrowinning and furnace stack. The results of the modelling indicate that even if discharges from the carbon regeneration stack were incorporated into the model, the predicted concentrations are still highly unlikely to exceed any of the relevant air quality guideline concentrations. The results also indicate even if the metal emissions were to vary from assumed in the model (e.g. due to variations in the ore metal content the predicted concentrations would still not exceed the relevant guideline limits. Table 6-2. Predicted maximum non-mercury metal concentrations predicted at the most impacted nearby dwellings Contaminant Averaging period Predicted maximum concentration (µg/m3) Guideline concentration (µg/m3) Guideline concentration (%) Arsenic 1-hour 0.000056 0.2 0.03% 8-hour 0.000016 0.015 0.11% annual 0.0000005 0.0055 0.01% Cadmium annual 0.000046 0.0056 0.82% Chromium (VI) annual 0.0000014 0.0011 0.12% Manganese 8-hour 0.00024 0.17 0.14% annual 0.0000040 0.09 0.004% Nickel 1-hour 0.00083 0.2 0.42% 8-hour 0.00024 0.06 0.40% annual 0.0000072 0.014 0.05% Lead 3-month 0.000089 0.2 0.04% Selenium annual 0.00023 20 0.00%
RkJQdWJsaXNoZXIy MjE2NDg3