Electrical (i) Undertake continuous 18 S/cm 30 S/cm - - (i) Electrical conductivity is monitored accurately Conductivity and monitoring of electrical and continuously. Magnesium conductivity and event-based (ii) Electrical conductivity Investigation Trigger is sampling for magnesium. not exceeded at downstream compliance sites (ii) When the electrical (without accompanying exceedances at 1 mg/L 2 mg/L Derived from 3 mg/L conductivity Investigation Trigger upstream control sites) without reasonable (42 S/cm for > 6 hours) is cause. exceeded, convert continuous (iii) Sufficient magnesium data are collected to exposure (Chronic exposure electrical conductivity data to enable reliable and accurate estimation of Guideline for for exposures magnesium concentration data. magnesium concentrations from electrical exposures < 72 72 hours) ≥ (ii) Report and act on Trigger conductivity data. hours) Value exceedances at the (iv) Magnesium pulse exposure Guideline downstream compliance sites. Trigger Values are not exceeded at downstream (iii) Minimise mine derived compliance sites (without accompanying magnesium at the downstream exceedances at upstream control sites) without compliance sites to the greatest reasonable cause. extent practicable. (v) Magnesium Limit is not exceeded at the downstream compliance sites without accompanying exceedances at upstream control sites. (vi) All Trigger Value exceedances are investigated and reported as outlined in Section 4 of the Revised Water Quality Objectives for Magela Creek and Gulungul Creek (2015) Invoked by Trigger Value “Actions Exceedances”. (vii) Electrical conductivity and magnesium concentrations will not deteriorate compared to those measured in previous wet seasons, without reasonable cause.
Electrical Conductivity and Magnesium (i) Undertake continuous monitoring of electrical conductivity and event-based sampling for magnesium. (ii) When the electrical conductivity Investigation Trigger (42 S/cm for > 6 hours) is exceeded, convert continuous electrical conductivity data to magnesium concentration data. (ii) Report and act on Trigger Value exceedances at the downstream compliance sites. (iii) Minimise mine derived magnesium at the downstream compliance sites to the greatest extent practicable. 18 S/cm 1 mg/L 30 S/cm 2 mg/L - Derived from exposure Guideline for exposures < 72 hours) - 3 mg/L (Chronic exposure for exposures ≥ 72 hours) (i) Electrical conductivity is monitored accurately and continuously. (ii) Electrical conductivity Investigation Trigger is not exceeded at downstream compliance sites (without accompanying exceedances at upstream control sites) without reasonable cause. (iii) Sufficient magnesium data are collected to enable reliable and accurate estimation of magnesium concentrations from electrical conductivity data. (iv) Magnesium pulse exposure Guideline Trigger Values are not exceeded at downstream compliance sites (without accompanying exceedances at upstream control sites) without reasonable cause. (v) Magnesium Limit is not exceeded at the downstream compliance sites without accompanying exceedances at upstream control sites. (vi) All Trigger Value exceedances are investigated and reported as outlined in Section 4 of the Revised Water Quality Objectives for Magela Creek and Gulungul Creek (2015) “Actions Invoked by Trigger Value Exceedances”. (vii) Electrical conductivity and magnesium concentrations will not deteriorate compared to those measured in previous wet seasons, without reasonable cause.
ir638.docx