The risk assessment for the Willows Road portal entrance and WUG uses the qualitative rating of likelihood and consequence presented inAppendix K Table 1andAppendix K Table 2below. Appendix K Table 1: Qualitative rating of likelihood1 Frequency rating Descriptor Explanation A Very Likely Almost certain or expected to occur if all conditions met B Likely Good chance that it might occur under normal operating conditions C As likely as not Might or might not occur depending on conditions D Unlikely Could occur but is not expected to occur under normal operating conditions E Improbable Theoretically possible, but extremely remote chance of occurrence. 1. Adapted from Table 3 “Likelihood qualitative descriptors”, Risk Assessment Methodology for Hazardous Substances, EPA, January 2020 Appendix K Table 2: Qualitative rating of consequence1 Effect rating Descriptor Spill to environment Human health or property 1 Insignificant Negligible environmental damage No injuries 2 Minor On-site release contained First aid treatment required, minor damage to property 3 Moderate Minor environmental damage First aid treatment required, damage to off-site property 4 Major Major environmental damage to immediate environment Extensive injuries, moderate damage to off-site property 5 Catastrophic Widespread environmental damage. Fatalities both on and off-site, major exposure to toxic release by numerous people. 1. From AS/NZS 4360:1999 The likelihood and consequence ratings for each event are selected based on experience and judgement. These ratings are then combined to assess the overall level of risk associated with each hazard. The risk assessment matrix is shown inAppendix K Table 3. Appendix K Table 3: Risk matrix1 Consequence Likelihood Severity Insignificant Minor Moderate Major Catastrophic (1) (2) (3) (4) (5) Almost certain (A) Significant Significant High High High Likely (B) Moderate Significant Significant High High Moderate (C) Low Moderate Significant High High Unlikely (D) Low Low Moderate Significant High Rare (E) Low Low Moderate Significant Significant 1. From AS/NZS 4360:1999
RkJQdWJsaXNoZXIy MjE2NDg3