Would only occur Expected to occur in most Could occur only in Could occur, but more Will probably under exceptional circumstances unusual circumstances than likely will not (e.g. 2 - 10 times/year; circumstances (e.g.>10 per year; could (e.g. once every 10 to 100 (e.g. once every 1 to 10 could occur on a (e.g. once every 100 to occur on a daily/ weekly years) years) monthly/quarterly basis) 1000 years) basis) Medium High High Very high Very high 5. Extreme 1 Low Medium High High Very high 4. Table Low Medium Medium High High 3. Moderate to Low Low Medium Medium Medium 2. Minor Consequence Refer Low Low Low Low Medium 1. Insignificant
Would only occur under exceptional circumstances (e.g. once every 100 to 1000 years) Could occur only in unusual circumstances (e.g. once every 10 to 100 years) Could occur, but more than likely will not (e.g. once every 1 to 10 years) Will probably (e.g. 2 - 10 times/year; could occur on a monthly/quarterly basis) Expected to occur in most circumstances (e.g.>10 per year; could occur on a daily/ weekly basis) Consequence 5. Extreme Refer to Table 1 Medium High High Very high Very high 4. Low Medium High High Very high 3. Moderate Low Medium Medium High High 2. Minor Low Low Medium Medium Medium 1. Insignificant Low Low Low Low Medium