Comprehensive Risk Assessment of Health-Related Hazardous Events in the Drinking Water Supply System from Source to Tap in Gaza Strip, Palestine

Table 1

Semiquantitative risk analysis matrix.

		Severity
		Insignificant or no impact—rating: 1	Minor compliance impact—rating: 2	Moderate aesthetic impact—rating: 3	Major regulatory impact—rating: 4	Catastrophic public health impact—rating: 5
Likelihood or frequency	Almost certain/once a day—rating: 5	5	10	15	20	25
	Likely/once a week—rating: 4	4	8	12	16	20
	Moderate/once a month—rating: 3	3	6	9	12	15
	Unlikely/once a year—rating: 2	2	4	6	8	10
	Rare/once every 5 years—rating: 1	1	2	3	4	5
Risk score		<6	6–9	10–15		>15
Risk rating		Low	Medium	High		Very high