Research Article

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

Table 4

Assessment of hazardous events at brackish desalination plants by seven raters.

HazardHazardous eventLikelihood avg (SD)Severity avg (SD)Risk level avg (SD)

MicrobialLow level of disinfection below the recommended limit3.27 (1.00)3.60 (1.05)12.71 (6.55) (high risk)

Chemical and microbialThe power outages affect the efficiency of the desalination process3.25 (3.23)2.24 (2.23)10.04 (9.99) (high risk)

Chemical and microbialDesalinated water is mixed with nondesalinated water2.49 (1.34)2.49 (1.38)7.95 (7.32) (medium risk)

Physical, chemical, and microbialThe cap of the desalinated water tank is absent or partially opened1.97 (1.07)2.27 (1.28)5.76 (5.79) (low risk)

MicrobialWater discontinuity or stored for an extended period inside the tank2.04 (0.94)2.25 (1.11)5.57 (4.87) (low risk)

Physical, chemical, and microbialPresence of foreign objects inside of desalinated water storage tank1.88 (0.89)2.23 (1.25)5.23 (4.79) (low risk)

MicrobialThe discharge pipes and hoses touch the ground1.95 (1.07)2.05 (1.19)5.22 (5.71) (low risk)

Physical and microbialAir vents unscreened allowing ingress of insects2.49 (1.07)1.83 (0.75)5.21 (3.90) (low risk)

Chemical, physical, and microbialThe desalination plant is unlicensed and nonmonitored by the Ministry of Health2.01 (1.60)1.60 (0.87)4.54 (5.64) (low risk)

Chemical and microbialExcessive algal formations in filters due to irregular backwashing of filters1.71 (1.21)1.76 (1.25)4.47 (6.46) (low risk)

MicrobialDesalination plant’s fence or roof cover inadequate, which are allowing animals or birds entry1.72 (0.82)1.91 (1.07)4.11 (4.26) (low risk)

ChemicalThe desalinated water storage tank made of corrosive metal1.69 (1.50)1.40 (0.90)3.68 (5.90) (low risk)

Chemical and microbialHuman excreta, sewage collection within 50 m of the desalinated water storage tanks1.44 (1.14)1.50 (1.27)3.60 (6.76) (low risk)

Chemical, physical, and microbialThe drainage hole at the bottom of the tank is not available1.83 (1.23)1.48 (0.75)3.53 (4.30) (low risk)

MicrobialThere is leakage between desalination points and desalinated water storage tank1.71 (0.81)1.68 (0.78)3.42 (3.01) (low risk)

MicrobialSpilled water forms stagnant ponding within 10 m of the desalinated water storage tanks1.71 (0.81)1.63 (0.71)3.32 (2.90) (low risk)

MicrobialThe desalinated water storage tank made of opaque plastic1.42 (1.13)1.41 (1.09)3.23 (6.10) (low risk)

Chemical and microbialThe water storage tank used to store other liquids other than desalinated water1.44 (0.93)1.43 (0.92)2.78 (4.09) (low risk)

ChemicalAccidental spillage of diesel within 100 m of the desalinated water storage tanks1.38 (1.07)1.26 (0.73)2.51 (4.53) (low risk)

ChemicalOverdosing of treatment chemicals (such as chlorine)1.06 (0.31)1.06 (0.31)1.23 (1.17) (low risk)

Risk level = likelihood ∗ Severity.