Frequent Alum pumps break down. | Loss of coagulation treatment (P, CH, M) | 2 | 3 | 6 | M | Li: it takes 3 months before it happens says operators, visual inspection reveals many broken alum pumps C: untreated water supply | ECM: Treatment process is halted to restore the problem E: Yes (but frequent breakdown need to be stopped) | 2 | 2 | 4 | M |
Trident pipe clogged | Improper sedimentation (P, CH, M) | 3 | 2 | 6 | M | Li: sanitary inspection C: leading to contamination | ECM: fishing road is used to flush it. E: effective | 1 | 2 | 2 | Lo |
Trident pipe breakage | Improper sedimentation (P, CH, M) | 2 | 3 | 6 | M | Li: sanitary inspection, discussion with plant operators C: it reduces the rate of sedimentation leading to contamination | ECM: Replacement is done for any breakage E: yes | 2 | 1 | 2 | Lo |
Decantation pipe blockage | Inadequate sludge removal from sedimentation tank (P, CH, M) | 1 | 2 | 3 | Lo | Li: operators interview (blockage occurrence is very rare) C: decantation pipe blockage only flushes sedimentation tank of flocculated material | ECM: No | 1 | 2 | 3 | Lo |
Corrosion and algal blooms in sedimentation tanks | Contamination of treated water (CH, M) | 3 | 3 | 9 | H | Li: visual inspection, water quality results (increased in concentration of some water parameters). C: contaminated water supply affects health | ECM: sedimentation tank is washed every 90 days E: no; problems observed by field visits | 3 | 3 | 9 | H |
Frequent Back washing Pump failures | Loss of backwashing, Clogging of filters which lead to reducing water quantity and quality (P, CH, M) | 3 | 3 | 9 | H | Li: discussion with plant operators reveals that C: it affects both quality and quantity of water | ECM: problem is restored with immediate action E: Yes but the frequent break down need to be curtailed | 3
| 2 | 6 | M |
Filter beds exceeded life span | Improper filtration (P, CH, M) | 3 | 3 |
| H | Li: site visits and discussion with plant operators, water analysis results (increased in concentration of some water parameters). C: improperly filtered water supply to the public | ECM: No | 3 | 3 | 9 | H |
Corrosion and algal blooms in Filtration tanks | Contamination of water (CH, M) | 3 | 2 | 6 | M | Li: site visits and visual inspection. C: contaminated supply | ECM: No | 3 | 2 | 6 | M |
Leakages in backwashing machine through gasket | Reducing water quantity and corrosion (CH, M) | 3 | 2 | 6 | M | Li: visual inspection C: loss of water supply, damage to facilities | ECM: No | 3 | 2 | 6 | M |
Head loss to know when to back wash. | Loss of signal by operators the time required to back wash filter | 3 | 2 | 6 | M | Li: visual inspection during site visit C: irregular backwashing time. | ECM: No | 3 | 2 | 6 | M |
Chlorine dosing pump break down | Loss of disinfection (M) | 3 | 3 | 9 | H | Li: visual inspection C: supplying water without disinfecting affects public health. | ECM: Manual chlorination E: No (chlorine over dosing/under dosing indicated by consumers survey affecting aesthetics) | 3 | 2 | 6 | M |
Post-liming pump break down | High acidity of treated water, corrosion (CH) | 3 | 2 | 6 | M | Li: visual inspection C: aesthetics, damage to facilities | ECM: No | 3 | 2 | 6 | M |