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close this bookOperation and Maintenance of Water and Sewerage Systems (Ministry of Water - Tanzania - Rwegarulila Water Resources Institute, 1999, 90 p.)
close this folderB. Operation and Maintenance in Tanzania
View the document1. What is operation and maintenance
View the document2. Constraints of operation and maintenance
View the document3. Strategies for operation and maintenance on sustainable basis
View the document4. Operational problems

4. Operational problems

4.1. Quality of Water

· Turbidity
· Bacterial contamination
· Odour
· Conductivity
· Hardness
· Algae, etc.

Turbidity of Water May come from

· Pumping station
· Pipe material (especially Cast Iron)
· Network fouling

Quality measurement Methods

· Single samples
· Continuously monitoring

Prevention of Contamination

· Always/pressure on the system (DAWASA!)
· Water pipe not close to servers or pit latrines (KIBINDU incidence)
· Avoid penetration of ground water during pipe laying/repair.
· Cover pipe ends during storage, transport to prevent infection by rain, dust, soil, animals.
· Brush pipe ends and joints
· After pipe laying/repair:

For Æ<100mm - clean pipe by flusting before putting into use
For Æ>100mm - clean pipeline by flusting, swabbing (use of pigs)

- If possible disinfect by filling with 20 mg/L active C/2 for 12-24 hours, followed by bacteriological sampling before putting pipe into use.

4.2 Quantity of Water

· Source not sufficient
· Population growth/migration
· Rapid industrial development
· Excessive leakages
· High peak factor

4.3 Administrative problems

· Quality control
· Leakage control
· Tariffs and revenue
· Crossing roads in new connection
· None Revenue Water etc.