Protection and maintenance of water supply

A water supply system consists of intake, treatment plant, pumps, pipes, reservoirs and valves, all of which deteriorate with time and use. Maintenance keeps it working properly.

Why maintenance is necessary

1. To give a continuous supply of safe, wholesome water at proper pressure.
2. To prevent breakdown, and to increase the life of the structures and machines.
3. To reduce water loss through leakage and save treatment and pumping cost.
4. To protect public health from contamination (cross connection, broken pipes).
5. It is cheaper to do regular maintenance than to repair major failures.

Types of maintenance

1. Regular (routine and preventive) maintenance - planned, done at fixed intervals.

• Cleaning of intake screens and catchment, removal of silt from sedimentation tanks, cleaning/backwashing of filters (sand scraping for slow sand filters).
• Checking and refilling chemical dosing (alum, chlorine) and residual chlorine tests.
• Greasing and oiling of pumps and valves; operating (exercising) sluice valves to keep them from jamming.
• Flushing of mains and dead ends; cleaning of reservoirs once or twice a year.
• Painting of exposed steel pipes and tanks; checking meters; leak detection survey.
• Keeping records and maintaining the catchment area fence.

2. Emergency (breakdown/corrective) maintenance - unplanned, done after a failure.

• Repair of burst or leaking pipes and replacing joints.
• Repair of pumps and motors after breakdown; arrangements for standby generator.
• Repair of the intake or the spring chamber after a flood or landslide.
• Disinfection after contamination, and supply of water by tankers.

An emergency team with spare pipes, fittings, tools and transport should always be kept ready, and the community should be trained and fees collected to pay for repairs (water user committees in Nepal).