Water Sanitation Health

Rehabilitating water treatment works after an emergency

Technical note 6 on drinking-water, sanitation and hygiene in emergencies


Steps 3 and 4: Pumps and power, works operation

Pumps (and the motors that drive them) are essential components of many treatment works. They have a variety of uses such as raising water from the intake into the works, between different elements in the works, or for adding and mixing chemicals. It will be essential to the overall operation of the works that they function well, so their rehabilitation must be a priority. Replacement parts may take time to be delivered, so ask an engineer to make an early assessment of the state of the pumps.

Power is also essential and an additional priority. If the mains supply is not working, install mobile generators.

Works operation

As soon as components of the treatment works have been recommissioned, their operation will need to be sustained. This will include:

Monitoring

The quality and quantity of water being produced by the works should be measured regularly to check whether everything is working correctly and that the output meets minimum standards (see the Sphere Guidelines for minimum standards for emergency water supplies). Simple test kits are available for measuring basic parameters of water quality.

Chemicals

Modern treatment works rely on the addition of chemicals to aid the treatment process. These include alum to help settlement, lime for adjusting the pH of the water and chlorine for disinfection. It may take a long time to replenish supplies so the need for chemicals should be identified and suppliers contacted as soon as possible. A reduced level of treatment can be provided if chemicals are in short supply, using point of use disinfection where it is most needed, such as in hospitals and schools.

Maintenance

This includes anual tasks, such as cleaning screens, removing settled sludge and lubricating pumps. The filters will become clogged with solids. Pipes will need to be checked for leaks.

Public information

The public should be kept informed of developments. This will ease concerns about water availability and help to reduce wastage, particularly if the public can help identify leaks in the distribution system.

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