An adequate supply of clean, safe drinking water is very important for the proper health and well-being of the community. When water and sanitation facilities break down, the public health is at risk. The chances of breakdown of water supply during the emergency situation cannot be ruled out.
In the aftermath of an earthquake, flood, or cyclone, there could be a serious water crisis. It, therefore, becomes very necessary to develop contingency action plans for meeting any emergency arising due to any of the natural or man made disasters. These contingency action plans should include:
- Coordinating measures to be taken up to ensure safe water supply
- A communication plan to alert and inform users of the supply
- Detailed plans to provide and distribute emergency supplies of water
Alternative safe water supply means have to be developed in the case of water supply system becoming in operational due to any disaster. Various practical and social considerations must be taken into account prior to assessing the emergency needs of the affected community, such as:
- Number of people to be served;
- Quantity of water can be calculated by taking at least 15-20 liters per person per day for needs like drinking, cooking, personal hygiene etc.;
- Quality of available water and level of contamination;
- Availability of water in the nearest source;
A) Urban water supply system:
If the disaster has affected an urban centre and a disruption to water supply scheme has taken place, the first priority should be to put the system back into operation. Damaged portion must be replaced or repaired and the supply must be quickly restored.
In the aftermath of the disaster, the water pressure and the chlorine concentration must be increased to avoid any contamination from polluted water. In case any of the portions of treatment plant gets affected by the disaster, it should be repaired and proper disinfection must be done prior to putting it back into operation.
B) Underground source:
Underground sources are usually free from disaster related contamination and may not require any treatment. When springs are being used as a source after a disaster, certain changes in the water quality may take place after earthquake or floods.
Hence, proper testing for water quality is required before restoration of supplies. As far as wells as the potential water sources are concerned, the location of these should be at least 30 meters away from the potential source of contamination like latrines and should be at a higher elevation. The wells must be properly covered. For additional precaution, the drinking water from these sources must be boiled or disinfected prior to use.
C) Surface water:
The usage of surface water as a water supply source should be the last option. Muddy, colored, polluted water should not be consumed. The water from the surface sources should be treated to remove turbidity, color and other impurities and should be disinfected. For this purpose mobile water treatment plants as an adhoc measure could be pressed into service. Mobile plants are available mounted on a truck along with all accessories, which include a centrifugal pump run by engine, a rapid sand filter unit, chemical solution tanks, chlorine salutation tank, and other necessary accessories.
Water storage in emergency situation:
Emergency storage of water can be done in canvas, rubber coated nylons and plastic containers. Polyethylene containers erected in pits dug to size can also be used as storage. The total storage capacity for water distribution should be equal to the amount required for 24 hrs.
Elevated water tanks must be erected using drums, iron sheeting and wooden poles. For long-term emergency camps, all the storage tanks must be covered to protect from dust, and other contaminations. Special attention must be paid to proper sanitation near these tanks.
Distribution of water:
In emergency situation water is usually distributed through tankers. The individual families and local groups must be provided with water containers to store waster. Special case has to be taken in checking the quality of water prior to transporting the water for distribution.
In long-term camps, distribution pipes with community taps must be installed for water supply.