Water Systems

Post-Disaster Water Collection and Treatment

Supplying a survival level of safe, potable water to meet basic human consumption needs in a relief setting is of paramount importance. The Sphere Project's Humanitarian Charter and Minimum Standards in Disaster Relief calculates a minimum daily standard water usage for drinking, cooking, and personal hygiene of at least 7.5–15 liters per person. The United Nations Children's Fund (UNICEF) suggests a minimum daily requirement of 25 liters per person, which includes two liters for drinking, and the remainder for cooking, bathing, animals, and a garden. This rate of water use is in contrast with an average of 300 liters per person daily in the United States. Following a disaster, the affected population may have to drink disease-carrying unsanitary water out of desperation, even when the water is known to be unsafe. Provision of potable water through rain catchment, local treatment, or importation is critical.

The importation and distribution of bottled water is a common response after a disaster. It is a convenient and often rapid intervention. However, the logistics of getting bottled water to a disaster area can be formidable, due to its weight and volume. Trucks, planes, and helicopters may be required, while competing with other supplies for limited space. The per-unit cost of bottled water is high, and empty bottles can cause a solid-waste dilemma.

Rainwater catchment and storage is an appropriate and quickly constructed system in some disaster zones, especially where precipitation is high and where fresh surface or groundwater is lacking. Rainwater harvesting consists of three basic elements: collection, conveyance, and storage. The collection area in most cases is the roof [Page 777]of a house or a building. A conveyance system usually consists of gutters or pipes that deliver rainwater from the rooftop to the storage facility, usually a cistern or tank. All elements of the system should be constructed of inert materials, such as wood, plastic, aluminum, fiberglass, or reinforced concrete, in order to avoid adverse effects on water quality.

The Defense Supply Center in Richmond, Virginia, supplies the military with reverse-osmosis water purification units like this one in Iraq. After the Haiti earthquake in January 2010, the center prepared water purification supplies for humanitarian relief in Haiti

The treatment of local surface or groundwater is an alternative to transported bottled water or rainwater catchment. Water treatment can be broadly defined as the transformation of water from its state within the environment to a quality sufficient for its intended use. Significant systems of water treatment include boiling, chemical treatment, filtration, distillation, ultraviolet rays, and reverse osmosis. Some systems are utilized concurrently.

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