The second-strongest storm to sweep through the western Caribbean since Hurricane Gilbert in 1988, Mitch left some 10,000 people dead and laid waste to the economies and infrastructures of Honduras, Nicaragua and El Salvador. Thousands of more lives are at risk for lack of sanitary drinking water.

In response, many of the disaster-relief efforts are bringing in "UV Waterworks," a small, simple device that uses ultraviolet light to quickly, safely, and cheaply disinfect water of the viruses and bacteria that cause cholera, typhoid, dysentery and other deadly diseases.

"This device can play an important role in getting clean water to affected communities throughout the region in the near term," Secretary of Energy Bill Richardson said yesterday at a Washington, DC conference to coordinate federal and private sector relief efforts. "For the long-term development that is needed, we have experts that can help with the recovery of the generation of electric power and the development of new sources of power."

UV Waterworks, which was invented by Ashok Gadgil, a scientist with Berkeley Lab's Environmental Energy Technologies Division, most often is used as a source of day-to-day drinking water but it's also ideally suited for emergency situations.

"Unlike other ultraviolet-based water purifiers, UV Waterworks does not require pressurized water-delivery systems and electrical outlets," says Gadgil. "It is designed to rely on gravity for water flow which means it can be used with any source of water."

Needing electricity only to operate its small UV lamp and automatic shutoff valve, UV Waterworks can be powered by a car battery or a 60-watt solar cell. About the size of a microwave oven and weighing seven kilograms (15 pounds), it can disinfect water at the rate of four gallons per minute, similar to the flow from a typical American bathtub spout. Passing water through ultraviolet light inactivates the DNA of pathogens and purifies the water at a cost of about five U.S. cents for every 1,000 gallons.

In addition to their deployment to the Central American countries hit by Hurricane Mitch, UV Waterworks devices are extensively used in Mexico and the Philippines. It is estimated that in Manila alone, several thousand people now purchase their daily drinking water from vending stations with UV Waterworks devices. Other countries in which the device is used include Nepal, Bangladesh, India, and South Africa.

UV Waterworks has won major awards from both Discover and Popular Science magazines. Earlier this year, the Smithsonian Institute added a UV Waterworks device to their permanent collection of medical inventions. This device is currently on display at the National Museum of American History. The UV Waterworks technology has been licensed to WaterHealth International, Inc., (WHI) which has been working with Central American relief organizations in response to the Hurricane Mitch crisis.

Gadgil has been busy designing a "disaster-relief" version of UV Waterworks with funding from DOE and WHI.

"This version has a pump, a hydrocyclonic separator, and a series of filters to remove silt, suspended solids, and turbidity from inlet water which can then be treated with UVWw to produce potable water," says Gadgil. "The system can be also configured with a granulated activated carbon filter to treat waters with low levels of organic chemical contaminants."

Although this new version of UV Waterworks can not handle "severe" chemical contamination of the water, it can be used to treat the soil, mud, and biological contaminants contaminants that are common in most disaster-relief situations. The research prototype of this new version of UV Waterworks weighs 100 kilograms (250 pounds) and can produce more than 5,000 gallons of drinking water daily.

Berkeley Lab is a U.S. Department of Energy national laboratory located in Berkeley, California. It conducts unclassified scientific research and is managed by the University of California.

Additional Information:

• Updated information on UV Waterworks and contact information
• WaterHealth International, which licensed and sells UV Waterworks