Not a drop to drink: Water in Bangladeshi wells is laced with naturally occurring arsenic. Credit: Amy Schoenfeld

The teenage craze of text messaging will soon enable Bangladeshi villagers to tap into safe water supplies. A new program developed by Columbia University scientists uses cell phones to help villagers digging wells avoid water contaminated with arsenic.

About half of Bangladesh's estimated 7 million private wells draw groundwater laden with naturally occurring arsenic. That puts nearly 35 million Bangladeshis at risk of being poisoned by arsenic in their drinking water, according to the World Health Organization.

People still don't know how to find safe water. Alexander van Geen, Columbia University's Lamont-Doherty Earth Observatory

“People still don't know how to find safe water,” says lead researcher Alexander van Geen, a geochemist at Columbia University's Lamont-Doherty Earth Observatory. “We want to provide information at the village level so people can dig safe wells.”

The Welltracker database tracks the concentrations of arsenic in 300,000 wells in 17 of Bangladesh's 520 districts. The team last year completed a pilot project and plans to incorporate 5 million more wells into the system for a nationwide launch in 2007.

Bangladesh began installing wells in the 1970s as an alternative supply of drinking water because surface water in most places teemed with bacteria. The move helped cut diarrheal diseases in half, but in the 1990s researchers discovered arsenic in the groundwater.

Because other drinking water sources are scarce, however, villagers continue to install wells despite the threat of skin lesions, cancers, cardiovascular disease and respiratory problems. The water is untainted—or, at least, contains less than 50 parts per billion of arsenic—below a certain depth, but finding that level is tricky.

“The level of arsenic varies a lot by location, it isn't as though there's a beautiful bell-shaped curve,” says Andrew Gelman, a statistics expert at Columbia University who helped develop the database. The water may be untainted at 100 feet in one well, for instance, and at more than 300 feet in a neighboring village.

With Welltracker, villagers can use text messaging—increasingly popular in the country—to find out how deep to dig and the odds that the water will be safe at that depth. Beginning in October, people in Indonesia also plan to use text messaging to rapidly relay information about bird flu.

“It's certainly the most straightforward way to make the information easily available to anyone,” says Charles Harvey, a hydrologist at the Massachusetts Institute of Technology, who is not involved with either project.

Installing wells can cost about $1 for every foot villagers dig. By helping find safe water at shallower levels, the database will cut the cost of digging new wells, the researchers say.

Before the project can be expanded, the World Bank must first release data from a study it funded on arsenic concentrations in 5 million wells across the country. The researchers hope to obtain that information later this year.