This is the VOA Special English Development Report.

Jeffrey Schwarz making a filter in the pot shop at the Braddock Carnegie Library

The Braddock Carnegie Library in Braddock, Pennsylvania, looks like an ancient castle. The bottom floor was once a bathhouse. Today, it houses a workshop for an arts program. But the library basement also has another use -- as a studio for making ceramic water filters for the developing world.

Placing it there was the idea of Richard Wukich, an art professor at Slippery Rock University in Pennsylvania. One of his former students, Jeffrey Schwarz, helped remake the basement to use for pottery-making classes for the community.

Jeff Schwarz is a potter and a member of the national service program AmeriCorps. He works with volunteers to produce the water purifiers.

The original design of the ceramic filter came from a chemist in Guatemala, Fernando Mazariegos. Ron Rivera, a ceramics artist and activist in the group Potters for Peace, saw it and recognized its value.

Ron Rivera improved the design after a deadly storm, Hurricane Mitch, struck Central America in nineteen ninety-eight. He also worked with other groups to set up places to make the filters. He died last year. By that time, hundreds of thousands of the filters were in use in developing countries.

Tests have shown that the filter produces safe drinking water.

The plan is to train water filter technicians to work with potters in other countries

On a good day, Jeffrey Schwarz says the studio in the library can produce twenty filters. To make one, clay is mixed with a material that burns. It could be sawdust or agricultural waste like grain hulls, cocoa or coffee shells. Pine needles can also be used.

The mixture is shaped into a cone and then fired. Burning away the material added to the clay leaves tiny holes. These holes let water slowly pass through the walls of the filter.

A protective coating of colloidal silver is painted on the inside and outside of the filter to kill bacteria. Colloidal silver is made from water with microscopic particles of silver.

The water filter costs little to make. An international service project called Pure Water for All helps support the work. The Forest Hills Rotary Club in western Pennsylvania launched the project. The project Web site is purewaterforall.org.

Jeff Schwarz will end his service for AmeriCorps soon. But he plans to continue making the water filters in the depths of the library.

And that's the VOA Special English Development Report, written by Jerilyn Watson, with Rosanne Skirble in Braddock, Pennsylvania. Archives of our reports are at voaspecialenglish.com. I'm Steve Ember.