BLOOMINGTON | The Amazon River awes Pam and Marty O'Neall of rural Cooksville. But they have no particular desire to dip a cup and drink from it.

As part of Christian missions teams to Brazil the past four years, they have traveled through remote riverside villages that are vastly different from the glitzy beaches of Rio de Janeiro or the mega-city Sao Paulo.

The O'Nealls base their work in the northern area in two spots. Manaus is an inland port city of about 1.5 million people, and in an area called the Interior, composed of villages along the mighty Amazon.

In the Interior, the "roads" are the rivers, the vehicles are canoes, boats and planes that land on water, and living is subsistence. Those on the trips bring bottled water. The villagers drink straight from the river.

And according to data from the Amazon Water Project, about 80 percent of illness contracted by the river people comes from parasites and bacteria in the water.

As missionaries travel to Brazil's rain forest each year, it's safe water for the villagers that remains at the top of the to-do list.

So the O'Nealls and others in Central Illinois started Operation Amazon, a tax-exempt, nondenominational organization to bring water filters to villages near the Amazon.

The concrete filters, which use gravity and have no moving parts and require no repair, can clean a liter of water in one minute and can serve the needs of four families when placed in a communal area. Cheap by American standards, a single filters costs $45 to build and deliver.

It's the delivery process that has suffered setbacks. Operation Amazon has delivered only a handful of filters so far, and during a trip last year the group's boat sank and had to be completely refurbished.

But the boat is almost ready now, and Ralph Maurer, a Bloomington resident and the president of Operation Amazon, plans to be aboard this month during deliveries of the filters already in stock.

Maurer has expertise in water treatment; he spent 20 years as a nuclear chemist. He believes the filters are optimal for the needs and ways of the Amazon people.

"I really believe we are on the verge of breakthrough," he said.