There is a traffic jam in front of the Iglesia Central Assemblies of God Church in San Cristobal, Dominican Republic. All day and into the evening, cars, SUVs, motorcycles, bicycles, burros, and pedestrians converge by the hundreds, sometimes for two blocks. For the most part, the people wait patiently.

They're here for water—the cleanest and cheapest water in town.

The church dispenses approximately 60,000 gallons of water per month to residents, charging a mere five pesos to fill a five-gallon jug. Local stores charge twenty-five pesos (about $1) or more for the same amount. And the store's water is not as clean as the church's.

"It tastes divine," said one resident, standing in line with one of the ever-present blue water containers.

The water comes from a purification system installed by Healing Waters International, a Denver-based nonprofit organization. Since last year, Healing Waters has been installing about one water system per month in Dominican churches. By June, nine systems were functioning and another two wells were being drilled. World Vision and other organizations have expressed interest in helping the agency install more systems at a faster pace. Expansion plans include Haiti and Mexico for next year.

The Healing Waters idea came after Tom and Dana Larson left their business careers in 1997 to live for a year in La Victoria, Dominican Republic, as volunteer missionaries to their Denver church's sister congregation. Tom was an award-winning advertising copywriter. Dana was a business systems consultant with Arthur Andersen and J. D. Edwards.

Disillusionment set in almost immediately after their arrival in La Victoria.

"We were miserable," Tom Larson said. "Just to show how pathetic we were, we would go to the Santo ...