MAHASKA COUNTY - Quake survivors and aid workers in Haiti are using a water-purifying technique developed by Iowans to make safe drinking water.Near the small town of New Sharon, a lot of work is being done inside Earl Ratcliff’s garage on a device that is helping hundreds of Haitians."This is a tool to help folks who don't have access to pure water to have that simple necessity we all take for granted,” explained Ratcliff.The Chlorine Producing Unit (CPU) was developed by Safe Water International Ministries – based in Washington, Iowa – in 2004 as a way to give all people around the world the opportunity for safe water.The CPU costs $150 to build. Most of the materials used to construct the gadget can be purchased in a hardware store. Making one CPU takes about 75 minutes.Once built, Ratcliff hooks up the CPU to a 12-volt battery. He pours five ounces of water and about one teaspoon of salt in a bottle and shakes it up. Then, Ratcliff pours the mixture through the device five times. The reaction of electricity, salt and water creates chlorine.A few drops of the newly-made chlorine are then added to a gallon of dirty water. After an hour, the bacteria inside the unhealthy water are killed, the smell dissipates and the water is safe to drink, explained Ratcliff.Physicians and service groups in Haiti are using it not only to make drinking water, but also to disinfect hospitals. More than 110 CPU’s are expected to be in Haiti within the next several weeks.Ratcliff says knowing his Christian-based group’s project is helping so many in need give them a sense of accomplishment."We're just thankful to be able to help,” he said.