How does distillation work to treat well water?

Water distillation treatment systems, or water distillers, boil water and then collect the water as it cools, leaving behind most of the pathogens and chemicals that were in the water. Water distillation treatment systems are available across the United States, but they are not a common method of water purification. For home use, filtration and reverse osmosis systems tend to be more popular, as water distillers generally use more energy and take longer than other water treatment systems. Distilled water may taste flat due to the removal of dissolved solids which many people do not like. Distillation is primarily used in specialized applications, such as laboratories, hospitals, and industries requiring ultra-pure water.

Water distillation works by boiling water into steam and then cooling that steam back into liquid form, leaving behind contaminants that don’t evaporate at the same temperature as water. This process effectively removes substances with higher boiling points, such as heavy metals (lead, arsenic, mercury), calcium, and magnesium. Also, most pathogens such as bacteria and viruses are killed during the process due to the heat required.

This process may not remove certain volatile chemicals that boil at a temperature lower than water. These chemicals can vaporize along with the water and re-contaminate the distilled water if not removed prior to distillation. Some distillation units have activated carbon filters added to remove volatile organic chemicals during the distillation process. Another issue that can arise, if a distiller is not used for a significant while, is growth of bacteria in the cooling coils. When the distiller is used again, the distilled water can become contaminated with bacteria.