Alkaline water: water that has a high pH level than normal drinking water. The pH of pure water is neutral at 7.0. Alkaline water has a higher pH and may be produced with additives or may be naturally sourced from springs or wells. Alkaline water has been marketed with the claim that drinking it can neutralize acid in the bloodstream and help prevent disease. However, there is no medical or scientific evidence that shows the alkaline water has any health benefit.