At 77 degrees Fahrenheit, the pH of pure water is approximately 7. The pH value describes the acidity or basicity of an aqueous solution. Acids have pH values of less than 7 while bases have pH values greater than 7. A pH value of 7 is neutral.
Different types of water may have slightly higher or lower pH values than pure drinking water due to the minerals and gases present in them. Surface water may contain pH values of 6.5 to 8.5. Ground water has pH values of 6 to 8.5. Acidic water is corrosive and may damage metal pipes. Basic water is hard water and can form deposits on pipes.