pH is a measure of how acidic or basic a substance is. It is a logarithmic scale of 0-14, meaning that each whole number on the scale represents a difference of 10 times. A pH of 7 is considered neutral, neither acidic or basic. pH values below 7 are more acidic. A pH above 7 is basic or alkaline. Therefore, a pH of 8 is ten (101) times more basic than neutral. A pH of 2 is 100,000 (105) times more acidic than neutral. Drinking water should be close to neutral 7. The closer to neutral the pH is, the cleaner the water. Substances with either a very low or a very high pH are generally very harmful to most life forms.
The EPA recommends that drinking water pH is within the range of 6.5 to 8.5. There is no regulation requiring a certain pH for drinking water.