The pH of drinking water can vary depending on several factors, including the weather, but tap water typically has a pH of about 7.5. The pH scale ranges from 0 to 14, with 7 being neutral. Water with a pH lower than 7 is acidic, while water with a pH greater than 7 is alkaline (basic) . The U.S. Environmental Protection Agency (EPA) recommends that municipal drinking water suppliers keep their water supply at a pH of 6.5 to 8.5. The pH of most drinking water lies within the range of 6.5 to 8.5. There has been no evidence of harm found in drinking water with a pH of between 7 and 8.5. Water with a very low or high pH can be a sign of chemical or heavy metal pollution.

In summary, the best pH level for drinking water is a neutral 7, and the EPA recommends that municipal drinking water suppliers keep their water supply at a pH of 6.5 to 8.5. Drinking water with a pH of between 7 and 8.5 is safe, and water with a very low or high pH can be a sign of chemical or heavy metal pollution.