What are the government guidelines for PH levels in drinking water?

Our drinking water PH level varies between 6.5 and 9.5.

the safest PH level of drinking water would be 7 which is the PH level of PURE WATER.

When water has a low pH level it is called "soft water." Soft water is more acidic; with the pH between 6 and lower, it can be harmful to metals and cause stain in clothes. When water has high pH level, it is "hard water." Hard water isn't harmful but can cause many things. Hard water has a bad taste and it causes build up on Plumbing. Hard water can also create a strange appearance to your clothing and dishware and even make your hair look dull. PH levels of water cannot affect your health largely but it can cause problems.