MSHA - Code of Federal Regulations - 30 CFR 71.601
30 CFR § 71.601
Drinking water; quality.
(a) Potable water provided in accordance with the provisions of
§71.600 shall meet the applicable minimum health
requirements for drinking water established by the State or community in
which the mine is located.
(b) Where no such requirements are applicable, the drinking water
provided shall conform to the Public Health Service Drinking Water Standards,
42 CFR part 72, subpart J.