飲み水としての使用が認められている一部の井戸を除き、あくまでも生活用水として使うのが大原則です。(article)
The difficulty I have is that according to this definition of 生活用水, 飲用 is one of the utilizations so I don't know how I should interpret the sentence since if the waters are recognized as suitable for 生活用, they should also be suitable for 飲み水としての使用.
What I understand from the japanese sentence: "Excepting the wells where the usage of the water as a drinking water is approved,using the water as a daily life water is generally acceptable".
If a certain water is not approved as a drinking water, it also shouldn't be approved as a "daily life water" since in the japanese definition of the japanese term for daily life water, drinking is one of the daily life uses. So it doesn't seem to make sense to separate waters according to these two terms.