Yes, in principle, the term should include drinking water as well, especially when contrasted with "industrial water" or "agricultural water". But in this context you have no choice but understanding this word as "domestic water other than drinking" because the article repeatedly reminds us so.
>
>
> 96
>
>
I don't particularly find the usage very strange, probably because when we simply say "use water" in Japanese (not sure whether in English), we don't typically associate with "drinking". (Just in case, means "water for use" or "water usage" literally.) It's something like a mismatch that all of us now know _shellfish_ and _jellyfish_ are not _fish_ while still calling them so.