Why do you guess that? The sentence includes both "safe" and "healthy"; the latter is redundant on your guess about the former. This is basic reading comprehension really.
Interpreting "healthy" as "healthy ecosystem" doesn't really make sense in the context of an initiative focused on people being able to swim.
This thread gives me the vibes of arguing for the sake of arguing. The first point mentions "safe" and "healthy", of course this initiative cares about both good water quality and safety from drowning, because those are quite important things for people wanting to swim.
You must be new around here
The commenter you respond to joined HN 4 years before you, with 10 times more karma points.
I know; it was a tentative to make the thread more serious than these snarky, unconstructive comments.
Really? Do you need to attack the parent and make them seem dumb?