Is there some sort of legalese question you can ask to learn if the body of water you're about to enter is classified as a lake? Like: "is this a pool?". Sounds like a pretty big hole in the safety laws!
"Clean" is definitely not a word I'd use to describe this finding:
“Although the N. fowleri was not detected in the Surf Resort, Lazy River, or the Royal Flush, the presence of fecal indicator organisms, high turbidity, low free chlorine levels, and other amoeba that occur along with N. fowleri indicate conditions favorable for N. fowleri growth”
They're being charitable in their interpretation of the CDC's findings, to say the least.