88JM said: "It seems that the NWT and RNWT butcher the translation though (the New American Standard Bible also looks bad)." (Underline added)
‘Butcher’? Isn't that a hasty assumption?
The WH/Nestle-Aland/UBS Greek texts literally say: "Neither salt sweet to make water."
The Greek Byzantine text has this reading: "So no spring yields both salt water and fresh."
NWT (2013 REVISION): "Neither can salt water produce fresh water."
NWT (1984 EDITION): "Neither can salt water produce sweet water."
Darby Translation: "Neither [can] salt [water] make sweet water." (Brackets his.)
ASV: "Neither can salt water yield sweet."
Orthodox Jewish Bible: "Neither can salt water yield sweet water.."
Robert H. Gundry: "Nor [can] salty [water] make water sweet, [can it]?" (Brackets his.)
Williams NT: "And a salt spring cannot furnish fresh water."
Christian Community Bible: "Neither is the sea able to give fresh water."
Kenneth Wuest Translation: "Neither is salt water able to produce sweet water."