I've not tried or tested myself, but I'm sure Coney Island and sea gate water is fine since it's open waters from the Atlantic, I wouldn't trust water from under the Verrazano though. Fish only, softie tank pretty sure it really wouldn't be a problem, but pest, trace element, etc would be something to consider. For more delicate species, that's a different story, but to OP are you really sure you want to risk your expensive live stock for a couple dollars of salt? I can tell you, it hurts when you're tank crashes from failing chillers, to hurricane sandy and power outage for 4-5 days.
hurricane sandy has flooded my home, my 150 g tank too, brought my motorcycle in my home too, nature just didnt show mercy that day. nearly died that day when my family went for a break in the car to a leave, stranded 3 blocks, went out to find them. mother nature is just RELENTLESS.