Nope "Water" is the most abundant resource on the Planet, you mean "fresh" water is more precious, so please feel free to shave with all the ocean water you would like... :)
You could also if you are a true Environmentalist use Gray water for shaving, or being as you are in NY, really use Ocean water, re-cycled/purified through a
simple Gravel/Sand filtering system that you could build out of re-cycled parts and have a never ending supply of shaving water ... This of course would be
heated using sunlight ...Just some thoughts