I would be curious what the TDS would be. I might put out a empty cup out tomorrow on the way to work, see what I get. In theory the strong winds should have blown away the suspended air born pollution and since this moisture is coming from over the ocean it should be pretty clean. But the question is how do you collect it? If it is run off from a roof you will have contaminants. I guess you could put out a kidde pool in the yard but what will that get you? 5 -10 gallons over the whole week?