Nope, haven't tested for that, but we are a mile inland from the Intercoastal, and our well goes 170ft. down. We've been irrigating with the well water for over 3 years now, and the only problem we've seen is chlorosis when it's been really dry. Late fall, winter and spring most commonly, and we hardly water at all in winter.
This plumeria usually gets rainwater from the cisterns, since it is near my veggie growing area. But when it doesn't rain enough to fill the cisterns, well water is pumped into them to keep the level up. It doesn't happen that often, and almost never in the summer, when the plumeria are growing. But this year the rain has been falling all around us.
It's finally catching up on rain, and we had three good heavy showers today, so I'm keeping watch on the plumie and hope the problems don't recur.
