I don’t think there’s any volatile compounds of lead, which would be the risk. Obviously don’t go off of just my guess, though. You wouldn’t think osmium would produce a lot of volatiles, and yet it’s frigging oxide is.

Of course, depending on where this is and how much water you use that might obviate the need for a well anyway. If you’re distilling it all surface water or just straight up wastewater might work fine.