I'd advise against putting the eggs/baby snails into local waterways. It can negatively impact the ecosystem, and is likely illegal.
If they are indeed
mystery snails, I'm surprised that the turtle hasn't eaten them yet but they shouldn't cause health problems if the turtle does.
Mystery snails will lay a "clutch" of eggs on the tank wall or top edge above the water line -
. Unless the tank is mostly enclosed and that area is fairly humid, they likely will dry out and not hatch unfortunately.
If they do manage to hatch, you could leave them in the tank and the turtle will likely start picking off the small ones. I personally wouldn't just get rid of the eggs or baby snails, simply because I've tried to breed
mystery snails in the past and always failed miserably
but if you really don't want them, list them on craigslist and I'm sure someone will take them off your hands quite quickly!
Also, just because the snails have been crawling around on each other doesn't necessarily mean that eggs are on their way. And if you really want to keep the two snails you have, I'd suggest moving them to their own tank with more "peaceful" mates like tropical fish. It's been my experience that anything living in a tank with a RES is a potential meal, even if they've been getting along just fine for months before.