“Ahhhhhhh! My nice, black, seal coated asphalt. Nothing compares to seeing the new surface for the first time especially with bright yellow striping. This will last forever.”
Then it rains and there’s a white substance lining your sealed asphalt. What’s going on? It’s your ground water bubbling through to the surface. The moisture from the ground is hard water and has a lot of metals and lime in it. When it rains or the ground water comes bubbling up, it reacts to the sealer leaving some staining.
What do you do? Nothing. In a short time, the sealer will cure and the staining wears off, usually in a few weeks. When the white lime marks show up, it can be a little stark. Normal traffic and curing will clean it off.