How do I get rid of bees that live in sand?

have bees that have several neasts (I believe) the float on top of the sand and will sometimes disappear ( I think they go into there nests) its so bad I can’t even get near the sand. We tried spraying bee and wasp killer and within a day there back. What’s a good way to keep them back? The sand is in a large area (not a sand box but a beach). Please help me out!