Uh? Hornsea? Hornsea as in my home town? Well gee, I guess someone must have cleared up the rotting seaweed, dead seagulls and dog excrement, then.
Checking the official list, I discovered that Hornsea did indeed win a Quality Coast Award. Quite what the difference is between a Blue Flag Award and a Quality Coast Award I don't know; I'm guessing that a Blue Flag Award means that not only is the beach clean, but it isn't subjected to icy north winds and driving rain at the height of summer, which would explain why Hornsea didn't win one, then.
Strictly speaking, it's not Hornsea's beach that's clean, it's Atwick's cliffs. That's coastal erosion and longshore drift for you...