I clear up after ME, if my horse poohs in the arena then its me that clears it. We take turns to pooh pick the fields and brush the yard etc. Large maintainence is the YO but we all give a hand.
I think we're just supposed to pick up any poo. I don't use the school myself but the others use the quad to level it once they've used it, not sure if they're supposed to though...
Its DIY only, so I don't think any of the livery goes towards school maintenance.
I am a yard owner and I grade the school at least once a week. I insist that each livery clears up after themselves in the school, removing all droppings and putting away any jumps/poles. Also if they have created any holes in arena through jumping or lunging I want them raked. basically leave the arena as you would wish to find it.
Pick up any poo, the school is watered almost every day and flattened. If we break poles we have to own up and pay, if its while having a lesson you don't have to pay
We do everything. The YO does mow the grass sometimes and will harrow the school once in a blue moon but that's it. We maintain the fields and the fencing and have to arrange to have it harrowed and rolled ourselves if we want it done. We also have to deal with the muck heap.
On the up side we have good (if slightly run down) facilities at a reasonable cost and can do what we like re turn out etc.