I clean up all the left over food from the last feeding and I am noticing this opposom keeps coming around any safe ways to get it scared off without hurting it
Are you talking about food leftovers from feeding a sulcata? Unless you're feeding a lot of Mazuri chow, I can't think of anything that is part of a good diet that would bring in a possum. Keep in mind though, the tortoise it's self is see as a food source for a possum. For my russian outdoor pen, I have a charged fence,(hot line) 3"-4" above the outside wall slightly towards the outer area. This is a painful, none injurious step to keep all manner of critters away from my sleeping, tortoises.
I'm sorry, I see you mean an American dessert tortoise. What I posted still applies. Remember, even a hungry mouse can do real damage to a sleeping tortoise.
Bring your tortoise in, to be safe and to be sure. If you can trap the possum humanely, you can relocate it. Take no chances. You do not need a possum taking a bite, or more, off your baby.
Opposum are turned off by the smell of Ammonia and moth balls. If they are coming into your yard by way of tree branches or over a fence, try hanging socks with moth balls or rags soaked in Ammonia over tree limbs or fences where you have seen Opposums coming and going. Other than that a humane trap and relocation are the answer. You might call your Humane Society or Dog catchers and ask them what you can do, they may be able to help.
When we lived in So. Calif. we found heads of fruit rats in our backyard. Evidentally, they eat Fruit Rats. We saw Opposum on fences and even running phone lines. The Humane Society did come out a pick up a dead opposum and gave us those tips of moth ball socks and ammonia soaked rags. Perhaps they can bring out some humane traps to you and relocate them if you can get them trapped.