If it is an Eastern Painted it had to come from some pond or some body of water, unless it was a pet and was let loose or escaped from someone's pond. Can't you bring it to a Vet and ask if they could take it? Or do you have an ASPCA or other animal ficility near you. It has to be in water to eat. They cannot eat out of the water. So putting it in a mud puddle will not do. It will only die. Are you sure it is a water turtle? Please find someone to take it who knows what it is and how to care for it. Please don't let it go. It needs water to survive.