It is a wooden sandbox that was biult last year and sand has sat it in for months now. I took the lid off (which yes-leaked water) and now its gross and molded. I want to clean it all out very well and get new sand but I don't know what to do with the old sand. Is it safe to put it in some rough places in our yard to even it out. Im very hesitant to do that since its so moldy. I dont know what to do with it.