So I'm cleaning out my run. I noticed a while back that the dirt had a weird hollow sound when I walked on it, so I dug up a little of it. It comes up in huge 1" thick slaps of poop and under it is the leaves I put in last fall, it's all wet under and STINKS like the sewer. Right now I'm digging out all the poop layers and figure I should let it dry before putting down fresh dirt, but is there something I can do to keep this from happening?