One distiller I questioned on this topic said they are allowed to dump there mash down the drain by law. He's in a major city so maybe they can more readily handle it. Everyone else that I've asked said they gave it to farmers. One distiller had a truck and tank, both supplied by the farmer, sitting on site. They put everything from the mash to the rinse from the still in the tank. The farmer picked it up a couple of times a week. Put an ad on Craig's list and see if you get any responses.