I dump mine in a small stream behind the house. It used to make a mess but small kids and ducks play in the stream now and it keeps it mixed up enough that the only thing that shows is some film. Yeah, when it rains there's a bit of sludge but that gets into the tires I dump there too and keeps the mesquitoes down a bit - Kind of my way of controlling pests since I can't use DDT anymore. Well I got to get out back, seems the wind has changed a bit and its blowing the weed killer my sons are spraying. I've got to tell them to put their hands over their noses. The last time this happened I had to cut funny warts off their backs. Anyway, the wife and the siamese twins are due back from shopping any minute and I promised to dump some of that used oil on the street to keep the dust down before they got back - Gotta go...
Ahh, auto parts store.
