Trouble with oil and oil products are the indexers, viscosity enhancers and other additives that cause lingering pollution problems. It was once acceptable to pour the used oil on weeds, oil roads etc., today it would not only be unwise, but irresponsible to dump it. The amount of cars and trucks in the US today reflect an ever increasing amount of used oil. Where I live, the government vehicles use recyled/rerefined oil to lubricate their vehicles. Of course since its being done by a government agency I suspect they pay somewhere around $10.00 a quart for the product. When we purchase oil here in CA. they tack on a disposal fee so getting rid of it is handled when you purchase it making disposal considerably easier for even the cheapest of folks to do.