"RST Engineering" wrote
Those rerefiners have a regular "circuit" that they make on a daily basis
on
a 500 mile radius of their home base. You might want to talk your local
airport commission into an investigation -- as I recall, the rerefiner
pays
a few bucks a gallon to the county for the privilege.

My brother-in-law drives a pick-up route for one such rerefiner. He's told
me that their company filters and re-refines it down to #4 fuel oil which
they mainly sell to asphalt plants that burn it in their asphalt heating
furnaces.

Here on the farm we collect it in a 500 gallon tank and sell it to a
rerefiner that picks it up once a month. Right now they'er paying about
$0.85 per gallon, but they take anything that's dumped into the tank.
(hydraulic fluid, brake fluid, ect.) They'll pay more if it's strictly used
motor oil.

Jim