Old fuel disposal or use ?

I had to do the research some years ago when I was dealing with HAZMAT in NoCal. We had a 250 gallon fuel tank in the yard that had to be removed/destroyed and it probably had about 30 gallons left in it. I found the recommended formula was 1 gallon of old gasoline to 10 gallons of new. Transfered it to a 55 gallon drum and burned it up in the shop truck without issue.