The Ethanol Mandate requires refineries to add a number of gallons of ethanol to gasoline, according to the article in the link, 13 billions of ethanol last year. So, as I unserstand it, if the refineries use the mandated amount during the year, they are free to produce non-ethanol blends, in other words it's not illegal to produce non-ethanol gasoline as long as they use the mandated amount to make ethanol blends.
What I found interesting, in my trip to South Dakota this year, is that every gas station I visited in SD sold 87 octane non-ethanol gas and 89 octane with 10% ethanol. So here you have a state that lobbies hard to keep the ethanol mandate (to benefit local farmers in SD), but yet sells non-ethanol gas at every pump in the state. That just ain't right..
http://blog.heritage.org/2012/11/19/congress-should-permanently-waive-the-ethanol-mandate/