And can vary station to station in a city. I have several Shell stations around me and only one is E-free. None of the Chevron stations are.
And this is going to create a whole new problem for most stations. Most stations are set up to receive only reg and premium fuels (only 2 or 4 underground tanks). They then blend the fuel to make the middle grade. If there becomes a push to req this new e15 gas it will cause most dealers to quit offering premium as it is the slowest seller they have.
I remember in the late '60's or early '70's it was PURE stations that came up with what was called back then "White Gas" read No Leaded gas and there was like only 1 or 2 stations in Orlando that sold it and it didn't go over well as you could buy Sunoco 260 which was the highest octane gas back then and I believe it was 106 octane and cost a whopping .50c a gal!