US refiners still dependent on heavy crude imports?

Bloomberg/Fuel Fix:

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Thanks to booming shale production, the U.S. reduced shipments from the Persian Gulf to a 30-year low last year. Still, Middle East crude makes up more than 10% of U.S. imports. With new oil production records being set in the Permian Basin, the country’s energy growth engine, America’s thinning reliance on Middle East crude isn’t about to reverse course.

Before the “shale revolution,” as American drillers call it, Gulf coast refiners invested millions of dollars to process relatively cheap heavy oil from the Middle East and Latin America. At the same time, shale oil is much lighter and lower in sulfur compared with supply from the Persian Gulf, and not ideal for most American refineries.
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One of the problems is that refiners are having to waste money on ethanol requirements that could be used to switch their operation completely to the light crude being produced here.  They are still diluting the heavy crude with the light and using more than they were.   It is ironic that ethanol was supposed to reduce dependence on foreign oil, but is now having the opposite effect.