In June 2006, the U.S. Environmental Protection Agency required 80% of highway diesel fuel sold in the U.S. to meet new ultra-low sulfur standards similar to those needed for low-polluting gasoline.

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In April 2012, the federal Environmental Protection Agency issued a notice of violation to Green Diesel, alleging it improperly generated credits that track and boost renewable fuel production.

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That is because the Environmental Protection Agency recently approved retrofit technology for big rigs that lets them burn LNG and diesel.

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The Environmental Protection Agency has granted a nationwide waiver for fuel blends to make more gasoline and diesel fuel available throughout the country.

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The Department of Energy is releasing supplies from the nation's Strategic Petroleum Reserve to limit disruptions of supplies to oil refineries, which "will help take some pressure off of gas prices, " and the Environmental Protection Agency has waived rules requiring low-pollution blends in some areas in order to increase availability of gas and diesel, he said.

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