The U.S. Environmental Protection Agency's chief was in San Diego on Tuesday, celebrating fuel efficiency gains by the nation's trucking fleet.
Gina McCarthy told truckers with the American Trucking Association that tougher standards are reducing the industry's carbon footprint.
The EPA chief also hailed ongoing discussions that will likely lead to even more stringent guidelines.
"This is the time when we're free to sit down and do a lot of work with the industry itself, to identify what technologies are available and how we can utilize the technologies that are coming on board to establish standards for fuel efficiency and greenhouse gas reductions, that are reasonable and achievable," McCarthy said.
The American Trucking Association trade group said trucks will haul more than 70 percent of the nation's freight this year.
Meanwhile, McCarthy also announced the federal government is spending more than $8 million on various clean water projects along the U.S.-Mexico border.
