SALT LAKE CITY — A legislative committee heard Wednesday that new vehicle and fuel standards rolling out from the U.S. Environmental Protection Agency will have a signficant impact on the Wasatch Front's air pollution problem over the coming years.

As aging vehicles are replaced beginning with 2017 models, direct fine particulate emissions per vehicle will drop by 70 percent — welcome news on the Wasatch Front where the Utah Department of Environmental Quality says vehicles are responsible for 48 percent of all emissions.

In a briefing before a legislative committee interim meeting, Glade Sowards, with the department's Division of Air Quality, said the new federal regulations will have immediate impacts as the fleet turns over.

Sowards, a policy analyst with the division's planning branch, said the new standards that are phased in through 2025 will result in a reduction of 80 percent of all smog-causing pollutants from passenger vehicles in the overall fleet.

In addition, there will be improved emissions from some light and heavy-duty vehicles that come about with the EPA standards, he said, and the useful life of a vehicle will be extended from 120,000 miles to 150,000 miles.

On the fuel front, the new standards require sulfur reductions to 10 parts per million. Sulfur deposition in motor vehicle fuels interferes with the efficiency of catalytic converters, or the emission control devices on cars.

Sowards, in his presentation to members of the Natural Resources, Agriculture and Environment Committee, said the question for Utah motorists rests on the availability of those low sulfur fuels in the state's supply of gasoline from local refineries.

Over the last five years, refineries serving Utah motorists have decreased the sulfur content in gasoline by half, dropping from roughly 44 parts per billion to 22 parts per billion, according to new data from the EPA.

"It illustrates that the refining industry has already done quite a lot in terms of getting sulfur not only out of gasoline but diesel as well," Sowards said. "You can see this steady progress; we are about halfway there."

Sowards said studies show that use of the Tier 3 gasoline in even the older fleet or Tier 2 model cars results in a 13 percent reduction in emissions. When both Tier 3 fuel and the latest vehicle standards are working together, the EPA found that pollutants such as nitrogen oxide and volatile organic compounds are reduced by as much as 55 percent.

The potential problem facing Utah is the EPA regulations allow refineries to average sulfur reductions across their corporate profile, so a Salt Lake City refinery with a Gulf Coast counterpart would not necessarily have to make the required sulfur reductions, Sowards said.

"While that is a positive thing for the refining industry and helps them have flexibility, it does create the potential issue where we could meet the fuel standard via credits but not actually have the fuel in the ground, in the tank here in Utah," he said.

Lee Peacock, executive director of the Utah Petroleum Association, said meeting the new fuel standard, which becomes effective in January, will cost local refineries anywhere from $10 million to $20 million on the low end or approaching $100 million on the high end.

"This is no small investment for these small refineries," he said. "The refineries are now weighing their alternatives on how to best comply with EPA's new rule."

Utah's fleet of refineries, which produce under 75,000 barrels per day, are also granted a three-year extension by the EPA because they are considered small producers.

Legislation ran and passed last session provides financial incentives for Utah refineries to invest in new equipment to upgrade to the Tier 3 standards, Peacock added.

"That said, our fuel right now is cleaner than it has ever been," he said. "We have refineries now that are producing gasoline in the teens as far as sulfur content, and that is going to continue to improve."

Email: amyjoi@deseretnews.com

Twitter: amyjoi16