The U.S. Environmental Protection Agency plans to propose new rules to slash pollution emissions from heavy-duty trucks and engines, a person familiar with the matter said.
The proposal is designed to significantly cut smog-forming nitrogen oxide emissions from big rigs and their engines, said the person, who asked not to be identified discussing plans that are not yet public.
EPA officials are expected to announce the plans as soon as Monday.
The move comes after the EPA in December 2016 agreed to begin working on rules to lower big-rig NOx emissions. Several state and county air-quality authorities had urged the EPA earlier that year to toughen NOx standards for heavy-duty trucks — levels that were last updated in 2000 and took effect starting in the 2007 model year.
The South Coast Air Quality Management District, which covers the Los Angeles area, asked EPA to issue rules reducing allowable NOx emissions by 90 percent from current levels. In granting the petition, EPA said it could not commit to a specific level but agreed to begin preparing a notice of proposed rule-making, which it estimated would take about two years.