US EPA to initiate rulemaking for low-NOx emission standards for heavy-duty on-road engines
23 December 2016
The US Environmental Protection Agency (EPA) said it intends to initiate a rulemaking to propose revisions to the federal on-highway heavy-duty NOx emissions control program, to provide additional NOx reductions from this category of vehicles and engines.
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The EPA has received several petitions to develop more stringent NOx emission standards for heavy-duty engines. One of the petitions was submitted on June 3, 2016 by a group of state environmental agencies, including two of California air quality management districts (South Coast and Bay Area AQMD) and a number of environmental protection departments in other states.
California requires further reductions in NOx emissions from heavy-duty engines in order to achieve the state’s air quality goals. In 2014, the California Air Resources Board (ARB) adopted Optional Low NOx Standards, with the intention to ultimately transform the program into mandatory low NOx standards, preferably via a federal EPA regulation. California has also indicated that in the absence of a federal regulatory action by the EPA, the ARB would develop and adopt California-only mandatory low NOx emission standards, and would work with the Section 177 states who would have the choice of adopting the new California standards.
In a memorandum issued on December 20th, the EPA responded to the petition and agreed that additional NOx reductions from heavy-duty engines are needed, particularly in areas of the country with elevated levels of air pollution. The EPA intends to initiate the rulemaking process, in cooperation with the California ARB and other stakeholders, to develop new harmonized Federal and California NOx emission standards that would be in effect beginning in the 2024 model year (MY).
The timing of this announcement, issued after months of uncertainty, suggests that the EPA intends to start the internal work on this project before the US and EPA administration change on January 20, 2017.
Source: US EPA