California State Motor Vehicle Pollution Control Standards; Amendments to On-Highway Heavy-Duty Vehicle In-Use Compliance Program, Amendments to 2007 and Subsequent Model Year On-Highway Heavy-Duty Engines and Vehicles, and Amendments to Truck Requirements; Notice of Decision

The Environmental Protection Agency (``EPA'') is granting the California Air Resources Board's (``CARB's'') request for a waiver of Clean Air Act preemption for its On-Highway Heavy-Duty Vehicle In-Use Compliance program (``In-Use Regulation''). EPA is also confirming that CARB's amendments to its 2007 and Subsequent Model Year On-Highway Heavy-Duty Engines and Vehicles regulation (``2007 Amendments'') and CARB's amendments to its Truck Idling requirements (``Truck Idling Amendments'') are within the scope of previous waivers issued by EPA. The In-Use Regulation establishes a manufacturer-run in-use compliance program using portable emission measurement systems (``PEMS''). The 2007 Amendments specify the NOX emission standard for heavy- and medium-duty diesel engines to two significant figures and provide manufacturers the option to certify chassis-certified diesel vehicles within the phase-in compliance provisions of the 2007 and Subsequent Model Year On-Highway Heavy-Duty Engines and Vehicles regulation. The Truck Idling Amendments exempt armored cars and workover rigs (a mobile self-propelled rig used to perform remedial operations on producing oil or gas wells to restore or increase well production) from the new engine requirements of the preexisting California Truck Idling regulation. This decision is issued under the authority of the Clean Air Act (``CAA'' or ``the Act'').