In 2007, the Air Resources Board (ARB) adopted a regulation to reduce diesel particulate matter (PM) and oxides of nitrogen (NOx) emissions from in-use (existing) off-road heavy-duty diesel vehicles in California. With the March 1, 2010 deadline looming over the construction industry for complying with the off-road regulation, ARB issued a statement yesterday postponing any enforcement actions for noncompliance with the regulation. Because of the faltering economy, reduced construction activity, and associated reduced emissions, "effective immediately, and until further notice, no enforcement action will be taken for noncompliance."  

On March 11, ARB will hold an Executive Officer hearing at which stakeholders can testify regarding whether the off-road regulation should be further modified to account for the economy and resultant reduction in emissions. The information gathered at that hearing will be provided in an update to the full board at its regularly scheduled April meeting.

An earlier FAQ issued by ARB regarding the March 1 compliance obligations is available here, while further information regarding the off-road regulation in general can be found here.