This page last reviewed March 3, 2011


image of California Map The California Clean Air Act (Act) of 1988 directs the Air Resources Board (ARB or Board) to assess the contribution of ozone and ozone precursors in upwind basins or regions on ozone concentrations that violate the State ozone standard in downwind basins or regions.

The movement of ozone and ozone precursors between basins or regions is referred to as transport.In addition, the Act directs the ARB to establish mitigation requirements for upwind districts commensurate with their contributions to the air quality problems in downwind basins or regions.

In response to the California Clean Air Act of 1988, the ARB has published several transport reports that include technical assessments of transport relationships between air basins and regions in California. Along with these technical assessments the reports have included mitigation requirements for ensuring that upwind areas do their part to limit the effects of transport on their downwind neighbors. These two important components, transport assessments and transport mitigation, are further described as separate sections. Web page links are provided to gain historical perspective and to obtain copies of the reports.

Those who are interested in receiving email notifications when information related to transport regulations is posted on ARB’s website can register for the transport list serve.


For more information on transport assessments or transport mitigation, please contact Gayle Sweigert at (916) 322-6923.