California Air Resources Board Approves Strategy to Drastically Cut Air Pollution

On Sept. 27, the California Air Resources Board (ARB) approved "an ambitious, multi-faceted plan" to significantly improve air quality throughout the state, along with announcing new measures on two regional plans geared toward meeting federally mandated emissions standards and deadlines for the South Coast and San Joaquin Valley.

"The 2007 State Implementation Plan shows how California expects to attain clean air through a combination of innovative and cost-effective measures," said Mary Nichols, ARB chairperson. "With this vital document in place, we have a roadmap to the future that will keep us on track to meet our air quality goals."

In addition to the state strategy, the ARB approved a plan submitted by the South Coast Air Quality Management District (SCAQMD) to hasten emissions reductions through cooperative measures to be implemented by both ARB and the SCAQMD. This plan, which will reduce emissions of the smog precursor oxides of nitrogen (NOx) by more than 500 tons per day by 2014, now becomes part of the state implementation plan (SIP), which will be forwarded to the U.S. EPA for final approval. NOx reacts with sunlight to form ozone, a key ingredient of smog.

Also approved was an expedited strategy to improve ozone air quality in the San Joaquin Valley some 90 percent by 2018 in terms of the federal standard. For example, the strategy calls for ARB to clean up emissions from farm equipment and to partner with the San Joaquin Valley Air Pollution Control District to accelerate the timeline of the recently passed off-road construction rules by offering financial incentives to valley businesses aimed at getting older, dirtier engines retrofitted or replaced.

Both the South Coast and San Joaquin plans focus on efforts to meet federal deadlines specifically for ground-level ozone and fine particulate matter (PM2.5) emissions. Target dates for compliance are 2014 for PM2.5, and 2023 for ozone in areas designated by the EPA as having "extreme" air pollution such as the San Joaquin Valley and South Coast Air Basin.

While the federal ozone attainment date for the San Joaquin Valley remains 2023, ARB's new proposal this week will fast-track efforts to get 90 percent compliance by 2018. The last 10 percent will require new technologies that are not readily available now.

Because ARB scientists determined that reducing emissions of one pollutant, nitrogen oxide (NOx), is the most beneficial in reducing levels of both ozone and PM2.5, the state plan focuses on curbing pollution from the sources that produce nearly 90 percent of the state's NOx. These sources include cars, heavy duty trucks, large off-road equipment, ships and locomotives.

For more information, contact ARB at

Check out the archives of Environmental Protection magazine's Web site for additional articles related to ARB, including: "Study: Indoor Air Purifiers That Produce Ozone Are Unsafe."

This article originally appeared in the 09/01/2007 issue of Environmental Protection.

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