Bay Area Air Quality District Takes The Plunge

After much thrashing about and hesitancy to act by air quality regulators throughout California and the nation, on June 2, 2010, the Bay Area Air Quality Management District (BAAQMD), which has jurisdiction over the nine counties of the San Francisco Bay area, became the first air quality regulator to adopt guidelines for numerical thresholds of significance for greenhouse gas (GHG) emissionsfor development projects of all types.The BAAQMD action creates

quantifiable GHG thresholds to determine levels of significance in a GHG emissions analysis. A threshold of significance is an identifiable quantitative, qualitative or performance level of an air quality effect used to determine the environmental impacts from a project. This action will lead the way for other regulators in California to control GHG emissions indirectly through the environmental review portion of the project approval process under the California Environmental Quality Act or CEQA.Bay Area


The South Coast Air Quality Management District (SCAQMD), which has jurisdiction over Orange County and the urban portions of Los Angeles, Riverside and San Bernardino counties, by comparison has merely gotten its feet wet concerning thresholds of significance for GHG emissions. The SCAQMD has adopted a GHG significance threshold for a relatively small group of projects only (i.e., industrial projects where the SCAQMD is the “lead agency” for CEQA review). As to commercial and residential projects, the SCAQMD has yet to act. To see where its working group on these significance thresholds stands, see www.aqmd.gov/hb/2008/December/081231a.htm.

Although strictly speaking, standards adopted by a regional or local agency only have legal effect in the geographical area covered, parties supporting or challenging a project frequently urge a government agency elsewhere to apply the “imported” standard on the basis that it represents the current best practice, promotes uniformity across the state or based on other policy or legal considerations. Therefore, even though the SCAQMD has not adopted across the board thresholds of significance, parties may argue that BAAQMD’s standards should apply. If the past is any guide, these standards will be heavily and repeatedly challenged through litigation before long. The outcome of these regulatory efforts and ensuing litigation battles likely will have a profound impact on California’s ability to achieve its ambitious mandate adopted in 2006 (AB 32) to clamp down on GHG emissions in the State in future years.