SFPUC 2001 Alameda Watershed Management Plan

III. ENVIRONMENTAL SETTING AND IMPACTSF. AIR QUALITYcalm winds in all seasons, while summer afternoons and evenings are quite breezy. Strong windsare usually associated with winter storms.1.2 AIR QUALITY PLANS, POLICIES, AND STANDARDSRegulation of air pollution is achieved through both national and state ambient air qualitystandards and emission limits for individual sources of air pollutants, as described below.FederalThe 1977 federal Clean Air Act (CAA) required the U.S. Environmental Protection Agency(EPA) to identify National Ambient Air Quality Standards, or national standards, to protectpublic health and welfare. National standards have been established for six criteria airpollutants: ozone, carbon monoxide, nitrogen dioxide, sulfur dioxide, suspended particulatematter (PM-10), and lead. These pollutants are called “criteria” air pollutants because standardshave been established to meet specific public health and welfare criteria set forth in the CAA.Table III.F-1 lists the national standards established for the six criteria air pollutants.Under the CAA, air quality plans (known as State Implementation Plans, or SIPs) were requiredto be prepared for areas classified as “nonattainment” for any of the national standards. Theseplans were to contain a strategy for improving air quality and achieving the national standards.Pursuant to the 1990 federal Clean Air Act Amendments, the EPA reclassified air basins (orportions thereof) as either “attainment” or “nonattainment” for each criteria air pollutant, basedon whether or not the national standards had been achieved. The attainment status of each of thecriteria air pollutants is discussed below.Based on monitoring data in the 1970s, the Bay Area was designated “nonattainment” withrespect to the national standards for ozone and carbon monoxide, and a SIP for the Bay Area wasprepared. This 1982 SIP was intended to bring the Bay Area into compliance with the nationalstandards by 1987. Under the federal Clean Air Act Amendments of 1990, SIPs were required tobe revised to meet new requirements for those areas, like the Bay Area, that did not meet the1987 deadline.With respect to ozone, a SIP revision for the Bay Area was prepared pursuant to the federalClean Air Act Amendments of 1990. This ozone SIP, the Ozone Maintenance Plan, wasdeveloped for the Bay Area in anticipation of a change in designation to “attainment.” In 1995,the EPA approved the BAAQMD’s request to change the Bay Area’s designation to “attainment”for ozone based on monitoring data which indicated that the Bay Area had achieved the nationalstandard. At the same time, the EPA also approved the Ozone Maintenance Plan, which thenbecame part of the current ozone SIP for the Bay Area. However, the EPA recently announcedits final decision to reclassify the entire Bay Area as “nonattainment” for ozone based onmonitored violations in 1995 and 1996. As a result of that decision, a revised SIP will berequired.NOP 96.223E: Alameda Watershed Management Plan III.F-2 ESA / 930385January 2001