Res 2002-037 - Laserfiche WebLink

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Central Texas, is one of the pollutants for which standards have been promulgated. Under the I-hour ozone standard, exceedance of the standard occurs when measured peak ozone levels for any I-hour period is 125 parts per billion (Ppb) or higher. The standard is violated when I-hour peak levels are at or above 125 ppb more than 3 days over a 3- year period. In 1997, EP A set a new standard for ground-level ozone in response to concerns that the I-hour standard was inadequate to protect public health. EP A changed the standard to 85 ppb (the effective standard given rounding protocols) and introduced the "rolling 8-hour average" as the tool for measuring exceedances. The 8-hour average approach addressed the concern that longer periods of exposure were more of a health threat than exposures to I-hour peak levels. Using the rolling average, EPA calculates the average reading over 8-hour blocks of time throughout a 24-hour time period to determine the highest 8-hour average for a given day. An exceedance of the standard occurs when this 8-hour average is 85 ppb or higher. The fourth highest 8-hour average for the year is averaged with the fourth highest readings for the previous two years. An area violates the 8-hour standard when the average for three consecutive years of these readings is 85 ppb or higher. Central Texas is designated attainment for the I-hour ozone standard and continues to monitor attainment of that standard. The region has not exceeded the I-hour standard since 1985. However, Central Texas has experienced monitored violations of the 8-hour ozone standard in 1997-1999 and 1998-2000. As such, the region meets the criteria in EP A's guidelines for participation in an 03 Flex Agreement. Because monitored violations indicate concentrations of ground-level ozone which are inconsistent with protecting public health and the environment, elected officials in the five-county Central Texas region (Bastrop, Caldwell, Hays, Travis, and Williamson counties) have agreed to consider entering into an 03 Flex Agreement with EP A and TNRCC, with the intent of taking voluntary and prompt actions to improve air quality in the region. Resolutions to pursue development of an 03 Flex Plan were unanimously approved by county commissioners courts in each of the five counties. City councils in Bastrop and Elgin (Bastrop County), Lockhart and Luling (Caldwell County), San Marcos (Hays County), Austin (Travis County), and Round Rock (Williamson County) also unanimously approved resolutions. A Letter of Intent, with these resolutions, was submitted to representatives from EP A Region VI and TNRCC on April 11, 2001. 1.3 Central Texas' 03 Flex Proposal Government, business, and community leaders in Central Texas are committed to initiating effective and sustainable programs that will significantly improve air quality and will assure that the region stays in attainment of the I-hour ozone standard. The first phase in achieving these goals is the 03 Flex Agreement with TNRCC and EP A. To the extent practicable, 03 Flex Agreement programs will be launched for the 2002 ozone season, and, in any event, no later than the 2003 ozone season. Descriptions of these 3