COMPLIANCE INFO_1991-2006 - Laserfiche WebLink

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0 Vehicle traffic , industrial processes, and other urban activity will result in incremental increases in air pollutant emissions in the Manteca area. The incremental ambient air quality impacts of such emission increases cannot be reliably estimated for regional pollutants such as ozone (the major component of photochemical smog) . It is , however, practical to estimate the incremental change in carbon monoxide concentrations associated with traffic from urban development. . The carbon monoxide concentrations associated with traffic from existing and projected development in Manteca have been estimated using the CALINE3 dispersion model and EMFAC7C vehicle emission rate data from the California Air Resources Board. Carbon monoxide emissions from existing and projected peak-hour traffic were modeled for major roadways in the Manteca area. Expected ambient concentrations were estimated for 48 locations generally located 100 feet from roadway centerlines at major intersections. The state carbon monoxide standard for a 1-hour averaging time is 20 ppm (parts per million) . The federal 1-hour carbon monoxide standard is 35 ppm. No violations of the state or federal 1-hour carbon monoxide standard are expected in Manteca under either existing or future traffic conditions. Both the state and federal governments have adopted carbon monoxide air quality standards of 9 ppm for an 8-hour averaging time. Monitoring data from urban locations throughout California indicate that the maximum 8-hour carbon monoxide level at any particular monitoring station is usually about 65 percent of the peak 1-hour value. As with the 1-hour standard, no existing or future carbon monoxide problems are anticipated. The sizing of the proposed project does not conform to the currently-approved Air Quality Plan for the San Joaquin Valley Air Basin. The City will be required, through a grant condition, to implement mitigation measures identified in an updated Air Quality Plan. 2. Agricultural Land: The sewer plant expansion may result in conversion of prime farmland to urban uses. The loss of prime soils can be partially mitigated by implementing a policy of phased development. By ensuring contiguous development away from such soils as long as practicable, the city can postpone the conversion of these valuable agricultural soils. However , since full buildout would ultimately convert these areas , the impact would eventually be significant. Sewer plant expansion facilitates conversion of land currently in agricultural use to urban uses. Approximately 1 ,311 acres are expected to be ultimately converted by this expansion. The total loss of agricultural land around Manteca is a relatively small portion of the total agricultural land in San Joaquin County (i .e. , less than one percent) . However, the loss resulting from the urbanization of the Manteca area contributes cumulatively to the overall significant loss of farmland in the county. 11