V. AIR QUALITY

1. The Fulton Substation and southern end of the Geysers Unit 11-Fulton transmission line are located in the northern portion of the San Francisco Bay Area Air Basin and lie within the jurisdiction of the Bay Area Air Quality Management District (BAAQMD). The northern end of the line and the Geysers site are located within the southern portion of the North Coast Air Basin and lie within the North Coast Air Pollution Control District (NSCAPD).

   Construction activities for the project would temporarily increase particulate concentrations in and around the project sites. The substation sites have been previously graded so they are essentially flat. Approximately 400 feet of new, graded roads would be developed at the Geysers site to provide vehicle access to two of the proposed poles. Construction equipment and vehicles would generate dust during clearing and excavation and produce minor short-term emissions from vehicles and construction machinery. Ten workers would commute to the project during construction.

   The Bay Area Air Quality Management District (BAAQMD) considers construction emissions to be significant only if project-appropriate mitigation measures are not implemented. A similar consideration is assumed for the NSCAPD. Dust is comprised of large particles (i.e., larger than 10 microns in diameter) which settle out rapidly on nearby horizontal surfaces and are easily filtered by human breathing passages. Much of the dust generated by construction is, therefore, of concern more as a soiling nuisance rather than for its unhealthful impacts. The remaining fraction of small particulates (under 10 micron diameter, referred to as PM-10), tend to remain suspended in the air and could have the potential to violate the state 24-hour average PM-10 standard in the vicinity of construction. PG&E has committed to BAAQMD mandatory control measures, which include sprinkling the construction areas with water to reduce particulate generation. As a result, the impact would be less than significant.

   The nearest sensitive receptor to the Geysers site is located several miles away and the closest receptor to the Fulton site is located approximately 500 feet away. The proposed installation of six poles at the Fulton site would require minimal ground disturbance. The proposed installation of five poles and the road facilities at the Geysers site would require ground disturbance and grading lasting on the order of one day to several days. Construction activities with mitigation proposed by PG&E are not expected to be a significant generator of particulate material.

   Operation of the proposed facilities at the Fulton and Geysers sites would not result in an increase in vehicle trips to either site. The project would not cause or contribute to a violation of any federal, state, or local air quality standards.

   The proposed project would allow for the delivery of electricity that would otherwise not be transmitted. Approximately 40 percent of California's electricity is generated by fossil fuels, the combustion of which results in air pollutant emissions at power plants. It is assumed that the existing sites operate within air emission caps created by the local air districts. The project itself would not induce demand for generation of additional electricity.

2. Implementation of the proposed facilities would not create on-site stationary pollution sources. As discussed in the response to item V.a, above, the nearest sensitive receptor to the Geysers site is located several miles away and the closest sensitive receptor to the Fulton site is located approximately 500 feet away. The construction and operation of the proposed facilities would not impact sensitive receptors at either of the two sites.

3. The proposed project would not be a source of thermal emissions and would not represent the type of facilities or their operation that could cause alteration of air movement, moisture, or temperature, or cause any change in climate. The project would not alter operations of existing geothermal facilities and, therefore, would not affect air emissions related to their operation. Therefore, there would be no impacts related to climate change.

4. Operation of the proposed project would not generate long-term objectionable odors. The proposed project would not result in changes in geothermal facility operations that generate hydrogen sulfide (H2S), which is a source of odors at the Geysers.

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