CC1 Bay Area Air Quality Management District (BAAQMD) Regulation 9, Rule 11 prohibits PG&E from burning any fuel other than natural gas in the steam boilers, unless the plants are restricted from using natural gas under force majeure. A detailed discussion on emergency conditions under force majeure is given in footnote #6 on page 4.5-17 of the DEIR. Since 1994, there have been no emergency conditions requiring the use of residual fuel oil, and the PG&E plants have burned only natural gas in the boilers and expect to continue to do so in the future. If an emergency situation were to occur, diesel fuel would not be used, but residual fuel oil might be used for short periods. The acute and chronic health risks from such an emergency condition would be similar to the scenarios treated in the AB2588 health risk assessments (HRAs) that were carried out in 1992. In these HRAs, the maximum acute and chronic health risks (covering all categories of persons listed by the commenter) were shown to be less than the significance levels, which for carcinogenic risks are than 10 in a million and for acute and chronic hazard indices less than 1.

CC2 The health risks were evaluated for all of the maximum operating conditions using natural gas in the steam boilers and distillate in the combustion turbines.

CC3 There will be no diesel fuel emissions at the Pittsburg plant, since there are no provisions for using that fuel. The only power generators that can burn distillate, a derivative of diesel fuel, are the combustion turbines at the Potrero plant. These turbines are permitted to operate no more than 870 hours per year to supply power during times of peak demand. The health risks from burning distillate fuel in the combustion turbines at the Potrero plant were evaluated in the DEIR. The DEIR also evaluated plant emissions (at the plant’s Analytical Maximum of operation) combined with existing background emission levels and found no significant impact (see pages 4.5-67 and 4.5-68).

CC4 The Pittsburg Power Plant site lies within the jurisdiction of Contra Costa County, and it is therefore the County’s land use designations that govern land use planning on the site. The site is already designated in the County General Plan as Heavy Industrial. With respect to areas within the jurisdiction of the City of Pittsburg that are zoned for industrial use, the commenter’s question does not relate to the adequacy of the DEIR or to potential environmental effects that could result from implementation of the proposed project. It would be speculative to conclude that all industrial-zoned lands within the City of Pittsburg would be rezoned for heavy industrial use. The DEIR in Chapter 5, Cumulative Impacts, includes and evaluates all projects proposed in the vicinity of the plants at the time of DEIR preparation.

CC5 There have been several studies published in the last several years that link particulate matter in the ambient air, especially fine particulate matter, to increased respiratory related ailments, including asthma, and cardiovascular disease. A number of these studies attempt to provide a quantitative link between the level of exposure and the degree of illness for various population sectors. However, it is difficult to accurately relate exposure levels to the extent of illness, partly because of confounding factors, such as the role of other pollutants and because of the wide range of susceptibilities for various sectors of the population. Also see response to Comments F62 and F74.

Even with these uncertainties, the EPA has promulgated a fine particulate matter standard (PM-2.5) to protect the public from exposure. The new PM-2.5 standards, which were promulgated in July 1997, were set to protect the most sensitive populations. The rationales used by the EPA to establish these new standards were also used to asses the impacts of fine particulate matter emissions from the PG&E plants.

The impacts of other existing plants and industries in the area were included by using the maximum particulate matter ambient air concentrations that were measured in the region as the background. These maximum measured values for the regions around the three plants, which are identified in Tables 4.5-29, 4.5-31, and 4.5-32, were added to the modeled concentrations from the PG&E power plants to determine the potential worst-case impacts. Using the maximum background is standard practice when conduct air quality analyses, and is very conservative, since a portion of the measured maximum levels may already include emissions from the existing PG&E plants. Thus, the reported total ambient air PM-10 concentrations may be double counting contributions from the PG&E plants.

Please also see the response to Comment CC4.

CC6 The cumulative analysis described in Chapter 5 of the DEIR identifies future projects in the area that may occur, none of which will generate significant increases in commercial traffic, including diesel operated trucks. Therefore, there are no measurable health risks expected from traffic related to these projects in conjunction with the sale of the Pittsburg plant.

Please also see the response to Comment CC4 and the DEIR’s discussion of growth-inducing impacts beginning on page 4.2-7.

CC7 The DEIR reported the maximum health risk contributions from the plant in the area (see pages 4.5-29, 4.5-30 and 4.5-72). The risks from plant emissions were considered to be less than significant. The impacts at other locations, such as those identified in the comment, would be less than the reported maximum risks and would also be less than significant.

CC8 The issue of how emissions in the Bay Area can affect air quality in the Central San Joaquin Valley and Sacramento air basins has been the subject of much debate and study in the past few years. These studies are part of the Air Quality Attainment Plans that are being carried out for both the Bay Area and the San Joaquin Valley, and they include cumulative emissions in each airshed. This issue is complicated by difficulties in being able to accurately quantify emissions from all sources in the Bay Area and in being able to simulate the complicated atmospheric processes involved in the long-range transport of these pollutants. The main issue of concern for air quality in the Central San Joaquin Valley involves the transport of pollutants that would affect ozone levels in the Valley. The principal ozone precursor emissions from the PG&E plants are nitrogen oxides. The DEIR states on page 4.5-17 that emissions of nitrogen oxides precursor emissions will be reduced from the PG&E steam boilers each year beginning in 1997 until a final reduction of 90 percent is reached by 2005. Thus, the project will not contribute to any cumulative impacts that ozone precursor emissions may have on air quality in the San Joaquin Valley. The commenter’s concern for air quality impacts due to heavy industrialization of the area is not an impact of the project since such an occurrence could occur with or without the sale of the plants.

CC9 With respect to air pollutant impacts and the use of Best Available Control Technology (BACT), please see response to Comment U5.

As indicated in the Noise setting section of the DEIR, the Pittsburg plant currently operates within the noise compatibility guidelines of the County General Plan for a industrial land use bordering a residential land use. The analysis in Impact 4.10-2 of the DEIR indicates that increased frequency of operations at the plant would not result in a significant noise impact, relative to noise and land use compatibility. Consequently, there is no requirement (i.e., noise ordinance) or County policy (i.e., General Plan goal or policy) that would obligate a new owner to install additional noise control equipment.

CC10 The Pittsburg plant was assumed in the DEIR to continue operating as a power plant. It is noteworthy that the plant is designated by the Independent System Operator as a "must-run" plant for reliability purposes and the plant site is designated in the Pittsburg General Plan as UT (utility) and zoned for heavy industry. The options suggested by the commenter would require closure of the Pittsburg plant and its replacement by radically different (in three out of four proposed scenarios) operations. Please see response to Comment AA1 for a discussion of the reasons closure of the Pittsburg plant was not analyzed in the DEIR.

CC11 The EIR relies on the best available information to determine both background concentrations and incremental concentrations due to emissions from the Pittsburg Power Plant. For background concentrations, the EIR uses the monitoring data from the Pittsburg monitoring station, which is 0.7 miles south of the plant. Conventional modeling techniques were used to estimate incremental concentrations from the power plant at locations in the vicinity. The two values are added together and then compared to ambient air quality standards or applicable significance criteria (see Table 4.5-32 of the DEIR). Since the localized air quality impact of the project was determined to be less than significant, no mitigation or corresponding monitoring is required.

CC12 Since the project involves existing emissions sources, which are operated under air district permits, and since the estimated emissions increases would require neither permit modifications nor additional permits, no offsets would be required to offset the increases in power plant emissions described in the DEIR.