GG1 Baseline conditions are described in the DEIR based on background concentration data from a Bay Area Air Quality Management District (BAAQMD) monitoring station in Pittsburg. Table 4.5-32 of the DEIR shows how maximum power plant concentrations compare to background concentrations and compares the combined result (i.e., power plant plus background) with the applicable ambient air quality standard. Table 4.5-32 indicates that maximum power plant concentrations together with maximum background concentrations of PM-10 do exceed the state 24-hour standard. However, the DEIR concluded that the increase in short-term PM-10 contribution from the plant is not significant (see page 4.5-64). Table 4.5-32 also indicates that maximum one-hour average nitrogen dioxide concentrations may exceed the corresponding standard, but those estimates have been revised for the Final EIR, and potential violations of that standard are no longer predicted to occur even under worst-case conditions (see response to Comment B11).

GG2 This comment does not pertain to the adequacy of the DEIR or to any potential environmental effects that would result from implementation of the proposed project. With respect to the potential combined impacts of the project together with known proposed power plants in the vicinity, please see responses to Comments B15 and R11.

GG3 The effects on the marine life from the intake and discharge of cooling water from the plants have been evaluated in several studies (see Section 4.7.3). These studies have led to a Resource Management Plan to operate the Pittsburg and Contra Costa plants in ways that minimize losses of fish; the redesign of the plants’ cooling water intake systems to implement Best Technology Available; and a determination that the elevated temperature of the discharged water was not adversely affecting the abundance or diversity of aquatic species. The local Regional Water Quality Control Boards have placed limits on the quality of the effluent that can be discharged, and these limits would not change with the sale of the plants.

A number of chemicals are used throughout the plants for such purposes as cleaning and lubricating machinery. The wastes from these activities may be treated at on-site treatment plants and discharged with the cooling water or discharged to the sewer. These discharges are regulated by the Regional Water Quality Control Boards or the pertinent cities.

GG4 The regulations of the Regional Water Quality Control Boards would apply to the new owner(s) in the same way that they now apply to PG&E. The divestiture of these power plants will not change requirements related to water quality and the protection of aquatic plants and animals. Please refer also to response to Comment GG3.