BB1 Noise impacts of the proposed sale of the Pittsburg Power Plant are addressed in Section 4.10 of the DEIR. The analysis included noise monitoring at the plant’s eastern boundary during summertime operations. Noise monitoring revealed that summertime operations of the plant are within the County’s land use compatibility guidelines for industrial land uses bordering residential land uses

The analysis in Impact 4.10-2 of the DEIR indicates that increased frequency of generation operations at the plant would not result in a significant noise impact, relative to noise and land use compatibility. Because power plant noise does not change substantially over a range of loads for each unit, the potential for increased noise would result from more frequent operation of multiple units. If a new operator wished to increase plant output over PG&E baseline operational levels, it could do so by either operating units at a higher capacity or operating more units simultaneously. However, given the time required to bring additional units on-line, an operator would have a tendency to increase output of units in operation before bringing additional units on-line. Because multiple unit operations currently occur within the land use compatibility guidelines of the County General Plan Noise Element, potential increases in multiple unit operations would be minimal (would not affect average noise levels) compared to existing operations that occur within County standards.

BB2 As stated in the Noise setting section of the DEIR, noise complaints from plant operations have primarily been the result of safety relief valves. Periodically, the automatic safety relief valves for the boilers are activated, resulting in the release of high-pitched noise levels for a short period of time. Currently, safety relief valves are activated very infrequently (estimated at two to three occurrences per year by the plant manager at the Pittsburg plant). The duration of these events is generally less than one minute and is a necessary function of power plants to avoid a boiler explosion.

Based on the relative infrequency and the short duration of these events, in addition to their importance relative to safety to plant workers and surrounding communities, the potential for increases in safety relief valve activation would not be considered significant. It is not foreseeable that major equipment failures would occur more frequently under new owners compared to PG&E ownership.

BB3 Noise impacts of the proposed sale of the Pittsburg Power Plant are addressed in Section 4.10 of the DEIR. The analysis included noise monitoring at the plant’s eastern boundary during summertime operations. As stated on page 4.10-4 of the DEIR, daytime ambient noise measurements were conducted around the perimeter of the plant on July 2, 1998. At the time of monitoring, Units 5 and 7 were operating. These are two of the larger units of the plant. While monitoring events did not capture simultaneous operation of all units, such an event was a rare occurrence in 1998.

BB4 Please see response to Comment BB1.