PITTSBURG -- City Council members approved a proposal for a 20-megawatt solar facility that would sell electricity to Pacific Gas & Electric, one week after the owner of a recycling center raised environmental questions about the project.

Garaventa Enterprises has since withdrawn its opposition. In a one-page letter submitted to the council about 2½ hours before Monday night's meeting, it said it now supports the project.

The 3-0 vote clears the way for Columbia Solar Energy, a subsidiary of New York-based LS Power, to build the facility on a leased 115-acre grassland parcel owned by USS-Posco Industries.

Garaventa Enterprises, which operates the Mount Diablo Recycling Center on Loveridge Road next to the project site and provides garbage service in several East County cities, raised concerns about the project just two hours before the April 8 council meeting began.

Garaventa officials did not return phone calls seeking comment on why it no longer opposes the project.

At the April 8 council meeting, Garaventa officials submitted a 14-page letter that questioned whether the project's negative declaration adequately addressed environmental issues associated with the project, such as visual impacts on nearby residences.

The city stood by the negative declaration, saying it provided an "appropriate level of environmental review" and that the project would "generate electric output from the sun during daylight hours without air, water or noise emissions."

The city did not require the project developer to prepare an environmental impact report as part of the approval process. City staff determined the project would not have a significant impact on the environment, provided the developer follows mitigation guidelines such as limiting construction to daytime hours outlined in the negative declaration.

The 115-acre parcel was once used as a landfill for waste produced by the steel mill. The parcel went through an extensive cleanup process several years ago under the direction of the state Department of Toxic Substances.

The electricity generated by the solar project would be sold to PG&E to help it meet a state mandate requiring 33 percent of energy produced by investor-owned utilities come from renewable resources by 2020. Construction is slated to begin later this year and be finished in 2014.

The project came to the city for approval based on a unanimous recommendation made by the Planning Commission at its March 12 meeting.

Contact Eve Mitchell at 925-779-7189. Follow her at Twitter.com/EastCounty_Girl.