The environmental group Save Mount Diablo is claiming a “major” victory in its challenge to the city of Pittsburg’s approval of the 1,650-unit Faria/Southwest Hills development, proposed by Seeno company Discovery Builders.

On Feb. 10, a Contra Costa County Superior Court judge ruled the city’s environmental impact report was inadequate — the basis of Save Mount Diablo’s legal challenge to the project, which the Pittsburg City Council approved in February 2021.

“The court’s decision says to developers, ‘You don’t get to kick the can down the road. You have to do a thorough analysis of your project’s impacts before you lock in project approvals,’” said Winter King, Save Mount Diablo’s attorney, on the group’s website. “The court got it right.”

Online court records on Thursday didn’t indicate an appeal of the decision has been filed. Pittsburg’s city attorney was not available to comment on the city’s next move, which could be to redo the environmental report.

The massive residential subdivision was planned for 606 acres of ridgeline and hillside grazing land in what is currently unincorporated land just south of Pittsburg, which would annex the development.

Save Mount Diablo contends the property is a “biologically rich site (that) supports sensitive wildlife species and rare plants and is in one of the most visible and most environmentally constrained areas of the county.”

The group also says, “The Faria project would have fragmented open space and damaged wildlife corridors. The proposed housing development would have changed the beautiful green hills forever by annexing the property to the city of Pittsburg and locating 1,650 new residences far from jobs, transit, and services.”

According to Save Mount Diablo, the court found the environmental report deficient in four areas: it didn’t properly analyze the impact of 150 accessory dwelling units that were added to the project; it didn’t include a baseline description of biological resources that could be impacted; it didn’t consider the water supply or air quality impacts.