The Environmental Council of Sacramento and the Sierra Club have sued Sacramento County over its approval of the Cordova Hills development on the eastern edge of the county.
"This project is classic leapfrog sprawl development," said Sean Wirth, conservation chair for the Mother Lode Chapter of the Sierra Club, in a news release.
In late January, county supervisors approved the 2,700-acre development, which calls for up to 8,000 housing units off Grant Line Road next to Rancho Cordova.
In the lawsuit filed Friday in Superior Court, environmentalists accuse the county of violating the California Environmental Quality Act. The county's environmental impact report failed to take into account that the developer has not secured a university for the project, which means residents of the new development will drive more to reach employment and create more pollution, the lawsuit claims.
The impact report wrongly makes the assumption that the university will offset pollution that would otherwise be expected, according to the lawsuit.
County supervisors approved the project even after the head of the Sacramento Area Council of Governments told them it could push the region out of compliance with SB 375, a state law requiring reduction of greenhouse gases that cause global warming.
Sacramento County officials were not able to immediately provide a response to the lawsuit.