Playa Vista Critics Ask Judge to Block $7-Billion Project : Development: Save Ballona Wetlands group argues that builder’s environmental studies failed to assess the effect of additional traffic and air pollution.

Opponents of the vast Playa Vista development near Marina del Rey asked a judge this week to block the planned $7-billion project, saying that a study of its environmental impact was flawed and that Los Angeles officials should not have approved it.

A lawyer for Save Ballona Wetlands said the study by developer Maguire Thomas Partners failed to disclose the cumulative effects the project would have on Westside traffic and air pollution.

Kate M. Neiswender, the attorney, called the voluminous environmental impact report “grossly deficient.”

Lawyers for the developer and the city, meanwhile, defended the project as being environmentally sound.

The group--not to be confused with Friends of Ballona, another local environmental group--filed its lawsuit against the city under the state’s Environmental Quality Act after the City Council approved the project’s first stage in September.

The trial, which began Tuesday in Santa Monica Superior Court, is scheduled to conclude early next week. A decision by Judge David M. Rothman is expected later.

As part of its approval last year, the City Council voted to settle a long-simmering lawsuit by Friends of Ballona aimed at ensuring that the developer spends up to $10 million to restore and preserve the 270-acre Ballona Wetlands on the property.

The Friends of Ballona, whose settlement agreement with the developer would be jeopardized if Save Ballona Wetlands were to succeed in court, has joined with the city and the developer in opposing the group’s lawsuit.

The suit represents the last legal obstacle in Maguire Thomas’ effort to construct what could eventually become the largest development project in the city’s history.

Although financing has yet to be arranged for the first stage, Maguire Thomas officials have said that progress is being made and that they hope to make an announcement in a few months.

The first stage involves construction of 3,246 residential units, 1.25 million square feet of office space, 35,000 square feet of retail space and 300 hotel rooms.

Ultimately, Playa Vista would become a community of 29,000 residents, and serve as a workplace for 20,000 people. It would have 5 million square feet of office space, 595,000 square feet of retail space--roughly equivalent to that of the Westside Pavilion--and 1,050 hotel rooms.

Playa Vista, which stretches for three miles from the San Diego Freeway almost to the Pacific Ocean, would also have its own yacht harbor with docks for up to 840 boats.

Civic, business and labor leaders have hailed the project as a potential boon to the area’s ailing economy.

But opponents have argued that the project is too big, will create too much air and water pollution and overwhelm traffic in the heavily congested corridor between Santa Monica and Los Angeles International Airport.