SAN JOSE -- At a meeting packed with hundreds of parents and children, Rocketship Education won the go-ahead to develop an industrial site near the Tamien light-rail station into its eighth charter school in San Jose.

But plans to open the K-5 school in August could be stalled by neighborhood opponents who vowed to sue to block it.

The Santa Clara County Board of Education voted early Thursday morning to exempt the 1.4-acre site from zoning rules. That means Rocketship will start working on preparing the parcel for development, said Erik Schoennauer, the school's land-use consultant.

Proponents argued the board should allow Rocketship to fulfill its mission to educate poor children, many from immigrant and non-English-speaking families. "Our parents truly do not have a choice," said Jessica Garcia-Kohl, director of community development for Rocketship Bay Area. She said students attending Rocketship's seven schools live in areas served by the lowest-performing public schools in the county, based on state standardized tests.

"Let's get these kids educated," said Mary Anne Guzman, 70, a Tamien resident who hired tutors for her own children.

But opponents from the neighborhood and elsewhere presented a host of objections. They argued that toxic residue left from the cannery that occupied the land for decades makes it unsuitable for a school. Others protested that the school would generate traffic from out-of-area families, and that Rocketship's presence would hurt their neighborhood school, Washington Elementary.

"We already have enough schools," said Jesus Hernandez, a Washington fifth-grader. His mother, Maria Marcelo, objected strongly to increasing traffic. Instead, she said, the site should house a middle school that could draw from the neighborhood.

Teresa Castellanos, a newly elected San Jose Unified School District trustee, urged the board to allow residents to help decide what schools should serve the area.

After nearly two hours of discussion, the board voted 5 to 1 to grant the zoning exemption. Trustee Anna Song dissented, and trustee Darcie Green abstained.

Schoennauer said the Tamien site is no more contaminated than other parcels in the valley, with residue from agricultural pesticides and asbestos-laden runoff from serpentine rock in the hills. Earlier this month, the San Jose City Council declared that locating the school at the city-owned site would cause no significant environmental impacts.

On the Tamien site, "there is a routine level of contamination," Schoennauer said.

Neighbors as well as San Jose Unified and other school districts allege that the county school board doesn't have the authority to grant the zoning exemption, and that the board erred in issuing public notices about proceedings. Resident Brett Bymaster, who has spearheaded the opposition, said that San Jose attorney Christopher Schumb plans to file suit over the county school board's action.

For others, opening a new school and developing the vacant site can't come soon enough.

"It is a waste and a crime magnet," Tamien resident Dione Johnson-Tyson, the mother of two girls who attend Rocketship Alma school, said about the site. She urged the board to allow another Rocketship to open in her neighborhood.

Contact Sharon Noguchi at 408-271-3775. Follow her at Twitter.com/NoguchiOnK12.