The state’s highest court affirmed a ruling Tuesday that New York city officials violated state environmental law when they approved construction of a South Bronx school complex on industrial ground known to contain toxic chemicals, yet failed to disclose their plans for long-term maintenance and monitoring of the site.

The case dates back to 2007 when the Department of Education and the School Construction Authority approved construction of the Mott Haven Educational Campus in the South Bronx, on a site that used to contain a railroad yard, a laundry, and a manufactured gas plant. The site was known to have contaminated soil and ground water. The SCA undertook remediation efforts which were disclosed to the public and cost upwards of $230 million.

However, by refusing to detail how it intended to protect students and the community from future contamination in an environment impact statement, the authority violated the State Environmental Quality Review Act, or SEQRA, according to the New York Court of Appeals. Environmentalists applauded the ruling this week. They said it would influence the way city agencies monitor — and prevent future contamination — at remediated sites across the city.

“It’s an extremely important case for communities,” said Dawn Philip, an environmental justice attorney for the New York Lawyers for the Public Interest, which filed the 2007 suit on behalf of the Bronx Committee for Toxic Free Schools, a coalition of parents and community organizations. “Contamination issues are rampant in New York City schools,” Philip added.

Philip’s co-counsel, David Berz, head of the environmental practice at Weil, Gotshal & Manges LLP, said the ruling sets an important precedent for how city agencies must notify the community when beginning such projects.

“What it means is that they have to follow the precise procedures,” Berz said. The site, which is now home to a complex of four secondary schools and athletic facilities, was “a regular chemical soup,” Berz said, “but the city did a pretty good job of cordoning them off and doing some removal.” The issue, he said,was that the SCA’s operations and maintenance plan should have specified the steps the city would take to ensure long-term protection from contamination.

Janet Zaleon, a senior counsel from the city’s law department, stressed that the issue was not the remediation effort itself, which was considered to be fair by all parties, but rather the documentation of the monitoring and prevention efforts.

“The Mott Haven campus remediation was an extensive and thorough undertaking that spanned several years, included significant public comment, and was approved by the state,” Zaleon said in a statement. “Those who brought this lawsuit never disputed the remediation effort, or the validity of the city’s long-term measures to ensure that this site is protected from future contamination. The focus of this lawsuit was whether long-term monitoring measures should have been described in the project’s environmental impact statement. The Court has now asked that we prepare a supplemental statement to include that information, and we will do so.”

The Mott Haven Educational Campus is home to New Explorers High School, Urban Assembly for Careers in Sports, Bronx Leadership Academy II High School and KIPP Academy Charter School.

The School Construction Authority has been criticized for its lack of transparency before. Earlier this year, SCA president Lorraine Grillo apologized for a lack of communication over an asbestos removal project at a Cobble Hill school. Parents have also expressed concern about the removal of polychlorinated biphenyls, or PCBs, environmental toxins that are present in the light fixtures of over 700 city schools.

Dawn Philip said that NYLPI first heard of the case through Councilwoman Maria del Carmen Arroyo, who was approached by members of the Bronx Committee for Toxic Free Schools. Jane Maisel, a former public school teacher who is part of the group, said that the ruling was “a victory for families, teachers, and members of the community who raised their voices to protect our children’s health.”

John Fielder, a founding member of the committee and a longtime Mott Haven resident, said the decision had “forced the hand” of the SCA. “In the Bronx especially there are a lot of schools and houses being built on old industrial grounds and there’s no way of knowing that the toxins aren’t coming in,” Fielder said. “We decided that as parents we needed to do something.”

The Bronx Supreme court ruled in favor of the coalition in 2008. The city then went to the appellate court which upheld the decision in 2011. The current ruling by the New York Court of Appeals is final and binding.

“They were looking for a principle that they can dictate how these processes go,” co-counsel Berz said. But, he added, the drawn-out process and the repeated unsuccessful appeals meant the city should be very clear on what is expected in the future. “Everyone at the highest level understands what the rules of the game are now.”