The Brentwood Union Free School District has filed a lawsuit to try and stop the controversial Heartland Town Square project, which it says will have a devastating impact on students.

The project, one of the largest ever proposed on Long Island, includes 9,000 residential units, 1 million square feet of retail space and 3 million square feet of office space on the grounds of the former Pilgrim State Psychiatric Hospital in Brentwood.

The district has filed suit against Heartland's developers and the Town of Islip, claiming the project would overburden a school system that's already overcrowded. The district estimates that Heartland would add more than 7,300 kids to its rolls. School officials say that means building new and expanded schools and forcing taxpayers to foot the bill.

“This is absolutely unfair to everyone,” says Board of Education president Robert Feliciano. “The only person who is walking away with a huge benefit is the developer of this project.”

Heartland developer Jerry Wolkoff says the project will attract young people and empty nesters - not large families. He says the district will collect enough property taxes from it to handle the extra students.

“The taxes that I will give them will overcome anything,” says Wolkoff.

Some civic groups say the school district has it wrong and that the Heartland Town Square project will only benefit the region.

“We believe their intentions are good, but we think this is shortsighted,” says Michael Capuano, of Citizens for a Better Islip.

But others like Brentwood’s Nicole Tricoche are not convinced.

“If they really want this maybe they should build a charter school or send some kids to Deer Park, which is right over here,” says Tricoche.

Go HERE for extended footage from Friday's news conference.