Dig underneath the concrete rubble at the old General Motors site and you’ll find the hopes of many Sleepy Hollow residents for a rich, sustainable area that links directly to the Hudson River.

But the nearly 96.5-acre site also brings in its fair share of questions about safety, traffic, pollution and future costs. This was evident Tuesday when the Sleepy Hollow village board held its public hearing on General Motors’ special permit application to create a mixed use development with 1,177 residential units, 137,000 square feet of retail space and 35,000 square feet of office space.

GM is seeking the special permits for the river property, located just off of River Street and Beekman Avenue, because it will likely make the land easier to sell to an investor.   The property has remained dormant since the company shut down its assembly plant in 1996.

“The site has laid fallow now for well over a decade, unproductive to the village’s tax base or economy and the site still provides no public connections to the Hudson River ,” said Jeff Ancevino, director of land use advocacy for Scenic Hudson. “It is critical that the remaining issues between Scenic Hudson, GM, village residents and other stakeholders— including Tarrytown— be resolved as soon as possible so that GM and a potential development partner can have certainty about what can be built there.”

For one, advocates believe that the village board needs to do a more thorough environmental review of the site to make sure that property is clean and safe from any toxins.

An environment plan was conducted years earlier when GM tried to develop another plan on the site with Roseland Property, a real estate development firm in with properties in New Jersey, New York, Virginia and Massachusetts. Roseland’s plan was similar to GM’s current plan except it had a few more residential units, less retail and office space, more open space and it didn’t feature a roundabout at it’s entrance.

The Roseland plan fell through after a series of legal actions  that culminated in a decision that was made Januray 2010 in state Supreme Court. In that decision, Judge James Hubert upheld many of the conditions that village set for the property, including buffering, density and contributions to the village’s municipal facilities.

Philip Musegaas, Hudson River program director for the environmental group Riverkeeper, said the village board was to hasty in giving negative declaration for the state environmental review of GM’s new plan.

Musegaas said the village board didn’t take into account new studies that have been done impact of sea level rise on the river. He also said that state Department of Environmental Conservation records from 2007 showed that only the first phase remediation was ever completed at the site and there addition actions that need to take place.

Musegaas asked the board to ask for a supplemental environmental impact statement before moving forward.

“The village has a duty to its citizens to do this right the first time,” Muesgaas said.

Ancevino said that the GM site was perhaps the most important redevelopment site along the Hudson River because of its proximity to  the Tappan Zee Bridge, Metro-North Railroad, New York City, Kingsland Park and Philipsburg Manor.

While the plan has continued to evolve for the better during the past few years, Ancevino noted that other factors have changed and he also urged the board to do another supplemental environmental impact statement.

“Principally, the economic climate has changed dramatically, and the present economy may not support the scale of development approved before the financial crisis,” Ancevino said. “Also, some of the findings [in the 2007 adoption of the Findings statement] have been rejected by legal action taken against the village.”

Richard Plano, a Sleepy Hollow resident, believes the village is pushing the project through to quickly in an effort to get the property back on the tax rolls. Although GM could give the village as much as $11.5 million for services related to the new development, Plano worries that the village could be stuck with any future costs related to environment clean up.

“We have been told that GM, while still in existence, will retain that liability (for future environmental remediation), and insurance will be provided to cover any liability on the village’s part,” Plano said. “As someone engaged professionally on the insurance side, I would like to point out that environmental insurance, if available, is a manuscript contract and will conform to the issues of whoever is paying the bill.”

Chuck Lankester, of Sleepy Hollow Manor, agreed.

“We’re up against a tough competitor,” Lankester said. “They will play rough with us and I’m not sure we’re up for the challenge.”

Other concerns about the plan centered around traffic, water and sewage and  the viewshed.

Mario Belanich, a Sleepy Hollow resident, said he wanted to see the project move forward and he wanted to see more proof about any safety hazards at the site. He noted that he worked at the site for 40 years and hasn’t experienced any health issues.

“I’m still alive...I still have my hair,” Belanich said.

Village Mayor Ken Wray said the public hearing will be continued at the board’s next regularly scheduled board meeting on Feb. 22. The hearing is scheduled to begin at 7 p.m. inside village hall, located at 28 Beekman Avenue.