As the enormous water filtration plant project in Van Cortlandt Park moves farther away from the original plan outlined in 2003, the project’s monitoring committee, local activists and city planning experts say it’s becoming glaringly apparent that the plan didn’t account for significant impacts on the community.

Changes from the original design may have led to the project’s soaring cost and changes in construction plans could lead to unforeseen environmental impacts.

The design for the Croton Water Filtration Plant is “dramatically” different than the one presented by the Department of Environmental Protection (DEP) in 2003 to the public and politicians in the Final Environmental Impact Statement (FEIS), said George Sweeting, a deputy director at the Independent Budget Office (IBO), which conducted an analysis of the project’s budget.

It’s unclear exactly what changes were made, but Sweeting said the DEP told the IBO it was at least 30 percent different.

One immediate result of the design change is that the DEP is now planning to gobble up additional parkland that was supposed to be returned to the public. It’s unclear how much parkland the DEP is taking, but it’s significant enough that local activists and the local community board have formally requested the land be returned and the design changed.

The price tag for the plant has more than doubled from an original estimate of $1.3 billion to the tune of over $3 billion and the DEP can’t account for nearly 50 percent of the overruns, according to the IBO’s report. The IBO said the design change was probably a significant factor, but didn’t go into detail.   

The DEP did not address specific questions for this article, but said in a statement: “The IBO recognized that a number of factors, including general inflation in the construction industry and the highly competitive construction market in New York City, contributed to the rise in construction costs for the Croton Plant. The IBO also noted that the scope of the plan evolved, as is the case with all major construction projects.”

Apart from the design changes for the plant, the DEP is now planning to employ controversial methods of excavation and debris removal for a connected, but separate, project at the Jerome Park Reservoir. Those methods were never mentioned in the original plans.

Greg Faulkner, who chairs the filtration plant’s oversight committee, said he’s especially concerned with the DEP’s plan to truck hundreds of cubic feet of rock from the Reservoir site, which he says will lead to more traffic congestion in densely populated neighborhoods. The original plan was for debris to be trucked through a tunnel and out of the site in Van Cortlandt Park, a less populated area.

“They need to do a new EIS,” Faulkner said. “They’ve made significant alterations without saying how it’s going to impact the community.”

In the past, the DEP has maintained it doesn’t need to do a supplemental EIS to address changes in the plan.

Karen Argenti, an activist and one of the project’s most vigilant watchdogs, believes the FEIS, which is supposed to include all project plans and studies of all its negative impacts (physically and economically), has become irrelevant.

Argenti and local residents mounted a legal effort to stop the DEP from blasting away rock at the Reservoir based on the fact that it was a significant change from the original plan. But the DEP backed away from blasting and a legal judgment was never made. Instead, the DEP plans to use a drilling method called hoe-ramming, a method also left out of the FEIS.

Tom Angotti, a city land use expert and a professor at Hunter College, said city agencies are loath to do supplemental environmental impact studies during major construction projects. The only way you’ll see an additional study is if a judge orders an agency to conduct one, he said.  

“Once a project is approved and the final EIS is approved, there is a tendency among everybody [in government] to not look back,” Angotti said. “There’s no systematic follow-up by an independent part of government.”

The skyrocketing cost of the project, and the IBO’s declaration that much of it can’t be accounted for, upsets project watchdogs who say it’s evidence the DEP deliberately underestimated the cost of building at the Van Cortlandt Park site.

Local activist Anne Marie Garti said she’s convinced the DEP hid costs in the FEIS to make it more competitive with other similar sites. Whether the agency deliberately lowballed the numbers, Garti said, we will probably never know for sure. “They’ve probably done a pretty good job of covering their tracks,” she said.

The DEP’s actions may not be illegal, but that doesn’t mean it’s right, Angotti said. “It is unethical to force an unpopular project on the public without a full understanding of the cost involved,” he said. “That is an environmental impact, the economic impact.”