As it moves forward with a plan to sell Plum Island to the highest bidder, the federal government plans to conduct a new environmental impact study of the island that will include information a federal lawsuit argues was missing from a previous study done in 2013.

The U.S. General Services Administration has been working to sell the 840-acre government-owned island off the north fork of Long Island since 2008, when Congress voted to close the animal disease research center there and move it to Kansas.

The General Services Administration has been marketing the island to private bidders over the objections of town officials, members of Congress from both Connecticut and New York and environmental advocates who want to protect the island, which is just over a mile from Orient Point, from development. 

The nonprofit Connecticut Fund for the Environment/Save the Sound led a group of organizations in a lawsuit to block the sale in 2016, alleging the General Services Administration and the Department of Homeland Security did not follow federal law during an environmental review process for the proposed sale.

The suit claimed that the government's 2016 environmental impact study failed to address the protection of endangered and threatened species that have flourished on the island since the Department of Homeland Security limited public access after the disease center was built, leaving most of the island untouched by human development.

Calling the 2013 study "basically a real estate appraisal," Rep. Joe Courtney, D-2nd District, co-sponsored legislation in the House last year that would have required the General Services Administration to stop spending money on trying to sell the island until a new study was completed that provides conservation options for the island's future.

The government's order for a new study, announced last week, said officials will "document conditions that have changed and new information," including the results of a biological inventory of the island, any U.S. Fish & Wildlife Service activity on the island since 2013 and a zoning plan enacted by the Town of Southold in 2013.

Initial work on the new study is scheduled to begin in 2019.

Connecticut Fund for the Environment/Save the Sound Legal Director Roger Reynolds said Wednesday that he believes the lawsuit prompted the General Services Administration to order the new study.

"You can't tell what somebody else is thinking but this is the relief we were requesting in our lawsuit," Reynolds said. "Our lawsuit claimed that the environmental impact statement was insufficient because it did not adequately study the flora and fauna of the island."

A spokesman for the General Services Administration said Thursday that the supplemental study is part of the typical process of preparing government property for sale. He said it will not affect the anticipated schedule for selling the island, which Congress voted should be completed by 2023.

Reynolds said the new study won't address a major complaint in the suit: that the government has not considered the possibility of preserving the island as public land or selling it for conservation purposes.

"There's no indication that they intend to consider that," Reynolds said. "That was a prominent part of our lawsuit."

He said the plaintiffs are trying to determine how the new study will affect their case against the government.

"We just have to consider this and determine whether and how much of the case we want to go forward with at this time," Reynolds said.

Lawyers for the General Services Administration and the U.S. Department of Homeland Security filed a motion to dismiss the Connecticut Fund for the Environment/Save the Sound case last year, claiming they had not yet completed their full environmental review of the sale, among other complaints. A judge in U.S. District Court for the Eastern District of New York denied that motion in January, allowing the case to go forward.

m.shanahan@theday.com