Suffolk details sewer pipe replacement plan

Suffolk County officials disclosed their first detailed plans to tunnel 80 feet below the bottom of the Great South Bay to replace an aging 2.6-mile sewer pipe in danger of failing, saying it will save money and avoid environmental problems.

Public works officials presented their preliminary plans to the Council on Environmental Quality in hopes of a quick ruling that the project has no significant negative environmental impact. But the council tabled the proposal to give the public and 30 local agencies a month to react to the county's proposal.

The council must also decide whether to become the lead agency under the State Environmental Quality Review Act and whether to require a full environmental impact study.

Mary Ann Taylor, county consultant from CDM Smith of Woodbury, said the tunneling was chosen because the $197 million cost is the least expensive of the six options, including one that cost nearly $1 billion.

Unlike the original 7-foot-diameter pipe that was laid in a trench across the bay in the mid-1970s, Taylor said a new 10-foot-diameter pipe under the bay would avoid construction limits imposed because of fish and shellfish habitats and water issues. "The whole point . . . was to eliminate any impact on the Great South Bay," she said.

Taylor said the only areas that would be temporarily disturbed are about three acres at the Bergen Point sewage treatment plant in West Babylon and another three acres near Cedar Beach, for which the county has an easement. She said both sites would be restored after construction, which is to last three years after all capital funds become available in 2016.

The tunnel route would be within 75 feet of the current pipeline. The plan does not affect the ocean outfall pipe to which it will be linked, which runs another 17,200 feet into the Atlantic Ocean.

The plan for a new pipe arose in 2008 after public works officials became aware of problems with other projects across the country using the same type of pipe. Officials found that the hundreds of wires wrapped around the concrete sheath were loosening or snapping, which consultants warned could eventually lead to leaks of treated sewage.

Public works officials say no leaks have occurred and they have reduced flow pressure in pipes to reduce the threat, and have an emergency plan if a failure occurs.

However, council members peppered the public works officials with questions, including how sand would be removed in tunneling, the amount of fuel oil that would be stored on site to power equipment, and what plans the county has to deal with emergency issues such as storm surge during construction or a collapse of the tunnel. They were also concerned about what will happen to the old pipe.

Officials say that up to 90,000 cubic yards of dredge spoil would be removed and the county could use the material to replenish other beaches, but no final decision has been made. They added that plans would be developed to deal with emergencies, and no decision has been made on the old pipe, but it may just be left in place.

The officials said some details are still to be worked out because design work has not been done.

Several council members expressed support for tunneling but felt more detail is needed. "You've selected the right alternative," said council member Larry Swanson, but he is leaning toward seeking a full environmental impact statement because of the size of the project, the importance of the bay and public interest in the issue. James Bagg, council chairman, said part of the environmental review may be needed to better inform the public on details of the project.

"You got to let people know what you're planning and how you're going to proceed," he said.