Underwater pipe proposed to improve health of Shinnecock Bay

Southampton Town is exploring a multimillion-dollar concept to improve water quality in Shinnecock Bay through a 2,200-foot underwater pipe beneath Dune Road that would pump ocean water to flush out the waterways.

The state Office of General Services and the Department of Environmental Conservation have commissioned the Fairfax, Virginia-based engineering consulting firm Dewberry to study the issue. A July study summary shortlisted three options, one of which calls for placing an underwater pipe near Triton Lane in East Quogue, one calling for a permanent cut and another calling for a seasonal cut on Dune Road. Town officials say they favor the pipe concept, and they expect the final report soon.

The health of western Shinnecock Bay is impaired "predominantly due to lack of tidal flushing with the ocean, and watershed pollutant loadings," the summary reads. The lack of flushing causes lower oxygen levels and has led to harmful algal blooms.

Southampton Town Supervisor Jay Schneiderman estimated the pipe project could run between $30 million and $50 million, but said that would be less than replacing thousands of aging septic systems that contribute to nitrogen pollution. The results could also be quicker.

"Shinnecock Bay is a very important water body, particularly for shellfish and marine habitat," said Schneiderman, adding that the town could look to federal grants to offset the project’s cost. "We’ve lost a lot of these areas to shellfishing, so we’ve been looking for additional ways to improve water quality."

The town will use the feasibility study to select the best option and the town will own, manage and operate the implemented project, according to the DEC. The agency does not have a preferred option.

Meanwhile, the town will continue its incentive program offering grants to install nitrogen-reducing septic systems that cost roughly $30,000.

"It’s a long-term solution, [but] it will take decades before we see any significant result from doing that," Schneiderman said.

However, he noted that a pipe in the Triton Lane location would not do much to improve water quality in areas farther west, such as Tiana Bay, Quantuck Bay or Weesuck Creek. Instead, the town paid $50,000 for Dewberry to analyze an additional alternative calling for a 7-foot diameter pipe extending 2,200 feet from Dune Road at the Surf Club of Quogue. The town is awaiting those results.

Town officials pointed to a breach on Fire Island after superstorm Sandy in 2012 that improved water quality in the Great South Bay as proof that the concept works. And the Long Island Express hurricane in 1938 created the Shinnecock Inlet which improved the quality of eastern Shinnecock Bay.

"There is nothing extraordinarily exotic" about bay to seawater exchange, said Councilman John Bouvier, a retired mechanical engineer who has been a proponent of the concept. "With more flushing and the more volume of movement, we get a healthier system."

Kevin McAllister of the Sag Harbor-based nonprofit Defend H20 cautioned the town to take into account how much management will be needed to maintain infrastructure along a constantly changing, and eroding, shoreline like Dune Road.

"I just think it presents a host of issues they are not necessarily realizing," said McAllister, who has called for a managed retreat from the area. "I believe we should try to minimize our presence in there on dynamic Dune Road."

By Vera Chinese

vera.chinese@newsday.com@VeraChinese

Vera Chinese covers Suffolk County government and politics. She joined Newsday in 2017 after working as an editor for the East End lifestyle publication northforker and a general assignment reporter for the New York Daily News.