Planned Propel work under Hempstead Harbor raises concerns for gas line, shellfish

Underwater work plans for a proposed high-voltage cable project through North Shore waterways have heightened concerns about impacts on wildlife, landowner rights and disruption of a major natural gas line.

In state filings and public comments over the past several months, groups and at least one municipality, among them the Village of Sea Cliff, the Hempstead Harbor Protection Committee, Gladsky Commercial Marine and the Iroquois Gas Transmission System, have raised high-stakes questions about Propel NY Energy’s plan to set high-voltage cable lines in Hempstead Harbor, the East River and Long Island Sound.

Several entities also raised concerns about undersea construction impacts to shellfish, including Propel’s "Hard Clam Impact Minimization Plan" that Bruce Kennedy, administrator of the Village of Sea Cliff, said "conservatively assumes 100% mortality for any hard clams within bore disturbance and vessel anchoring."

Some have raised their concerns to the U.S. Army Corps of Engineers, a Trump administration-controlled agency which has yet to issue a permit for the work.

"Hempstead Harbor is not an expendable construction site," Kennedy wrote in one 29-page filing that aggregates many of the concerns.

Propel's developers say the concerns are unwarranted, and that the work will be done in the least harmful way if, as planned, construction starts later this year. They've asked judges overseeing the case to, among other things, disregard the objections. 

Among the more serious concerns, according to a Newsday review of thousands of pages of documents filed in the past year, is Iroquois’ concern that Propel’s work could impact a vital natural gas line into the metropolitan area.

Iroquois in a July 17 letter expressed serious concerns that points at which Propel proposes to intersect its vital natural gas line into the region "risk damaging co-located gas infrastructure" while "negatively impacting service to existing utility customers."

Iroquois wants legal assurances that Propel won't be allowed to start construction on "any segment of the project" without the consent of those that hold property or easement rights. 

Iroquois’ 414-mile gas pipeline system extends from the U.S.-Canadian border through New York State, western Connecticut and under Long Island Sound to South Commack before it goes back under Long Island Sound to an endpoint at Hunts Point in the Bronx. It services Con Edison and National Grid, among others, including Long Island power plants.

Ruth Parkins, government and stakeholder relations director for Iroquois, noted that the issue "has not yet been resolved" in the state Public Service Commission review of Propel. Iroquois, she said, continues to participate in the state process to "protect its interests in ensuring the safe and reliable delivery of natural gas to customers throughout the New York City metropolitan area" and Long Island.

Propel, whose plan for a $3.26 billion, 90-mile series of high-voltage cables and substations would stretch from western Suffolk to Westchester and the Bronx, has objected to the Iroquois filing and sought to have it disallowed.

In a statement, Propel developers at the New York Power Authority and New York Transco, said they have enough experience to avoid damage to Iroquois. 

Propel's team "knows the importance of protecting existing infrastructure and is confident in the measures put in place to cross the Iroquois line safely," NYPA spokeswoman Susan Craig wrote in responses to Newsday.

She noted a condition of the joint proposal that requires "consultation with co-located infrastructure owners, including making good-faith efforts to negotiate agreements" to make sure equipment isn’t damaged by construction or operation of the cable.

But it’s not just Iroquois that’s concerned about property rights.

An attorney for Gladsky Commercial Marine, an operation on Shore Road on Hempstead Harbor, raised similar concerns.

"The proposed Propel transmission cable route cuts a wide swath down Hempstead Harbor, touches recreational boat anchorages on the east side of the harbor, and would eliminate navigation and incident anchoring of large barges at the Gladsky facility," according to a July 23, 2025, letter filed by attorneys for Gladsky to the U.S. Army Corps and shared with the state. "This proposed route transverses the anchorage in Hempstead Harbor at Glenwood Landing where Gladsky Marine moors its vessels as well as where other commercial vessels may moor due to adverse weather conditions."

"The planned cable route converts the entire middle of this navigable harbor into power cable conduit without the benefit of a concrete conduit and restricts navigation and anchorage rights of shoreline and underwater property owners such as the Gladsky Facility," the company’s lawyers wrote.

The Village of Sea Cliff in its filings with the state objects to the undersea cable route because of potential infringement of its property rights in the harbor and for environmental reasons.

Kennedy, pointing to two large holdings of properties by the village, requested that the PSC not decide on how Propel "may construct across Hempstead Harbor until the [developer] establishes where it proposes to construct, who owns or controls the affected lands, and what legal authority it has to occupy and burden them."

Propel according to filings had previously responded to the village that "the underwater lands within the project corridor are owned by the state and National Grid."

But Kennedy found "at least two substantial conveyances of lands under Hempstead Harbor to the Incorporated Village of Sea Cliff," including one of 522,325 square feet and a second of 356,701 square feet. He called for a "current, survey-supported title investigation," among other things, to clarify the issue before any work starts.

He also wrote to the U.S. Army Corps, charging that Propel "has not established who owns or controls the lands under Hempstead Harbor that it proposes to occupy, cross, disturb, or burden."

Kennedy and other officials took particular issue with how the construction plan for the project in the harbor would affect shellfish — including hard clams and the more than 2 million oysters seeded into the harbor — because of the use of a sea-bed jet plow to lay the 345,000-volt cables.

In one filing on the construction plan, Kennedy noted, Propel "does not merely acknowledge that some incidental hard-clam mortality might occur. It expressly states that, because direct impacts cannot be avoided, ‘Propel NY conservatively assumes 100% mortality for any hard clams within bore disturbance and vessel anchoring.’ "

NYPA’s Craig responded that Propel "will help prevent blackouts ... while protecting Hempstead Harbor through robust environmental safeguards, proven construction methods and regular monitoring."

Craig said Propel's work will occur "within a very small, localized area of Hempstead Harbor," adding that the developers’ assumption of 100% mortality for hard clams within the direct construction footprint is a "conservative, standard environmental permitting practice used to evaluate the worst-case impacts and avoid underestimating any potential impacts."

"Given the limited footprint and temporary nature of the work, the project does not anticipate any measurable impacts on the overall hard-clam population in Hempstead Harbor," Craig wrote, adding that the total "direct seafloor disturbance equates to less than 0.0001% of Hempstead Harbor."

Entities specifically concerned about the health of Hempstead Harbor and prior efforts to restore it expressed particular concern about elements of the construction. U.S. Rep Tom Suozzi mentioned potential impacts to the harbor and his efforts to restore it as one reason he doesn't support the current Propel plan.

The Hempstead Harbor Protection Committee, made up of representatives from municipalities around it, including the villages of Roslyn, Sands Point, City of Glen Cove, the towns of Oyster Bay and North Hempstead and Nassau County, said it could not support Propel given a laundry list of concerns in project filings.

Executive director Eric Swenson wrote on July 3 that the group "cannot support" approval of the proposal because it "does not appear to adequately address and incorporate the harbor-specific protections previously requested" by the group to lessen impacts.

Those comments raised concerns about protections "sediment disturbance, turbidity controls, construction methods, jet plowing speed and pressure," and protection of shellfish resources, among others.

The coalition wants assurances that the construction will operate jet plowing of the sea bottom and cable-laying at the "lowest possible speeds" to reduce harm to shellfish seeded in the harbor. The group wants "turbidity curtains" mandated around oyster beds to prevent harm.

"There is no discussion of protecting oysters or any shellfish for environmental restoration purposes." The 2 million-plus oysters "need to be protected," the committee wrote.

Craig said, "The project will adhere to a comprehensive framework for safe construction, operation and maintenance."

Among the many groups that have written in support of the plan, including some awarded work contracts, is a nationally known environment group. In public comments submitted Aug. 5, the National Resources Defense Council downplayed opponents' concerns.

"Some parties and community members have raised concerns regarding ... protection of navigation, fisheries, water quality, and other resources in Hempstead Harbor and adjoining waterways, and alternative routes," NRDC wrote in its comments.

The group said those concerns have already received "substantial consideration" through the state review and settlement process, while Propel has already addressed noise controls, "restoration obligations, protections for wetlands and water resources, and requirements governing horizontal directional drilling and work near sensitive areas."