A plan to hook up the ambitious $538 million Ronkonkoma Hub to the Southwest Sewer District, once touted to save millions of dollars, has come in $10 million over budget, forcing the county to throw out bids and split the work into two parts.

The project, budgeted at $26.4 million, had four bids, opened on July 12. They ranged from a low of $36.8 million from a joint venture of J.D. Posillico and Bove Industries to a high of $44.1 million from John P. Picone Inc.

Experts were divided about how the sewer bids will impact the 1,450-unit transit-related development with 545,000 square feet of office and retail space.

“This obviously puts a big question mark on the future of the Ronkonkoma Hub,” said Brookhaven Town Supervisor Edward P. Romaine, a hub supporter.

Romaine, a Republican, opposed the connection to the Southwest Sewer District, and instead backed an on-site sewage plant to recharge water into the aquifer.

“I await with great anticipation how the county executive will address this issue,” Romaine said.

advertisement | advertise on newsday

But Mitchell Pally, chief executive of the Long Island Builders Institute, speaking for developer Tritec Real Estate, downplayed any difficulty.

“This is a hiccup, not a roadblock,” Pally said. “In a project that is going to bring $1 billion in economic development, this is not a large number.”

Pally said Tritec is ready to begin construction and is asking the county for a temporary solution to handle sewage while it rebids work. He said the county is “very confident” a rebid will lower costs significantly.

Suffolk jettisoned the idea of an on-site treatment plant in 2014, saying a hookup to the county’s largest sewer plant would cost less — from $20 million to $22 million.

Islandia also sued the county to block the route through the village, but later settled. Also, lawmakers raised concerns that Southwest Sewer District residents might be saddled with some of the Hub’s sewer costs, but backed off after the resolution was changed.

Jason Elan, spokesman for Suffolk County Executive Steve Bellone, said a sweeping project such as the Hub is “bound to include some challenges.” Elan defended the hookup to the district’s Bergen Point treatment plant as the “best solution” because it uses “a small portion” of capacity and has “no significant environmental impact.”

Attorney Paul Sabatino, who is suing the county for overcharging sewer district residents, said higher bids should force the state comptroller to review plans. “This is just one more fiscal insult for the overtaxed people of the Southwest Sewer District,” he said.

Gil Anderson, county public works commissioner, said an adjusted estimate made just before bids went out indicated work might come in above budget, “but this is $5-6 million higher than we ever expected.” He said a recovering economy has spurred more construction work in New York City, increasing costs.

advertisement | advertise on newsday

Anderson said new bids that will go out in a month will divide the project into two parts — one for the pump stations, and a second for the sewer lines to be installed beneath streets. Anderson said he hopes that dividing the project will spur competition from a wider range of contractors, cutting costs. New bids for street work will be opened one month after they are put out, while pump station bids will be opened two months after advertised. Anderson said he still hopes to start work this fall.

“This is a transformative project that will create a lot of jobs,” said presiding officer DuWayne Gregory (D-Copiague), who said he hoped a rebid will lower costs.

Legis. Kevin McCaffrey (R-Lindenhurst), head of the GOP caucus, said he backs the project but a “hard look” at costs is necessary.