In the latest twist of its protracted struggle to build a new complex at its Mahackeno Outdoor Center, the Westport Weston Family Y on Monday withdrew its application to build a sewer line to the site.

The turnabout came just three days before the proposal faced its first public hearing and surprised some officials and residents. But as opposition mounted, Y officials conceded they faced an "uphill battle."

Just eight weeks ago, the Y announced it wanted to tie the proposed 55,000-square-foot complex into the municipal sewer system rather than build a septic system on its 32-acre property.

The plan would have required expansion of the town's sewer system, and opponents had become more vocal as the first hearings neared.

"It had become clear to us that the process would become too long and too expensive, and that, in the end, we may not be successful," said Bonnie Strittmatter, president of the Y's Board of Directors. "We have a clear path to go forward. We're not going to spend time on an uphill battle."

But putting the septic-system costs back into the Y's plans will tax a Mahackeno fundraising drive that is about $5 million short of its goal with only a month left to raise it.

If that money is not raised, Y officials have said, the institution's future in Westport would be in jeopardy and ultimately could make waste treatment moot.

The "uphill battle" Strittmatter cited for the sewer line would have included winning approvals from five separate local and state bodies and likely would have been lengthy.

Approvals were needed from the Board of Selectmen in its capacity as the town's Water Pollution Control Authority, the Conservation Commission, the Flood and Erosion Control Board, the Planning and Zoning Commission and the state Department of Energy and Environmental Protection.

The plan called for a 4-inch line to run from the existing sewer system west under Lee's Pond -- part of the Saugatuck River -- to the adjacent Mahackeno property.

The selectmen have canceled the first scheduled review of that plan on Thursday.

MULTIPLE ISSUES

Because Mahackeno lies outside the so-called "blue line" that defines the sewer district's boundaries, the selectmen's approval would have had to include amending those borders.

Such a change may also have obligated them to amend the town's sewer avoidance policy -- which stipulates the conditions under which a sewer connection can be granted to properties outside the blue line.

Y leaders had said the sewer line would have been more environmentally friendly and cost less than installing a septic system at Mahackeno.

But the prospect of changing the blue line and the sewer avoidance policy -- which has not been modified since its adoption in 2005 -- attracted increasingly vocal opposition in recent weeks from several quarters, including Save Westport Now, a citizens group and political party that focuses on land-use issues.

"I'm relieved that they've come to their senses," Valerie Seiling Jacobs, a Save Westport Now vice chairman, said Monday.

Other sewer-line opponents also welcomed the Y's decision to abandon it.

"I think the Y is doing the right thing," said Indy Goldberg, the co-director of Y Downtown, a citizens group that wants a Y complex in the town center. "I think it's great that they are listening to what people have to say."

Matthew Mandell, chairman of the Representative Town Meeting's Planning and Zoning Committee, had a similar reaction.

He said he thought the Y should move ahead with plans that already have been approved, including the septic system.

"The idea of changing the blue line ... for their proposal was inappropriate," he said. "I'm glad they recognized it."

`FAST' SYSTEM

The Y said it will proceed with its initial plan to install a new septic facility at Mahackeno. That system includes an "alternative treatment" unit known as the Fixed Activated Sludge Treatment system, which is produced by a Kansas company, Smith & Loveless.

The FAST system includes wastewater treatment processes such as aerobic treatment and nitrogen removal, which supplement the traditional tanks, distribution piping and leaching fields. About five FAST systems currently operate in Connecticut, according to DEEP officials.

The FAST system was approved for Mahackeno by the Flood and Erosion Control Board, the Conservation Commission, the Planning and Zoning Commission and DEEP during a two-year approval process between 2006 and 2008.

Still, several town officials and local environmentalists contend the system is unreliable and would pollute local waterways.

In 2007, the RTM rejected by a narrow margin two petitions challenging the Flood and Erosion Control Board's and Conservation Commission's approvals of the septic system.

Debate about the FAST system's performance figured significantly in the RTM's review of those appeals. Y officials this week reiterated their confidence in the system.

"We don't have concerns about the septic system," said Rob Reeves, the Y's chief executive officer. "We'll go forward with what we know will work."

The Y still must submit plans and specifications for the system to DEEP and receive a state permit to operate the apparatus.

DEEP officials have maintained that a FAST system at Mahackeno would be reliable and meet the state standard of discharging no more than 10 milligrams of nitrogen per liter of wastewater, provided that it is properly maintained and supervised.

"Their track record is similar to all the other alternative systems that are in place," said Michael Hart, a supervising engineer in DEEP's Water Permitting and Enforcement Division. "All the ones that are properly staffed, funded and maintained usually operate pretty well."

None of the on-site wastewater treatment facilities with FAST systems in Connecticut have experienced problems related to their FAST units, Hart said. One of those FAST systems -- at a Stop & Shop supermarket in Madison -- had a hydraulic problem related to its leaching field. That setback was "minor" and did not cause any water pollution, Hart added.

But the Y's decision to drop its sewer plan will likely further encumber an already arduous fundraising process for its Mahackeno center. To meet financial and construction deadlines to move forward with an October groundbreaking, the Y will need to have raised "significantly close" to $12.5 million by mid-May, Reeves said.

The Y has so far raised about $7.2 million -- roughly $5 million short of what it needs, even after a recent $500,000 pledge from Allen Raymond, Westport's town historian and a former Y president.

The septic system would cost around $1.2 million, according to Peter Romano, a partner at Westport-based Land-Tech Consultants. Building a sewer line to Mahackeno would have cost about the same, Reeves said.

But on top of installation costs, the Y will have to fund an emergency reserve that would pay for the replacement of its septic system if it were to fail, a fiscal obligation mandated by an ordinance approved in 2006 by the RTM.

Facing an outlay of more than $2 million for installing and operating its septic system, the Y will seek to offset its wastewater treatment expenditures by reducing some of its building costs for the $36 million Mahackeno complex, Reeves said.

"We're not going to cut out a gymnasium or cut out a pool... because then the operations will not generate the revenue we need to cover the borrowing we have planned," he said. "There are ways to use [less expensive] products that are less aesthetically pleasing but just as functional."

The Y already has scaled back its plans. It originally proposed a 102,000-square-foot complex. But facing a $17 million funding shortfall in February, the Y scaled back to about half that size.

Y'S FUTURE AT STAKE

If the Y does not raise about another $5 million in the next month, the Mahackeno project likely would collapse.

Y officials appear to have ruled out the possibility of suspending the fundraising campaign and resuming it later -- perhaps when the economy improves. Pursuing an extended fundraising schedule, they argue, would only create "escalation costs" that would make building the Mahackeno complex even more expensive.

"If we wait another couple of years, the escalation costs would overpower anything that we would continue to raise," Reeves said.

Remaining at its downtown complex at 59 Post Road East also appears unworkable. The Y agreed in 2006 to sell its downtown building to Bedford Square Associates, a consortium whose principals include Westport-based developer David Waldman.

In 2009, bruised by an already protracted review process, the Y renegotiated its contract with Bedford Square, which agreed to let the Y stay in its downtown complex until the end of 2014 -- three years later than its original deadline to vacate. The Y will not seek another extension, Reeves said.

"They've been very good with us," he said of Bedford Square Associates. "We've got an agreement that we're going to hold to."

Meanwhile, other funding sources, such as the Y's national organization, or even the town, are not considered viable options, officials said.

"The national organization provides guidance and advocacy," Reeves said. "But they don't have that kind of budget to donate money to Ys."

If the Mahackeno project foundered, the Y could find itself with no facilities beyond its Mahackeno property after 2014. Contributions to the Mahackeno capital campaign would be returned to donors, not re-allocated to finance another building, officials said.

"We won't be looking for another site," Strittmatter said. "We'd be trying to figure out what to do with the charitable mission and the assets that we have left."

In Raymond's view, such an outcome would affect the entire town.

"Westport doesn't know how important the Y is until it's gone," he said. "Westport has always been an up-and-forward town doing exciting things. To have it suddenly lose its crown jewel would be terrible."

pschott@bcnnew.com; 203-255-4561, ext. 118; twitter.com/paulschott