Heavy-equipment operator Mike Impagliazzo spends his days shoveling human waste-turned-fertilizer at the city sludge plant, steeped in the odors of his trade, loving his job "like a second wife."

"But this one doesn't take the money," the 33-year Water Department veteran shouts over the rumble of his front-end loader. "It gives money."

Surrounded by 6,000 tons of dark-brown "cake" - the usable, organic product of what 2.1 million people in Philadelphia and surrounding areas flush down their toilets - Impagliazzo is the kind of character who inhabits the 70-acre Philadelphia Biosolids Recycling Center.

And this troop, 60 strong, many of them committed and highly trained, is battling the Water Department's efforts to privatize its sludge operation because the workers don't believe anyone can do their jobs better.

That opposition killed the proposal while John F. Street was mayor, but Mayor Nutter is now behind it and lobbying Council to approve the idea.

Yesterday, over cascading boos from at least 100 union members, City Council's Finance Committee recommended approval of a 23-year contract with a partnership led by waste-processor Synagro Technologies Inc. of Houston.

The legislation could go before Council for a final vote as early as next week, though committee chairwoman Marian B. Tasco said the administration had questions to answer first.

City officials say they can save at least $100 million over the life of the contract, eliminate what remains of the odors that once wafted over Eastwick and Southwest Philadelphia, and create a system that doesn't depend on landfills or the uncertain prospect of other states' accepting Philadelphia's waste.

"The way we're doing things right now is not sustainable," Water Commissioner Bernard Brunwasser said in an interview. "Who knows who's going to be accepting it in five, 10, 20 years?"

Under the plan, Impagliazzo and his 59 coworkers would be transferred elsewhere in the Water Department, with the same seniority, salary and responsibilities.

Even so, for District Council 33 of the American Federation of State, County, and Municipal Employees, opposition to the plan is instinctive - some see it as a slippery slope to privatizing other areas of the Water Department.

"Of course, we're union; we're always going to be concerned about jobs and always opposed to privatization," said Jeff Gilliam, business agent for AFSCME Local 394, which represents 1,200 Water Department employees.

But, Gilliam said, the union has worked with management to reduce the number of employees at the plant by 75 percent since the early 1990s. The workers tasked with turning the region's excrement into a useful and safe product, who average $50,000 to $60,000 a year with overtime, say Water Department officials are trying to rid themselves of a critical public responsibility.

"They want to wipe their hands of it," said Michael Keough, an operations crew chief and shop steward at the plant.

Situated in a heavily industrial tract under the Platt Bridge, sandwiched by the Schuylkill and Interstate 95, the Biosolids Recycling Center was the environmentally friendly answer to handling the city's sludge, which was dumped in the ocean until 1980.

When the center opened in 1988, the plan was to turn 30 percent of the sludge into compost, mixing it with wood chips and leaving it in piles over the 72-acre site to let bacteria break it down into a product not even considered waste. (Residents can go to the center and collect buckets of the stuff free.)

At the time, it was the largest composting biosolids plant in the country, Deputy Water Commissioner Debra McCarty said.

But that process created a stench that could radiate for more than a mile - one neighbor described the odor as "the 'Welcome to Philadelphia sign' " for visitors coming from the airport.

Last year the center stopped composting entirely, and the smell was drastically reduced, though Water Department officials say they are still in violation of air-management regulations because an odor does extend to the fence line.

Now all the center produces is the sludge "cake," which still smells and contains pathogens, though officials say it is completely safe for landfill and fertilizer use.

It is also subject to government regulation and is not always popular, and finding places to send it is a constant challenge, city officials say. Right now, the city pays to send it to landfills, farms (as fertilizer), and old strip mines (as filler and fertilizer). Under the proposed contract with the city, Synagro alone would be responsible for disposal.

In 2003 the Water Department decided it needed a stench-free method of creating the unregulated biosolids that were easier to dispose of, and in 2004 it sent out a request for proposals. It got only one response, leading union officials to say it was tailored to Synagro, which uses a thermal-drying process that takes most of the water out of the product and turns it into tiny pellets that form a coarse, gray sand.

Plant manager James Golembeski describes a model workplace where employees and management cooperate to work more efficiently and have fun doing it.

McCarty, who rose through the ranks as a wastewater engineer, said she didn't believe it was just about jobs for the employees. The union has offered a number of alternative technologies that, it says, the department has ignored.

"The employees here don't see that it makes sense for the Water Department, the ratepayers, and the city of Philadelphia," said McCarty, who was also showered with boos at yesterday's hearing. "And that's the hardest part for me."