Residents of a polluted neighborhood sued the city and a waste recycling company today, saying that putrid odors emanating from two nearby sewage facilities are ruining their lives.

Residents at the Hunts Point neighborhood of the Bronx complain that the stench from the plants infiltrates homes and schools, keeping families from enjoying their yards, or even hanging clothes out to dry. At a local school, students don’t go out to play when the odor hits.

“It smells like someone is passing gas in the house all the time or someone is going to the bathroom,” a 44-year-old hospital administrative assistant and mother of three, Chrystal Francis, who lives five blocks from plants, said. “Nobody has done anything, nobody listens to us. They don’t care about the South Bronx because we’re just working-class people.”

The lawsuit, filed in state Supreme Court, is focused on two plants in the neighborhood. One is a city-run sewage facility that takes in the waste of about 600,000 New Yorkers. The other is the privately run New York Organic Fertilizer Co., which transforms city sewage into fertilizer pellets.

The private plant is owned by Synagro Technologies Inc., of Houston, which operates in 33 states as America’s largest recycler of organic waste. Synagro’s parent company is the Carlyle Group, a global private equity firm.

The city’s Department of Environmental Protection said it was reviewing the lawsuit. It said in a statement that it is “actively working with the Hunts Point community to address complaints about odors over the past several years” while trying to improve response to complaints.

A Carlyle Group spokesman referred requests for comment to Synagro, which did not immediately return calls.

The plaintiffs are demanding only that the facilities “take simple steps to make upgrades to eliminate or reduce the odors,” said an attorney, Albert Huang, of the Natural Resources Defense Council, a national nonprofit that filed the suit on behalf of the Bronx residents. They are not seeking monetary damages.

He joined residents and environmental groups in announcing the lawsuit at Barretto Point Park, the congested neighborhood’s only green oasis, built in 2006 at the behest of Mayor Bloomberg. The well-tended park looks on the Bronx River and the Manhattan skyline.

Mr. Huang says the scenario in Hunts Point is being repeated across America, with sewage plants operating “in blighted, low-income communities that lack the resources and political influence to hold these companies accountable.”

At Detroit, Synagro recently signed a contract to build another facility that converts sludge to fertilizer pellets. The community fought the purchase over their concerns about odors and other effects, but the City Council approved the deal; the FBI is now investigating charges that Council staff received money before the vote.

The U.S. attorney’s office and FBI officials won’t comment on the probe, but one council member and a former consultant to another say they have met with investigators.

At Baltimore, a Synagro-owned facility is being penalized by the Maryland state environmental agency for creating a nuisance for residents from the odors.

At the New York plants’ barbed-wire entrance, on a weed-infested street few people ever walk, a sign reads: “Call 311 for any odor complaint” — referring to the 24-hour hot line created by the mayor to help New Yorkers with just about any problem.

Residents believe the sewage plants present health issues as well.

The Bronx has one of the highest asthma rates in the country — partly a result of the pollution from roads that are main arteries for trucks delivering supplies to New York.

The sludge and sewer odors don’t help the asthma, says Dr. Alan Jay Shapiro of the Montefiore Medical Center, who often sees patients with severe asthma. He believes the odors coming from the sewer and sludge facilities “aggravate asthma … especially when the exposure occurs on hot days or on days when air quality is at its worst,” according to the complaint.