PROVIDENCE — An environmental group sued the owners and operators of Rhode Island’s Central Landfill on Monday for allegedly violating provisions of the Clean Air Act, including failing to collect gases the lawsuit says pose significant public health threats.

The suit filed by the Conservation Law Foundation names the Rhode Island Resource Recovery Corp., the quasi-public agency that operates the landfill in Johnston, and Broadrock Gas Services, which collects gas at the site. A Broadrock subsidiary, Rhode Island LFG Genco, which converts the gas into energy, is the third defendant.

The nonprofit Boston-based group said the system in place to capture methane, hydrogen sulfide and other gases doesn’t work properly and pollutants are being released into the air, causing a public health hazard for nearby residents.

“They’re failing to adequately capture the gas,” said Tricia Jedele, director of the Rhode Island office of the Conservation Law Foundation. “We need to be treating this more comprehensively and be managing this as a major source of air pollution, not just as a source of odors that sometimes bother the neighborhoods.”

Reached by telephone, Michael OConnell, executive director of Resource Recovery, said he hadn’t seen the complaint and couldn’t comment. A spokesman for Broadrock didn’t immediately respond to a message.

The town of Johnston earlier this year settled two lawsuits it filed over horrible odors coming from the landfill for a total of $8 million.

The law foundation said previously that monitoring at the landfill has shown releases of too much gas hundreds of times since 2011. One measurement in January 2012, for example, found 100 times the methane that is allowed under federal law. The suit also alleges the landfill has been operating without a federally required permit for 16 years, and other permit violations.

The group is seeking a properly functioning gas collection system and civil penalties of up to $37,500 a day per violation.