What's that sound? Bristol residents are fed up with nagging noise

There’s a nagging noise in Bristol that has homeowners talking. And in some cases, it’s keeping them up at night, too.

You know when you hear a clock ticking, and the noise is not necessarily loud, but once you hear it, you can’t get it out of your head?

That’s how Bristol residents, and even folks in nearby Plainville and Southington, have described this incessant sound.

They believe the noise is coming from the Covanta plant in Bristol.

It processes more than 220,000 tons of waste each year for 14 Connecticut communities, according to its website.

In addition, the website says the plant produces enough electricity to power 10,000 homes annually and recovers enough metal each year to be recycled which could be used to build 6,000 cars.

“Well, I’m sure the plant, they provide a valuable service to the community, but as taxpayers in the area, it’s frustrating to know you are paying taxes and you have a noise that’s keeping you up at night,” said John Arnoso, of Bristol.

“Once you hear it, you can’t ignore it psychologically,” he said.

He and others tell NBC CT Responds that it’s a hard-to-describe noise, but it’s frequent and frustrating.

“It’s like a low-frequency pulsating noise and it kind of sounds like ‘mmm, mmm.’ Just like that, over and over,” said Arnoso, who has lived all over the country and in big cities, too.

When he finally settled down in Bristol, he immediately began to regret buying his home here.

“I’ve never been bothered by car or highway noise and things like that, but this noise, whatever it is, this low-frequency noise it just can keep you up at night,” Arnoso said.

In Facebook groups and an email exchange, Arnoso and other community members have been asking the city of Bristol for help.

He and others tell NBC CT Responds that the sound can’t be drowned out by noise machines or other things they’ve tried.

There’s nothing you can do to stop it. We’ve tried using fans, the window HVAC unit running during the summer, and the noise still comes through that.

John Arnoso

In one noise complaint reported by a resident to Bristol Police, the investigating sergeant wrote he could hear “a constant, low whirring humming sound off in the distance.”

He later confirmed in his report that the sound was coming from the Covanta plant.

Because of all the complaints, Covanta hired an independent noise expert to do acoustic testing at the facility and in 12 locations off-site at different distances and directions from the facility, too.

The mayor recently shared a summary of those findings with residents, and it found the noise peculiar rather than loud.

After 12 days of testing in December between the hours of 8:30 p.m. and 10 p.m., the report found that all locations tested “were below City of Bristol’s Noise Ordinance noise limits for both Residential and Business Types of Zones.”

But the survey did detect what it describes as “an unusual noise phenomenon” and the experts believe the sound may be coming from two induced draft fans "that exhaust into the stack."

“I love that they’re using the word phenomenon because it’s like, ‘Yes, that’s what we’ve all been saying,’” said a Bristol mother, who asked us not to name her.

She said these results are a relief. There’s finally paper proof that she and so many others aren’t losing their minds.

“People aren’t so nice when you write things about what you’re hearing or what you’re experiencing…People saying negative comments like it being aliens,” she said.

“I am pleased to see that Covanta responded to requests from our office and the residents to investigate the complaints. I also appreciate the efforts of the Bristol Burlington Health Department (BBHD) that has taken the lead for the three communities that appeared to be affected,” Bristol Mayor Jeffrey Caggiano told NBC CT Responds.

BBHD Director of Health Marco Palmeri told us via email that Covanta won’t share the full report with them.

He says the company has told him "deficiencies were identified and, to date, corrective action has been implemented."

But in a statement to NBC CT Responds this week, Covanta says, in part, that it’s "treating this matter with utmost seriousness" and the company is working with city officials and experts to identify the noise source and, “Should it be linked to us, we will promptly address and rectify the issue.”

Those we spoke to say they’re still hearing a nagging noise.

“I’m just really curious if and when it will be addressed because it’s still consistently happening,” said the Bristol mom, who told us while “the sound has been changing in frequency” since the summary was released, it’s still “loud, consistent, droning, and very annoying.”

Palmeri said BBHD is “committed to mitigating these complaints and improving the quality of life for those residents impacted by these issues," like those who spoke out at Bristol’s January city council meeting.

“This is torture,” Christine Bravo, of Plainville, said. She asked for help during the public comment period of that meeting.

Ellen Slipski, of Southington, spoke up there, too.

“I’ve been suffering from this noise,” Slipski said. “I don’t want to move.”

It’s driving these residents insane.

Christine Bravo, of Plainville

Covanta tells NBC CT Responds, “Our operations are conducted in compliance with our permits, and we remain committed to transparently addressing the concerns of our neighbors…”

NBC CT Responds asked Covanta to share the full report with us, but hasn't heard back.