How loud is too loud? Denver considers new noise rules for a growing, denser city

One recent night at 10 p.m., Denver public health investigator Justin LaMascus rolled up at a west side dance club and bar, responding to complaints from next-door apartments alleging drunken debauchery, fighting, and gunplay.

Violence wasn’t his focus, though he’s been issued a bullet-proof vest for protection. He stood in a halo of pale security light between the apartments and the bar’s back doors holding a beige box with a protruding sensor measuring sound levels. A man emptied bins of empty beer bottles, crashing them into a metal waste container. Amplified music spilled out the doors. Just the background din of traffic in the area exceeded the city’s 50-decibel limit for residential areas at night.

“There’s more people, more things making noise, more complaints about the noise. The denser Denver’s population gets, the more people are on top of each other,” he said at the site.

Complaints, made through the city’s 311 system, decreased during the COVID pandemic after a 2019 high of 667 but rebounded last year to 503, up from 300 in 2004. So far this year, 330 complaints have been filed.

Even more often, residents called the Denver Police Department, logging 35,795 complaints since 2019 about noise, according to police records.

Denver is now working on changes to its noise regulations. The latest proposal would let trash haulers, a main target of complaints, begin pick-ups two hours earlier (5 a.m.) in central Denver and an hour earlier (6 a.m.) everywhere else. A higher limit of 85 decibels, up from 80 decibels, for special events such as music festivals before 10 p.m. would give greater latitude. (That’s louder than a kitchen blender. The World Health Organization, Environmental Protection Agency, and National Institute for Occupational Safety and Health recommend ear protection to prevent hearing loss from 8-hour exposure at 85 decibels.)

The city’s current exemptions from decibel limits would remain for lawnmowers, school marching bands, church bells, barking dogs, trash hauling, and construction — along with time-of-day restrictions. Noise law enforcers could rely on smartphone videos sent by residents as evidence of construction violations.

Denver spokeswoman Emily Williams characterized the overhaul as balancing the sounds that appeal to residents of a hip, music-loving city with hearing protection.

Nothing’s been finalized. City County members must vote on changes.

Noise investigators stretched

Whatever the outcome, the city’s plan to install tens of thousands of new housing units as part of high-density mixed-used development has LaMascus and the two other noise investigators anticipating heavier workloads. They’re tasked with responding to complaints within three days if possible.

That work carries them into an auditory odyssey, largely at night, investigating myriad disturbances: electronic bird chirps from parking lot gates, beeps from trucks backing up, the popping of pickleballs, portable toilet doors slamming at dawn, thuds as trash trucks slam garbage containers, the roar of air-cooling and heating.

“Most of this stuff happens before 7 a.m. or after 10 p.m. and has to do with people trying to sleep,” said LaMascus, a former music industry worker who has observed developers building “residential housing anywhere and everywhere” for seven years.

Living next to the bar in west Denver, the residents who complained said the high cost of housing meant they couldn’t move.

LaMascus had sent a warning letter to the bar owner. First offenses receive a warning. Noise law violators then face fines of $250, doubling up to $5,000 for repeated offenses.

As he measured sound levels in a glass-strewn parking lot, bar managers confronted him. LaMascus identified himself as a city noise investigator looking into complaints about amplified music and unruly patrons. He told them the trash dumping after 10 p.m. was illegal and must stop.

“We try to keep them out front,” a woman said, referring to patrons. “I hear you. I’ll get a message to the owner. The place is under new management.”

Denver public health authorities issued 138 tickets in 2019 for noise violations. The city hiked fines in 2021, raising potential penalties to $5,000. Since then, city officials have issued fewer than 60 tickets a year. Police records show 57 arrests made since 2019 with charges related to noise levels.

Denver’s density has increased since 2000 from 3,625 residents per square mile to 4,674 – a 29% spike that roughly matches the population growth, census data shows.

“I cannot enjoy my backyard, cannot sit out in springtime,” Joe Dentremont lamented recently in front of his house east of downtown between Colfax Avenue and the Montclair neighborhood.

Periodic night music events and exercise classes across the alley are to blame, he said. City investigators responded to his complaints, measuring sound levels — and eventually cited property owners for noise violations.

Dentremont said he needs tighter enforcement and stricter limits to live comfortably.

“There should be more city inspectors,” he said. “And when it is time to go to bed, go to bed. If you want to operate a nightclub, put it out on Colfax. If your business involves making noise, it needs to be in a designated area. This is a residential area.”

“Things will get noisier”

City leaders’ goal of installing 44,000 new affordable housing units over the next decade, interspersed with businesses and concentrated around transit hubs, will affect the overall urban sound environment, said Stuart McGregor, president of Engineering Dynamics, who has measured sound in cities for more than 30 years and provides sound-proofing solutions.

“Overall, things will get noisier,” McGregor said, though possible shifts to electric RTD buses and quieter cars could mitigate the impacts of increased population and density.

“We know that chronic noise exposure increases risks for cardiovascular diseases. It elevates the heart rate and increases stress hormones,” said internal medicine Dr. Megan Hiles, director of wellness and prevention clinics for National Jewish Health in Denver.

“Sleep disturbances can increase a whole host of health risks. I would suggest that folks engage in personal noise mitigation.” She recommends noise-canceling headphones – “make sure those are good fitting” – and “stress management – important for reducing chronic inflammation,” including installation of “sound-absorbing things” in bedrooms.

“Building with density, that’s probably done with an eye toward sustainability and affordable housing. Those are pretty important. But noise is a very underappreciated health risk factor,” Hiles said. “It should be at the top of the list as we consider these things.”

35 decibels for good sleep

Denver’s chief noise investigator Paul Riedesel advised ensuring sound levels at 35 decibels or less in sleeping areas. That’s less than half as loud as the nighttime 50-decibel limit for residentially zoned areas (55 decibels during day).

The sound limits were set to reflect activities most common in what once were separate parts of the city: 65 decibels (60 at night) in commercial areas, 75 decibels (70 at night) in “public space,” and 80 decibels (75 at night) for industrial zones.

Over the last two decades, Riedesel has wrestled with the progressive blurring of those zones. “Now we’ve got mixed-use everywhere in town – even more so due to office space that is not getting used that they are converting to residential,” he said.

“People are moving into noisier areas. The noise maybe isn’t new. But there didn’t used to be people living next to it.”

Nighttime chirping

Meanwhile, an overall background din, mostly from vehicle traffic, complicates the enforcement of point source noise limits.

LaMascus went to the transformed area around the former Gates rubber factory last week motivated by multiple complaints from residents.

They complained that an annoying electronic beeping alarm – like constant bird chirps — had been preventing their sleep. “At 3 o’clock in the morning, these residents hear it, and it is driving them crazy,” LaMascus said.

The chirping emanated from a broken parking lot gate, an orange box tagged with graffiti. Vandals had ripped down the bar, triggering the alarm.

He calibrated his sound-measuring device, then measured the background noise in this area by the intersection of South Broadway and Mississippi Avenue — registering 57 decibels. That was already louder than the residential limit without factoring in the constant alarm. In cases like this, Denver’s approach has been to accept the elevated background din as a higher baseline and only assess violations if a sound exceeds the baseline by 3 or more decibel points.

LaMascus measured the electronic chirping at 80 decibels close up, dissipating slightly depending on where he stood.

He could pursue a violation, which often takes months.

But he wanted to just stop the noise. The parking gate was made in Italy. He used his smartphone to look up a customer service phone number. He dialed, waited on hold for 15 minutes and, after identifying himself and describing the problem, waited another 15 minutes. A supervisor informed him he’d have to locate a U.S.-based installer.

“The investigation continues,” LaMascus said, shaking his head.

The constant chirping continued, too, for another five days. He had mailed a letter to the owner of the parking lot property. He had pressed the apartment building managers.

At the end of the week, he emailed a woman who’d complained, asking if she still heard the alarm.

It stopped,” she replied. “Thank you for all your help!”

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