(Fauquier Times) -- It's been 18 months since residents of Great Oak, a 291-home subdivision south of Manassas, began to hear the mind-numbing noise—a low-pitched roar topped with a tinny screech—from a complex of Amazon data centers next door. Now, after many meetings with Amazon and costly engineering work, the data center operator has managed to reduce the sound by 10 decibels—cutting its loudness in half.
The work is not done. Residents say the screechy part of the noise remains, and Amazon is working on that too. But overall, things are quieter in the tidy, tree-lined streets of Great Oak.
"It's helped. Obviously, they have done something, because it doesn't roar through the house anymore," said John Biess, a Great Oak resident who, with his wife Gloria, has been taking daily measurements of the noise since May 2022.
"Residents confirm that the steps we're taking at the facility are already having a positive impact and we continue to reengineer and install new equipment to further reduce unwanted sounds," Amazon spokesman Duncan Neasham in an email. "We are constantly innovating our data center designs to minimize the impact on our neighbors and the environment."
But the assurances from Amazon don't entirely capture the struggle Great Oak residents endured to make their neighborhood quiet again. According to Dale Browne, the homeowners' association president, it took two months to get Amazon into talks, which were hampered at first by company pushback. After an initial try at muffling didn’t work, Amazon started testing the complicated fix that made a difference.
The saga also holds some lessons. One is that neighbors who want data centers to change their ways must be "determined and tenacious," said Browne. Another is it helps to get public officials involved. A third is that citizen demonstrations and heavy media coverage do not hurt.
And the last is that data centers don't have to be noisy. They can be retrofitted to be quieter or they can be built quieter to start with.
The data center planned Amazon is planning for Warrenton will use rooftop cooling units muffled with insulation. But Amazon has yet to deliver studies to the town to predict the noise those units will produce.
How it started: A Great Oak resident called the cops on Amazon
One key date in the saga is May 16, 2022. That's when John Biess and his wife Gloria called the county police to complain that the screech, hum and roar coming from the just-built data centers 600 feet to the north, behind a forest of oaks, were likely louder than the county's nose ordinance allowed.
"The first officer that came over (and) he said, 'Yeah, that's pretty loud,'" Biess recalled.
It was not just the Biesses and the police officer. Other residents said the non-stop noise made it difficult to sleep, gave them headaches and ruined outdoor activities. Some said it was worse at night—a point later confirmed by the Biess's decibel meter, which detected up to 65 decibels of noise at night. (The county noise ordinance limits noise to 55 decibels at night in residential areas, but at the time exempted noise from cooling systems.)
One Great Oak resident, Carlos Yanes, ordered $20,000 worth of new windows and moved his 1-year-old's crib to the basement. Several talked of leaving. They would later mount demonstrations in front of the offending Amazon data center complex on Tanner Way off Godwin Drive, southwest of the City of Manassas.
On May 23, 2022, with complaints increasing, Browne emailed his county supervisor, Yesli Vega, R-Coles. She contacted then-county acting planning director Rebecca Horner, who asked Amazon for a meeting. It was finally scheduled for July 22, 2022, and began a series of 15 in-person and Zoom meetings with Amazon officials that stretched over a year.
Amazon sent a half-dozen people, led by Rob Corradi, their chief of public policy for the Mid-Atlantic. The residents had their own experts. Browne had been technical director of a financial institution that had three data centers. John Biess had run a small Bitcoin minting operation. Yanes worked with air conditioning. From the county came Horner, and three aides to supervisors. Other area residents included Kathy Kulick, vice-chair of an association of homeowners’ associations that joined forces to object to data center proliferation, and John Lyver, a former NASA engineer who had studied noise issues.
How the meetings proceeded is a matter of some dispute. Amazon, in a written statement, said, "From the moment we were made aware of this situation we immediately started engaging with the community …We've met with, and continue to meet with, local residents to advise them on our plans."
The Great Oak contingent has a different recollection. They say it took six weeks, even with the help of county officials, to get Amazon to the table. Then, they said, Amazon officials were reluctant to share how their cooling system worked or what might be causing the noise. Amazon said it was all proprietary.
As the meetings moved along, it became clear that the problem stemmed from the method of server cooling: outside air is drawn into the building through large louvered windows high on their exterior walls. That air, cooled by indoor air conditioning units, is forced across hot computer servers and then blown out of the building through rooftop exhaust tubes. Each building's roof has more than 100 of these steel tubes, each one about 5 feet in diameter and 8 feet tall with a huge fan inside.
Realizing that the fans and the exhaust tubes were the source of much of the noise, Amazon first tried wrapping the tubes in padded blankets. Even then, Browne says, Amazon was reluctant to share details. That ended when Browne used a drone and a telephoto camera to get photos of the rooftop operations and showed them to Amazon at a meeting.
"Their community is getting the results they're getting because the folks in their HOA just wouldn't take no for an answer," said Kulick.
After that, Tim Hall, Amazon's vice president of infrastructure operations for the Americas, took over the team and Browne said by October 2022 communication improved. (Hall declined to be interviewed.)
Amazon engineers try Plan B
Amazon, it turned out, had a Plan A and a Plan B. Plan A was the padded blankets, or "shrouds" as Amazon called them. But they were not cutting the sound, so even as Amazon doubled them up, it turned to Plan B.
That involved a serious engineering project: making the fans quieter and more efficient and making the tubes 3 feet taller. Taller tubes would exhaust the air more vertically and less toward neighboring Great Oak. Meanwhile, the company was working on redesigning the fan controls to turn them slower and synchronizing them for efficiency.
The installation required two huge cranes and took four months. But by August 18, all 424 rooftop exhaust tubes and fans had been replaced with the new extended tubes. The sound level immediately dropped 10 points to around 50 decibels, according to both residents’ and Amazon’s measurements.
Amazon will not say what it cost other than "considerable engineering and resources," according to an Amazon statement.
Browne guesses it cost as much as $30 million, based on informal conversations with Amazon officials at the meetings.
"The noise coming off the fans, those 450 fans on the roof has really dropped off," said Biess. But he said there is still a screeching sound emanating from the open louvers in the buildings' sides. He thinks it comes from small fans on the computer equipment; Brown thinks it comes from the fans that move the cooling air.
Whatever it is, Amazon vows to fix it next. "We are also in the process of designing acoustical louvers. When installed, they will further reduce sound," the company said.
Browne thinks the noise drop is pretty remarkable but notes that his subdivision will still suffer from the "additive noise of multiple centers" surrounding it.
Great Oak will soon have to contend with more data centers. Another two-story data center, known as "Project Gold," is nearly finished across from the four-building Amazon data center complex.
Another complex is planned next door to Amazon's. Called Digital Second Manassas, it will consist of four two-story buildings with more than 1.6 million square feet of data center space. Both projects are about two-tenths of a mile from the nearest Great Oak home.
And a quarter mile from Great Oak, across Prince William Parkway from Amazon, a CloudHQ campus with three 100-foot-high buildings is planned.
Browne and the Great Oak residents hope they won't have to fight this battle again. If someone else does, they can offer some advice:
"You have to keep kind of banging the drum—and be loud," Browne said. "Engage respectfully, but in an affirmative way. Use the county and be noisy with the media. Know what you need, know what you want, know what should be right and wrong. And hold them to account."