Scientific Study Says Data Center Noise Would Hinder Operations at Bristow, Gainesville Schools

Dr. John Lyver updates his Prince William data center sound study


A slew of data centers has been approved or proposed in western Prince William County over the past few years. In the case of the Prince William Digital Gateway, the center is enormous and would house 50-90 buildings. In other cases, the Prince William County Board of Supervisors has approved medium data centers ranging in size from two to 15 data centers next to homes and schools. Considering many of those data centers are clustered together, the result is equivalent to a mass data campus at the nexus of Gainesville, Bristow and Manassas. 

On Feb. 7, Prince William County Supervisors will vote on whether to approve Devlin Technology Park, a center that would house approximately 14 90-foot data buildings along Linton Hall Road and Devlin Road in Bristow. It will be situated next to Chris Yung Elementary School and within earshot of many other schools and thousands of homes.

Former NASA Scientist Dr. John Lyver and Heritage Hunt resident believes this would be a mistake. He conducted a noise study on the proposed and existing data centers, analyzing the way noise travels through the air and over the topography. 

Last week, Lyver released an updated version of his study and findings. It shows sound radiating from data centers would reach sound levels that would violate the county sound ordinance of 55-60 decibels, thus disrupting the peace. However, HVAC systems are currently exempt from such ordinances in Prince William County.

Among multitudes of concerns surrounding data centers, noise pollution has emerged as the most concerning. Data center HVAC systems produce a low hum, which the brain has difficulty filtering out. Lyver contends that so many large data buildings all within close proximity would amplify the sound. That level of sound could travel as far as 2.5 miles. 

People living near data centers, such as those in Chandler, Arizona claim to experience health problems, stress, and difficulty sleeping. Constant noise has negative effects on the body even in other forms such as construction sound, which could go on for 10-20 years as data centers are being built in the area. 

Thus far Prince William County has not conducted nor contracted an official sound study. Lyver believes an independent sound study if conducted fairly by an expert, would allow Prince William County Supervisors to make a more educated decision about approving data centers. While additional tax revenue is positive, quality of life and the need to retrofit buildings is a concerns that should not be ignored. He further believes it is not wise to take in tax money from data centers only to then use it to attempt to remedy problems that the industry has created. 

Containing sound is not an easy or inexpensive fix (which is the reason data centers are reluctant to handle the problem on their end.) Protecting classrooms at Chris Yung Elementary School could cost an estimated $20 million, according to Dr. Lyver's research. 

Extrapolated from the Study

Most language has been taken directly from the study.

This study provides a predictive analysis of the noise intensities that will be generated by currently operating and planned data centers in northern Virginia.

Up through the date of this study, the Prince William County (PWC) government has not performed ANY noise analyses for any of the data centers within PWC. In fact, the PWC Planning Office has stated that they do not have the capability to perform a holistic noise assessment study nor the permission to do so.

While the author of this study does not contend that the results presented in the study are exact, it is believed through numerous verification methods that the values presented are very representative of the noise intensities that will be generated and most likely conservative in nature. Noise levels in each small area, each school, and public safety facility are projected to significantly exceed the applicable noise ordinance levels by as much as over 15 decibels.

Scope of the study

This sound study looks at the following data centers within the Gainesville, Haymarket Manassas and Bristow Areas that fall within a 2.5-mile radius of Gainesville High School.

Data Centers & their buildings within the 2.5-mile radius of schools, homes

  • Prince William Digital Gateway 2 campuses, 50-100 buildings (proposed, near national, state parks, residential communities and rural homes)
  • John Marshall Commons 2 buildings (near homes, schools); Village Place 4, I-29/66 6, (near homes and schools)
  • Gainesville Crossing 5 buildings (near residential); John Marshall Highway/ Atlantic Research 11 (homes)
  • Digital Realty, buildings TBD, Hunter on Linton Hall 11, Mango 3 build(near residents and schools)
  • Devlin Tech Park, 13-14 (Proposed, near schools, residents) 14,
  • Microsoft TBD (Near residential and schools)
  • South Point phase II 2, Iron Mountain 2 (mainly industrial)
  • Amazon, Amazon TBD

Total: Low Estimate: 115

High Estimate: 160

Without PWDG: 65 Estimate

Data/Analysis provided by Prince William County

Official Noise Levels are unknown

PWC has NOT done ANY credible noise studies looking at the potential noise levels that will be created by the current data centers (DC) or building additional data centers.

The current exemption in the Noise Ordinance for Heating, Ventilation, and Air Conditioning systems operating needs to be removed so that data centers do not claim these exemptions.

This study shows that external noise levels are already excessive at several schools, and it is predicted that internal noise levels will exceed ANSI-recommended classroom noise levels.

Other public facilities like libraries, and hospitals, need to be studied for noise impacts.


Health Impacts

PWC has NOT done ANY credible studies looking at the potential noise-related health impacts that will be created by the current data centers or by building additional data centers.


PWC has NOT done ANY credible studies looking at the need for mitigation to Public Schools, Private Schools, or Public Safety Facilities due to the elevated noise levels.


Noise mitigation should be mandated at data center sites currently operating and should be an integral part of the design for data centers in the planning process.

The county should demand strong, contractual commitments for noise control.

The PWC Schools should immediately test and prepare noise mitigation strategies inside classrooms.

Local government should NOT permit this essential consideration to be an afterthought, only addressed through belated enforcement measures.

Bottom Line

This study shows that many residential areas, schools and public safety facilities will be negatively impacted as data centers are built.

No additional rezoning permits should be approved until PWC has done a comprehensive noise study for each proposed site.

Lyver's Noise Study

Prince William County’s noise ordinance does not include construction or HVAC noise. Regardless, for the purpose of this study, consider the standard noise ordinance is 60 decibels during the day and 55 decibels at night. Those decibel levels are the level of an ordinary conversation when one is standing within a few feet of the people conversing.

The neighborhoods and schools would all hear the data center humming to such a degree as to violate the noise ordinance.

Small Areas where data centers would violate the noise ordinances


  • Bristow Run ES,
  • Chris Yung ES,
  • George P. Mullen ES,
  • Tyler ES,
  • Victory ES,
  • Gainesville MS,
  • Gainesville HS,
  • PACE West
  • Bristow Montessori,
  • Minnieland Academy Gainesville,
  • Youth For Tomorrow.

Schools where the noise ordinances would be violated, and a number of data buildings located within a half-mile radius of them. 

  • Tyler ES & Pace West ES (12)
  • Gainesville MS, Gainesville HS, Piney Branch ES (25+)
  • Bristow Run ES (28)
  • Bristow Montessori (17)
  • Chris Yung ES (17+)
  • Parks- Near the Manassas National Battlefield (50-95) Prince William Digital Gateway 50-90 (NOT to be confused with the high school). 

The effects of noise on private schools may come at too great a cost, said Lyver.

"These schools will need to perform sound mitigation inside the classroom to meet the reference  specifications, or they may have to close their doors.”

These levels of noise will impact student learning in three ways:

  1. excessive noise in the classroom will disrupt the quality of learning,
  2. a vital part of a rounded education is for students to play, learn, and interact outside the school building in learning and physical activities,
  3. and stress-induced health issues in children and school staff personnel.

Basically, they will not escape the noisy environment. Some of the schools with predicted noise levels of over 70dB(A) after full ‘build-out’ of data centers.

With excessive noise around our schools, students may experience the health effects that a stressful environment will produce because they will wake up in the noisy environment, be at school in a noisy environment, play at home, and sleep in the noise environment.

Bottom Line Conclusion

  1. The PWC should immediately have a professionally done noise analysis performed covering ALL of the materials discussed in this Study at a minimum. To date, NO such study has been done.
  2. The PWC should immediately freeze the processing of rezoning applications and site/building plans until a quality noise ordinance has been approved and quality noise studies performed. Penalties for violating the noise ordinance should be increased to be taken seriously.
  3. Additionally, the City of Manassas should begin a thorough noise analysis to help protect its citizens, school children, and public safety personnel. Noise is a serious issue that MUST be taken seriously!

Background, methods and data can be provided upon request.

What is the importance of keeping the noise down inside classrooms? 

“The PWC School Board NEEDS to prepare for possible upgrades for noise attenuation in the public schools,” said Lyver. He cites the American National Standards Institute's [ANSI]  recommendations for noise levels in classrooms.

The ANSI provides the national standard many school systems across the nation adopt, although they do so voluntarily (this may vary by state.) 

“The American National Standards Institute (ANSI) 5 recommends that noise in an unoccupied classroom should not exceed 35dB (A), and the difference between the voice of the teacher and the background noise should be more than 15dB to the children's ears.”

Both in-classroom and outside noise can be distracting to students and harmful to their learning environment. Many studies have been done on this issue that predicate the data center issue. 

Lyver encourages parents to hold Prince William County Board accountable to make sure their classrooms do not exceed the recommended sound levels.

He also disagrees with the numbers the county estimates on tax center revenue. 

"The PWC School Board Chair is still thinking that the PWC Schools will get the 53% of the $700 million per year for their Prince William Digital Gateway," Lyver said.  But according to Lyver's fiscal analysis the county would only make $130 million per year from the Prince William Digital Gateway after 21 years, and the schools would receive less than half of that number. 

Is denying data center applications the only option? And isn't it too late for that? 

Dr. Lyver recommends lawmakers deny approval of data centers near residential areas, parks and schools (especially those within a 0-1.5 mile radius.) However, some data centers have already been approved despite abutting neighborhoods and schools, such as the one on the Hunter property near Amberleigh Station and Kingsbrooke.

At a meeting on the Devlin Road Tech Park last week, J. Truett Young, Northern Virginia V.P. of Land for the Stanley Martin Co. said the data center will be required by proffers to stay within the noise ordinance. Residents, including Lyver, were not convinced the proffers would be enough to secure that policy since the county planning commission can override a proffer. But Young said a new noise ordinance would be forthcoming. Lyver remained skeptical and in the case of the Devlin Technology Park advocated that the proposal not be rushed through on Feb. 7.

How can this study be accurate if we don't know which mitigations data centers will put in place?

The purpose of the study is to make the public aware of just how noisy data centers can be and put pressure on elected officials to manage the problem. The study takes into account small tree barriers but does not assume the noise will stop at the property line as some applicants have promised. It does not assume that will be the case when they have not provided information on how this muffling would be accomplished only that it would be. 

People say not all data centers are not the same. Lyver has based his source sound on existing data centers in the county. This does not preclude the possibility that data centers utilize alternatives to HVAC use advanced sound-muffling systems. These scenarios were not included.

Lyver also notes the situation could be worse than that what he has presented in the study. Some data centers have requested larger building sizes and campuses. Additionally, some information on data centers is unavailable to him due to nondisclosure agreements. 

UPDATE: According to an aide to Supervisor Lawson, most regional data centers are quieter than the Amazon data which some Great Oaks community members can hear from their backyards. That is an old building not up to Prince William's current standards. While Prince William currently has a standard for the exterior of the building, newer modern-looking buildings also tend to be quieter. And, it is easier for data centers to build quieter systems than to retrofit them afterward. 

At the Feb. 2 town hall meeting, Supervisor Jeanine Lawson promised to vote against Devlin Tech Park. She said stronger mitigations are needed. The barriers are too short and do not offer enough sound protection. And even if the noise ordinance is changed to include large HVAC systems, she said there needs to be a stronger consequence for breaking the sound ordinance. 

However, even if those conditions are met she said she will oppose the project because the residents do not want it there. She said the data center industry has become a Godzilla in the county. Residents told her they did not agree to live next to industrial development. 


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  • astoeger

    Dr. John Lyver has performed an enormous community service by looking at the ADDITIVE impact of so many mega data center campuses, spaced so close to each each other, and so close to homes and schools. The Board of County Supervisors must hit the STOP button on further data center approvals until this issue -- and so many other issues related to ADDITIVE environmental impacts of so many data center projects are worked out. Why the rush? We are just 9 months away from a Board of County Supervisors election. Let the current Supervisors vote on their record and let the people of PWC decide if they favor moving forward with this massive transformation of PWC.

    Friday, February 3 Report this