When county planning staffers reviewed the rezoning application of the Prince William Digital Gateway for environmental effects, they found the application lacking in several major ways. The plans did not contain enough natural open space, that is, native forests, marshes and grasslands.

Power lines could run through those open spaces, shrinking them further, and the lines might encroach on wildlife corridors, too. Landscaping plans were missing. The plans also allow for “unlimited disturbances” in Chesapeake Bay resource protection areas, which are protected by law.

For those and other reasons, the planners wrote in an Oct. 27 critique of the application, “The proposed rezoning is not (emphasis theirs) favorably aligned with the county’s strategic plan goals associated with environmental conservation.” 

Because of these negative environmental impacts—as well as an overall lack of information and the rezonings’ noncompliance with what the supervisors laid out in their comprehensive plan amendment for the Digital Gateway— the county’s professional planning staff recommended that the applications be denied. 

The data center developers submitting the applications, Compass Datacenters and QTS Data Centers, rushed to respond to the planning office’s critique last week. Whether the adjustments they made in their latest filing on Nov. 1 will satisfy the planners’ objections will be seen at Wednesday’s planning commission hearing when the data center operators argue their case.

But even if the developers are able to satisfy the planners’ concerns, other environmental components that will affect the lives of neighbors and the community as a whole remain unaddressed. 

Those include how much noise the data center complex would make, how much water it would use, how much power it will need, how many diesel generators would be installed on site—as well as the huge question of  how the developer and the county will provide for hundreds of acres of parkland that were  promised as  part of the complex. 

Noise: Both Compass and QTS promise in legally binding “proffers” that their operations won’t exceed county noise limits of 60 decibels in the day and 55 at night. (Noise from construction work and —emergency generators would be exempted.) Both developers promised to do noise studies that show their buildings will be quieter than the county limits before obtaining building permits. If the studies show that the buildings will be too loud, Compass says it will mitigate excessive noise “to the extent feasible” before getting a building permit; QTS says it will “minimize noise impacts.” 

In a news application filed on Nov. 1, QTS presented a study that said  its data center noise would not exceed county limits. But John Lyver, a former NASA engineer who has studied data center noise, says the study is flawed and recommended the county hire a noise consultant to check noise analyses. Compass has not yet filed a noise study  

The best test, of course, is the noise the buildings make after they are built.  Residents living in Great Oak, a subdivision next to an Amazon data complex south of Manassas, find that it is taking more than a year for the company to reduce its sound to comfortable levels.  

Even so, county noise limits were not designed to deal with the constant, never-ending drone or howl night and day, seven days a week, from data centers that neighbors find maddening. A group of citizens and county officials is working on a data center-specific noise ordinance, but a proposal is nine months away. Dale Browne, president of the Great Oak homeowners’ association, is a member of the group and said they are aiming at requiring developers to submit noise models with zoning applications—not after they are approved.

Diesel-powered generators: None of the applications state how many of the cargo-container-sized, diesel-engine generators will be installed for each of the Digital Gateway’s up to 37 buildings. Plans for one Amazon data center in Warrenton that is about the same size as a typical Digital Gateway building show 29 generators. If the 37 buildings depicted on gateway plans each had 20 generators, the site would host 740. 

Environmental concerns over generators focus mainly on the noise they generate, which is generally louder than air-conditioning noise, and the pollutants they put in the air. 

In normal times, data centers say they test-run each generator for perhaps 10 minutes twice a month, but citizens protested mightily back in February when the Virginia Department of Environmental Quality proposed relaxing controls on the generators to let them run unlimited hours day and night in the case of power shortages. In April, the DEQ dropped the proposal. 

Power: The digital gateway’s power use will affect construction of transmission lines, feeder lines and Dominion Energy generation. Dominion has already said in its latest resource planning document that in order to satisfy the huge energy hunger projected for data center alley, it may need to keep online coal-fired plants that were slated for closure. Closer to home, county planners note that transmission lines feeding the gateway will cut through its planned open spaces.

Neither Digital Gateway developers nor Dominion have stated how much power the dozens of data centers will use. One per-square-foot measure of power use that some say is outdated would ascribe 1,554 megawatts to the 22.2-million-square-foot complex. Julie Bolthouse, land use director at the Piedmont Environmental Council, said Dominion officials told her they were assuming 60 megawatts for each of the gateway’s 37 buildings — a total of 2,220 megawatts. But she thinks that the power intensities demanded by artificial intelligence could raise the number to 90 megawatts per building, or a total of more than 3,000 megawatts. That’s enough to power 750,000 homes— five times the number of households in Prince Willliam County.

Water and watershed: Compass says in its application that it “shall not use groundwater, surface water withdrawals or surface water discharges to cool the data center buildings on the property.” QTS says much the same thing and adds that it intends to use air or closed-loop cooling systems for all buildings. However, QTS does not say how much water it would need to fill a closed-loop cooling system. The closed-loop data center Amazon plans to build in Warrenton will require a one-time fill of 191,000 gallons of potable water. Digital gateway developers plan for up to 37 similarly sized buildings. 

According to the planning office, QTS reported that 55% of its property will be impervious. With Compass’s buildings, adjacent pads, substations and roads, approximately 1,000 acres would be waterproof. In its 17-page critique of Compass and QTS applications, Prince William County’s watershed branch, the professional planners who focus on environmental impacts, does not comment on the effects of the impervious footprint on the aquifer or runoff into the Occoquan Reservoir other than to say in some cases the developers’ stormwater management plans go “beyond minimum standards.” 

In February 2022, when Prince William was weighing the comprehensive plan amendment that would allow for the gateway project, Fairfax County objected. The project, Fairfax’s planning director wrote, “will add a significant amount of impervious cover to an environmentally sensitive area” affecting runoff, pollutants, erosion and groundwater recharge. Fairfax said the Digital Gateway “would not be compatible with the critical need” to protect the Occoquan Reservoir, which provides drinking water for about 800,000 residents of Northern Virginia.  Prince William supervisors voted 5-0 in August 2022 to participate in a regional study of the effects of the Digital Gateway and other development on the reservoir, but they also agreed not to wait for the study before voting on the gateway project.

Parks: Also not addressed by the developers nor the county planners are the parks that are missing from the development plans. Maps of the comprehensive plan amendment show four large areas to be set aside as parkland. A “southern community park” of 89 acres is slated just east of the Conway Robinson State Forest. Another large zone of about 100 acres at the northwest corner of the project is dubbed a “cultural and natural resources park.” 

Both are missing from the rezoning applications. So are two other areas in the middle of the complex identified by Supervisor Bob Weir, R-Gainesville, that total more than 100 acres. On earlier Digital Gateway maps, these areas were labeled “parks and open space” and contained portions of what was called the “Catharpin Creek Greenway Extension.”

Weir says it was all a false promise. The data center developers are “not going to pay for (that acreage) because they would have to pay data center rates for parkland. And they’re not going to do that,” he said in an interview.

Lack of open space: The comprehensive plan amendment the county supervisors approved for the Digital Gateway in November 2022 to guide the area’s development stipulates that 30% of the project’s land area remain “natural open space,” which is defined as forests, wetlands and habitats for threatened species.

County planners, in their critique of both applications, note that Compass is planning to leave only 16.9% of its development as natural open space, while QTS’s two development areas, dubbed “QTS North and QTS South, will preserve 15.9% and 21.8%, respectively. QTS said in its application that reduced open space is necessitated by other CPA policies calling for “a technology corridor and other economic development related objectives.”

To reach the 30% open space goal, the developers will plant trees on other acreage. By reforesting 233 acres, the developers reach a 30.8% goal of what they call “protected open space.

But the watershed staffers note that the CPA does not allow for combining reforested land and natural spaces—it calls for 30% natural open space, period. The county officials say that if the developers were to follow their plan, they “might meet their protected open space almost exclusively from land already disturbed” instead of preserving areas of “existing native forest and wetland habitats.”

The Virginia Department of Forestry wrote a letter objecting to the project on March 20 and has not changed its views since. 

“These three projects could have a substantial impact on the local forest and associated ecosystem services,” wrote forestland conservation coordinator Clinton Folks. He said the construction “could have major impacts on water quality in this watershed.”

 Even tree plantings and reforestation would not fully mitigate the destruction of forests, which benefit “flood mitigation, water quality, clean air, habitat for biodiversity and scenic value,” Folks said, adding that the proposal “offers no quantifiable mitigation plan for the loss of open space land and riparian forest.”

Reach Peter Cary at [email protected]