Board approves Wellington Glen data-center proffer amendment over neighborhood objections

The Prince William County Board of Supervisors on April 1 approved a proffer amendment permitting a two‑building data‑center campus at the Wellington Glen site near Sudley Manor Drive, voting 5–3 after hours of public comment and debate.

The applicant, SDC Capital Partners, scaled back an earlier, larger proposal and offered new proffers to address neighbors’ concerns: maximum building height of 65 feet with a separate 10‑foot allowance for rooftop mechanical equipment, a lower-than‑typical floor‑area ratio (about 0.35 FAR), additional tree conservation and reforestation acreage, commitments on building fenestration and 30% glass along principal facades, and a noise threshold capped at 50 decibels at adjacent residential property lines. The developer also proffered traffic and construction routing measures and removed data‑center entitlement from two adjacent land bays (H and I) previously associated with the larger Wellington Glen approval. The applicant said it will source power via an off‑site substation served by underground distribution rather than overhead lines visible from neighborhoods.

Why it matters: the vote permits more data‑center square footage on the site than earlier approvals allowed but adds multiple design and operational commitments that county staff and the developer said are improvements over what could be built “by‑right.” Neighbors, however, argued the additional capacity will increase demand on the local transmission system, raise noise and light impacts, and exacerbate water and air concerns tied to generator exhaust.

What the Board approved and why. Supervisors acknowledged the property already sits inside the county’s Data Center Opportunity Overlay and zoning that allow data‑center uses. The amendment consolidates previously allowed square footage, moves the on‑site building envelopes farther from nearby housing (applicants said the proposed building lines are roughly 200–300 feet further away than previously permitted at certain points), and restricts rooftop mechanical height and noise exposure. Supporters on the dais said the proffers and design commitments raise the bar for architecture, noise mitigation and landscaping compared with a by‑right facility where fewer controls would be available until site plan.

Opposition and concerns. Dozens of residents from nearby Independence and Arcadia Run and others from across the county urged the board to deny the change. Speakers cited the 2024 JLARC report on data‑center impacts, potential additional transmission and substations in the corridor, cumulative noise from multiple facilities, and long‑term water and air quality concerns. Residents also disputed the developer’s visual simulations and raised questions about how loudness would be enforced and what penalties would apply if monitoring showed exceedances.

County planner Alex Venegas told supervisors staff found the amendment consistent with the land‑use plan and recommended approval with the March 17 proffer package; he noted the applicant removed data‑center rights on the southern parcels (H and I), provided a detailed master zoning plan, and added buffer, trail and sidewalk commitments. The applicant told the board they reduced height, lowered total square footage compared with earlier submissions, and would use selective technical controls—catalytic reduction on standby generators and air‑cooled chillers—to reduce emissions and water demand.

Board vote and next steps. The board approved the proffer amendment 5–3; supervisors Vega and Weir and one other voted no. The approval clears the way for the applicant to move to site and building plan review subject to the new proffers. County staff will monitor proffer compliance through plan review and subsequent inspections. The applicant and several county departments said they will continue coordinating with Dominion Energy and other utilities over transmission and substation routing; Dominion has filed regional transmission proposals for the corridor but routes are under state review.

What remains unresolved. Neighbors and several supervisors said the region still lacks a single, countywide accounting of proposed and approved data‑center capacity and the cumulative infrastructure needs those projects will create — transmission, substations, water and environmental mitigation. Multiple speakers urged more conservative limits or a county policy that better matches capacity needs to community tolerance. The board did not adopt any additional county‑wide moratorium or new overlay limits at this meeting.

Ending. The approved proffers substitute an explicitly proffered, pro‑design outcome for some of the uncertain outcomes that a by‑right build could have produced. Whether the design and operational commitments the developer made will prevent the cumulative infrastructure and quality‑of‑life concerns neighbors raised will be decided in the coming months as the applicant moves through site and building permitting and as regional transmission proposals progress.