Below the Curve: What Virginia Counties Chose Not to Measure
Of the 75 adopted local noise instruments in this volume's census, 67 carry no tonal provision and 65 no low-frequency provision, so most cannot register the low, steady hum people living beside data centers describe. The volume follows the choices about the measuring instrument that produced that gap, made in public, at stated prices, for stated reasons, in Loudoun, Prince William and Chesapeake.
As of October 2026 Virginia has a budget mandate for state data center noise regulations due by the end of 2029, a governor's order to speed them up, and a growing list of local ordinances. Most of the local instruments cannot register what people living beside the buildings describe, a low and steady tonal hum: of the 75 adopted instruments in this volume's census, 67 carry no tonal provision and 65 no low-frequency provision. The reason is a set of choices about the measuring instrument, made in public, at stated prices, for stated reasons.
The volume follows those choices. In 2016 Loudoun County staff recommended against regulating tonal noise, priced the alternative at $1,000, and gave the reason in writing: regulating it "may place the County at a competitive disadvantage." That rationale is absent from the two staff reports that preceded the July 2016 public hearing and present in the September report that followed it. In 2025 Prince William County built an octave-band standard with its own consultants, raised every value in it by six decibels, demoted it to an advisory appendix, and adopted a C-weighted limit instead, exempting the generator testing that its own definition names. In 2026 Chesapeake's staff proposed Prince William's numbers as "the most stringent adopted noise standards we identified in Virginia." The City Council adopted no number at all.
The competitive-disadvantage claim does not survive the Virginia record. Warrenton imposed the strictest data center permit conditions among the approvals examined and the applicant stayed, although nothing has been built there to test them; in King George the applicant proffered limits below the county's own ordinance. The cost the industry has not named in any Virginia venue examined can be estimated against a verified construction benchmark: Loudoun's $1,000 is 2.3 parts per million of one forty-megawatt building, and on this volume's estimate a designed-in mitigation package runs about one to two percent. What collapses after approval is leverage, not affordability.
Of the 75 adopted instruments in a census of 76 across 43 jurisdictions, more than half carry no numeric decibel limit, and eight carry any tonal provision. The volume closes on what Virginia's localities and the Department of Environmental Quality could adopt from instruments already written: a C-minus-A screening trigger, testing procured by the locality, and a measured pre-construction baseline.
Deposited with the volume: a claim-and-source companion grading each endnoted claim, and the ordinance census workbook (76 instruments, 43 jurisdictions).