Make the best the standard. Data center rules residents can enforce, in the ordinance and in every approval.

Loudoun County collected more than a billion dollars in data center taxes last year, and this summer its board began weighing a moratorium on new ones.¹ The complaints driving that conversation are specific and legitimate: diesel generators running on test days, cooling systems drawing on local water, the hum of a facility that never shuts off, and transmission lines routed past homes to serve it all.

Whatever the board decides about new applications, those complaints are about how facilities are built and operated, and they deserve an answer of their own. The industry itself has already shown what that answer can look like.

Look at what the best operators do, then require it

Data centers are not all built the same way. Across the region there are facilities that cool with closed-loop or air systems that use a fraction of the water of older designs, facilities whose generators are enclosed and tested on scheduled daytime hours with cleaner fuels, facilities built with sound walls and setbacks that keep nighttime noise at the property line to the level of a quiet street, and facilities that paid for the substation that serves them.² These practices exist. They can be measured. And right now they are optional.

Our proposal is to make them the floor, and a locality has two ways to do it. It can write them into its ordinance, so they apply to every facility: this is how much water a facility of this size may draw and where it must come from; this is the sound limit at the property line, measured at night, with generator testing restricted to specified hours; this is what backup power must look like and how it will be inspected; this is where a facility may be sited relative to homes and schools; and this is how the grid connection will be paid for. And it can write them into each siting approval, as conditions of the rezoning or special use permit for a specific project, so a community can hold a particular facility to a particular standard on a particular site. The two work together. The ordinance sets the floor. The approval raises it where the site calls for it.

Why this is the standard the community should set

• Residents get rules they can enforce. A noise limit with a number on it, whether it sits in the ordinance or in the conditions of a siting approval, can be measured by a county inspector and enforced. A vague assurance cannot.
• Responsible operators get certainty. A clear standard tells a builder what the community expects before the first drawing. Projects that meet it move faster. Projects that can't, don't come.
• The revenue keeps coming. Data centers supply roughly 40% of Loudoun's General Fund and about 28% of Prince William's general revenue.³ Those counties have the lowest real estate rates in the region because of it. Standards let a community keep that base while fixing what residents object to.

Where this is headed

Loudoun has said it will rewrite its data center standards over the coming year. Prince William is revisiting its zoning. Fairfax adopted siting rules of its own, and every county in the region has applications coming before it. Each ordinance rewrite and each siting approval is a chance to do what we are describing: study the best facilities already operating in this region, write down what makes them good neighbors, and require it. That is a yes the community can be confident in, and we will put the case, with the numbers behind it, in front of residents before each of those decisions.