Montgomery County's 11-member council voted unanimously on July 29 to ban new data center construction for 18 months, a move that freezes building permits countywide while officials study how the massive facilities would affect electricity bills, water supplies and neighborhood quality of life.

The moratorium, passed under Expedited Bill 19-26, replaces a shorter six-month pause that County Executive Marc Elrich imposed by executive order in June. It also blocks projects already under review but not yet issued a building permit.

For Bethesda-area residents served by Pepco, the stakes are concrete. PJM Interconnection, the regional power grid operator, estimates Maryland ratepayers will shoulder roughly $4.3 billion in costs tied to electrical-load growth driven largely by data centers, according to The Banner's statewide FAQ on data centers. The Maryland Office of People's Counsel filed a complaint at the Federal Energy Regulatory Commission on May 7, arguing that PJM's cost allocation rules assign Maryland customers, mostly Pepco and BGE ratepayers, approximately $1.6 billion in added transmission costs over the next decade. That works out to roughly $345 per average residential customer.

"Nothing will happen until we answer all the questions our community deserves," Councilmember Evan Glass said at the July 29 council meeting. "There are a lot of questions about what happens to the water in the Potomac River, what happens to our utility bill rate payers and what happens to the community as a whole?"

The council simultaneously passed Zoning Text Amendment 26-01, which for the first time defines a data center in county code: a building or group of buildings with an aggregate monthly electricity demand of at least 25 megawatts. The amendment prohibits hyperscale facilities countywide until long-term zoning rules are written.

What prompted the freeze

A proposal from Atmosphere Data Centers, a California-based company, to build a five-building, 360-megawatt campus on the site of a decommissioned coal plant in Dickerson helped galvanize opposition. The company had challenged Elrich's earlier executive-order pause, arguing he overstepped his authority. Council President Natali Fani-González said the legislatively enacted moratorium is harder to contest: "They can't appeal it. It's done."

The 18-month timeline was itself a compromise. Glass had proposed six months; Councilmembers Will Jawando and Kristin Mink pushed for two years. Jawando said the council plans to examine noise, water usage, tax rates and clean energy standards during the pause, and has discussed developing a data center tax rate similar to Loudoun County, Virginia's 4% levy.

Utility and environmental concerns

A single data center in Northern Virginia uses about 18,000 gallons of water per day, the equivalent of nearly 200 single-family homes, according to The Banner. Backup diesel generators at data centers are also a health concern: researchers at Virginia Commonwealth University found some facilities already release 30% or more of their permitted emissions.

At least four data centers already operate in Montgomery County, according to the planning board. The moratorium does not affect those existing facilities.

Montgomery County is not alone. Nearly 77% of Maryland's population now lives under some form of data center moratorium, according to the Chesapeake Climate Action Network. Harford County banned data centers outright; Prince George's County approved a two-year moratorium.

What's next

A state study on data center impacts, conducted by the Maryland Department of the Environment, the Maryland Energy Administration and the University of Maryland School of Business, is due to Gov. Wes Moore and the General Assembly by Sept. 1. The Maryland Tech Council warned in a statement that the moratorium risks foreclosing on what it called a generational economic opportunity.

No specific public meeting date for the council's regulatory work plan has been announced.