Calvert County faces big questions on data centers as environmental commission urges pause and public pressure mounts

Calvert County commissioners spent the June 2 meeting reviewing proposed zoning and technical conditions for large data‑center projects and fielding hours of public testimony urging a pause while independent studies are completed.

Planning and zoning director Jason Brinkley and staff summarized draft text amendment 26‑23, which would narrow where data centers are permitted, require a county‑reviewed water services plan prepared and stamped by a Maryland‑licensed professional engineer, prohibit use of groundwater wells for cooling, require Tier‑4 (or equivalent) emission standards for stationary diesel generators, and allow county‑funded third‑party review when technical compliance needs verification. The planning commission recommended additional steps including longer buffers, tree and berm screening, mandatory decommissioning bonds and continuous noise monitoring with stop‑work triggers.

The Environmental Commission — citing the county’s complex shoreline, aquifer reliance, and the Chesapeake Bay’s sensitivity — urged a pause and asked the board to require cumulative‑impact and independent studies on: water withdrawals and cooling approaches; generator emissions and air quality; low‑frequency and tonal noise (and school impacts at Southern Middle School, identified repeatedly by speakers); heat‑island effects and potential impacts on bay temperature and fisheries; and ecological surveys for species identified in earlier Army Corps and Maryland DNR studies. The commission said county staff does not have local experience with hyperscale data‑center operations and recommended third‑party, independent technical reviews before any final approvals.

Residents and community groups gave extended public comment, raising consistent themes: uncertainty about cooling plans and water consumption; fears about emergency generator emissions and particulate pollution; worries about noise and infrasound (particularly for schools and nearby residents); concerns about long‑term decommissioning and fiscal guarantees; and requests that the county preserve rural character and fisheries‑based livelihoods. Speakers cited studies and asked for baseline monitoring (noise, air, water temperature and quality) and independent verification of applicant submittals.

Commissioners described two parallel workstreams. Staff emphasized that a concept Category‑1 site plan is only the start of a lengthy multi‑agency review (concept, detailed site development, final stage), and stressed that Maryland is a late‑vesting state (projects do not achieve vested rights until construction activity is begun). Staff said a complex Category‑1 project submitted now was unlikely to reach the planning commission before fall or winter in any event. Planning staff requested roughly 30 days to draft specific ordinance language that reflects the planning commission’s recommendations and the environmental commission’s input; commissioners tentatively scheduled a July work session to review draft text amendments and discussed a possible September adoption timeline after public hearings and additional review.

Supporters and opponents pressed competing priorities. Business and economic advocates noted potential new tax revenue and infrastructure capacity, while conservation‑minded residents urged caution and independent technical review. The board debated a motion to schedule a public hearing on a two‑year moratorium; the motion was moved and seconded, debated at length and did not carry. Commissioners emphasized that text amendments — once adopted — will control building permits, and staff reiterated that the county’s current policy prevents issuance of building permits for data centers until the new text amendments (or other applicable regulations) are adopted and in effect.

What’s next: staff will return with draft ordinance language addressing the core issues raised — water use and metering, generator emissions standards and testing windows, required third‑party reviews and bonds, noise limits and continuous monitoring, setbacks, and decommissioning plans. The board signaled it expects the drafts within about 30 days and will schedule further public review sessions before any adoption vote.

Votes at a glance: The board approved its consent agenda (items 1–3 and 5–9) and separately approved the Chesapeak(e) Hills Golf Course liquor license renewal after recusal disclosure. The board unanimously adopted budget amendment BA2026‑815 to accept an additional $176,541 in Rural Maryland Economic Development grant funds for the Armory Site Development project. A motion calling for a public hearing on a two‑year moratorium was proposed and debated but did not pass.

Why it matters: Hyperscale data centers are large, long‑lived industrial uses that can introduce new and unfamiliar impacts — steady daytime/nighttime noise and tonal components, intensive power demand (and backup generator use during grid events), and site‑scale cooling decisions that affect water use and local water chemistry. The Environmental Commission and numerous residents argued Calvert County’s shoreline geography, proximity to schools, and fisheries‑dependent economy make thorough independent study and precautionary safeguards imperative before any project proceeds.

Who said what (representative): “We do not have the information to make informed decisions,” Abby Barr, chair of the Environmental Commission, told the board, urging additional studies and independent review. Planning director Jason Brinkley repeated that a Category‑1 concept does not grant a building permit and that changes to regulations will be applied to projects that have not yet vested by construction. Davenport & Company (on the county’s debt advisory agenda unrelated to the data‑center discussion) reminded the board that reserve policy and long‑term planning affect credit ratings and fiscal flexibility.

Bottom line: The county’s formal rule‑making process is the primary vehicle the board will use to impose new standards. Commissioners and staff have signaled they will pursue robust ordinance language, including third‑party review authority and measurable monitoring requirements; opponents continue to press for a temporary pause while independent, site‑specific studies are completed.